System and method for controlling the speed of a displacement member of a surgical stapling and cutting instrument
阅读说明：本技术 用于控制外科缝合和切割器械的位移构件的速度的系统和方法 (System and method for controlling the speed of a displacement member of a surgical stapling and cutting instrument ) 是由 F·E·谢尔顿四世 D·C·耶茨 J·L·哈里斯 于 2018-05-17 设计创作，主要内容包括：本发明公开了一种机动化外科器械。该外科器械包括：位移构件；马达,该马达联接到位移构件,该马达能够操作以使位移构件平移；控制电路,该控制电路联接到马达；以及位置传感器,该位置传感器联接到控制电路。该控制电路被配置为能够接收位置传感器的指示位移构件的至少一个位置的位置输出,以及控制马达的速度以使位移构件以与位置输出相对应的多个速度平移。该多个速度中的每一个保持在预定区域中。(The invention discloses a motorized surgical instrument. The surgical instrument includes: a displacement member; a motor coupled to the displacement member, the motor operable to translate the displacement member; a control circuit coupled to the motor; and a position sensor coupled to the control circuit. The control circuit is configured to receive a position output of the position sensor indicative of at least one position of the displacement member, and control a speed of the motor to translate the displacement member at a plurality of speeds corresponding to the position output. Each of the plurality of speeds is maintained in a predetermined region.)
1. A surgical instrument, comprising:
a displacement member;
a motor coupled to the displacement member, the motor operable to translate the displacement member;
a control circuit coupled to the motor; and
a position sensor coupled to the control circuit;
wherein the control circuitry is configured to be capable of:
receiving a position output of the position sensor indicative of at least one position of the displacement member; and
controlling a speed of the motor to translate the displacement member at a plurality of speeds corresponding to the position output, wherein each of the plurality of speeds remains in a predetermined area.
2. The surgical instrument of claim 1, wherein the control circuit is configured to maintain translation of the displacement member at a first speed in a first region and at a second speed in a second region, and wherein the second region is distal to the first region.
3. The surgical instrument of claim 2, wherein the second speed is greater than the first speed.
4. The surgical instrument of claim 3, wherein the control circuit is configured to maintain translation of the displacement member at a third speed in a third region, and wherein the third region is distal to the second region.
5. The surgical instrument of claim 4, wherein the third speed is greater than the second speed.
6. The surgical instrument of claim 2, further comprising a timer circuit coupled to the control circuit, wherein the timer circuit is configured to measure time elapsed during translation of the displacement member to a predetermined initial position.
7. The surgical instrument of claim 6, wherein the control circuit is configured to determine the first velocity based on time elapsed during translation of the displacement member to the predetermined initial position.
8. The surgical instrument of claim 1, further comprising an end effector comprising a staple cartridge containing a plurality of staples, and wherein translation of the displacement member from a proximal position to a distal position causes deployment of the staples from the staple cartridge.
9. The surgical instrument of claim 1, wherein the control circuit is configured to determine the first speed based on a force or current experienced by the motor.
10. A surgical instrument, comprising:
a displacement member;
a motor coupled to the displacement member, the motor operable to translate the displacement member;
a control circuit coupled to the motor; and
a position sensor coupled to the control circuit;
wherein the control circuitry is configured to be capable of:
receiving a position output of the position sensor indicative of at least one position of the displacement member; and
driving the motor to translate the displacement member at a displacement member speed corresponding to a position of the displacement member.
11. The surgical instrument of claim 10, wherein the control circuit is configured to increase the displacement member velocity at a linear rate from a starting velocity.
12. The surgical instrument of claim 11, further comprising a timer circuit coupled to the control circuit, wherein the timer circuit is configured to measure time elapsed during translation of the displacement member to a predetermined initial position.
13. The surgical instrument of claim 12, wherein the control circuit is configured to determine the starting velocity based on time elapsed during translation of the displacement member to the predetermined initial position.
14. The surgical instrument of claim 10, further comprising an end effector comprising a staple cartridge containing a plurality of staples, and wherein translation of the displacement member from a proximal position to a distal position causes deployment of the staples from the staple cartridge.
15. The surgical instrument of claim 10, wherein the control circuit is configured to determine the first speed based on a force or current experienced by the motor.
16. A surgical instrument, comprising:
a displacement member;
a motor coupled to the displacement member, the motor operable to translate the displacement member;
a control circuit coupled to the motor; and
a position sensor coupled to the control circuit;
wherein the control circuitry is configured to be capable of:
receiving a position output of the position sensor indicative of at least one position of the displacement member along a distance between a proximal position and a distal position; and
driving the motor at a plurality of duty cycles corresponding to the position output, wherein each of the plurality of duty cycles remains in a predetermined region between the proximal position and the distal position.
17. The surgical instrument of claim 16, wherein the control circuit is configured to drive the motor at a first duty cycle in a first region and at a second duty cycle in a second region, and wherein the second region is distal to the first region.
18. The surgical instrument of claim 17, wherein the second duty cycle is greater than the first duty cycle.
19. The surgical instrument of claim 18, wherein the control circuit is configured to drive the motor at a third duty cycle in a third region, and wherein the third region is distal to the second region.
20. The surgical instrument of claim 19, wherein the third duty cycle is greater than the second duty cycle.
21. The surgical instrument of claim 17, further comprising a timer circuit coupled to the control circuit, wherein the timer circuit is configured to measure time elapsed during translation of the displacement member to a predetermined initial position.
22. The surgical instrument of claim 21, wherein the control circuit is configured to determine the first duty cycle based on time elapsed during translation of the displacement member to the predetermined initial position.
23. The surgical instrument of claim 16, wherein the control circuit is configured to determine the first speed based on a force or current experienced by the motor.
Technical Field
The present disclosure relates to surgical instruments and, in various instances, to surgical stapling and cutting instruments and staple cartridges therefor that are designed for stapling and cutting tissue.
Background
In motorized surgical stapling and cutting instruments, it may be useful to control the speed of the cutting member, or to control the articulation speed of the end effector. The velocity of the displacement member may be determined by measuring the elapsed time at a predetermined position interval of the displacement member or measuring the position of the displacement member at a predetermined time interval. The control may be open loop or closed loop. Such measurements may be used to assess tissue conditions such as tissue thickness, and to adjust the speed of the cutting member during the firing stroke to account for the tissue conditions. The tissue thickness may be determined by comparing the expected speed of the cutting member with the actual speed of the cutting member. In some cases, it may be useful to articulate the end effector at a constant articulation speed. In other cases, it may be useful to drive the end effector at an articulation speed that is different from a default articulation speed at one or more regions within the scanning range of the end effector.
During use of the motorized surgical stapling and severing instrument, it is possible that the firing force experienced by the cutting member or firing member may vary significantly based on the position of the cutting member or the firing during the firing stroke. Generally, the first zone is the highest loaded zone and the last zone is the least loaded zone. Accordingly, it may be desirable to define a firing stroke as different regions of each region having different cutting member advancement speeds based on the firing force load experienced by the firing system, and to vary the firing speed of the cutting member based on the position of the cutting member along the firing stroke. It is desirable to set the firing speed at the slowest speed in the first region where the cutting or firing member is at the highest load and increase the speed in each subsequent region. It may be desirable to set the velocity in the first region by determining the tissue thickness or tissue gap by measuring any combination of current through the motor, time to advance the cutting member to a predetermined distance, displacement of the cutting member within a predetermined time, or any proxy for loading on the motor.
Disclosure of Invention
In one aspect, the present disclosure provides a surgical instrument. The surgical instrument comprises a displacement member; a motor coupled to the displacement member, the motor operable to translate the displacement member; a control circuit coupled to the motor; and a position sensor coupled to the control circuit; wherein the control circuitry is configured to be capable of: receiving a position output of the position sensor indicative of at least one position of the displacement member; and controlling a speed of the motor to translate the displacement member at a plurality of speeds corresponding to the position output, wherein each of the plurality of speeds is maintained in a predetermined area.
In another aspect, the surgical instrument includes a displacement member; a motor coupled to the displacement member, the motor operable to translate the displacement member; a control circuit coupled to the motor; and a position sensor coupled to the control circuit; wherein the control circuitry is configured to be capable of: receiving a position output of the position sensor indicative of at least one position of the displacement member; and driving the motor to translate the displacement member at a displacement member speed corresponding to the position of the displacement member.
In another aspect, the surgical instrument includes a displacement member; a motor coupled to the displacement member, the motor operable to translate the displacement member; a control circuit coupled to the motor; and a position sensor coupled to the control circuit; wherein the control circuitry is configured to be capable of: receiving a position output of the position sensor indicative of at least one position of the displacement member along a distance between a proximal position and a distal position; and driving the motor at a plurality of duty cycles corresponding to the position output, wherein each of the plurality of duty cycles remains in a predetermined region between the proximal position and the distal position.
Drawings
The novel features believed characteristic of the aspects described herein are set forth with particularity in the appended claims. However, these aspects, both as to organization and method of operation, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings.
Fig. 1 is a perspective view of a surgical instrument having an interchangeable shaft assembly operatively coupled thereto according to one aspect of the present disclosure.
Fig. 2 is an exploded assembly view of a portion of the surgical instrument of fig. 1, according to one aspect of the present disclosure.
FIG. 3 is an exploded assembly view of portions of an interchangeable shaft assembly according to one aspect of the present disclosure.
Fig. 4 is an exploded view of an end effector of the surgical instrument of fig. 1, according to one aspect of the present disclosure.
Fig. 5A-5B are block diagrams of control circuitry of the surgical instrument of fig. 1 spanning two pictures according to one aspect of the present disclosure.
Fig. 6 is a block diagram of the control circuit of the surgical instrument of fig. 1 showing the interface between the handle assembly and the power assembly, and between the handle assembly and the interchangeable shaft assembly, according to one aspect of the present disclosure.
Fig. 7 illustrates a control circuit configured to control aspects of the surgical instrument of fig. 1 in accordance with an aspect of the present disclosure.
Fig. 8 illustrates a combinational logic circuit configured to control aspects of the surgical instrument of fig. 1 in accordance with an aspect of the present disclosure.
Fig. 9 illustrates sequential logic circuitry configured to control aspects of the surgical instrument of fig. 1 in accordance with an aspect of the present disclosure.
Fig. 10 is an illustration of an absolute positioning system of the surgical instrument of fig. 1, wherein the absolute positioning system includes a controlled motor drive circuit arrangement having a sensor arrangement, according to one aspect of the present disclosure.
Fig. 11 is an exploded perspective view of a sensor structure of an absolute positioning system showing the relative alignment of a control circuit board assembly and a sensor element arrangement according to one aspect of the present disclosure.
FIG. 12 is an illustration of a position sensor including a magnetic rotary absolute positioning system according to an aspect of the present disclosure.
FIG. 13 is a cross-sectional view of the end effector of the surgical instrument of FIG. 1 illustrating the firing member travel relative to tissue clamped within the end effector, according to one aspect of the present disclosure.
Fig. 14 illustrates a block diagram of a surgical instrument programmed to control distal translation of a displacement member according to one aspect of the present disclosure.
Fig. 15 shows a diagram plotting two exemplary displacement member strokes performed in accordance with an aspect of the present disclosure.
Fig. 16 depicts two graphs showing a closing Force (FTC) as a function of closing stroke displacement (d) to close the anvil of the surgical instrument of fig. 1 and a firing force (FTF) as a function of time to fire the surgical instrument of fig. 1, in accordance with one aspect of the present disclosure.
FIG. 17 illustrates a logic flow diagram showing an example of a process that may be executed by a surgical instrument (e.g., control circuitry of the surgical instrument) to implement a control program or logic configuration for the I-beam firing stroke in accordance with one aspect of the present disclosure.
FIG. 18 is a graph illustrating velocity (v) of an I-beam as a function of firing stroke displacement (d) according to one aspect of the present disclosure.
FIG. 19A is a logic flow diagram representing a process of firing control routine or logic configuration according to one aspect of the present disclosure.
FIG. 19B is a logic flow diagram representing a process of firing control routine or logic configuration according to one aspect of the present disclosure.
FIG. 20 depicts two graphs showing a firing force (FTF) as a function of time to fire the surgical instrument of FIG. 1 and a motor duty cycle (speed%) of a motor driving the I-beam as a function of I-beam displacement (d), according to one aspect of the present disclosure.
Fig. 21 depicts two graphs showing motor duty cycle (speed%) as a function of I-beam displacement (d) and Pulse Width Modulation (PWM) as a function of I-beam displacement (d) for a motor driving an I-beam according to one aspect of the present disclosure.
Fig. 22 depicts two graphs showing a closing force as a function of time to close the anvil of the surgical instrument of fig. 1 and a firing force as a function of time to fire the surgical instrument of fig. 1 in accordance with one aspect of the present disclosure.
FIG. 23 illustrates an anvil according to one aspect of the present disclosure.
Detailed Description
The applicants of the present application have the following patent applications filed concurrently herewith and each incorporated herein by reference in its entirety:
attorney docket number END8191USNP/170054 titled control MOTOR vehicle position OF a SURGICAL STAPLING AND CUTTING INSTRUMENT basic OF artificial OF cultivation filed on 20.6.2017 by inventor Frederick e.shelton, IV et al;
attorney docket number END8192USNP/170055 titled SURGILINSTRUMENT WITH VARIABLE DURATION TRIGGER ARRANGEMENT, filed 2017 on 20.6.2017 by inventor Frederick e.shelton, IV et al;
attorney docket number END8193USNP/170056 titled SYSTEMSAND METHODS FOR CONTROLLING DISPLACEMENT MEMBER MOTION OF A SURGICAL STAPLINGAND CUTTING INSTRUMENT filed by inventor Frederick e.shelton, IV et al on 20.6.2017;
attorney docket number END8194USNP/170057 entitled SYSTEMSAND METHODS FOR CONTROLLING MOTOR VELOCITY OF A SURGICAL STAPLING AND cuttinginto concrete available and open END OF END EFFECTOR, filed by inventor Frederick e.shelton, IV et al on 2017 on 20/6;
attorney docket number END8195USNP/170058 titled SYSTEMSAND METHODS FOR CONTROLLING MOTOR VELOCITY OF A SURGICAL STAPLING AND cutting genstrin, filed 2017 on 20.6.2017 by Frederick e.shelton, IV et al;
attorney docket number END8196USNP/170059 titled SURGILIN SURRUMENT HAVING CONTROL ARTICULATION VELOCITY filed 2017 on 20.6.7 by inventor Frederick E.shelton, IV et al;
attorney docket number END8198USNP/170061 titled SYSTEMSAND METHODS FOR CONTROLLING DISPLACEMENT MEMBER VELOCITY FOR A SURGICALINSTRUMENT filed 2017 on 20.6.2017 by inventor Frederick e.shelton, IV et al;
attorney docket number END8222USNP/170125 titled control MOTOR vehicle OF surface STAPLING AND CUTTING insulation basic on earth OF organic OF 20 filed on 20.6.2017 by inventor Frederick e.shelton, IV et al;
attorney docket number END8199USNP/170062M titled TECHNIQUES FOR ADAPTIVE CONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND DCUTTING INSTRUMENT, filed 2017 on 20.6.2017 by Frederick E.Shelton, IV et al;
attorney docket number END8275USNP/170185M titled TECHNIQESFOR CLOSED LOOP CONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTING SYSTEN filed 2017 on 20.6.7 by inventor Raymond E.Parfett et al;
attorney docket number END8268USNP/170186 entitled CLOSED loop feedback CONTROL OF MOTOR vehicle OF a MOTOR vehicle OF CONTROL STAPLING AND current recording OF MOTOR vehicle OF recording vehicles filed 2017 ON 20.6.7 by inventor Raymond e.parfett et al;
attorney docket number END8276 user/170187 entitled CLOSED loop feedback CONTROL OF MOTOR vehicle ON MEASURED TIME OVER A SPECIFIED DISPLACEMENT DISTANCE filed 2017 ON 20.6.2017 by the inventor Jason l harris et al;
attorney docket number END8266USNP/170188 titled close loop FEEDBACK CONTROL OF MOTOR vehicle position OF a surface STAPLING AND cut input system position DISPLACEMENT DISTANCE TRAVELED OVER A SPECIFIEDTIME INTERVAL filed by inventor Frederick e.shelton, IV et al ON 2017 ON 20.6 months;
attorney docket NUMBER END8267USNP/170189 entitled close loop FEEDBACK CONTROL OF MOTOR vehicle OF a MOTOR vehicle OF closed catalyst TIME STAPLING AND cut TIME OVER A SPECIFIED NUMBER OF short records filed by inventor Frederick e.shelton, IV et al ON 2017 ON 20.6 months;
attorney docket number END8269USNP/170190 entitled SYSTEMS and methods FOR CONTROLLING DISPLAYING MOTOR FOR a SURGICAL instument, filed by inventor Jason l harris et al on 20/6/2017;
attorney docket number END8270USNP/170191, titled system and methods FOR CONTROLLING MOTOR SPEED acquisition TO USER INPUT FOR a surgicalinstunt, filed by inventor Jason l.harris et al on 20/6/2017;
attorney docket number END8271USNP/170192 entitled "closed loop FEEDBACK CONTROL OF MOTOR vehicle position OF a minor STAPLING AND cutstating base SYSTEM CONDITIONS" filed 2017 ON 20.6.2017 by Frederick e.shelton, IV et al.
Attorney docket number END8274USDP/170193D titled GRAPHICAL USERINTERFACE FOR A DISPLAY OR PORTION THEREOF filed 2017 on 20.6.2017 by inventor Jason l.harris et al;
attorney docket number END8273USDP/170194D titled GRAPHICAL USERINTERFACE FOR A DISPLAY OR PORTION THEREOF filed 2017 on 20.6.2017 by inventor Jason l.harris et al;
attorney docket number END8272USDP/170195D titled GRAPHICAL USER INTERFACE FOR A DISPLAY OR PORTION THEREOF filed 2017 on 20.6.2017 by inventor Frederick e.shelton, IV et al.
Certain aspects are shown and described to provide an understanding of the structure, function, manufacture, and use of the disclosed apparatus and methods. Features illustrated or described in one example may be combined with features of other examples, and modifications and variations are within the scope of the disclosure.
The terms "proximal" and "distal" are relative to a clinician manipulating a handle of a surgical instrument, where "proximal" refers to a portion closer to the clinician and "distal" refers to a portion further from the clinician. For convenience, the spatial terms "vertical," "horizontal," "upper," and "lower" used with respect to the drawings are not intended to be limiting and/or absolute, as the surgical instrument may be used in many orientations and positions.
Exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, such devices and methods may be used for other surgical procedures and applications, including, for example, open surgical procedures. The surgical instrument may be inserted through a natural orifice or through an incision or puncture formed in tissue. For example, the working or end effector portions of these instruments can be inserted into the body directly or through an access device having a working channel through which the end effector and elongate shaft of the surgical instrument can be advanced.
Fig. 1-4 depict a motor-driven surgical instrument 10 for cutting and fastening, which may or may not be reusable. In the illustrated example, the surgical instrument 10 includes a housing 12 including a handle assembly 14 configured to be grasped, manipulated and actuated by a clinician. The housing 12 is configured to be operably attached to an interchangeable shaft assembly 200 having an end effector 300 operably coupled thereto that is configured to perform one or more surgical tasks or procedures. In accordance with the present disclosure, various forms of interchangeable shaft assemblies may be effectively employed in connection with robotically controlled surgical systems. The term "housing" may encompass a housing or similar portion of a robotic system that houses or otherwise operatively supports at least one drive system configured to be capable of generating and applying at least one control motion that may be used to actuate the interchangeable shaft assembly. The term "frame" may refer to a portion of a hand-held surgical instrument. The term "frame" may also refer to a portion of a robotically-controlled surgical instrument and/or a portion of a robotic system that may be used to operably control a surgical instrument. The interchangeable shaft assemblies may be used with various robotic systems, instruments, components and methods disclosed in U.S. patent 9,072,535 entitled "SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS," which is hereby incorporated by reference in its entirety.
Fig. 1 is a perspective view of a surgical instrument 10 having an interchangeable shaft assembly 200 operably coupled thereto according to one aspect of the present disclosure. The housing 12 includes an end effector 300 comprising a surgical cutting and fastening device configured to operatively support a surgical staple cartridge 304 therein. Housing 12 may be configured for use with interchangeable shaft assemblies that include end effectors adapted to support different sizes and types of staple cartridges, having different shaft lengths, sizes, and types. Housing 12 may be used with a variety of interchangeable shaft assemblies, including assemblies configured to apply other motions and forms of energy, such as Radio Frequency (RF) energy, ultrasonic energy, and/or motions, to end effector arrangements suitable for use in connection with various surgical applications and procedures. The end effector, shaft assembly, handle, surgical instrument, and/or surgical instrument system may utilize any suitable fastener or fasteners to fasten tissue. For example, a fastener cartridge including a plurality of fasteners removably stored therein can be removably inserted into and/or attached to an end effector of a shaft assembly.
The handle assembly 14 may include a pair of interconnectable handle housing segments 16, 18 interconnected by screws, snap features, adhesives, or the like. The handle housing sections 16, 18 cooperate to form a pistol grip 19 that can be grasped and manipulated by a clinician. The handle assembly 14 operatively supports a plurality of drive systems configured to be capable of generating and applying control motions to corresponding portions of the interchangeable shaft assembly operatively attached thereto. A display may be provided under the cover 45.
Fig. 2 is an exploded assembly view of a portion of the surgical instrument 10 of fig. 1, according to one aspect of the present disclosure. The handle assembly 14 may include a frame 20 that operatively supports a plurality of drive systems. The frame 20 may operatively support a "first" or closure drive system 30 that may impart closing and opening motions to the interchangeable shaft assembly 200. The closure drive system 30 may include an actuator such as a closure trigger 32 pivotally supported by the frame 20. The closure trigger 32 is pivotally coupled to the handle assembly 14 by a pivot pin 33 such that the closure trigger 32 can be manipulated by a clinician. The closure trigger (32) may pivot from a start or "unactuated" position to an "actuated" position and more specifically to a fully compressed or fully actuated position when the clinician grasps the pistol grip portion 19 of the handle assembly 14.
The handle assembly 14 and the frame 20 can operatively support a firing drive system 80 configured to apply firing motions to corresponding portions of the interchangeable shaft assembly attached thereto. The firing drive system 80 may employ an electric motor 82 located in the pistol grip portion 19 of the handle assembly 14. The motor 82 may be a DC brushed motor having a maximum rotational speed of about 25,000 RPM. In other constructions, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The electric motor 82 may be powered by a power source 90 that may include a removable power pack 92. The removable battery pack 92 may include a proximal housing portion 94 configured to be attachable to a distal housing portion 96. The proximal housing portion 94 and the distal housing portion 96 are configured to operably support a plurality of batteries 98 therein. Batteries 98 may each include, for example, a Lithium Ion (LI) or other suitable battery. The distal housing portion 96 is configured for removable operative attachment to a control circuit board 100 that is operatively coupled to the electric motor 82. A number of batteries 98 connected in series may power the surgical instrument 10. The power source 90 may be replaceable and/or rechargeable. The display 43, located below the cover 45, is electrically coupled to the control circuit board 100. The cover 45 may be removed to expose the display 43.
The electric motor 82 may include a rotatable shaft (not shown) operatively interfacing with a gear reducer assembly 84 mounted in meshing engagement with drive teeth 122 of a set or rack on the longitudinally movable drive member 120. The longitudinally movable drive member 120 has a rack of drive teeth 122 formed thereon for meshing engagement with the corresponding drive gear 86 of the gear reducer assembly 84.
In use, the polarity of the voltage provided by the power source 90 may operate the electric motor 82 in a clockwise direction, wherein the polarity of the voltage applied by the battery to the electric motor may be reversed to operate the electric motor 82 in a counterclockwise direction. When the electric motor 82 is rotated in one direction, the longitudinally movable drive member 120 will be driven axially in the distal direction "DD". When the electric motor 82 is driven in the opposite rotational direction, the longitudinally movable drive member 120 will be driven axially in the proximal direction "PD". The handle assembly 14 may include a switch that may be configured to enable the polarity applied to the electric motor 82 by the power source 90 to be reversed. The handle assembly 14 may include a sensor configured to detect the position of the longitudinally movable drive member 120 and/or the direction in which the longitudinally movable drive member 120 is moving.
Actuation of the electric motor 82 is controlled by a firing trigger 130 pivotally supported on the handle assembly 14. The firing trigger 130 may be pivotable between an unactuated position and an actuated position.
Turning back to fig. 1, the interchangeable shaft assembly 200 includes an end effector 300 that includes an elongate channel 302 configured to operatively support a surgical staple cartridge 304 therein. The end effector 300 may include an anvil 306 pivotally supported relative to the elongate channel 302. The interchangeable shaft assembly 200 can include an articulation joint 270. The construction and operation of the end effector 300 and ARTICULATION joint 270 is set forth in U.S. patent application publication No. 2014/0263541 entitled ARTICULATABLE SURGICAL INSTRUMENTC PRIMING AN ARTICULATION LOCK, which is incorporated herein by reference in its entirety. The interchangeable shaft assembly 200 can include a proximal housing or nozzle 201 comprised of nozzle portions 202, 203. The interchangeable shaft assembly 200 can include a closure tube 260 extending along a shaft axis SA that can be used to close and/or open the anvil 306 of the end effector 300.
Turning back to FIG. 1, the closure tube 260 is translated distally (direction "DD") to close the anvil 306, for example, in response to actuation of the closure trigger 32, in the manner described in the aforementioned reference U.S. patent application publication 2014/0263541. The anvil 306 is opened by translating the closure tube 260 proximally. In the anvil open position, the closure tube 260 is moved to its proximal position.
Fig. 3 is another exploded assembly view of portions of an interchangeable shaft assembly 200 according to one aspect of the present disclosure. The interchangeable shaft assembly 200 can include a firing member 220 supported for axial travel within the spine 210. The firing member 220 includes an intermediate firing shaft 222 configured to be attached to a distal cutting portion or knife bar 280. The firing member 220 may be referred to as a "second shaft" and/or a "second shaft assembly. The intermediate firing shaft 222 may include a longitudinal slot 223 in the distal end configured to receive a tab 284 on the proximal end 282 of the knife bar 280. The longitudinal slot 223 and the proximal end 282 may be configured to allow relative movement therebetween, and may include a slip joint 286. The sliding joint 286 can allow the intermediate firing shaft 222 of the firing member 220 to articulate the end effector 300 about the articulation joint 270 without moving, or at least substantially without moving, the knife bar 280. Once the end effector 300 has been properly oriented, the intermediate firing shaft 222 can be advanced distally until the proximal side wall of the longitudinal slot 223 contacts the tab 284 to advance the knife bar 280 and fire a staple cartridge positioned within the channel 302. The spine 210 has an elongated opening or window 213 therein to facilitate assembly and insertion of the intermediate firing shaft 222 into the spine 210. Once the intermediate firing shaft 222 has been inserted into the shaft frame, the top frame segment 215 may be engaged with the shaft frame 212 to enclose the intermediate firing shaft 222 and knife bar 280 therein. The operation of the firing member 220 can be found in U.S. patent application publication No. 2014/0263541. The spine 210 may be configured to slidably support a firing member 220 and a closure tube 260 that extends around the spine 210. The spine 210 may slidably support an articulation driver 230.
The interchangeable shaft assembly 200 can include a clutch assembly 400 configured to selectively and releasably couple the articulation driver 230 to the firing member 220. The clutch assembly 400 includes a lock collar or lock sleeve 402 positioned about the firing member 220, wherein the lock sleeve 402 is rotatable between an engaged position in which the lock sleeve 402 couples the articulation driver 230 to the firing member 220 and a disengaged position in which the articulation driver 230 is not operatively coupled to the firing member 220. When the locking sleeve 402 is in the engaged position, distal movement of the firing member 220 can move the articulation driver 230 distally; and accordingly, proximal movement of the firing member 220 can move the articulation driver 230 proximally. When the locking sleeve 402 is in the disengaged position, movement of the firing member 220 is not transmitted to the articulation driver 230; and, thus, the firing member 220 may move independently of the articulation driver 230. The nozzle 201 may be used to operatively engage and disengage the articulation drive system from the firing drive system in various ways described in U.S. patent application publication No. 2014/0263541.
Interchangeable shaft assembly 200 can include a slip ring assembly 600, which can be configured to conduct electrical power to and/or from end effector 300, and/or to communicate signals to and/or from end effector 300, for example. Slip ring assembly 600 may include a proximal connector flange 604 and a distal connector flange 601 positioned within slots defined in nozzle portions 202, 203. The proximal connector flange 604 may comprise a first face and the distal connector flange 601 may comprise a second face adjacent to and movable relative to the first face. The distal connector flange 601 is rotatable relative to the proximal connector flange 604 about an axis SA-SA (FIG. 1). The proximal connector flange 604 may include a plurality of concentric or at least substantially concentric conductors 602 defined in a first face thereof. The connector 607 may be mounted on the proximal face of the distal connector flange 601 and may have a plurality of contacts, where each contact corresponds to and is in electrical contact with one of the conductors 602. This arrangement allows for relative rotation between the proximal connector flange 604 and the distal connector flange 601 while maintaining electrical contact therebetween. The proximal connector flange 604 may include an electrical connector 606 that may, for example, place the conductor 602 in signal communication with a shaft circuit board. In at least one example, a wire harness including a plurality of conductors may extend between the electrical connector 606 and the shaft circuit board. The electrical connector 606 may extend proximally through a connector opening defined in the chassis mounting flange. U.S. patent application publication 2014/0263551 entitled "STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM" is hereby incorporated by reference in its entirety. U.S. patent application publication 2014/0263552 entitled "STAPLE CARTRIDGE TISSUE THICKNESSENSOR SYSTEM" is hereby incorporated by reference in its entirety. More details regarding slip ring assembly 600 may be found in U.S. patent application publication 2014/0263541.
The interchangeable shaft assembly 200 can include a proximal portion that can be fixedly mounted to the handle assembly 14, and a distal portion that can be rotated about a longitudinal axis. The rotatable distal shaft portion may be rotated relative to the proximal portion about the slip ring assembly 600. The distal connector flange 601 of the slip ring assembly 600 may be positioned within the rotatable distal shaft portion.
Fig. 4 is an exploded view of the end effector 300 of the surgical instrument 10 of fig. 1, according to one aspect of the present disclosure. The end effector 300 may include an anvil 306 and a surgical staple cartridge 304. The anvil 306 may be coupled to the elongate channel 302. For example, an aperture 199 can be defined in the elongate channel 302 to receive a pin 152 extending from the anvil 306 so as to allow the anvil 306 to pivot from an open position to a closed position relative to the elongate channel 302 and the surgical staple cartridge 304. The firing bar 172 is configured to translate longitudinally into the end effector 300. The firing bar 172 may be constructed from one solid section, or may comprise a laminate material comprising a stack of steel plates. The firing bar 172 includes an I-beam 178 and a cutting edge 182 at a distal end thereof. Distal protruding ends of the firing bar 172 may be attached to the I-beam 178 to help space the anvil 306 from the surgical staple cartridge 304 positioned in the elongate channel 302 when the anvil 306 is in the closed position. The I-beam 178 may include a sharp cutting edge 182 for severing tissue as the I-beam 178 is advanced distally by the firing bar 172. In operation, the I-beam 178 can actuate or fire the surgical staple cartridge 304. The surgical staple cartridge 304 can comprise a molded cartridge body 194 that holds a plurality of staples 191 disposed on staple drivers 192 located in respective upwardly opening staple cavities 195. The wedge sled 190 is driven distally by the I-beam 178 to slide over the cartridge tray 196 of the surgical staple cartridge 304. The wedge sled 190 cams staple drivers 192 upward to extrude staples 191 into deforming contact with the anvil 306 while the cutting edges 182 of the I-beam 178 sever clamped tissue.
The I-beam 178 may include an upper pin 180 that engages the anvil 306 during firing. The I-beam 178 can include a middle pin 184 and a bottom base 186 that engage portions of the cartridge body 194, the cartridge tray 196, and the elongate channel 302. When the surgical staple cartridge 304 is positioned within the elongate channel 302, the slot 193 defined in the cartridge body 194 can be aligned with the longitudinal slot 197 defined in the cartridge tray 196 and the slot 189 defined in the elongate channel 302. In use, the I-beam 178 can be slid through the aligned longitudinal slots 193, 197, and 189, wherein, as shown in fig. 4, the bottom base 186 of the I-beam 178 can engage a groove extending along the bottom surface of the elongate channel 302 along the length of the slot 189, the middle pin 184 can engage the top surface of the cartridge tray 196 along the length of the longitudinal slot 197, and the upper pin 180 can engage the anvil 306. The I-beam 178 may space or limit relative movement between the anvil 306 and the surgical staple cartridge 304 as the firing bar 172 is advanced distally to fire the staples from the surgical staple cartridge 304 and/or incise tissue captured between the anvil 306 and the surgical staple cartridge 304. The firing bar 172 and the I-beam 178 can be retracted proximally, thereby allowing the anvil 306 to be opened to release the two stapled and severed tissue portions.
Fig. 5A-5B are block diagrams of control circuitry 700 of the surgical instrument 10 of fig. 1 spanning two pulled webs according to one aspect of the present disclosure. Referring primarily to fig. 5A-5B, the handle assembly 702 can include a motor 714 that can be controlled by a motor driver 715 and can be used by a firing system of the surgical instrument 10. In various forms, the motor 714 may be a DC brushed driving motor with a maximum rotational speed of about 25,000 RPM. In other arrangements, the motor 714 may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The motor driver 715 may include, for example, an H-bridge driver including a Field Effect Transistor (FET) 719. The motor 714 may be powered by the power assembly 706, which is releasably mounted to the handle assembly 200 for providing control power to the surgical instrument 10. The power assembly 706 may include a battery that may include a plurality of battery cells connected in series that may be used as a power source to power the surgical instrument 10. In some cases, the battery cells of power component 706 may be replaceable and/or rechargeable. In at least one example, the battery cell may be a lithium ion battery that may be detachably coupled to the power assembly 706.
Shaft assembly 704 can include a shaft assembly controller 722 that can communicate with safety controller and power management controller 716 through an interface when shaft assembly 704 and power assembly 706 are coupled to handle assembly 702. For example, the interface can include a first interface portion 725 that can include one or more electrical connectors for coupling engagement with corresponding shaft assembly electrical connectors and a second interface portion 727 that can include one or more electrical connectors for coupling engagement with corresponding power assembly electrical connectors, thereby allowing electrical communication between shaft assembly controller 722 and power management controller 716 when shaft assembly 704 and power assembly 706 are coupled to handle assembly 702. One or more communication signals may be transmitted over the interface to communicate one or more of the power requirements of the attached interchangeable shaft assembly 704 to the power management controller 716. In response, the power management controller may adjust the power output of the battery of power assembly 706 according to the power requirements of attached shaft assembly 704, as described in more detail below. The connector may include switches that may be activated after the handle assembly 702 is mechanically coupled to the shaft assembly 704 and/or the power assembly 706 to allow electrical communication between the shaft assembly controller 722 and the power management controller 716.
For example, the interface may facilitate the transmission of one or more communication signals between the power management controller 716 and the shaft assembly controller 722 by routing such communication signals through the main controller 717 located in the handle assembly 702. In other instances, the interface may facilitate a direct communication link between power management controller 716 and shaft assembly controller 722 through handle assembly 702 when shaft assembly 704 and power assembly 706 are coupled to handle assembly 702.
The main controller 717 may be any single-core or multi-core processor, such as those provided by Texas Instruments under the trade name ARM Cortex. In one aspect, master controller 717 can be, for example, an LM4F230H5QR ARM Cortex-M4F processor core available from Texas instruments, which includes: 256KB of single cycle flash memory or on-chip memory of other non-volatile memory (up to 40MHz), prefetch buffer for performance improvement over 40MHz, 32KB of single cycle Serial Random Access Memory (SRAM), load with
The safety controller may be a family of two controller-based safety controller platforms such as TMS570 and RM4x, also known by Texas Instruments and under the trade name Hercules ARM Cortex R4. The safety controller may be configured specifically for IEC 61508 and ISO26262 safety critical applications, etc., to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options.
The power component 706 may include power management circuitry that may include a power management controller 716, a power regulator 738, and a current sensing circuit 736. The power management circuitry can be configured to regulate the power output of the battery based on the power requirements of shaft assembly 704 when shaft assembly 704 and power assembly 706 are coupled to handle assembly 702. The power management controller 716 may be programmed as a power regulator 738 that controls the power output of the power component 706, and the current sensing circuit 736 may be used to monitor the power output of the power component 706 to provide feedback regarding the power output of the battery to the power management controller 716 so that the power management controller 716 may adjust the power output of the power component 706 to maintain the desired output. Power management controller 716 and/or shaft assembly controller 722 may each include one or more processors and/or memory units that may store a plurality of software modules.
The surgical instrument 10 (fig. 1-4) may include an output device 742, which may include a means for providing sensory feedback to a user. Such devices may include, for example, visual feedback devices (e.g., LCD display screens, LED indicators), audio feedback devices (e.g., speakers, buzzers), or tactile feedback devices (e.g., haptic actuators). In some cases, the output device 742 can include a display 743 that can be included in the handle assembly 702. The shaft assembly controller 722 and/or the power management controller 716 can provide feedback to a user of the surgical instrument 10 via an output device 742. The interface may be configured to connect the shaft assembly controller 722 and/or the power management controller 716 to the output device 742. The output device 742 may alternatively be integral with the power assembly 706. In such instances, communication between the output device 742 and the shaft assembly controller 722 can be accomplished through the interface when the shaft assembly 704 is coupled to the handle assembly 702.
The control circuit 700 includes a circuit segment configured to control the operation of the powered surgical instrument 10. The safety controller section (section 1) includes a safety controller and a main controller 717 section (section 2). The safety and/or main controller 717 is configured to be able to interact with one or more additional circuit segments such as an acceleration segment, a display segment, a shaft segment, an encoder segment, a motor segment, and a power segment. Each of the circuit segments may be coupled to a safety processor and/or a main controller 717. The main controller 717 is also coupled to a flash memory. The main controller 717 also includes a serial communication interface. The main controller 717 includes a plurality of inputs coupled to, for example, one or more circuit segments, a battery, and/or a plurality of switches. The segmented circuit may be implemented by any suitable circuit, such as, for example, a Printed Circuit Board Assembly (PCBA) within the powered surgical instrument 10. It is to be understood that the term "processor" as used herein includes any microprocessor, processor, microcontroller, controller or other basic computing device that combines the functions of a computer's Central Processing Unit (CPU) onto one integrated circuit or at most a few integrated circuits. The main controller 717 is a multipurpose programmable device that receives digital data as input, processes it according to instructions stored in its memory, and provides the results as output. Because the processor has internal memory, it is an example of sequential digital logic. The control circuit 700 may be configured to implement one or more of the processes described herein.
The acceleration segment (segment 3) includes an accelerometer. The accelerometer is configured to detect movement or acceleration of the powered surgical instrument 10. Inputs from the accelerometer can be used to transition to and from sleep mode, identify the orientation of the powered surgical instrument, and/or identify when the surgical instrument has been dropped. In some examples, the acceleration segment is coupled to a safety processor and/or a master controller 717.
The display segment (segment 4) includes a display connector coupled to a main controller 717. The display connector couples the main controller 717 to the display through one or more integrated circuit drivers for the display. The integrated circuit driver of the display may be integrated with the display and/or may be located separately from the display. The display may include any suitable display, such as, for example, an Organic Light Emitting Diode (OLED) display, a Liquid Crystal Display (LCD), and/or any other suitable display. In some examples, the display segment is coupled to the secure processor.
The shaft segment (segment 5) includes controls for coupling to the interchangeable shaft assembly 200 (fig. 1 and 3) of the surgical instrument 10 (fig. 1-4) and/or one or more controls for coupling to the end effector 300 of the interchangeable shaft assembly 200. The shaft section includes a shaft connector configured to couple the main controller 717 to the shaft PCBA. The shaft PCBA includes a low power microcontroller with Ferroelectric Random Access Memory (FRAM), articulation switch, shaft release hall effect switch, and shaft PCBA EEPROM. The shaft PCBA EEPROM includes one or more parameters, routines and/or programs that are specific to the interchangeable shaft assembly 200 and/or the shaft PCBA. The shaft PCBA may be coupled to the interchangeable shaft assembly 200 and/or integral with the surgical instrument 10. In some examples, the shaft segment includes a second shaft EEPROM. The second shaft EEPROM includes a plurality of algorithms, routines, parameters, and/or other data corresponding to one or more shaft assemblies 200 and/or end effectors 300 that may be interfaced with the powered surgical instrument 10.
The position encoder section (section 6) comprises one or more magnetic angular rotary position encoders. The one or more magnetic angular rotational position encoders are configured to identify the rotational position of the motor 714, interchangeable shaft assembly 200 (fig. 1 and 3), and/or end effector 300 of the surgical instrument 10 (fig. 1-4). In some examples, a magnetic angular rotational position encoder may be coupled to the safety processor and/or the main controller 717.
The motor circuit section (section 7) includes a motor 714 configured to control movement of the powered surgical instrument 10 (fig. 1-4). The motor 714 passes through an H-bridge driver including one or more H-bridge Field Effect Transistors (FETs) and a main microcontroller processor 717 of the motor controller. The H-bridge driver is also coupled to the safety controller. A motor current sensor is coupled in series with the motor to measure the current draw of the motor. The motor current sensor is in signal communication with the main controller 717 and/or the safety processor. In some examples, the motor 714 is coupled to a motor electromagnetic interference (EMI) filter.
The motor controller controls the first motor flag and the second motor flag to indicate the state and position of the motor 714 to the main controller 717. The main controller 717 provides a Pulse Width Modulation (PWM) high signal, a PWM low signal, a direction signal, a synchronization signal, and a motor reset signal to the motor controller through the buffer. The power segment is configured to be capable of providing a segment voltage to each of the circuit segments.
The power section (section 8) includes a battery coupled to a safety controller, a main controller 717 and additional circuit sections. The battery is coupled to the segmented circuit by a battery connector and a current sensor. The current sensor is configured to be able to measure the total current consumption of the segmented circuit. In some examples, the one or more voltage converters are configured to be capable of providing a predetermined voltage value to the one or more circuit segments. For example, in some examples, the segmented circuit may include a 3.3V voltage converter and/or a 5V voltage converter. The boost converter is configured to be able to provide a boost voltage up to a predetermined amount, such as up to 13V, for example. The boost converter is configured to be able to provide additional voltage and/or current during power intensive operations and prevent a reduced voltage condition or a low power condition.
A plurality of switches are coupled to the safety controller and/or the main controller 717. These switches may be configured to control the operation of the segmented circuit of the surgical instrument 10 (fig. 1-4) and/or to indicate the status of the surgical instrument 10. An emergency door switch and hall effect switch for an emergency are configured to indicate the status of the emergency door. A plurality of articulation switches, such as, for example, a left articulation switch, a left right articulation switch, a left center articulation switch, a right left articulation switch, a right articulation switch, and a right center articulation switch, are configured to control articulation of the interchangeable shaft assembly 200 (fig. 1 and 3) and/or the end effector 300 (fig. 1 and 4). The left hand and right hand commutation switches are coupled to a main controller 717. The left switches (including a left articulation switch, a left right articulation switch, a left center articulation switch, and a left reversing switch) are coupled to the main controller 717 through a left flex connector. The right switches (including the right left articulation switch, the right articulation switch, the right center articulation switch, and the right reversing switch) are coupled to the master controller 717 through a right flex connector. The cocking switch, clamp release switch, and shaft engagement switch are linked to the main controller 717.
Any suitable mechanical, electromechanical or solid state switch may be used in any combination to implement the plurality of switches. For example, the switch may be a limit switch operated by movement of a component associated with the surgical instrument 10 (fig. 1-4) or the presence of an object. Such switches may be used to control various functions associated with the surgical instrument 10. Limit switches are electromechanical devices consisting of an actuator mechanically connected to a set of contacts. When an object comes into contact with the actuator, the device operates the contacts to make or break the electrical connection. The limit switch is durable, simple and convenient to install, reliable in operation and suitable for various applications and environments. The limit switches can determine the presence or absence, the passage, the location, and the end of travel of the object. In other implementations, the switches may be solid state switches that operate under the influence of a magnetic field, such as hall effect devices, Magnetoresistive (MR) devices, Giant Magnetoresistive (GMR) devices, magnetometers, and the like. In other implementations, the switch may be a solid state switch that operates under the influence of light, such as an optical sensor, an infrared sensor, an ultraviolet sensor, and so forth. Likewise, the switches may be solid state devices such as transistors (e.g., FETs, junction FETs, metal oxide semiconductor FETs (mosfets), bipolar transistors, etc.). Other switches may include wireless switches, ultrasonic switches, accelerometers, inertial sensors, and others.
Fig. 6 is another block diagram of the control circuit 700 of the surgical instrument of fig. 1 illustrating the interface between the handle assembly 702 and the power assembly 706 and between the handle assembly 702 and the interchangeable shaft assembly 704 according to one aspect of the present disclosure. The handle assembly 702 may include a main controller 717, a shaft assembly connector 726, and a power assembly connector 730. The power component 706 may include a power component connector 732, a power management circuit 734, which may include a power management controller 716, a power regulator 738, and a current sensing circuit 736. The shaft assembly connectors 730, 732 form an interface 727. Power management circuit 734 may be configured to regulate the power output of battery 707 based on the power requirements of interchangeable shaft assembly 704 when interchangeable shaft assembly 704 and power assembly 706 are coupled to handle assembly 702. The power management controller 716 may be programmed as a power regulator 738 that controls the power output of the power component 706, and the current sensing circuit 736 may be used to monitor the power output of the power component 706 to provide feedback to the power management controller 716 regarding the power output of the battery 707, such that the power management controller 716 may adjust the power output of the power component 706 to maintain the desired output. The shaft assembly 704 includes a shaft processor 719 coupled to a non-volatile memory 721 and a shaft assembly connector 728 to electrically couple the shaft assembly 704 to the handle assembly 702. The shaft assembly connectors 726, 728 form an interface 725. The main controller 717, the axis processor 719, and/or the power management controller 716 may be configured to be capable of implementing one or more of the processes described herein.
The surgical instrument 10 (fig. 1-4) may include an output device 742 for providing sensory feedback to the user. Such devices may include visual feedback devices (e.g., LCD display screens, LED indicators), audible feedback devices (e.g., speakers, buzzers), or tactile feedback devices (e.g., haptic actuators). In some cases, the output device 742 can include a display 743 that can be included in the handle assembly 702. The shaft assembly controller 722 and/or the power management controller 716 can provide feedback to a user of the surgical instrument 10 via an output device 742. Interface 727 may be configured to connect shaft assembly controller 722 and/or power management controller 716 to output device 742. The output device 742 may be integral with the power component 706. When the interchangeable shaft assembly 704 is coupled to the handle assembly 702, communication between the output device 742 and the shaft assembly controller 722 can be accomplished through the interface 725. Having described the control circuit 700 (fig. 5A-5B and 6) for controlling the operation of the surgical instrument 10 (fig. 1-4), the present disclosure now turns to various configurations of the surgical instrument 10 (fig. 1-4) and the control circuit 700.
Fig. 7 illustrates a control circuit 800 configured to control aspects of the surgical instrument 10 (fig. 1-4), according to one aspect of the present disclosure. The control circuitry 800 may be configured to implement various processes described herein. The control circuit 800 may include a controller including one or more processors 802 (e.g., microprocessors, microcontrollers) coupled to at least one memory circuit 804. The memory circuit 804 stores machine-executable instructions that, when executed by the processor 802, cause the processor 802 to execute machine instructions to perform the various processes described herein. The processor 802 may be any of a variety of single-core or multi-core processors known in the art. The memory circuit 804 may include volatile storage media and non-volatile storage media. The processor 802 may include an instruction processing unit 806 and an arithmetic unit 808. The instruction processing unit may be configured to be able to receive instructions from the memory circuit 804.
Fig. 8 illustrates a combinational logic circuit 810 configured to control aspects of the surgical instrument 10 (fig. 1-4) in accordance with an aspect of the present disclosure. The combinational logic circuit 810 may be configured to implement the various processes described herein. The circuit 810 may comprise a finite state machine including combinatorial logic 812 configured to receive data associated with the surgical instrument 10 at an input 814, process the data through the combinatorial logic 812, and provide an output 816.
Fig. 9 illustrates a sequential logic circuit 820 configured to control aspects of the surgical instrument 10 (fig. 1-4), according to one aspect of the present disclosure. Sequential logic circuitry 820 or combinational logic circuitry 822 may be configured to implement the various processes described herein. Circuitry 820 may include a finite state machine. Sequential logic circuit 820 may comprise, for example, combinational logic 822, at least one memory circuit 824, and a clock 829. The at least one memory circuit 820 may store a current state of the finite state machine. In some cases, sequential logic circuit 820 may be synchronous or asynchronous. The combinational logic circuit 822 is configured to receive data associated with the surgical instrument 10 at an input 826, process the data through the combinational logic circuit 822, and provide an output 828. In other aspects, the circuitry may comprise a combination of the processor 802 and a finite state machine to implement the various processes herein. In other aspects, the finite state machine may comprise a combination of combinational logic circuit 810 and sequential logic circuit 820.
Aspects may be implemented as an article of manufacture. An article of manufacture may comprise a computer-readable storage medium arranged to store logic, instructions, and/or data for performing various operations of one or more aspects. For example, an article of manufacture may comprise a magnetic disk, optical disk, flash memory, or firmware containing computer program instructions adapted for execution by a general purpose or special purpose processor.
Fig. 10 is an illustration of an absolute positioning system 1100 of a surgical instrument 10 (fig. 1-4) according to one aspect of the present disclosure, wherein the absolute positioning system 1100 includes a controlled motor drive circuit arrangement that includes a sensor arrangement 1102. The sensor arrangement 1102 for the absolute positioning system 1100 provides a unique position signal corresponding to the position of the displacement member 1111. Turning briefly to fig. 2-4, in one aspect, displacement member 1111 represents a longitudinally movable drive member 120 (fig. 2) including a rack of drive teeth 122 for meshing engagement with a corresponding drive gear 86 of gear reducer assembly 84. In other aspects, the displacement member 1111 represents the firing member 220 (fig. 3), which can be adapted and configured as a rack including drive teeth. In another aspect, the displacement member 1111 represents the firing bar 172 (FIG. 4) or the I-beam 178 (FIG. 4), each of which may be adapted and configured to include a drive tooth of a rack gear. Thus, as used herein, the term displacement member is used generally to refer to any movable member of the surgical instrument 10, such as the drive member 120, the firing member 220, the firing bar 172, the I-beam 178, or any element that may be displaced. In one aspect, the longitudinally movable drive member 120 is coupled to the firing member 220, the firing bar 172, and the I-beam 178. Thus, absolute positioning system 1100 may actually track the linear displacement of I-beam 178 by tracking the linear displacement of longitudinally movable drive member 120. In various other aspects, displacement member 1111 may be coupled to any sensor suitable for measuring linear displacement. Thus, the longitudinally movable drive member 120, firing member 220, firing bar 172, or I-beam 178, or combinations thereof, may be coupled to any suitable linear displacement sensor. The linear displacement sensor may comprise a contact displacement sensor or a non-contact displacement sensor. The linear displacement sensor may comprise a Linear Variable Differential Transformer (LVDT), a Differential Variable Reluctance Transducer (DVRT), a sliding potentiometer, a magnetic sensing system comprising a movable magnet and a series of linearly arranged hall effect sensors, a magnetic sensing system comprising a fixed magnet and a series of movable linearly arranged hall effect sensors, an optical sensing system comprising a movable light source and a series of linearly arranged photodiodes or photodetectors, or an optical sensing system comprising a fixed light source and a series of movable linearly arranged photodiodes or photodetectors, or any combination thereof.
The electric motor 1120 may include a rotatable shaft 1116 operably interfaced with a gear assembly 1114 mounted in meshing engagement with a set or rack of drive teeth on the displacement member 1111. The sensor element 1126 may be operatively coupled to the gear assembly 1114 such that a single rotation of the sensor element 1126 corresponds to a certain linear longitudinal translation of the displacement member 1111. The arrangement of the transmission and sensor 1118 may be connected to a linear actuator via a rack and pinion arrangement, or to a rotary actuator via a spur gear or other connection. A power source 1129 supplies power to the absolute positioning system 1100, and an output indicator 1128 may display the output of the absolute positioning system 1100. In fig. 2, displacement member 1111 represents a longitudinally movable drive member 120 including drive teeth 122 formed thereon for a rack gear in meshing engagement with a corresponding drive gear 86 of gear reducer assembly 84. Displacement member 1111 represents a movable longitudinal firing member 220, a firing bar 172, an I-beam 178, or a combination thereof.
A single revolution of sensor element 1126 associated with position sensor 1112 equates to a longitudinal linear displacement d1 of displacement member 1111, where d1 is the longitudinal linear distance that displacement member 1111 moves from point "a" to point "b" after a single revolution of sensor element 1126 coupled to displacement member 1111. The sensor arrangement 1102 may be connected via a gear reduction that causes the position sensor 1112 to complete one or more revolutions for the full stroke of the displacement member 1111. Position sensor 1112 may complete multiple revolutions for the full stroke of displacement member 1111.
A series of switches 1122a-1122n (where n is an integer greater than one) may be used alone or in conjunction with a gear reduction to provide unique position signals for more than one rotation of position sensor 1112. The state of the switches 1122a-1122n is fed back to the controller 1104, which applies logic to determine a unique position signal corresponding to the longitudinal linear displacement d1+ d2+ … dn of the displacement member 1111. The output 1124 of the position sensor 1112 is provided to the controller 1104. The position sensor 1112 of the sensor arrangement 1102 may include a magnetic sensor, an analog rotation sensor such as a potentiometer, an array of analog hall effect elements that output a unique combination of position signals or values.
Absolute positioning system 1100 provides the absolute position of displacement member 1111 upon instrument power-up without retracting or advancing displacement member 1111 to a reset (clear or home) position as may be required by conventional rotary encoders that simply count the number of forward or backward steps taken by motor 1120 to infer the position of the device actuator, drive rod, knife, etc.
In various aspects, the controller 1104 may be programmed to perform various functions, such as precise control of the tool and the speed and position of the articulation system. In one aspect, the controller 1104 includes a processor 1108 and a memory 1106. The electric motor 1120 may be a brushed DC motor with a gearbox and machinery connected to an articulation or knife system. In one aspect, the motor drive 1110 can be a3941 available from Allegro Microsystems, inc. Other motor drives can be readily substituted for use in absolute positioning system 1100. A more detailed description of the absolute positioning system 1100 is described in U.S. patent application No. 15/130,590, entitled SYSTEMS AND METHODS FOR CONTROLLING A SURGICAL STAPLING AND CUTTING NSTRUMENT, filed 4, 15, 2016, the entire disclosure of which is incorporated herein by reference.
The controller 1104 may be programmed to provide precise control of the speed and position of the displacement member 1111 and the articulation system. The controller 1104 can be configured to calculate a response in software of the controller 1104. The calculated response is compared to the measured response of the actual system to obtain an "observed" response, which is used for the actual feedback decision. The observed response is a favorable tuning value that equalizes the smooth continuous nature of the simulated response with the measured response, which can sense external influences on the system.
The absolute positioning system 1100 may include and/or be programmed to implement feedback controllers such as PID, state feedback, and adaptive controllers. The power supply 1129 converts the signal from the feedback controller into a physical input, in this case a voltage, to the system. Other examples include Pulse Width Modulation (PWM) of voltage, current, and force. In addition to the position measured by position sensor 1112, other sensors 1118 may be configured to measure physical parameters of the physical system. In a digital signal processing system, the absolute positioning system 1100 is coupled to a digital data acquisition system, wherein the output of the absolute positioning system 1100 will have a limited resolution and sampling frequency. The absolute positioning system 1100 may include comparison and combination circuitry to combine the calculated response with the measured response using an algorithm such as a weighted average and theoretical control loop that drives the calculated response toward the measured response. The calculated response of the physical system takes into account properties such as mass, inertia, viscous friction, inductive resistance, etc. to predict the state and output of the physical system by knowing the inputs. The controller 1104 can be the control circuit 700 (fig. 5A-5B).
The driver 1110 may be a3941 available from Allegro Microsystems, inc. A3941 driver 1110 is a full-bridge controller for use with an external N-channel power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) specifically designed for inductive loads such as brushed DC motors). Driver 1110 includes a unique charge pump voltage regulator that provides full (>10V) gate drive for battery voltages as low as 7V and allows a3941 to operate with reduced gate drive as low as 5.5V. A bootstrap capacitor may be used to provide the above-mentioned battery supply voltage required for the N-channel MOSFET. The internal charge pump of the high-side drive allows for direct current (100% duty cycle) operation. The full bridge may be driven in fast decay mode or slow decay mode using diodes or synchronous rectification. In slow decay mode, current recirculation can pass through either the high-side or low-side FETs. The power FET is protected from breakdown by a resistor adjustable dead time. The overall diagnostics indicate undervoltage, overheating, and power bridge faults, and may be configured to protect the power MOSFETs in most short circuit situations. Other motor drives may be readily substituted for use in absolute positioning system 1100.
Having described aspects for implementing the absolute positioning system 1100 with respect to the sensor arrangement 1102, the present disclosure now turns to fig. 11 and 12 to obtain a description of one aspect of the sensor arrangement 1102 of the absolute positioning system 1100. Fig. 11 is an exploded perspective view of a sensor arrangement 1102 of an absolute positioning system 1100 showing relative alignment of elements of the sensor arrangement 1102 and a circuit 1205, according to one aspect. The sensor arrangement 1102 of the absolute positioning system 1100 comprises a position sensor 1200, a magnet 1202 sensor element, a magnet holder 1204 which rotates per full stroke of the displacement member 1111, and a gear assembly 1206 for providing a gear reduction. Referring briefly to fig. 2, displacement member 1111 may represent a longitudinally movable drive member 120 including a rack of drive teeth 122 for meshing engagement with a corresponding drive gear 86 of gear reducer assembly 84. Referring to fig. 11, a structural element such as a bracket 1216 is provided to support the gear assembly 1206, the magnet holder 1204, and the magnet 1202. The position sensor 1200 includes a magnetic sensing element such as a hall element and is placed in proximity to the magnet 1202. As the magnet 1202 rotates, the magnetic sensing element of the position sensor 1200 determines the absolute angular position of the magnet 1202 over one rotation.
The sensor arrangement 1102 may include any number of magnetic sensing elements, such as, for example, magnetic sensors that are classified according to whether they measure the total or vector components of the magnetic field. The techniques for producing the two types of magnetic sensors described above encompass a number of aspects of physics and electronics. Technologies for magnetic field sensing include detection coils, flux gates, optical pumps, nuclear spins, superconducting quantum interferometers (SQUIDs), hall effects, anisotropic magnetoresistance, giant magnetoresistance, magnetic tunnel junctions, giant magnetoimpedances, magnetostrictive/piezoelectric composites, magnetodiodes, magnetotransistors, optical fibers, magneto-optical, and magnetic sensors based on micro-electromechanical systems, among others.
The gear assembly includes a first gear 1208 and a second gear 1210 that are in meshing engagement to provide a 3:1 gear ratio connection. Third gear 1212 rotates about shaft 1214. The third gear 1212 is in communication with the displacement member 1111 (or 120 as shown in fig. 2) and rotates in a first direction when the displacement member 1111 is advanced in the distal direction D and rotates in a second direction when the displacement member 1111 is retracted in the proximal direction P. The second gear 1210 also rotates about the axis 1214, and thus, rotation of the second gear 1210 about the axis 1214 corresponds to longitudinal translation of the displacement member 1111. Thus, one full stroke of the displacement member 1111 in the distal direction D or the proximal direction P corresponds to three revolutions of the second gear 1210 and a single revolution of the first gear 1208. Since magnet holder 1204 is coupled to first gear 1208, magnet holder 1204 makes one full rotation with each full stroke of displacement member 1111.
The position sensor 1200 is supported by a position sensor holder 1218, which defines an aperture 1220 adapted to contain the position sensor 1200 in precise alignment with a magnet 1202 rotating within an underlying magnet holder 1204. The clamp is coupled to bracket 1216 and circuit 1205 and remains stationary as magnet 1202 rotates with magnet holder 1204. The hub 1222 is configured to mate with the first gear 1208 and the magnet holder 1204. Also shown are a second gear 1210 and a third gear 1212 coupled to the shaft 1214.
Fig. 12 is an illustration of a position sensor 1200 including a magnetic rotary absolute positioning system for an absolute positioning system 1100 according to an aspect of the present disclosure. The position sensor 1200 may be implemented AS an AS5055EQFT monolithic magnetic rotary position sensor available from australian microsystems, AG. The position sensor 1200 interfaces with a controller 1104 to provide an absolute positioning system 1100. The position sensor 1200 is a low voltage and low power component and includes four hall effect elements 1228A, 1228B, 1228C, 1228D in a region 1230 of the position sensor 1200 that is located above the magnet 1202 (fig. 15 and 16). A high resolution ADC 1232 and a smart power management controller 1238 are also provided on the chip. CORDIC processor 1236, for COordinate Rotation digital computers (COordinate Rotation digital computer), also known as the bitwise and Volder algorithms, is configured to implement simple and efficient algorithms to compute hyperbolic and trigonometric functions that require only addition, subtraction, bit-shifting and table-lookup operations. The angular position, alarm bits, and magnetic field information are transmitted to the controller 1104 over a standard serial communication interface, such as SPI interface 1234. The position sensor 1200 provides 12 or 14 bit resolution. The position sensor 1200 may be an AS5055 chip provided in a small QFN 16-pin 4 × 4 × 0.85mm package.
The hall effect elements 1228A, 1228B, 1228C, 1228D are located directly above the rotating magnet 1202 (fig. 11). The hall effect is a well-known effect and will not be described in detail herein for convenience, however, in general, the hall effect produces a voltage difference (hall voltage) across an electrical conductor transverse to the current in the conductor and a magnetic field perpendicular to the current. The hall coefficient is defined as the ratio of the induced electric field to the product of the current density and the applied magnetic field. It is a property of the material from which the conductor is made, as its value depends on the type, number and properties of the charge carriers that make up the current. In the AS5055 position sensor 1200, the hall effect elements 1228A, 1228B, 1228C, 1228D can generate a voltage signal that indicates the absolute position of the magnet 1202 AS a function of the angle of the magnet 1202 after a single revolution. This value calculated by CORDIC processor 1236 AS the angle of the unique position signal is stored on AS5055 position sensor 1200 in a register or memory. The angle value, which indicates the position of the magnet 1202 through one rotation, is provided to the controller 1104 in a number of techniques, such as at power-up or upon request by the controller 1104.
The AS5055 position sensor 1200 requires only a few external components to operate when connected to the controller 1104. A simple application using a single power supply requires six wires: two wires are used for power and four wires 1240 are used for SPI interface 1234 with controller 1104. A seventh connection may be added to send an interrupt to the controller 1104 to inform that a new valid angle can be read. Upon power up, the AS5055 position sensor 1200 performs a full power up sequence, including an angle measurement. The completion of this cycle is represented as the INT output 1242 and the angle value is stored in an internal register. Once the output is set, the AS5055 position sensor 1200 pauses into the sleep mode. The controller 1104 can respond to an INT request at the INT output 1242 by reading the angle value from the AS5055 position sensor 1200 through the SPI interface 1234. Once the controller 1104 reads the angle value, the INT output 1242 is cleared again. Sending a "read angle" command by controller 1104 to position sensor 1200 through SPI interface 1234 also automatically powers up the chip and begins another angle measurement. As soon as the controller 1104 completes reading the angle value, the INT output 1242 is cleared and the new result is stored in the angle register. Completion of the angle measurement is again indicated by setting the INT output 1242 and the corresponding flag in the status register.
Due to the measurement principle of the AS5055 position sensor 1200, only a single angular measurement is performed in a very short time (-600 μ s) after each power-up sequence. AS soon AS the measurement of an angle is completed, the AS5055 position sensor 1200 is suspended to the power-down state. On-chip filtering of the angle values by digital averaging is not implemented, as this would require more than one angle measurement and therefore longer power-up time, which is undesirable in low power applications. Angular jitter may be reduced by averaging several angular samples in the controller 1104. For example, averaging four samples can reduce jitter by 6dB (50%).
Fig. 13 is a cross-sectional view of the end effector 2502 of the surgical instrument 10 (fig. 1-4) illustrating the firing stroke of the I-beam 2514 relative to tissue 2526 clamped within the end effector 2502 according to one aspect of the present disclosure. The end effector 2502 is configured to operate with the surgical instrument 10 illustrated in fig. 1-4. The end effector 2502 includes an anvil 2516 and an elongate channel 2503, with a staple cartridge 2518 positioned in the elongate channel 2503. The firing rod 2520 can be translated distally and proximally along the longitudinal axis 2515 of the end effector 2502. When the end effector 2502 is not articulated, the end effector 2502 is aligned with the axis of the instrument. An I-beam 2514 including a cutting edge 2509 is shown at the distal portion of the firing bar 2520. A wedge sled 2513 is positioned in the staple cartridge 2518. As the I-beam 2514 translates distally, the cutting edge 2509 contacts and can cut tissue 2526 positioned between the anvil 2516 and the staple cartridge 2518. Also, the I-beam 2514 contacts and pushes the wedge sled 2513 distally, causing the wedge sled 2513 to contact the staple drivers 2511. The staple drivers 2511 can be driven upward into the staples 2505 such that the staples 2505 are advanced through the tissue and into pockets 2507 defined in the anvil 2516, which form the staples 2505.
An exemplary I-beam 2514 firing stroke is illustrated by a chart 2529 aligned with the end effector 2502. Alignment of exemplary tissue 2526 with the end effector 2502 is also shown. The firing member stroke may include a stroke start position 2527 and a stroke end position 2528. During the I-beam 2514 firing stroke, the I-beam 2514 can be advanced distally from a start of stroke position 2527 to an end of stroke position 2528. The I-beam 2514 is shown at one exemplary position at a stroke start position 2527. The I-beam 2514 firing member stroke chart 2529 shows five firing member stroke zones 2517, 2519, 2521, 2523, 2525. In the first stroke zone 2517, the I-beam 2514 may begin to advance distally. In the first stroke zone 2517, the I-beam 2514 may contact the wedge sled 2513 and begin to move distally. However, in the first region, the cutting edge 2509 may not contact the tissue and the wedge sled 2513 may not contact the staple drivers 2511. After the static friction force is overcome, the force driving the I-beam 2514 in the first region 2517 may be substantially constant.
In the second firing member stroke zone 2519, the cutting edge 2509 can begin to contact and cut tissue 2526. Also, the wedge sled 2513 can begin to contact the staple drivers 2511 to drive the staples 2505. The force driving the I-beam 2514 may begin to ramp up. As shown, due to the manner in which the anvil 2516 pivots relative to the staple cartridge 2518, tissue initially encountered may be compressed and/or thinned. In the third firing member stroke region 2521, the cutting edge 2509 can continuously contact and cut tissue 2526, and the wedge sled 2513 can repeatedly contact the staple drivers 2511. The force driving the I-beam 2514 may be smoothed in the third region 2521. With the fourth firing stroke area 2523, the force driving the I-beam 2514 may begin to fall. For example, tissue in the portion of the end effector 2502 corresponding to the fourth firing region 2523 may be compressed less than tissue closer to the pivot point of the anvil 2516, requiring less cutting force. Also, the cutting edge 2509 and wedge slide 2513 can reach the end of the tissue 2526 in a fourth region 2523. When the I-beam 2514 reaches the fifth region 2525, the tissue 2526 may be severed completely. The wedge sled 2513 can contact one or more staple drivers 2511 at or near the end of the tissue. The force to advance the I-beam 2514 through the fifth region 2525 may be reduced, and in some examples, may be similar to the force to drive the I-beam 2514 in the first region 2517. At the end of the firing member stroke, the I-beam 2514 can reach an end of stroke position 2528. The positioning of the firing member travel regions 2517, 2519, 2521, 2523, 2525 in fig. 18 is but one example. In some examples, the different regions may begin at different positions along the end effector longitudinal axis 2515, e.g., based on the positioning of tissue between the anvil 2516 and the staple cartridge 2518.
As discussed above and referring now to fig. 10-13, the firing system of the shaft assembly, including the I-beam 2514, can be advanced and/or retracted relative to the end effector 2502 of the shaft assembly using the electric motor 1122 positioned within the handle assembly of the surgical instrument 10 (fig. 1-4) in order to staple and/or incise tissue captured within the end effector 2502. The I-beam 2514 can be advanced or retracted at a desired speed or within a range of desired speeds. The controller 1104 may be configured to control the speed of the I-beam 2514. The controller 1104 may be configured to be able to predict the speed of the I-beam 2514 based on various parameters, such as voltage and/or current, for example, the power supplied to the electric motor 1122 and/or other operating parameters or external influences of the electric motor 1122. The controller 1104 may be configured to predict a current speed of the I-beam 2514 based on previous values of current and/or voltage supplied to the electric motor 1122 and/or previous states of the system, such as speed, acceleration, and/or position. The controller 1104 may be configured to sense the velocity of the I-beam 2514 using an absolute positioning sensor system as described herein. The controller may be configured to be able to compare the predicted speed of the I-beam 2514 to the sensed speed of the I-beam 2514 to determine if the power of the electric motor 1122 should be increased in order to increase the speed of the I-beam 2514 and/or if the power should be decreased in order to decrease the speed of the I-beam 2514. U.S. patent No. 8,210,411 entitled "MOTOR-driving MOTOR braking actuation," which is incorporated herein by reference in its entirety. U.S. patent No. 7,845,537 entitled "SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES," which is incorporated herein by reference in its entirety.
Various techniques may be utilized to determine the force acting on the I-beam 2514. The I-beam 2514 force may be determined by measuring the motor 2504 current, where the motor 2504 current is based on the negative of the I-beam 2514 experienced as it advances distallyAnd (4) loading. The I-beam 2514 force may be applied by positioning a strain gauge on the drive member 120 (fig. 2), the firing member 220 (fig. 2), the I-beam 2514 (I-beam 178, fig. 20), the firing bar 172 (fig. 2), and/or on the proximal end of the cutting edge 2509. Can be monitored to determine the time period T of consumption based on motor 2504 1The actual position of the I-beam 2514 moved at the desired speed followed by the current set speed and the actual position of the I-beam 2514 compared to the expected position based on the time period T 1The expected position of the I-beam 2514 at the current set speed of the motor 2504 at the end is compared to determine the I-beam 2514 force. Thus, if the actual position of the I-beam 2514 is less than the expected position of the I-beam 2514, the force on the I-beam 2514 is greater than the nominal force. Conversely, if the actual position of the I-beam 2514 is greater than the expected position of the I-beam 2514, the force on the I-beam 2514 is less than the nominal force. The difference between the actual position and the expected position of the I-beam 2514 is proportional to the force on the I-beam 2514 from the nominal force. Such techniques are described in attorney docket number END8195USNP, which is incorporated by reference herein in its entirety.
Fig. 14 illustrates a block diagram of a surgical instrument 2500 programmed to control distal translation of a displacement member according to one aspect of the present disclosure. In one aspect, the surgical instrument 2500 is programmed to control distal translation of a displacement member 1111, such as an I-beam 2514. The surgical instrument 2500 includes an end effector 2502, which can comprise an anvil 2516, an I-beam 2514 (including a sharp cutting edge 2509), and a removable staple cartridge 2518. The end effector 2502, anvil 2516, I-beam 2514, and staple cartridge 2518 may be configured as described herein, for example, with reference to fig. 1-13.
The position, movement, displacement, and/or translation of the liner displacement member 1111, such as the I-beam 2514, may be measured by the absolute positioning system 1100, the sensor arrangement 1102, and the position sensor 1200 as shown in fig. 10-12 and represented in fig. 14 as the position sensor 2534. Since the I-beam 2514 is coupled to the longitudinally movable drive member 120, the position of the I-beam 2514 can be determined by measuring the position of the longitudinally movable drive member 120 using the position sensor 2534. Thus, in the following description, the position, displacement, and/or translation of the I-beam 2514 may be achieved by the position sensor 2534 as described herein. The control circuit 2510, such as the control circuit 700 described in fig. 5A and 5B, may be programmed to control the translation of a displacement member 1111, such as an I-beam 2514, as described in connection with fig. 10-12. In some examples, the control circuitry 2510 can include one or more microcontrollers, microprocessors, or other suitable processors for executing instructions that cause the one or more processors to control a displacement member, such as the I-beam 2514, in the manner described. In one aspect, the timer/counter circuit 2531 provides an output signal, such as a real-time or digital count, to the control circuit 2510 to correlate the position of the I-beam 2514 as determined by the position sensor 2534 with the output of the timer/counter 2531, such that the control circuit 2510 can determine the position of the I-beam 2514 relative to a starting position at a particular time (t). The timer/counter 2531 may be configured to be able to measure elapsed time, count external events, or time external events.
The control circuit 2510 can generate a motor set point signal 2522. The motor set point signal 2522 may be provided to the motor controller 2508. The motor controller 2508 can include one or more circuits configured to provide motor drive signals 2524 to the motor 2504 to drive the motor 2504, as described herein. In some examples, motor 2504 may be a brushed DC motor, such as motors 82, 714, 1120 shown in fig. 1, 5B, 10. For example, the speed of motor 2504 may be proportional to the voltage of motor drive signal 2524. In some examples, the motor 2504 can be a brushless Direct Current (DC) electric motor, and the motor drive signals 2524 can include Pulse Width Modulated (PWM) signals provided to one or more stator windings of the motor 2504. Also, in some examples, the motor controller 2508 may be omitted, and the control circuit 2510 may directly generate the motor drive signal 2524.
Motor 2504 may receive power from energy source 2512. The energy source 2512 may be or include a battery, a super capacitor, or any other suitable energy source 2512. The motor 2504 may be mechanically coupled to the I-beam 2514 via a transmission 2506. The transmission 2506 may include one or more gears or other linkage components for coupling the motor 2504 to the I-beam 2514. The position sensor 2534 may sense the position of the I-beam 2514. The position sensor 2534 may be or include any type of sensor capable of generating position data indicative of the position of the I-beam 2514. In some examples, the position sensor 2534 may comprise an encoder configured to provide a series of pulses to the control circuitry 2510 as the I-beam 2514 translates distally and proximally. The control circuit 2510 may track pulses to determine the position of the I-beam 2514. Other suitable position sensors may be used, including, for example, proximity sensors. Other types of position sensors may provide other signals indicative of the movement of the I-beam 2514. Also, in some examples, position sensor 2534 may be omitted. In the case where the motor 2504 is a stepper motor, the control circuit 2510 can track the position of the I-beam 2514 by aggregating the number and direction of steps that the motor 2504 has been instructed to perform. The position sensor 2534 can be located in the end effector 2502 or at any other portion of the instrument.
The control circuitry 2510 can communicate with one or more sensors 2538. The sensors 2538 can be positioned on the end effector 2502 and adapted to operate with the surgical instrument 2500 to measure various derived parameters, such as gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors 2538 can include magnetic sensors, magnetic field sensors, strain gauges, pressure sensors, force sensors, inductive sensors such as eddy current sensors, resistive sensors, capacitive sensors, optical sensors, and/or any other suitable sensors for measuring one or more parameters of the end effector 2502. The sensor 2538 may include one or more sensors.
The one or more sensors 2538 can comprise a strain gauge, such as a micro-strain gauge, configured to measure a magnitude of strain in the anvil 2516 during a clamping condition. The strain gauge provides an electrical signal whose magnitude varies with the magnitude of the strain. The sensor 2538 can comprise a pressure sensor configured to detect pressure generated by the presence of compressed tissue between the anvil 2516 and the staple cartridge 2518. The sensor 2538 can be configured to detect the impedance of a section of tissue located between the anvil 2516 and the staple cartridge 2518, which is indicative of the thickness and/or degree of filling of the tissue located therebetween.
The sensor 2538 can be configured to measure the force exerted by the closure drive system 30 on the anvil 2516. For example, one or more sensors 2538 can be positioned at the point of interaction between the closure tube 260 (FIG. 3) and the anvil 2516 to detect the closing force applied to the anvil 2516 by the closure tube 260. The force exerted on the anvil 2516 may be indicative of tissue compression experienced by a section of tissue captured between the anvil 2516 and the staple cartridge 2518. One or more sensors 2538 can be positioned at various interaction points along the closure drive system 30 (FIG. 2) to detect the closure force applied to the anvil 2516 by the closure drive system 30. One or more sensors 2538 may be sampled in real time by a processor as described in fig. 5A-5B during a gripping operation. The control circuit 2510 receives real-time sample measurements to provide and analyze time-based information and evaluates the closing force applied to the anvil 2516 in real time.
A current sensor 2536 may be employed to measure the current drawn by the motor 2504. The force required to advance the I-beam 2514 corresponds to the current drawn by the motor 2504. The force is converted to a digital signal and provided to the processor 2510.
Using the physical characteristics of the instrument disclosed herein in connection with fig. 1-14, and with reference to fig. 14, the control circuit 2510 can be configured to be capable of simulating the response of the actual system of the instrument in the software of the controller. The displacement member may be actuated to move the I-beam 2514 in the end effector 2502 at or near a target speed. The surgical instrument 2500 may include a feedback controller, which may be one of any feedback controller including, but not limited to, for example, a PID, status feedback, LQR, and/or adaptive controller. Surgical instrument 2500 may include a power source for converting signals from a feedback controller into physical inputs such as, for example, a housing voltage, a Pulse Width Modulated (PWM) voltage, a frequency modulated voltage, a current, a torque, and/or a force.
The actual drive system of the surgical instrument 2500 is configured to drive a displacement member, cutting member, or I-beam 2514 via a brushed DC motor having a gearbox and mechanical connection to an articulation and/or knife system. Another example is an electric motor 2504 that operates a displacement member and articulation driver, e.g., an interchangeable shaft assembly. External influences are unmeasured, unpredictable effects of things such as tissue, surrounding body and friction on the physical system. This external influence may be referred to as a drag force acting against the electric motor 2504. External influences such as drag forces may cause the operation of the physical system to deviate from the desired operation of the physical system.
Before explaining the various aspects of the surgical instrument 2500 in detail, it should be noted that the exemplary aspects are not limited in application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative aspects may be implemented alone, in combination with other aspects, variations and modifications, and may be practiced or carried out in various ways. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative aspects for the convenience of the reader and are not for the purpose of limiting the invention. Moreover, it will be appreciated that one or more of the expressions of the following aspects, aspects and/or examples may be combined with any one or more of the expressions of the other following aspects, aspects and/or examples.
Various exemplary aspects relate to a surgical instrument 2500 that includes an end effector 2502 with a motor-driven surgical sealing and cutting tool. For example, the motor 2504 can drive the displacement member distally and proximally along the longitudinal axis of the end effector 2502. The end effector 2502 can comprise a pivotable anvil 2516, and when configured for use, the staple cartridge 2518 is positioned opposite the anvil 2516. The clinician may hold tissue between the anvil 2516 and the staple cartridge 2518 as described herein. When the instrument 2500 is ready to be used, the clinician may provide a firing signal, for example, by depressing a trigger of the instrument 2500. In response to the firing signal, the motor 2504 can drive the displacement member distally along the longitudinal axis of the end effector 2502 from a proximal stroke start position to an end of stroke position distal to the stroke start position. As the displacement member is translated distally, the I-beam 2514 with the cutting element positioned at the distal end can cut tissue between the staple cartridge 2518 and the anvil 2516.
In various examples, the surgical instrument 2500 can include a control circuit 2510 programmed to control distal translation of a displacement member, such as an I-beam 2514, for example, based on one or more tissue conditions. The control circuit 2510 can be programmed to sense a tissue condition, such as thickness, directly or indirectly, as described herein. The control circuit 2510 can be programmed to select a firing control program based on tissue conditions. The firing control routine may describe distal movement of the displacement member. Different firing control programs may be selected to better address different tissue conditions. For example, when thicker tissue is present, the control circuit 2510 can be programmed to translate the displacement member at a lower speed and/or at a lower power. When thinner tissue is present, the control circuit 2510 can be programmed to translate the displacement member at a higher speed and/or at a higher power.
In some examples, the control circuit 2510 can initially operate the motor 2504 in an open-loop configuration for a first open-loop portion of the stroke of the displacement member. Based on the response of the instrument 2500 during the open loop portion of the stroke, the control circuit 2510 can select a firing control program. The response of the instrument may include the translation distance of the displacement member during the open loop portion, the time elapsed during the open loop portion, the energy provided to motor 2504 during the open loop portion, the sum of the pulse widths of the motor drive signals, and the like. After the open loop portion, the control circuit 2510 can implement the selected firing control program for the second portion of the displacement member stroke. For example, during the closed-loop portion of the stroke, the control circuit 2510 can adjust the motor 2504 based on translation data that describes the position of the displacement member in a closed-loop manner to translate the displacement member at a constant speed.
Fig. 15 shows a diagram 2580 plotting two exemplary displacement member strokes performed in accordance with an aspect of the present disclosure. Fig. 2580 includes two axes. Horizontal axis 2584 indicates elapsed time. The vertical axis 2582 indicates the position of the I-beam 2514 between the start of travel position 2586 and the end of travel position 2588. On the horizontal axis 2584, the control circuit 2510 may receive a firing signal and begin at t 0An initial motor setting is provided. The open loop portion of the displacement member stroke is at t 0And t 1An initial period of time that may elapse in between.
A first example 2592 illustrates the response of the surgical instrument 2500 when thick tissue is positioned between the anvil 2516 and the staple cartridge 2518. During the open-loop part of the displacement member stroke, e.g. at t 0And t 1During the initial time period in between, the I-beam 2514 may traverse from the stroke start position 2586 to the position 2594. The control circuit 2510 can determine that position 2594 corresponds to a firing control program at a selected constant speed (V) Slow) Advancing the I-beam 2514 at t from example 2592 1Followed by an indication of the slope (e.g., in the closed loop portion). The control circuit 2510 can drive the I-beam 2514 to a speed V by monitoring the position of the I-beam 2514 and adjusting a motor setpoint 2522 and/or a motor drive signal 2524 SlowTo maintain V Slow. A second example 2590 illustrates the response of the surgical instrument 2500 when thin tissue is positioned between the anvil 2516 and the staple cartridge 2518.
At t 0And t 1During an initial period (e.g., an open loop period) in between, the I-beam 2514 may traverse from the stroke start position 2586 to the position 2596. The control circuitry may determine that position 2596 corresponds to a firing control program at a selected constant speed (V) Fast-acting toy) The displacement member is advanced. Because the tissue in example 2590 is thinner than the tissue in example 2592, it may provide less resistance to movement of the I-beam 2514. Thus, the I-beam 2514 may traverse a larger portion of the stroke during the initial time period. Also, in some examples, thinner tissue (e.g., a greater portion of the displacement member travel traversed during the initial time period) may correspond to a higher displacement member velocity after the initial time period.
Referring to FIG. 16, a graph 6040 depicts an example of the force applied during a closure stroke to close the end effector 2502 about tissue clamped between the anvil 2516 and the staple cartridge 2518, plotted as a function of closure stroke displacement (d). The illustration 6040 includes two axes. The vertical axis 6042 indicates the closing force in newtons (N) (FTC) of the closing end effector 2502. The horizontal axis 6044 indicates the distance the closure member, such as, for example, the closure tube 260 (FIG. 1), travels to cause the end effector 2502 to close. During a closure stroke, the closure tube 260 is translated distally (direction "DD") to move the anvil 2516 relative to the staple cartridge 2518, e.g., in response to actuation of the closure trigger 32 (fig. 1), in the manner described in the aforementioned reference, U.S. patent application publication 2014/0263541. In other examples, the closure stroke involves moving the staple cartridge relative to the anvil in response to actuation of the closure trigger 32. In other examples, the closure stroke involves moving the staple cartridge and anvil in response to actuation of the closure trigger 32.
The illustration 6040 indicates that the closing Force (FTC) of the closing end effector 260 increases as the closure tube 2502 is advanced distally. The closing Force (FTC) reaches a maximum force (F) when the closure tube 260 travels a distance (d) from the starting position max). The end effector 300, which is similar in many respects to the end effector 2502, compresses tissue to correspond to a maximum force (F) max) Is measured. Maximum force (F) max) Depending at least in part on the thickness of the tissue being grasped by the end effector 2502. In one example, the closure member is configured to be able to travel a distance (d) of about 0.210"(5.334mm) 1) To achieve a maximum force (F) of about 160 pounds force (711.715 newtons) max)。
FIG. 16 also depicts a graphic representation 6046 that depicts an example of a firing force (FTF) applied to fire the surgical instrument 2500. During a firing stroke of the surgical instrument 2500, a firing force (FTF) can be applied to advance the I-beam 2514. The illustration 6046 includes two axes. The vertical axis 6048 indicates the force in newtons (N) applied to advance the I-beam 2514 during the firing stroke. The I-beam 2514 is configured to advance the knife 2509 and actuate the driver 2511 to deploy the staples 2505 during the firing stroke. Horizontal axis 6050 indicates time in seconds.
The I-beam 2514 is advanced from a start time (t ═ 0). When the closing Force (FTC) of the closing end effector 2502 reaches a maximum force (F) max) Propulsion of the I-beam 2514 is initiated. Alternatively, as shown in FIG. 22, a waiting period may be applied before beginning the firing stroke. The waiting period allows fluid to flow from the compressed tissue, which reduces the thickness of the compressed tissue, thereby generating a maximum force (F) max) Is reduced.
Diagram 6046 indicates that the firing force (FTF) to fire the surgical instrument 2500 is at a peak6052 to a maximum force (F) at the top 2). Maximum force (F) when wedge sled 2513 2) At the initial segment of the firing stroke. The top of the lowest peak 6054 represents the maximum force (F) present at the final segment of the firing stroke 1). During engagement of the wedge sled 2513 with the distal staple driver 2511, the maximum force (F) 1) To the I-beam 2514. Further, an intermediate peak 6056 occurring between the peaks 6052 and 6054 at the mid-segment of the firing stroke outlines a downward slope 6053 of the firing force (FTF) required to fire the surgical instrument 2500 during the mid-segment of the firing stroke. Maximum force (F) at the top of the downward slope 6053 with the highest peak 6052 1) Corresponding time (t) 1) And begins. The downward ramp 6053 generally results from an excess time (t) as the I-beam 2514 advances the wedge sled 2513 through the firing stroke 1) Gradually reducing the load.
Fig. 17 illustrates a logic flow diagram that shows one example of a process 6030 that may be executed by the surgical instrument 2500 (e.g., the control circuitry 2510) to implement a control program or logic configuration for I-beam travel in response to tissue conditions and/or staple cartridge type. The control circuit 2510 can receive 6031 the firing signal. The firing signal may be received 6031 from a trigger 32 (FIG. 1) or other suitable actuation device. For example, the clinician may position the end effector 2502, clamp tissue between the anvil 2516 and the staple cartridge 2518, and then actuate the trigger 32 to begin an I-beam stroke. The trigger 32 may be configured to provide a firing signal to the control circuit 2510 upon actuation.
In response to the firing signal, the control circuit 2510 can provide 6032 an initial motor setting. For example, the initial motor setting may be a motor set point 2522 provided to the motor controller 2508. The motor controller 2508 can convert the initial motor set point 2522 into a PWM signal, voltage signal, or other suitable motor drive signal to drive the motor 2504. In some examples, (e.g., when the control circuit 2510 directly generates the motor drive signal 2524), the initial motor setting may be the motor drive signal 2524 provided directly to the motor 2504. The initial motor setting may correspond to a particular motor speed, power, or other suitable variable. In some examples where motor 2504 is a brushed dc motor, the initial motor setting may be a signal with a constant voltage. In some examples where the motor is a brushed DC motor, the initial motor setting may be a signal or set of signals having a constant phase, duty cycle, or the like.
The control circuitry 2510 can receive 6036I-beam member movement data. The E-member beam movement data may include information (e.g., from the position sensor 2534) describing the position and/or movement of the I-beam 2514. While receiving 6036I-beam member movement data may be part of the process 6030, in some examples, the control circuitry 2510 may receive 6036I-beam member movement data while the I-beam 2514 is in motion. For example, when the position sensor 2534 is an encoder, the control circuit 2510 can receive pulse signals from the encoder as the I-beam 2514 is moving, wherein each pulse signal represents an amount of movement. Also, in examples where the motor 2504 is a stepper motor, the control circuit 2510 can derive I-beam member movement data based on the total number of steps the control circuit 2510 is instructing the motor 2504 to perform.
The I-beam member movement data may indicate the distance the I-beam 2514 moved during an initial period of time, which may reflect tissue conditions, such as the thickness and/or toughness of the tissue present between the anvil 2516 and the staple cartridge 2518, as different types of tissue will provide different levels of resistance. For example, thicker or tougher tissue may provide greater mechanical resistance to the knife and staple. Greater mechanical resistance may cause the motor 2504 to run slower while the initial motor setting remains substantially constant. Similarly, thinner or weaker tissue may provide less mechanical resistance to the knife and staples. This may result in the motor running faster and moving a greater distance while the initial motor setting remains substantially constant.
After providing the initial motor setting, instrument 2500 may be operated in an open loop configuration in the diagnostic first portion (1a) of region 1, as shown in fig. 18. For example, the motor drive signal 2524 may remain substantially constant. Thus, actual characteristics of the motor 2504, such as motor speed, can drift based on factors including tissue condition (e.g., tissue thickness, tissue toughness, etc.). For example, when thicker or tougher tissue is present between the anvil 2516 and the staple cartridge 2518, the tissue may provide greater mechanical resistance to the knife and/or staples, which may tend to slow the I-beam 2514 while the motor settings remain substantially constant.
The control circuit 2510 can be configured to maintain an initial motor setting for an open loop portion of the I-beam stroke. In the example of fig. 17, the open loop portion of the I-beam stroke may continue until the I-beam 2514 has traversed the initial distance. Thus, the control circuit 2510 can be configured to be able to maintain an initial motor setting until the I-beam has traversed an initial distance. The initial distance may be, for example, a predetermined fraction of the total distance between the firing stroke start position and the firing stroke end position (e.g., 1/6, 1/4, 1/3, etc.). In one example, the initial open loop distance is the first initial portion (1a) of region 1, which spans a distance of about 0.200"(5.08 millimeters) from the trip start position 2527 (fig. 13). The control circuit 2510 can determine 6034 whether the I-beam 2514 has traversed an initial distance based on the received I-beam member movement data. If not, the control circuit 2510 can continue to provide 6032 an initial motor setting and receive 6036 additional I-beam member movement data.
In some examples, the initial open loop distance is a diagnostic first portion (1a) of the region 1a that spans a distance selected from a range of about 1 millimeter to about 10 millimeters. In some examples, the initial open loop distance spans a distance selected from a range of about 3 millimeters to about 7 millimeters.
If the control circuitry 2510 determines 6034 that the I-beam has traversed the initial distance, the process 6030 may continue. In some examples, the control circuit 2510 may maintain a running counter or timer 2531 (fig. 14) while traversing the initial distance. When the control circuit 2510 determines that the I-beam has traversed the initial distance, the control circuit 2510 may stop the timer 2531. The control circuitry 2510 can determine the I-beam velocity over the initial distance 6039. The control circuit 2510 can obtain the I-beam velocity by dividing the initial distance by the time required to traverse that distance.
Alternatively, in some examples, the open-loop portion may be an initial time period, which may also be referred to as an open-loop time period. The initial time period may be any suitable length, including, for example, 100 milliseconds. A position sensor, such as, for example, the position sensor 2534 (fig. 14), may track the position of the I-beam 2514 during an initial time period. The control circuit 2510 can determine the I-beam velocity over an initial time period. The control circuit 2510 may obtain the I-beam velocity by dividing the distance traversed by the I-beam 2514 during the initial time period by the initial time period. The velocity of the I-beam 2514 in the diagnostic first portion (1a) of the zone 1 can be indicative of a tissue condition such as the thickness and/or toughness of tissue present between the anvil 2516 and the staple cartridge 2518.
Alternatively, in some examples, the current (I) drawn by the motor 2504 in the open loop portion may be used to assess a tissue condition, such as the thickness and/or toughness of tissue present between the anvil 2516 and the staple cartridge 2518. A sensor such as, for example, a current sensor, can be used to track the current (I) consumed by the motor 2504 in the open loop portion. One example of a current sensor 2536 is shown in fig. 14.
Returning now to FIG. 17, the control circuit 2510 can select 6038 a firing control program or configuration based on, for example, the I-beam speed determined in the diagnostic first portion (1a) of zone 1 and/or the current (I) consumed by the motor 2504 in the open loop portion. The control circuit 2510 can execute 6041 the selected firing control program or logic configuration.
In some examples, the firing control program may determine a target value for movement of the I-beam 2514 during the remainder of the I-beam stroke. Figure 18 shows a graph 6100 depicting speed versus distance traveled along the firing stroke for three exemplary I-beam strokes 6106, 6108, 6110 that may be achieved by the firing control program selected at 6038. The illustration 6100 includes two axes. Horizontal axis 6102 represents firing stroke displacement in millimeters. The vertical axis 6104 indicates the speed of the I-beam 2514 in millimeters per second. As shown, in fig. 18, the examples 6106, 6108, 6110 initially have the same I-beam velocity in the diagnostic first portion (1a) of zone 1 of the firing stroke distance.
In the example 6106 of fig. 18, the firing control program is configured to maintain the speed of the I-beam 2514 at a predetermined constant or substantially constant speed. The constant velocity may be selected based on the movement of the I-beam during the diagnostic first portion (1a) of zone 1. In some examples, the firing control procedure may include driving the I-beam 2514 at a constant power. The control circuit 2510 can implement a firing control program or logic configuration that 6041 previously selected 6038. For example, the control circuit 2510 can drive the I-beam 2514 at a constant speed to maintain a constant speed by monitoring the position of the I-beam 2514 as indicated by the position sensor 2534 and adjusting the motor set point 2522 and/or the motor drive signal 2524. Similarly, the control circuit 2510 can drive the firing member 2514 at a constant power to maintain a constant power consumption by monitoring the voltage and/or current drawn by the motor 2504 and adjusting the motor setpoint 2522 and/or motor drive signal 2524.
As described above in connection with the illustration 6046 of fig. 16, the firing force (FTF) is gradually reduced as the I-beam 2514 is advanced during the firing stroke. As such, the firing force (FTF) of the firing I-beam 2514 is generally higher at the beginning of the firing stroke than at the middle of the firing stroke, and generally higher at the middle of the firing stroke than at the end of the firing stroke. Maintaining a reduced speed of the I-beam 2514 in the portion of the firing stroke where the I-beam 2514 experiences higher loads improves the performance of the motor 2504 and energy source 2512. First, the total current (I) consumed by the motor 2504 during the firing stroke is reduced, which extends the life of the energy source 2512 (fig. 14). Second, reducing the speed of the I-beam 2514 in the higher loaded portion of the firing stroke may protect the motor 2504 from stalling. The increased resistance may cause the motor 2504 to stall. Stall is a condition when the motor stops rotating. This condition occurs when the load torque is greater than the motor shaft torque.
To reduce the load or firing force (FTF) applied to the I-beam 2514, the control circuit 2510 employs an alternative firing control procedure. Two of the alternate firing control routines are represented in examples 6108, 6110 of fig. 18. Fig. 19B illustrates a logic flow diagram that shows one example of a process 6131 that may select 6038 and execute 6041 at 6041 by the surgical instrument 2500 (e.g., the control circuitry 2510) to implement a control program or logic configuration for I-beam travel in response to tissue conditions and/or staple cartridge type. The firing process 6131 may include driving the I-beam 2514 at a linearly increasing speed as the I-beam 2514 advances along a firing stroke, as shown in example 6108 of fig. 18.
The control circuit 2510 controls 6132 the motor 2504 to reach a start speed (v1) at a predetermined position at the start point 6101. By adjusting the motor set point 2522 and/or the motor drive signal 2524 to produce a linear or substantially linear increase in the speed of the I-beam 2514 as the I-beam 2514 advances along the firing stroke, the control circuit 2510 drives 6134 the I-beam 2514 at a speed that increases linearly at a predetermined rate as the I-beam 2514 advances along the firing stroke. The speed rate of the I-beam 2514 is maintained 6135 until the end of the firing stroke.
The control circuit 2510 can monitor the position of the I-beam 2514 as indicated by the position sensor 2534 and the time as indicated by the timer 2531. Data from the position sensor 2534 and the timer 2531 may be used by the control circuit 2510 to sample the speed of the I-beam 2514 at discrete positions along the firing stroke. The sampling rate may be compared to a predetermined threshold to determine how to adjust the motor set point 2522 and/or the motor drive signal 2524 to produce a linear or substantially linear increase in the speed of the I-beam 2514 as the I-beam 2514 advances along the firing stroke. In some examples, the speed of the I-beam 2520 is sampled at 1 millimeter intervals.
In some examples, the absolute positioning system 1100 (fig. 10-12) may be used to sense the position of the I-beam 2514, and the speed of the I-beam 2520 is sampled at intervals defined by one or more rotations of the sensor element 1126.
In some examples, the control circuit 2510 is configured to increase the speed of the I-beam 2514 at a constant or substantially constant rate as the I-beam 2514 is advanced through the firing stroke. The rate of increase of the speed of the I-beam 2514 may be selected based on the movement of the I-beam during the diagnostic first portion (1a) of zone 1. In one example, a lookup table may be employed to determine a rate of increase of the velocity of the I-beam 2514 based on measurements representative of movement of the I-beam during the diagnostic first portion (1a) of zone 1.
As shown in fig. 18, the linear increase in velocity of the I-beam 2514 begins at a start point 6101, which represents a start velocity (v1) at a predetermined position at the beginning of the second portion (1b) of zone 1. The starting velocity v1 may also be determined based on the movement of the I-beam 2514 during the diagnostic first portion (1a) of zone 1. In one example, a lookup table may be employed to determine the starting velocity v1 based on measurements representing movement of the I-beam 2514 during the diagnostic first portion (1a) of zone 1. Notably, the starting velocity (v1) of example 6108 is significantly lower than the constant velocity of example 6110, which results in a reduced Force To Fire (FTF) in example 6108.
The control circuit 2510 can also be configured to determine a starting velocity v1 and/or a rate of increase of velocity of the I-beam 2514 based on tissue conditions. As described above, tissue conditions, such as the thickness and/or toughness of the tissue present between the anvil 2516 and the staple cartridge 2518, may affect movement of the I-beam 2514 because different types of tissue will provide different levels of resistance. For example, thicker or tougher tissue may provide greater mechanical resistance to the I-beam 2520. Greater mechanical resistance may cause the motor 2504 to run slower while the initial motor setting remains substantially constant. Similarly, thinner or weaker tissue may provide less mechanical resistance to the I-beam 2520. This may result in the motor running faster and moving a greater distance while the initial motor setting remains substantially constant.
In the example 6110 of fig. 18, the firing control routine may include driving or holding the I-beam 2514 at a plurality of constant or substantially constant speeds at a plurality of discrete or continuous portions or regions within the firing stroke to reduce the load or firing force (FTF) as the I-beam 2514 is advanced through the firing stroke. The firing stroke distance is divided into three regions: region 1, region 2 and region 3. The I-beam 2514 experiences a greater load in zone 1 than in zone 2, and the I-beam 2514 experiences a greater load in zone 2 than in zone 3. To reduce the force-to-fire (FTF), as shown in example 6110 of FIG. 18, the I-beam 2514 is driven at three constant or substantially constant velocities v1, v2, and v3, respectively, in zone 1, zone 2, and zone 3.
In some examples, the number of zones and corresponding velocities may be greater or less than three, depending on the staple cartridge size and/or tissue condition. The positioning of the I-beam travel area in fig. 18 is merely an example. In some examples, the different regions may begin at different positions along the end effector longitudinal axis 2515, e.g., based on the positioning of tissue between the anvil 2516 and the staple cartridge 2518.
Fig. 19A illustrates a logic flow diagram that shows one example of a process 6111 that may select 6038 and execute 6041 at 6041 by the surgical instrument 2500 (e.g., the control circuitry 2510) to implement a control program or logic configuration for I-beam travel in response to tissue conditions and/or staple cartridge type. In region 1, where the I-beam 2514 is subjected to the highest load, the I-beam 2514 is driven at a slow constant or substantially constant speed (v 1). The control circuit 2510 controls 6114 the motor 2504 to reach speed (v1) at a starting point 6101 (fig. 18) representing a predetermined position at the beginning of the second portion (1b) of region 1. For the remainder of zone 1, starting at the starting point 6101, the control circuit 2510 maintains 6116 the speed of the I-beam 2514 at speed (v 1). At 6115, if the I-beam 2514 is located in zone 1, the control circuit 2510 maintains 6116 the speed of the I-beam 2514 at speed (v 1). However, if the I-beam 2514 is no longer located in zone 1, the control circuit 2510 controls 6117 the motor 2504 to reach speed (v2) at a start point 6103 (FIG. 18) representing a predetermined position in zone 2. Notably, the velocity (v1) is significantly lower than the constant velocity of example 6106, which reduces the Force To Fire (FTF) of example 6110 relative to example 6106.
In zone 2, where the I-beam 2514 is subjected to an intermediate load, the I-beam 2514 maintains 6119 at a constant or substantially constant velocity (v2) which is higher than the velocity (v1) of the rest of zone 2. If the control circuit 2510 determines 6118 that the I-beam 2514 is in zone 2, the control circuit 2510 maintains 6119 the speed of the I-beam 2514 at speed (v 2). However, if the I-beam 2514 is no longer located in zone 2, the control circuit 2510 controls 6120 the motor 2504 to reach a predetermined speed (v3) at a start point 6105 (FIG. 18) representing a predetermined position in zone 3. The control circuit 2510 maintains 6121 velocity (v3) until the I-beam 2514 reaches the end of the stroke 6122.
As described above, the control circuit 2510 can drive the I-beam 2514 at a constant speed by monitoring the position of the I-beam 2514 as indicated by the position sensor 2534 and adjusting the motor set point 2522 and/or the motor drive signal 2524 to maintain the constant speed.
The control circuit 2510 may select a velocity (v1), a velocity (v2), and/or a velocity (v3) based on movement of the I-beam 2514 during the diagnostic first portion (1a) of the zone 1. In some examples, the control circuit 2510 may select the speed (v1), the speed (v2), and/or the speed (v3) based on the I-beam speed determined in the diagnostic first portion (1a) of zone 1 and/or the current (I) consumed by the motor 2504 in the open loop portion. In one example, a lookup table may be employed to determine velocity (v1), velocity (v2), and/or velocity (v3) based on measurements representing movement of the I-beam 2514 during the diagnostic first portion (1a) of zone 1.
In one example, the control circuit 2510 can select a constant or substantially constant speed of the region of the firing stroke based on movement of the I-beam 2514 in one or more prior regions of the firing stroke. For example, the control circuit 2510 can select a velocity for the second or intermediate zone based on movement of the I-beam 2514 in the first zone. Also, the control circuitry 2510 can select a speed for the third zone based on movement of the I-beam 2514 in the first zone and/or the second zone.
As indicated by the example of fig. 18, the control circuit 2510 can be configured to be able to maintain a linear or substantially linear transition from speed (v1) to a higher speed (v2) in the initial portion of region 2. The control circuit 2510 may increase the speed of the I-beam 2514 at a constant rate to produce a linear or substantially linear transition from the speed (v1) to a higher speed (v 2). Alternatively, the control circuit 2510 may be configured to be able to maintain a non-linear transition from speed (v1) to a higher speed (v2) in the initial portion of region 2.
Further, the control circuit 2510 can be configured to be able to maintain a linear or substantially linear transition from speed (v2) to a higher speed (v3) in the initial portion of zone 3. The control circuit 2510 may increase the speed of the I-beam 2514 at a constant rate to produce a linear or substantially linear transition from the speed (v2) to a higher speed (v 3). Alternatively, the control circuit 2510 may be configured to be able to maintain a non-linear transition from speed (v2) to a higher speed (v3) in the initial portion of region 3.
As shown in the illustration 6230 of FIG. 20, the firing force (FTF) gradually decreases as the I-beam 2514 is advanced during the firing stroke. As such, the firing force (FTF) applied to the I-beam 2514 is generally higher at the beginning of the firing stroke than at the middle of the firing stroke, and generally higher at the middle of the firing stroke than at the end of the firing stroke. Operating the motor 2504 at a reduced or low duty cycle in the portion of the firing stroke where the I-beam 2514 is subjected to higher loads improves the performance of the motor 2504 and energy source 2512. As described above, the total current (I) consumed by the motor 2504 during the firing stroke is reduced, which extends the life of the energy source 2512 (FIG. 14). Second, operating the motor 2504 at a reduced duty cycle in the higher loaded portion of the firing stroke may protect the motor 2504 from stalling.
In some examples, the firing control routine may determine a target value for the duty cycle of the motor 2504 based on the position of the I-beam 2514 along the firing stroke. Fig. 20 shows a plot 6200 depicting the duty cycle of the motor 2504 versus the distance traveled along the firing stroke for three exemplary firing strokes 6206, 6208, 6210, which may be achieved by the firing control routine selected at 6038. In the illustration 6200, the horizontal axis 6202 represents firing stroke displacement in millimeters. The vertical axis 6204 indicates the duty cycle of the motor 2504 in percent. As shown, in fig. 20, examples 6206, 6208, 6210 initially have the same duty cycle in the diagnostic first portion (1a) of region 1 of the firing stroke distance. Fig. 20 shows an illustration 6230 that includes examples 6206', 6208', and 6210' that correspond, respectively, to examples 6206, 6208, and 6210 of illustration 6200. In the illustration 6200, the horizontal axis 6234 represents time in seconds. The vertical axis 6232 indicates the firing force (FTF) applied as the I-beam 2514 is advanced through the firing stroke.
In the example 6206 of fig. 20, the firing control routine is configured to operate the motor 2504 at a predetermined constant or substantially constant duty cycle. The constant duty cycle may be selected based on the movement of the I-beam during the diagnostic first portion (1a) of zone 1. Example 6206' represents an associated firing force (FTF) to run the motor 2504 at a predetermined constant or substantially constant duty cycle during a firing stroke.
To reduce the load or firing force (FTF), as shown by the firing force (FTF) profiles of examples 6208 'and 6210', an alternative firing control routine corresponding to examples 6208 and 6210 of illustration 6100 is selected at 6038. As shown in illustration 6230, examples 6208' and 6210' have lower Force To Fire (FTF) distributions than example 6206', and maximum force thresholds (F) than example 6206 3) Low threshold of maximum force (F) 1) And (F) 2)。
Example 6210' represents a Force To Fire (FTF) profile associated with operating motor 2504 in a closed loop. During the closed-loop portion of the stroke, the control circuit 2510 can adjust the duty cycle of the motor 2504 based on translation data that describes the position of the I-beam 2514. During the closed loop, the control circuit 2510 is configured to gradually increase the duty cycle of the motor 2504 as the I-beam 2514 advances along the firing stroke.
The control circuit 2510 may monitor the position of the I-beam 2514 as indicated by the position sensor 2534. Data from the position sensor 2534 may be used by the control circuit 2510 to set the duty cycle of the motor 2504. In some examples, the duty cycle of the motor 2504 is varied by the control circuit 2510 at 1 millimeter intervals. In one example, the control circuit 2510 is configured to maintain a substantially linear increase in the duty cycle of the motor 2504 as the I-beam 2514 is advanced through the firing stroke.
In some examples, the absolute positioning system 1100 (fig. 10-12) may be used to sense the position of the I-beam 2514, and the duty cycle of the motor 2504 may be set based on the position of the I-beam 2514 as evaluated by one or more rotations of the sensor element 1126.
In some examples, the control circuit 2510 is configured to increase the duty cycle of the motor 2504 at a substantially constant rate as the I-beam 2514 is advanced through the firing stroke. The rate of increase of the duty cycle of the motor 2504 may be selected based on the movement of the I-beam 2514 during the diagnostic time (t1) in the diagnostic first portion (1a) of zone 1. In one example, a lookup table may be employed to determine a rate of increase of the velocity of the I-beam 2514 based on measurements representing movement of the I-beam 2514 during a diagnostic time (t1) in a diagnostic first portion (1a) of zone 1.
In one example, a look-up table may be employed to determine the duty cycle of the motor 2504 based on measurements representing movement of the I-beam 2514 during the diagnostic first portion (1a) of zone 1. The control circuit 2510 can also be configured to determine the duty cycle of the motor 2504 at various positions along the firing stroke of the I-beam 2514 based on tissue conditions. As described above, tissue conditions, such as the thickness and/or toughness of the tissue present between the anvil 2516 and the staple cartridge 2518, may affect movement of the I-beam 2514 because different types of tissue will provide different levels of resistance.
Alternative examples 6208' represent a reduced firing force (FTF) profile associated with operating motor 2504 at multiple constant or substantially constant duty cycles at multiple discrete or continuous portions or regions within a firing stroke. As described above in connection with illustration 6100, the firing stroke distance is divided into three regions: region 1, region 2 and region 3. The I-beam 2514 experiences a greater load in zone 1 than in zone 2, and the I-beam 2514 experiences a greater load in zone 2 than in zone 3. To reduce the force-to-fire (FTF), the motor 2504 operates at three different duty cycles set at predetermined positions at points 6201, 6203, and 6205 of zone 1, zone 2, and zone 3, respectively, as shown in FIG. 20. In some examples, the number of regions and corresponding duty cycles may be greater or less than three, depending on the staple cartridge size and/or tissue condition. The positioning of the I-beam travel area in fig. 20 is merely an example. In some examples, the different regions may begin at different positions along the end effector longitudinal axis 2515, e.g., based on the positioning of tissue between the anvil 2516 and the staple cartridge 2518.
In region 1, where the I-beam 2514 experiences the highest load, the motor 2504 operates at a low duty cycle. As indicated by example 6208 of fig. 20, the control circuit 2510 is configured to be able to maintain the duty cycle of the motor 2504 at about 45% for the remainder of the region 1 starting from a point 6201, which represents a predetermined position at the start of the second portion (1b) of the region 1, for example.
In region 2, where the I-beam 2514 is subjected to an intermediate load, the motor 2504 operates at an intermediate duty cycle that is greater than the duty cycle maintained in region 1. At the beginning of zone 2, the control circuit 2510 is configured to be able to increase the duty cycle of the motor 2504 to a predetermined duty cycle which is maintained by the control circuit 2510 at a constant or substantially constant value for the remainder of zone 2. As indicated by example 6208 of fig. 20, the control circuitry 2510 is configured to be able to maintain the duty cycle of the motor 2504 at about 75% for the remainder of the region 2 starting from point 6203, which represents a predetermined position, for example.
In zone 3, where the I-beam 2514 experiences the lowest load, the motor 2504 operates at a duty cycle that is greater than the duty cycle maintained in zone 2. At the beginning of zone 3, the control circuit 2510 is configured to be able to increase the duty cycle of the motor 2504 to a predetermined duty cycle which is maintained at a constant or substantially constant value for the remainder of zone 3 by the control circuit 2510. As indicated by example 6208 of fig. 20, the control circuitry 2510 is configured to be able to maintain the duty cycle of the motor 2504 at, for example, about 100% for the remainder of the region 3 starting from point 6205, which represents the predetermined position.
The control circuit 2510 can select duty cycles for zones 1, 2, and 3 based on movement of the I-beam 2514 during the diagnostic first portion (1a) of zone 1. In some examples, the control circuit 2510 can select duty cycles for zones 1, 2, and 3 based on the I-beam speed determined in the diagnostic first portion (1a) of zone 1 and/or the current (I) consumed by the motor 2504 in the open loop portion. In one example, a lookup table may be employed to determine the duty cycles for zones 1, 2, and 3 based on measurements representing movement of the I-beam 2514 during the diagnostic first portion (1a) of zone 1.
While the firing control routine or logic configuration of example 6208 depicts three steps with constant or substantially constant duty cycles at 45%, 75%, and 100%, other duty cycles are also contemplated by the present disclosure. In one example, as shown in plot 6300 of fig. 21, the firing control routine may include operating the motor 2504 at a duty cycle of about 33% in a first region of the firing stroke, at a duty cycle of about 66% in a second region of the firing stroke, and at a duty cycle of about 100% in a third region of the firing stroke. For example, different duty cycles may be set to start at different I-beam positions along the firing stroke.
In one example, the control circuit 2510 can select a constant or substantially constant duty cycle for the motor 2504 for a region of the firing stroke based on movement of the duty cycle of the motor 2504 in one or more prior regions of the firing stroke. For example, the control circuit 2510 can select a duty cycle for the second or intermediate region based on the duty cycle in the first region. Also, the control circuit 2510 can select a duty cycle for the third region based on the duty cycles in the first region and/or the second region.
The plot 6300 shows a plot of duty cycle of the motor 2504 versus distance traveled along a firing stroke for an exemplary firing stroke 6310 that may be achieved by a firing control program selected at 6038. In the illustration 6300, the horizontal axis 6302 represents firing stroke displacement in millimeters. The vertical axis 6304 indicates the duty cycle of the motor 2504 in percentages. As shown in fig. 21, example 6310 indicates that the motor 2504 is operated at a duty cycle of about 33% in region 1 of the firing stroke, about 66% in region 2 of the firing stroke, and about 100% at region 3 of the firing stroke. The present disclosure contemplates other values for the duty cycle at region 1, region 2, and/or region 3.
In one example, the motor 2504 may operate at a duty cycle selected from a range of about 25% to about 50% in the initial region of the firing stroke. In one example, the motor 2504 may operate at a duty cycle selected from a range of about 50% to about 80% in the middle region of the firing stroke. In one example, the motor 2504 may operate at a duty cycle selected from a range of about 75% to about 100% in the final region of the firing stroke.
In some examples, the motor 2504 can be a brushless Direct Current (DC) electric motor, and the motor drive signals 2524 can include Pulse Width Modulated (PWM) signals provided to one or more stator windings of the motor 2504. Fig. 21 also shows a graph 6350 depicting an example 6360 indicating pulse width modulation signals corresponding to motor duty cycles of region 1, region 2, and region 3 of example 6310. The illustration 6350 includes two axes. Horizontal axis 6354 represents firing stroke displacement in millimeters. Vertical axis 6352 indicates the pulse width modulated signal.
The firing control routine of the example 6310 may vary the pulse width of the signal supplied to the motor 2504 depending on the position of the I-beam 2514 along the firing stroke. The first pulse width may be maintained in region 1. A second pulse width greater than the first pulse width may be maintained in region 2. A third pulse width greater than the second pulse width may be maintained in region 3.
In various examples, the above-described regions 1, 2, and 3 of the firing stroke may be equidistant or substantially equidistant. In other words, each of the three regions may be about one-third of the total distance the I-beam 2514 travels during the firing stroke. In other examples, the firing stroke distance may be divided into more or less than three zones that are equal or different in distance.
Referring to FIG. 22, the illustration 6400 depicts an example 6408 of force applied during a closure stroke to close the end effector 2502 against tissue clamped between the anvil 2516 and the staple cartridge 2518, which is plotted as a function of time. Illustration 6400 includes two axes. The vertical axis 6402 indicates the closing force in newtons (N) (FTC) to close the end effector 2502. Horizontal axis 6404 indicates time in seconds. During a closure stroke, the closure tube 260 is translated distally (direction "DD") to move the anvil 2516 relative to the staple cartridge 2518, e.g., in response to actuation of the closure trigger 32 (fig. 1), in the manner described in the aforementioned reference, U.S. patent application publication 2014/0263541. In other examples, the closure stroke involves moving the staple cartridge relative to the anvil in response to actuation of the closure trigger 32. In other examples, the closure stroke involves moving the staple cartridge and anvil in response to actuation of the closure trigger 32.
Example 6408 indicates that the closing Force (FTC) to close the end effector 2502 is at time (t) 0) The ending initial clamping period is increased. Closing Force (FTC) at time (t) 0) To reach a maximum force (F) 3). For example, the initial clamping time period may be about one second. A waiting period may be applied before the firing stroke is initiated. Waiting period admissionFluid is permitted to flow out of the tissue compressed by the end effector 2502, which reduces the thickness of the compressed tissue, creating a smaller gap between the anvil 2516 and staple cartridge 2518 and a reduced closing force (F) at the end of the waiting period 1). In some examples, a waiting period selected from a range of about 10 seconds to about 20 seconds is typically employed. In example 6408, a time period of about 15 seconds is employed. This waiting period is followed by a firing stroke, which typically lasts for a period of time selected from, for example, within the range of about 3 seconds to about 5 seconds. The closing Force (FTC) decreases as the I-beam 2514 advances through the firing stroke relative to the end effector.
Fig. 22 also shows a plot 6450 that plots three examples 6456, 6458, 6460 of forces applied to advance the I-beam 2514 during the firing stroke of the surgical instrument 2500. Figure 6450 includes two axes. The vertical axis 66452 indicates the force in newtons (N) applied to advance the I-beam 2514 during the firing stroke. The I-beam 2514 is configured to advance the knife 2509 and actuate the driver 2511 to deploy the staples 2505 during the firing stroke. Horizontal axis 6050 indicates time in seconds.
The I-beam 2514 advances from a stroke start position 2527 (fig. 13) to a stroke end position 2528 (fig. 13) at a start time (t ═ 0). As the I-beam 2514 is advanced through the firing stroke, the closure assembly hands over control of the staple cartridge 2518 and anvil 2516 to the firing assembly, which results in an increase in firing force (FTF) and a decrease in closure Force (FTC).
In an alternative example 6406, a stiffer anvil 6410 (fig. 23) is employed. The anvil 6410 of example 6406 has a stiffness greater than that of the anvil of example 6408. Maximum closing force (F) associated with the anvil of example 6408 3) And (F) 1) In contrast, a harder anvil 6410 is at time (t) 0) To generate a greater maximum closing force (F) 4) And generates a larger (F) at the end of the waiting period 2). Due to the increased stiffness, the anvil 6406 of example 6410 was less able to flex or bend away from the compressed tissue than the anvil of example 6408. Thus, the anvil 6410 of example 6406 may experience a greater load than the anvil of example 6408 during the entire closing stroke.
Examples 6456 and 6458 of fig. 6450 are the force-to-fire (FTF) corresponding to examples 6406 and 6408 of fig. 6400, respectively. The stiffer anvil 6410 of examples 6406 and 5458 experienced a smaller firing force (FTF) profile when encountering a larger closing Force (FTC) profile than the anvils of examples 6408 and 6456. In examples 6456 and 6458, the Force To Fire (FTF) distribution was reduced by about 20% due to the increased stiffness of the anvil 6410. Various techniques may be employed in increasing the stiffness of the anvil, as described in U.S. patent application serial No. 15/385,922 entitled motor inside WITH MULTIPLE FAILURE MODES mode filed on 21.12.2019, the entire disclosure of which is incorporated herein by reference.
A stiffer anvil 6410 has an elongated anvil body 6412 having an upper body portion 6414 with an anvil cap 6416 attached thereto. In the aspect depicted in fig. 22, the anvil cap 6416 is generally rectangular in shape and has an outer cap perimeter 6418. The periphery 6418 of the anvil cap 6416 is configured to be insertable through a correspondingly shaped opening formed in the upper body portion and received over an axially extending internal flange portion of the anvil body 6412. The anvil body 6412 and anvil cap 6416 may be made of a suitable metal to facilitate welding. The first weld 6420 may extend around the entire cap perimeter 6418 of the anvil cap 6416, or it may be located only along the long edge 6422 of the anvil cap 6416 and not along its distal end 6424 and/or proximal end 6426. The first weld 6418 may be continuous, or it may be discontinuous or intermittent.
The effective firing force (FTF) profile of example 6458 may be further improved by employing a firing control routine in combination with a stiffer anvil 6410, which may be selected at 6038 (fig. 17), as shown in example 6460. Any of the firing control procedures associated with the previous examples 6108, 6110, 6208, or 6210 may be used with a stiffer anvil 6410 to produce a more efficient firing force profile. In aspects of the example 6460, a stiffer anvil 6410 is combined with a firing control procedure that initially runs the I-beam 2514 at a faster speed, then at a slower speed when thicker tissue is encountered. With respect to example 6456 and 6458, respectively 2)、(t 3) The combination of the stiffer anvil 6410 and firing program may result in a shorter time (t) to reach a maximum firing force (FTF) 1). Further, corresponding times (t) relative to examples 6456 and 6458 5) And (t) 6) This combination may result in a shorter time (t4) to reach the end-of-stroke position 2528 (FIG. 13) of the firing stroke. As shown by plot 6450, this combination produces an additional 20% reduction in maximum (FTF) compared to the maximum (FTF) of example 6458. In some examples, the selected firing control program is configured to reduce the speed of the I-beam 2514 in the first portion of the firing stroke by about one-third relative to the speed used in conjunction with example 6458.
The functions or processes 6030, 6111, 6131 described herein may be performed by any processing circuitry described herein, such as the control circuitry 700 described in connection with fig. 5-6, the circuitry 800, 810, 820 described in fig. 7-9, the microcontroller 1104 described in connection with fig. 10 and 12, and/or the control circuitry 2510 described in fig. 14.
Various aspects of the subject matter described herein are set forth in the following numbered examples: