阅读说明：本技术 一种超声组织切割刀 (Ultrasonic tissue cutting knife ) 是由 姜兴刚 张德远 于 2021-07-23 设计创作，主要内容包括：本发明涉及医疗技术领域,特别涉及到一种超声组织切割刀。一种超声组织切割刀包括超声换能器及与超声换能器一端连接的刀头,超声换能器及刀头的轴向总长度为λ/2的整数倍,λ为超声波波长,且超声换能器工作时处于谐振状态。超声换能器包括压电振子和多级放大变幅杆组,多级放大变幅杆组为回转体结构,刀头与多级放大变幅杆组的前端连接,压电振子与多级放大变幅杆组的后端连接。由此,超声组织切割刀通过设置多级放大变幅杆组,提高了超声换能器的振幅放大比,在相同的超声电压信号激励下,提高了刀头的刀尖振幅,且在提高刀头的刀尖振幅的前提下简化了超声组织切割刀的结构。(The invention relates to the technical field of medical treatment, in particular to an ultrasonic tissue cutting knife. The utility model provides an ultrasonic tissue cutting knife includes ultrasonic transducer and the tool bit of being connected with ultrasonic transducer one end, and the axial total length of ultrasonic transducer and tool bit is the integral multiple of lambda/2, and lambda is the ultrasonic wave wavelength, and ultrasonic transducer is in resonance state when working. The ultrasonic transducer comprises a piezoelectric vibrator and a multi-stage amplification amplitude-changing rod group, wherein the multi-stage amplification amplitude-changing rod group is of a revolving body structure, a tool bit is connected with the front end of the multi-stage amplification amplitude-changing rod group, and the piezoelectric vibrator is connected with the rear end of the multi-stage amplification amplitude-changing rod group. Therefore, the ultrasonic tissue cutting knife has the advantages that the amplitude amplification ratio of the ultrasonic transducer is improved by arranging the multistage amplification amplitude transformer group, the knife tip amplitude of the knife head is improved under the excitation of the same ultrasonic voltage signal, and the structure of the ultrasonic tissue cutting knife is simplified on the premise of improving the knife tip amplitude of the knife head.)

1. An ultrasonic tissue cutting knife is characterized by comprising an ultrasonic transducer and a knife head connected with one end of the ultrasonic transducer, wherein the total axial length of the ultrasonic transducer and the knife head is integral multiple of lambda/2, lambda is the wavelength of ultrasonic waves, and the ultrasonic transducer is in a resonance state when working;

the ultrasonic transducer comprises a piezoelectric vibrator and a multi-stage amplification amplitude transformer group, wherein the multi-stage amplification amplitude transformer group is of a revolving body structure;

the tool bit is connected with the front end of the multistage amplification amplitude transformer group, and the piezoelectric vibrator is connected with the rear end of the multistage amplification amplitude transformer group.

2. An ultrasonic tissue cutting blade according to claim 1,

the multistage amplification amplitude transformer group comprises a plurality of coaxially connected amplitude transformers;

the amplitude transformer comprises a first rod section and a second rod section which are connected from back to front, and the diameter of the first rod section is D_nSaid second rod segment having a diameter d_nSaid D is_nGreater than d_nThe amplitude amplification ratio of the amplitude transformer is N_n＝D_n/d_n；

A＝A₀·N₁·N₂…N_n；

Wherein N is₁＜N₂＜N₃…N_nN is an integer greater than 1 and represents an nth-stage amplitude transformer; a is the amplitude of the tool bit, A₀The amplitude of the piezoelectric vibrator.

3. An ultrasonic tissue cutting blade according to claim 2,

the multistage amplification amplitude transformer group comprises a first-stage amplitude transformer and a second-stage amplitude transformer;

the diameter of the first rod section of the primary amplitude transformer is D₁The diameter of the second rod section of the primary amplitude transformer is d₁The amplitude amplification ratio of the primary amplitude transformer is N₁＝D₁/d₁；

The diameter of the first rod section of the secondary amplitude transformer is D₂The second-stage hornThe diameter of the two rod segments is d₂The amplitude amplification ratio of the secondary amplitude transformer is N₂＝D₂/d₂；

A＝A₀·N₁·N₂。

4. An ultrasonic tissue cutting blade according to claim 2,

said N is_nIs 1.2-3.5.

5. An ultrasonic tissue cutting blade according to claim 2,

A₀＝T_ea·U₀；

wherein, T_eaIs the electromechanical conversion coefficient of the piezoelectric vibrator and is constant within the elastic limit; u shape₀Is an ultrasonic excitation voltage applied to the piezoelectric vibrator.

6. An ultrasonic tissue cutting blade according to claim 2,

the axial total length of the piezoelectric vibrator and the primary amplitude transformer is lambda/2, the axial length of the secondary amplitude transformer is lambda/2, and the axial total length of the n-level amplification amplitude transformer and the cutter head is lambda/2;

λ is the ultrasonic wavelength.

7. An ultrasonic tissue cutting blade according to claim 2,

the piezoelectric vibrator is connected with the first rod section on the rearmost side, and the piezoelectric vibrator and the first rod section on the rearmost side are arranged along the same axis.

8. An ultrasonic tissue cutting blade according to claim 7,

the multistage amplification amplitude transformer group and the piezoelectric vibrator are internally provided with communicated through holes along the axial direction, one end of a connecting pipe is connected with the through holes, and the other end of the connecting pipe is used for being connected with a connecting port of an external water source;

the cutter head is provided with a closed through groove, and the through hole is communicated with one end of the closed through groove, which is far away from the cutter head.

9. An ultrasonic tissue cutting blade according to claim 8,

the connecting pipe is used for being in a round platform structure with one end connected with the connecting port.

10. An ultrasonic tissue cutting blade according to any one of claims 1 to 9,

the shell is of a revolving body structure;

the multistage amplification amplitude transformer group is arranged in the accommodating cavity of the shell and is coaxial with the shell;

the outer wall of the multistage amplification amplitude transformer group is in threaded connection with the inner wall of the sleeve.

Technical Field

The invention relates to the technical field of medical treatment, in particular to an ultrasonic tissue cutting knife.

Background

The core component of the ultrasonic tissue cutting knife is an ultrasonic piezoelectric transducer which generates mechanical vibration with the same frequency and micron-scale amplitude under the excitation of an external ultrasonic frequency electric signal and drives a knife head connected with the ultrasonic piezoelectric transducer to carry out excision operation on human tissues. Compared with the conventional scalpel, the medical scalpel has higher cutting efficiency and a hemostatic function, thereby being an energy-carrying medical surgical instrument with great development prospect.

Different from the ultrasonic hemostasis/coagulation scalpel, the ultrasonic tissue cutting knife needs to cut off tissues by the high-frequency impact force of the knife head, and when the bone tissues are cut, the cutting difficulty is high because the bone tissues are hard tissues, the ultrasonic tissue cutting knife is required to have high load energy, so that the higher requirement is provided for the design of the ultrasonic tissue cutting knife. In order to improve the mechanical impact force of ultrasonic tissue cutting knife, patent application with patent publication numbers CN209789951U, CN209789952U through the output power of increase piezoelectric ceramic piece's quantity in order to increase the cutting knife, and for solving the heat dissipation problem of many ceramic pieces, sets up all ceramic pieces along the interval segmentation of central axis direction, forms a plurality of pottery and piles, but the design of a plurality of pottery piles, not only the structure is complicated, and power loss is big moreover.

Disclosure of Invention

Technical problem to be solved

In order to solve the above problems in the prior art, the invention provides an ultrasonic tissue cutting knife, which improves the amplitude amplification ratio of an ultrasonic transducer, improves the amplitude of a knife tip of a knife head under the excitation of the same ultrasonic voltage signal, and further improves the mechanical impact force of the knife head.

(II) technical scheme

In order to achieve the purpose, the invention adopts the main technical scheme that:

the invention provides an ultrasonic tissue cutting knife which comprises an ultrasonic transducer and a knife head connected with one end of the ultrasonic transducer, wherein the total axial length of the ultrasonic transducer and the knife head is integral multiple of lambda/2, lambda is the wavelength of ultrasonic waves, and the ultrasonic transducer is in a resonance state when working;

the ultrasonic transducer comprises a piezoelectric vibrator and a multi-stage amplification amplitude transformer group, wherein the multi-stage amplification amplitude transformer group is of a revolving body structure;

the tool bit is connected with the front end of the multistage amplification amplitude transformer group, and the piezoelectric vibrator is connected with the rear end of the multistage amplification amplitude transformer group.

Preferably, the multi-stage amplifying horn assembly comprises a plurality of coaxially connected horns;

the amplitude transformer comprises a secondary coilTo a first and a second rod section connected in front, the diameter of the first rod section being D_nThe diameter of the second rod section being d_n，D_nGreater than d_nAmplitude amplification ratio of the horn is N_n＝D_n/d_n；

A＝A₀·N₁·N₂…N_n；

Wherein N is₁＜N₂＜N₃…N_nN is an integer greater than 1 and represents an nth-stage amplitude transformer; a is the amplitude of the tool bit, A₀The amplitude of the piezoelectric vibrator.

Preferably, the multistage amplification horn group comprises a primary horn and a secondary horn;

the diameter of the first rod section of the first-stage amplitude transformer is D₁The diameter of the second rod section of the first-stage amplitude transformer is d₁The amplitude amplification ratio of the first-stage amplitude transformer is N₁＝D₁/d₁；

The diameter of the first rod section of the secondary amplitude transformer is D₂The diameter of the second rod section of the secondary horn is d₂The amplitude amplification ratio of the secondary horn is N₂＝D₂/d₂；

A＝A₀·N₁·N₂。

Preferably, N_nIs 1.2-3.5.

Preferably, A₀＝T_ea·U₀；

Wherein, T_eaIs the electromechanical conversion coefficient of the piezoelectric vibrator and is constant within the elastic limit; u shape₀Is an ultrasonic excitation voltage applied to the piezoelectric vibrator.

Preferably, the axial total length of the piezoelectric vibrator and the first-stage amplitude transformer is lambda/2, the axial length of the second-stage amplitude transformer is lambda/2, and the axial total length of the n-stage amplification amplitude transformer and the cutter head is lambda/2;

λ is the ultrasonic wavelength.

Preferably, the piezoelectric vibrator is connected to the first rod section on the rearmost side, and the piezoelectric vibrator and the first rod section on the rearmost side are arranged along the same axis.

Preferably, through holes communicated with each other are axially formed in the multistage amplification amplitude transformer group and the piezoelectric vibrator, one end of the connecting pipe is connected with the through holes, and the other end of the connecting pipe is used for being connected with a connecting port of an external water source;

the cutter head is provided with a closed through groove, and the through hole is communicated with one end of the closed through groove, which is far away from the cutter head.

Preferably, one end of the connecting pipe, which is used for being connected with the connecting port, is of a circular truncated cone structure.

Preferably, the device further comprises a shell, wherein the shell is of a revolving body structure;

the multistage amplification amplitude transformer group is arranged in the accommodating cavity of the shell and is coaxial with the shell;

the outer wall of the multistage amplification amplitude transformer group is in threaded connection with the inner wall of the sleeve.

(III) advantageous effects

The invention has the beneficial effects that:

according to the ultrasonic tissue cutting knife provided by the invention, the amplitude amplification ratio of the ultrasonic transducer is improved by arranging the multistage amplification amplitude transformer, the knife tip amplitude of the knife head is improved under the excitation of the same ultrasonic voltage signal, the mechanical impact force of the knife head is further improved, the structure of the ultrasonic tissue cutting knife is simplified on the premise of improving the knife tip amplitude of the knife head, and the electromechanical energy conversion efficiency of the ultrasonic cutting knife is improved.

Drawings

FIG. 1 is a schematic structural view of an ultrasonic tissue cutting blade according to an embodiment;

FIG. 2 is a schematic structural diagram of a two-stage amplification horn group, a piezoelectric vibrator and a tool bit;

FIG. 3 is a schematic structural view of the housing of FIG. 1;

FIG. 4 is a schematic diagram of a two-stage amplification horn group, a piezoelectric vibrator, and a tool bit;

FIG. 5 is a schematic structural view of a closed through slot in a tool bit being a long strip;

FIG. 6 is a schematic structural view of the cutter head with one end of the closed through slot being T-shaped;

FIG. 7 is a schematic structural view of a cutter head in which one end of a closed through groove is in the shape of a circular arc;

FIG. 8 is a graph of the vibration displacement at the cutting tip measured with only one stage of horn included in the ultrasonic tissue cutting blade;

FIG. 9 is a graph of the vibration displacement at the blade tip as measured by the ultrasonic tissue cutting blade including a secondary amplification horn assembly.

[ description of reference ]

1: a cutter head;

2: a piezoelectric vibrator; 21: a piezoelectric ceramic stack; 22: front cover board: 23: a rear cover plate; 24: a nut; 25: fastening a bolt;

3: a multistage amplification amplitude transformer group; 31: a first-stage horn; 311: a first pole segment of a first-stage horn; 312: a second pole segment of the first-stage horn; 32: a secondary horn; 321: a first pole segment of a secondary horn; 322: a second pole segment of the secondary horn;

4: a housing; 41: an end cap; 42: a connecting cylinder; 43: a front end sleeve;

5: a through hole;

6: a connecting pipe; 61: a circular truncated cone structure;

7: and an electrode lead.

Detailed Description

For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.

As shown in fig. 1, the present embodiment provides an ultrasonic tissue cutting knife, which includes an ultrasonic transducer and a knife head 1 connected to one end of the ultrasonic transducer, wherein the total axial length of the ultrasonic transducer and the knife head 1 is an integral multiple of λ/2, λ is an ultrasonic wavelength, and the ultrasonic transducer is in a resonant state when in operation. In the embodiment, the ultrasonic transducer comprises a piezoelectric vibrator 2 and a multi-stage amplification amplitude transformer group 3, and the ultrasonic tissue cutting knife also comprises a shell 4. Specifically, the multistage amplification amplitude transformer group 3 and the shell 4 are both of a revolving body structure, the multistage amplification amplitude transformer group 3 is arranged in an accommodating cavity of the shell 4, the multistage amplification amplitude transformer group 3 and the shell 4 are coaxially arranged, and the outer wall of the multistage amplification amplitude transformer group 3 is in threaded connection with the inner wall of the sleeve. As shown in fig. 3, the housing 4 includes an end cap 41, a connecting cylinder 42 and a front end sleeve 43, the front end sleeve 43 is in threaded connection with an outer wall of one end of the connecting cylinder 42, the end cap 41 is clamped with an end face of the other end of the connecting cylinder 42, the multi-stage amplification horn group 3 is in threaded connection with an inner wall of the connecting cylinder 42 so as to facilitate installation and positioning of the multi-stage amplification horn, and the tool bit 1 extends out of the front end sleeve 43.

As shown in fig. 2, the cutter head 1 is connected to the front end of the multistage amplification horn group 3, and the piezoelectric vibrator 2 is connected to the rear end of the multistage amplification horn group 3. Because the axial total length of the ultrasonic transducer and the tool bit 1 is integral multiple of lambda/2, when the ultrasonic transducer is in a resonance state, the rear end surface of the piezoelectric vibrator 2, the tool tip of the tool bit 1 and the position of a joint surface between two adjacent stages of amplitude-change rods in the multistage amplification amplitude-change rod group 3 are all wave crests or wave troughs of vibration displacement. In the application, the piezoelectric vibrator 2 includes a piezoelectric ceramic stack 21, a front cover plate 22, and a rear cover plate 23, which are connected together by a fastening bolt 25. In this embodiment, in order to simplify the structure, the nut 24 and the rear cover plate 23 are integrated structures, the fastening bolt and the front cover plate 22 are integrated structures, in this embodiment, in order to further simplify the structure, the front cover plate 22 is the first rod section 311 of the one-level horn, the electrode lead 7 applies the ultrasonic frequency voltage excitation signal to the piezoelectric ceramic stack 21, the same-frequency mechanical vibration is generated on the end face of the piezoelectric ceramic stack 21, after the mechanical vibration is amplified by the multi-level horn group, finally, the ultrasonic frequency mechanical vibration with the vibration displacement larger than 100um is generated at the knife tip of the knife head 1, when the ultrasonic tissue cutting knife cuts human tissue, the knife head 1 generates a high-frequency impact force on the human tissue, so as to cut the human tissue.

This supersound tissue cutting knife has improved the amplitude of tool bit 1 under the same supersound voltage excitation signal of piezoelectric vibrator 2, and then has improved tool bit 1's mechanical impact force, and has simplified the structure of supersound tissue cutting knife under the prerequisite that improves the knife tip amplitude of tool bit 1, has promoted supersound cutting knife's electromechanical energy conversion efficiency.

As shown in fig. 4, the multi-stage amplification horn stack 3 comprises a plurality of coaxially connected horns comprising first and second pole segments connected along the back-to-front, i.e., from left to right in fig. 1, the first and second pole segments in the horn of each stage are of the same material, and the piezoelectric vibrator is disposed between the first and second pole segmentsThe sub-2 is connected with the first rod section at the rearmost side, and the piezoelectric vibrator 2 and the first rod section at the rearmost side are arranged along the same axis. Wherein the first rod section has a diameter D_nThe diameter of the second rod section being d_n，D_nGreater than d_nAmplitude amplification ratio of the horn is N_n＝D_n/d_nWithin a certain limit, the amplitude of the cutting edge increases as the amplitude amplification ratio of the horn increases. And the connection part of two adjacent stages of amplitude-change rods and the rod sections between the amplitude-change rods are transited through a chamfer or an arc surface so as to reduce the stress concentration.

See the formula: a ═ A₀·N₁·N₂…N_nN is an integer greater than 1 and represents the nth-order amplification horn, A is the amplitude of the cutter head 1, and A is the amplitude of the cutter head₀In order to amplify the amplitude of the piezoelectric vibrator 2 at the tip of the tool bit 1, it should be noted that in the present embodiment, the amplitude of the tool bit 1 refers to the amplitude of the tip of the tool bit 1, and the amplitude of the piezoelectric vibrator 2 refers to the amplitude of the end face of the piezoelectric vibrator 2. In order to ensure that the anti-load capacity of the ultrasonic transducer is not reduced after the length of the ultrasonic transducer is increased, the amplitude amplification ratio of the amplitude transformer meets N₁＜N₂＜N₃…N_n. Wherein A is₀＝T_ea·U₀，T_eaIs an electromechanical conversion coefficient, T, of the piezoelectric vibrator 2_eaConstant within elastic limits, U₀Is an ultrasonic excitation voltage applied to the piezoelectric vibrator 2.

In practical applications, since the ultrasonic wave exists in the transducer in the form of a standing wave along the axial direction, its energy is the same at different cross sections. Therefore, the designed resonant frequency of each amplitude transformer should be consistent with the resonant frequency of the half-wavelength transducer, i.e. the total axial length of the piezoelectric vibrator 2 and the primary amplitude transformer 31 is set to be lambda/2 in the embodiment, and the total axial length of the secondary amplitude transformer 32 is lambda/2.

In order to ensure that the ultrasonic energy can be effectively transmitted from the transducer to the load end, the output impedance of the upper-stage amplitude transformer needs to be matched with the input impedance of the lower-stage amplitude transformer.

As shown in FIG. 1, inIn practical use, the multi-stage amplification horn group 3 of the present embodiment includes a first-stage horn 31 and a second-stage horn 32, wherein the first-stage horn 31 and the second-stage horn 32 are detachably connected by a screw thread for easy mounting and dismounting. The first pole segment 311 of the first-stage horn has a diameter D₁The second pole section 312 of the first-stage horn has a diameter d₁The amplitude amplification ratio of the primary horn 31 is N₁＝D₁/d₁. The first rod segment 321 of the secondary horn has a diameter D₂The second pole section 322 of the secondary horn has a diameter d₂The amplitude magnification ratio of the secondary horn 32 is N₂＝D₂/d₂Wherein the amplitude of the cutting head 1 is A ═ A₀·N₁·N₂. It should be noted that the multistage amplification horn group 3 may be a three-stage amplification horn group, a four-stage amplification horn group, or the like, and is exemplified by a two-stage amplification horn group in the present embodiment.

Because the transmission form of the ultrasonic energy will be changed if the ratio of the first rod section to the second rod section in the horn exceeds a certain limit, the rigidity of the whole structure is deteriorated, the carrying capacity is reduced, and normal human tissue cutting cannot be realized, the coefficient of the multistage amplification horn in the embodiment is N_nPreferably 1.2 to 3.5, and N₁＜N₂＜N₃…N_nIn the practical application process, in order to accord with the human engineering, the diameter of the first rod section in the multistage amplitude transformer is smaller than 20mm, the diameter of the second rod section in the multistage amplitude transformer is larger than 5mm in order to ensure the strength of the rod section, and multiple experiments D are carried out₁Preferably 13 to 16mm, d₁Preferably 9-11mm, D₂Preferably 16-18mm, d₂The optimal selection is 5-7mm, so that the comfort level of a user holding the ultrasonic tissue cutting knife is ensured, the strength of the holding part of the ultrasonic tissue cutting knife is also ensured, and the safety performance in the operation process is further ensured.

In the present embodiment, the mechanical impact force of the tool bit 1 is F ═ ma ═ m ω²A, it can be seen that at the same ultrasonic voltage U₀Under excitation, the amplitude a of the tool bit 1 is increased, and the mechanical impact force F of the tool bit 1 is increased. Wherein ω is vibrationThe angular frequency, a, is the amplitude of the tool tip 1, m is the mass of the tool tip 1, and a is the amplitude of the mechanical vibration acceleration of the tool tip 1.

In order to improve the cooling effect of the ultrasonic tissue cutting knife head 1 and reduce the damage to human tissues during cutting, through holes 5 which are communicated with the multistage amplification amplitude transformer are axially arranged inside the multistage amplification amplitude transformer group 3 and the piezoelectric vibrator 2, wherein the through holes 5 which are communicated with the multistage amplification amplitude transformer are arranged on the central shaft of a fastening bolt 25 in the piezoelectric vibrator 2. The ultrasonic tissue cutting knife further comprises a connecting pipe 6, one end of the connecting pipe 6 is connected with the through hole 5 of the fastening bolt 25, the other end of the connecting pipe 6 is used for being connected with a connector of an external water source, wherein a closed through groove is formed in the knife head 1, one end of the closed through groove is close to the sharp part of the knife head 1, the through hole 5 on the multistage amplification amplitude transformer and the closed through groove are communicated with one end of the knife head 1, and therefore cleaning/cooling liquid in the through hole 5 can reach the sharp part and the cutting edge of the knife head 1 through the closed through groove after being sprayed out through one end of the closed through groove. Wherein, in order to make the structure of the ultrasonic tissue cutting knife simpler and more convenient, the connecting pipe 6 and the fastening bolt 25 are integrated.

As shown in fig. 5, since the closed through groove on the cutter head 1 is of a closed structure, and the through hole 5 is communicated with one end of the closed through groove far away from the tip of the cutter head 1, i.e. the front end of the through hole 5 is far away from the cutter tip, when human tissue is cut, the central through hole 5 is not easily blocked by tissue debris, thereby ensuring that the cleaning/cooling liquid smoothly reaches the cutter head 1. And because the front end of the through hole 5 does not penetrate through the cutter point, the additional load of the cutter head 1 is reduced, and the cutting efficiency of the cutter head 1 is improved. Under the action of ultrasound, the cleaning/cooling liquid is sprayed forwards in a fog shape at a high speed at the front end of the through hole 5, the whole cutter head 1 is cooled uniformly, the damage to human tissues is less, and the cleaning effect of the surgical interface is better.

As shown in fig. 6-7, in order to further ensure the cooling effect of the cutting head 1, so as to uniformly cool the cutting head 1 and further reduce the damage to human tissues during cutting, the end of the closed through groove close to the cutting tip may preferably be in a shape of an arc or T-shape matching with the cutting tip, so that the cleaning/cooling liquid is sprayed forward at a high speed in a mist form at the front end of the through hole 5 and then is guided by the front end of the closed through groove to be uniformly sprayed on the cutting tip and the cutting edge of the cutting head 1.

In order to improve the sealing performance of the joint of the connecting port of an external water source and the connecting pipe 6 and prevent water leakage, one end of the connecting pipe 6 connected with the connecting port is set to be the round platform structure 61, the structure is simple and compact, no additional connecting part is added, and no negative influence is generated on ultrasonic vibration, so that the round platform structure 61 solves the contradiction between the sealing performance and the ultrasonic vibration.

Examples

As shown in FIG. 8, the ultrasonic tissue cutting knife using a first-order horn in the experimental process was characterized in that the vibration displacement at the knife tip was measured using a laser micrometer under the excitation voltage of 500V, and the vibration displacement was only 130.58 um. Therefore, the mechanical impact force of the cutter head is insufficient, and the cutting efficiency is low.

As shown in figure 9, for the ultrasonic tissue cutting knife adopting the secondary amplitude transformer group in the experimental process, under the same conditions of the piezoelectric vibrator 2, the knife head 1 and the excitation voltage, the vibration displacement at the knife tip is measured by adopting a laser micrometer, the vibration displacement reaches 196.73um, and is improved by more than 50 percent compared with the ultrasonic tissue cutting knife adopting the primary amplitude transformer. Therefore, the mechanical impact force of the cutter head 1 is remarkably improved, and efficient cutting of human tissue can be realized.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium; either as communication within the two elements or as an interactive relationship of the two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, a first feature may be "on" or "under" a second feature, and the first and second features may be in direct contact, or the first and second features may be in indirect contact via an intermediate. Also, a first feature "on," "above," and "over" a second feature may be directly or obliquely above the second feature, or simply mean that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the second feature, or may simply mean that the first feature is at a lower level than the second feature.

In the description herein, the description of the terms "one embodiment," "some embodiments," "an embodiment," "an example," "a specific example" or "some examples" or the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are illustrative and not restrictive, and that those skilled in the art may make changes, modifications, substitutions and alterations to the above embodiments without departing from the scope of the present invention.