阅读说明：本技术 具有近侧和远侧压力或流量传感器以及远侧传感器追踪的血管内泵 (Intravascular pump with proximal and distal pressure or flow sensors and distal sensor tracking ) 是由 约瑟夫·P·希金斯 于 2019-07-30 设计创作，主要内容包括：本发明提供了一种血管内的血液泵,其包括没有流动导引件或扩散器的泵组件,以及近侧和远侧流量或压力传感器,其中在将血液泵放置在患者的脉管系统内之后,远侧流量或压力传感器可以被追踪到叶轮的远侧。(The present invention provides an intravascular blood pump that includes a pump assembly without a flow guide or diffuser, and proximal and distal flow or pressure sensors, wherein the distal flow or pressure sensor can be tracked to the distal side of the impeller after placement of the blood pump within the vasculature of a patient.)

1. A blood pump assembly having an inlet and an inlet housing and an outlet and adapted to be positioned within a patient's aorta and left ventricle comprising:

a motor in operable rotational engagement with an impeller assembly, the impeller assembly comprising an impeller housing, an impeller located within the impeller housing, the impeller comprising an impeller hub and blades operably engaged with the impeller hub, wherein the impeller assembly does not comprise a flow guide or a flow diffuser;

a sheath operatively connected with the impeller housing, and wherein the impeller assembly does not include a flow guide or a flow diffuser;

a flexible drive shaft translated through the sheath and operably connected to the proximal ends of the motor and impeller, wherein a lumen is disposed between the flexible drive shaft and the sheath as the drive shaft translates through the sheath;

a proximal pressure or flow sensor mounted at a location proximal of the impeller along the sheath, wherein the proximal pressure or flow sensor is located within the patient's aorta when positioned for operation; and

a distal pressure or flow sensor positioned at a first location proximal to the impeller, wherein the distal pressure or flow sensor is adapted to subsequently translate to a second location within the left ventricle of the patient and distal to the impeller location;

an external power source;

an external controller operatively connected to the external power source;

a first electrical lead operably connected to the proximal pressure or flow sensor, the external power source, and the external controller, the first electrical lead translating along a lumen between the drive shaft and the sheath; and

a second electrical lead operably connected with the distal pressure or flow sensor, the external power source, and the external controller, the second electrical lead translating through a lumen between the drive shaft and the sheath.

2. The blood pump assembly of claim 1, further comprising: a controller adapted to calculate a pressure or flow of the blood pump based on inputs received from the first and second pressure or flow sensors.

3. The blood pump assembly of claim 2, further comprising: a push wire operably connected to the distal pressure or flow sensor and adapted to translate the distal pressure or flow sensor to the second position.

4. A blood pump assembly having an inlet and an outlet adapted to be positioned within a patient's aorta and left ventricle comprising:

a motor in operable rotational engagement with an impeller assembly, the impeller assembly including an impeller housing, an impeller located within the impeller housing, the impeller including an impeller hub and blades in operable engagement with the impeller hub;

a sheath operably connected with the impeller housing, wherein the impeller assembly does not include a flow guide or a flow diffuser;

a flexible drive shaft translated through the sheath and operably connected with proximal ends of the motor and impeller;

a proximal pressure or flow sensor mounted at a location proximal of the impeller along the sheath, wherein the proximal pressure or flow sensor is located within the patient's aorta when positioned for operation; and

a distal pressure or flow sensor positioned at a first location proximal to the impeller, wherein the distal pressure or flow sensor is adapted to subsequently translate to a second location distal to the impeller within the left ventricle of the patient;

an external power source;

an external controller operatively connected to the external power source;

a first electrical lead operably connected to the proximal pressure or flow sensor, the external power source, and the external controller, the first electrical lead translating along a lumen between the drive shaft and the sheath; and

a second electrical lead operably connected with the distal pressure or flow sensor, the external power source, and the external controller, the second electrical lead translating through a lumen between the drive shaft and the sheath.

5. The blood pump assembly of claim 4, further comprising: a controller adapted to calculate a flow rate of the blood pump based on inputs received from the first and second pressure or flow sensors.

6. The blood pump assembly of claim 5, further comprising: a push wire operably connected to the distal pressure or flow sensor and adapted to translate the distal pressure or flow sensor to the second position.

7. A blood pump having a motor-driven rotating impeller, an inlet and an inlet housing, and an outlet and adapted to be positioned within a patient's aorta and left ventricle comprising:

a proximal pressure or flow sensor mounted at a location proximal of the impeller along the sheath, wherein the proximal pressure or flow sensor is located within the patient's aorta when positioned for operation; and

a distal pressure or flow sensor positioned at a first location proximal to the impeller, wherein the distal pressure or flow sensor is adapted to subsequently translate to a second location distal to the impeller within the left ventricle of the patient when the blood pump is positioned;

an external power source;

an external controller operatively connected to the external power source;

a first electrical lead operatively connected to the proximal pressure or flow sensor, the external power source, and the external controller; and

a second electrical lead operatively connected with the distal pressure or flow sensor, the external power source, and the external controller.

8. The blood pump assembly of claim 7, further comprising: a controller adapted to calculate a flow rate of the blood pump based on inputs received from the first and second pressure or flow sensors.

9. The blood pump assembly of claim 8, further comprising: a push wire operably connected to the distal pressure or flow sensor and adapted to translate the distal pressure or flow sensor to the second position.

10. A method for directly measuring pressure throughout a blood pump positioned within a patient's aorta and left ventricle during rotation of an impeller of the pump, comprising:

providing a proximal pressure or flow sensor secured to the blood pump proximal to the impeller of the positioned blood pump;

providing a distal pressure or flow sensor that translates to a position distal to an impeller of the positioned blood pump after the blood pump is positioned;

providing an external controller operably connected to the proximal and distal pressure sensors;

operating an impeller of the positioned blood pump to generate a flow of blood;

obtaining pressure or flow signals from proximal and distal pressure or flow sensors at the external controller; and

a pressure or flow is determined based on the obtained pressure or flow signal.

11. The method of claim 10, further comprising: a display is provided in operative connection and the obtained pressure or flow signal is displayed on the display.

Technical Field

The present invention relates to an intravascular blood pump having an expandable and collapsible inlet area.

Background

Referring to fig. 1, the human heart includes four chambers and four heart valves that facilitate the forward (antegrade) flow of blood through the heart. The chambers include the left atrium, left ventricle, right atrium, and right ventricle. The four heart valves include the mitral valve, the tricuspid valve, the aortic valve, and the pulmonary valve.

The mitral valve is located between the left atrium and the left ventricle and helps control the flow of blood from the left atrium to the left ventricle by acting as a one-way valve that prevents regurgitation into the left atrium. Similarly, the tricuspid valve is located between the right atrium and the right ventricle, while the aortic and pulmonary valves are semilunar valves located in arteries that supply blood to flow away from the heart. The valves are all one-way valves, having leaflets that open to allow forward (antegrade) blood flow. The normally functioning valve leaflets close under the pressure exerted by the reverse blood to prevent backflow (retrograde) of blood.

Thus, as shown, the general blood flow includes deoxygenated blood returning from the body, which is received by the right atrium via the superior and inferior vena cava and then pumped into the right ventricle, which is controlled by the tricuspid valve. The right ventricle functions to pump deoxygenated blood through the pulmonary arteries to the lungs, where it is reaerated and returned to the left atrium through the pulmonary veins.

Heart disease is a health problem with high mortality. The use of temporary mechanical blood pump devices is frequently used to provide short term acute assistance during surgery or as temporary bridging assistance to help patients to crisis. These temporary blood pumps have been developed and evolved over the years to supplement the pumping action of the heart on a short-term basis and to supplement blood flow as left or right ventricular assist devices ("LVADs"), the most commonly used devices at present.

Known temporary LVAD devices are typically delivered percutaneously (e.g., via the femoral artery) such that the LVAD inlet is located or positioned in the left ventricle and the outlet is in the ascending aorta of the patient, with the body of the device disposed across the aortic valve. As will be appreciated by those skilled in the art, an incision may be made below the groin of the patient to allow access to the femoral artery of the patient. The physician may then translate the guide wire (followed by the catheter or delivery sheath) through the femoral artery and the descending aorta until reaching the ascending aorta. The LVAD, with the rotating drive shaft attached thereto, may then be translated through a delivery catheter or sheath lumen, exposing the proximal end of the drive shaft outside the patient's body, and coupled with a prime mover, such as an electric motor or equivalent for rotating and controlling the rotational speed of the drive shaft and associated LVAD impeller.

Temporary axial flow blood pumps are generally comprised of two types, (1) axial flow blood pumps powered by a motor integrated into the device to which the pump's impeller is attached (see U.S. patent nos. 5,147,388 and 5,275,580); and (2) axial flow blood pumps powered by an external motor that provides rotational torque to a drive shaft (which in turn is connected to the impeller of the pump) (see U.S. patent No.4,625,712 to Wampler and U.S. patent 5,112,349 to Summers, each of which is incorporated herein by reference in its entirety).

Known temporary ventricular assist devices ("VADs"), including LVAD and RVAD (right ventricular assist) devices, whether having an integrated motor or an external motor, typically include the following elements (listed in order from inflow to outflow) mounted within a housing; a flow guide, known in the art as a component that directs fluid from an inflow orifice or inlet into the impeller; rotating the impeller; and flow diffusers and/or outflow structures, known in the art to function to straighten or redirect the rotational flow established by a rotating impeller into axial flow; and an outflow bore, as shown in the cross-sectional and cut-away views of the exemplary prior art pump and/or impeller assembly of fig. 2.

In fig. 2, the known device 2 is oriented with the inflow end (distal end) on the left side of the figure and the outflow end (proximal) on the right side, such that incoming blood in the ventricle flows through an inflow orifice (not shown) into the device housing, through a flow channel defined by the surrounding housing 14, and ultimately into the impeller/pump assembly 4. There, the incoming blood encounters the flow guide 6 before being propelled forward by the rotating impeller 8. The blood flow can then be altered by the flow diffuser 9 and exit into the aorta via the outflow hole 10 of the housing.

The known VAD or LVAD devices also include a delivery configuration and a functional or working configuration, wherein the delivery configuration has a lower profile or smaller diameter than the functional or working configuration, thereby facilitating, among other things, non-invasive delivery through the delivery sheath. In other words, the vanes of the housing and/or impeller of the VAD or LVAD may be expanded to achieve a functional or working configuration and contracted to achieve a delivery configuration in various ways. However, known devices contract and expand the impeller blades and/or the housing, wherein the retractable and expandable housing surrounds at least a portion of the impeller so as to be movable between an expanded or working configuration and/or require an integrated motor proximate the impeller. See, e.g., U.S. patent nos. 7,027,875; 7,927,068, respectively; and 8,992,163.

Known LVAD devices typically include an angled housing to accommodate the aortic arch, the angle or bend typically being in the range of 135 degrees.

LVAD devices with integrated motors in the housing must be small enough to allow for non-invasive intravascular translation and positioning within the heart. While various methods are known to cause some portions of the device (including the housing and/or impeller or components thereof, such as the blades) to contract while in a catheter or delivery sheath, the size of the constriction device may be limited by the integrated motor.

Additionally, known LVAD devices include delivery configurations in which the housing and/or impeller (e.g., blades on the impeller) may be reduced in diameter, and the collapsed elements may be expandable when delivered distally from a delivery catheter or sheath. These devices are limited in several respects. First, the contraction and expansion includes at least a portion of the casing occupied by the impeller. Second, the inflow region of the housing, i.e., the region distal to the rotating impeller and the stationary guide or flow straightener, includes a region that has the opportunity to optimize the flow of blood through the cannula or housing. Known LVAD or VAD devices do not take advantage of this opportunity. Third, known LVAD or VAD devices include flow guides or flow straighteners that blood encounters when entering the pump, which may cause thrombosis and/or hemolysis, among other things. Fourth, for the reasons discussed herein, it is critical to reduce the cross-sectional profile of a VAD or LVAD device, and design requirements are made more difficult by the need to extend electrical leads through or along the housing of the device, where the electrical leads may be used, for example, to power and/or communicate with a motor or sensor or other operable electrically powered element. In this regard, electrical leads need to be reduced in profile to maintain as low a cross-sectional profile as possible, and insulation and/or spacing between adjacent leads is required, where such insulation and/or spacing is necessary or desirable. Furthermore, a direct method of measuring pressure and/or flow is desired.

Various embodiments of the present invention address these problems, among others.

The figures and the detailed description that follow more particularly exemplify these and other embodiments of the invention.

Drawings

FIG. 1 is a cross-sectional view of a human heart;

FIG. 2 is a cross-sectional view of a prior art device;

FIG. 3 is a side cross-sectional view of one embodiment of the present invention;

FIG. 4 is a side cross-sectional view of one embodiment of the present invention;

FIG. 5 is a side cross-sectional view of one embodiment of the present invention;

FIG. 6A is a side cross-sectional view of one embodiment of the present invention; and is

FIG. 6B is a side cross-sectional view of one embodiment of the present invention.

Detailed Description

In general, various embodiments of the present invention are directed to mechanical assist devices for pumping blood within a patient. Improved temporary LVAD or VAD blood pumps delivered percutaneously and intravascularly are described herein.

Referring now to fig. 3, an exemplary LVAD blood pump 100 is shown having an inflow orifice 12 on the left side of the figure and an outflow orifice 10 on the right side of the device. The motor is shown at the proximal end of the device, outside the patient's body, and is connected to a rotary drive shaft, which in turn is connected to an impeller or rotor 8 or pump assembly. However, as is well known in the art, the motor may be located within the housing of the device itself, with the motor typically being mounted proximal to the rotor 8 or impeller or pump assembly. Any of these configurations may be used with the various embodiments of the invention described herein.

The entire length of the outer housing 14 is shown to include a relatively uniform diameter from the inlet or inflow bore 12 to the outlet or outflow bore 10. A guide wire 16 is positioned along the exterior of the device until the entry hole 12 is reached, where it enters the lumen of the cannula C and extends distally therefrom, as shown. Thus, the guide wire 16 does not pass through the impeller or rotor 8 or the pump assembly. The configuration shown in FIG. 3 may include a delivery configuration in which the expandable region 102 is compressed within an introducer or delivery sheath or catheter 200.

Referring generally to the figures, the device 100 may include an expandable region 102, which may be distal to the impeller or rotor or pump assembly, such that the diameter of the housing around the impeller or rotor or pump assembly does not change diameter during delivery or rotation. In other words, the proximal non-expandable region 122 may be provided and include at least an impeller or rotor or pump assembly, and the housing surrounding the assembly does not significantly expand or contract, but may be flexible. In addition, a distal non-expandable region 124 may be provided that includes at least an inlet region that includes at least the inlet aperture 12. Thus, the expandable region 102 includes a proximal end and a distal end. The proximal end of the expandable region 102 abuts or is adjacent to the distal end of the proximal non-expandable region 122, while the distal end of the expandable region 102 abuts or is adjacent to the proximal end of the distal non-expandable region 124. However, the housing H surrounding the non-expandable regions 122, 124 may be flexible or pliable, but they are not configured to bias expansion.

Alternatively, the housing H of the device 100 in fig. 3 may be non-expandable.

Fig. 4 illustrates an expandable embodiment of the device 100, and shows, in phantom, the change in diameter to/from a contracted, deformed expandable region to an exemplary expanded, undeformed expandable region, extending distally along the hollow cannula from a point distal to the end of the impeller, rotor and/or pump assembly to a point just proximal to the inlet bore. The expandable region 102 may be expanded to a maximum undeformed diameter in the range of 12-20Fr, more preferably between 16-20 Fr. In contrast, the unexpanded region maintains a substantially fixed diameter in the range of 9 to 12 Fr.

With continued general reference to fig. 3 and 4 and the remaining figures, the device 100 may include an expandable region 102 that may be partially or fully biased to an expanded configuration, and thus include a material or structure that facilitates expansion and may be biased to expand. An exemplary configuration of the expandable region 102 may include a support structure 130 surrounded by an outer material, such as a jacket or coating or sleeve of expanded plastic or polymeric material that accommodates underlying support structures known in the art. Support structure 130 may be formed from a shape memory material such as nitinol or the like. Other materials may include gold, tantalum, stainless steel, metal alloys, aerospace alloys, and/or polymers, including polymers that expand and contract when exposed to relative heat and cold. In other instances, at least a portion of the expandable region 102 (e.g., the central expandable section 104 discussed below) may include a sleeve of a polymer or other material configured to allow and/or accommodate expansion and contraction, and the support structure 130 may be omitted. Fig. 4 provides a rotary drive shaft connected to the impeller assembly and, in turn, to a prime mover, such as an electric motor, located outside the patient's body. However, it should be understood that the various embodiments of the invention discussed herein may also be used in conjunction with a blood pump that includes a motor integrated into the blood pump (i.e., without an external motor). Further, as noted above, the device 100 may include an expandable and collapsible housing H or region 102, or may be non-expandable.

In many of the embodiments described herein, the expandable region 102 may comprise a single expandable region without or without reason to distinguish between proximal, central, and/or distal transition sections.

In general, the expandable region 102 of the present invention may include a support structure 130 surrounded by a polymer coating or jacket that is adapted for expansion and contraction of the expandable region 102.

In addition, the support structure 130 may comprise an expandable stent-like structure formed from a series of cells formed by interacting and/or interconnecting wires and/or struts and allowing a structure (e.g., a stent) to contract and bias expansion, as is well known in the art. See, for example, the following U.S. patents: kanesaka, No.5,776,183; 5,019,090 to Pinchuk; 5,161,547 by Tower; 4,950,227 to Savin; fontaine 5,314,472; 4,886,062 and 4,969,458 by Wiktor; and 4,856,516 to Hillstead; the disclosure of each of these patents is incorporated herein by reference in its entirety.

The expandable region 102 described herein is merely exemplary and is not limiting in any way. Accordingly, any expandable housing H of the blood pump apparatus 100 is readily adaptable to various embodiments of the present invention involving insulation and/or spacing and/or reduction in profile or integration of electrical leads or conductors E within or along the blood pump housing. The expandable region 102 may also include a single region that is capable of expanding and contracting.

Turning now to fig. 5, an exemplary pump assembly or impeller assembly 200 is shown.

Initially, in contrast to the known impeller assembly shown in fig. 2 (which includes the flow guide 6 and the flow diffuser 9), the exemplary pump or impeller assembly of fig. 5 completely eliminates the flow guide 6 and the flow diffuser 9 of the impeller assembly found in the known pump as shown in fig. 2. The applicant has found that the guide 6 and/or the diffuser 9 do not require an effective control or operation of the inflow blood flow and that at least the additional fixed surface area and the interconnection between the guide 6 and the distal end of the rotating impeller 8 results in an increased risk of thrombosis. Thus, by actuating the pump or impeller assembly to rotate at a predetermined speed, blood is introduced to flow through the cannula without the assistance or need of a flow guide. Thus, blood flows directly to the rotating impeller 8, which includes the blades 11, and is pushed out of the cannula or lumen of the device by the rotating impeller blades 11 at the outflow orifice 10 without the aid or need of a flow diffuser or straightener.

Turning now to fig. 6A and 6B, a system 200 is provided for directly measuring flow. Currently known solutions provide aortic pressure measurements via a pressure sensor located proximal to the impeller pump housing assembly. In these known devices, the output flow is calculated based on the aortic pressure, impeller rotational speed and motor current. Thus, placing a pressure sensor in the left ventricle on a positioned blood pump device will allow LVDP pressure sensing and measurement to determine the unloading amount of the ventricle and the flow out of the left ventricle.

Laying the electrical leads along the housing of the device is difficult because known solutions require an increase in the crossing profile. The present invention solves this problem.

The diameter of the body lumen can be used in the present invention to calculate flow based on pressure data. Thus, a direct flow measurement sensor device may be provided within the blood pump at a location where the diameter is a fixed and known value, particularly in embodiments where the housing is not expandable. Alternatively, in embodiments where the housing may be expandable, the diameter may be assessed during the LVAD procedure by imaging or other well-known methods.

As shown in fig. 6, at least one distal sensor 202 (which may comprise a pressure sensor or an ultrasonic flow meter) may be initially in a first position L proximal to the impeller₁Within or along the blood pump device, and then translated distally with a push wire 204 or equivalent to a second position L within the patient's left ventricle when the blood pump device is operatively positioned₂Wherein the second position L₂Distal to the impeller.

Translation or tracking of the distal pressure sensor 202 from the first position to the second position is accomplished by an operator performing operations by means well known in the art, for example, using a push wire 204 or equivalent to move the distal sensor 202 to its second position L within the left ventricle₂. Alternatively, where the blood pump includes an expandable inlet using the expansion means and structures described above, the distal sensor 202 may be operably connected with the expandable inlet. In this embodiment, the constricted entry port (during insertion through the sheath) comprises a smaller diameter than when the entry port is expanded (working configuration). Thus, the distal sensor 202 may be operably attached to the portal such that when the portal is moved from the contracted position to the expanded position, the distal sensor is pulled distally to a point within the left ventricle.

At least one proximal pressure or flow sensor 206 may be mounted within the blood pump sheath (a region that, when operatively positioned, is generally located within the patient's aorta).

Electrical leads 208P, 208D for the sensors 206, 204 may run through the sheath from an externally located power source and controller along a lumen created outside the drive shaft as the drive shaft translates through the sheath, as shown. Thus, the sensors 202, 204 are operatively coupled and in communication with an external power source and controller and are adapted to transmit pressure or flow data to the controller.

The controller includes program instructions and a processor for executing the program instructions, which generates real-time sensor readings based on pressure data received from the sensors 202, 204 when the program instructions are executed. Real-time sensor readings may be communicated to a display to allow an operator to ensure that the pressure and/or flow generated during operation of the rotating impeller 8 is within an optimal range.

This method and system for measuring flow is improved because it is a direct measurement of flow, rather than an indirect method as in known systems that derive an estimate of flow based on measured pressure and motor speed.

The description of the present invention and as set forth herein is illustrative and is not intended to limit the scope of the invention. The features of the various embodiments may be combined with other embodiments within the concept of the invention. Variations and modifications of the embodiments disclosed herein are possible, and practical alternatives to and equivalents of the various elements of the embodiments will be understood by those skilled in the art after studying this patent document. These and other variations and modifications of the embodiments disclosed herein may be made without departing from the scope and spirit of the invention.