Ultrasonic scalpel with bent tail end of scalpel bar

Abstract

An ultrasonic scalpel with a bent scalpel rod tail end sequentially comprises a coupling part, a scalpel rod part, a scalpel rod tail end bent part and a scalpel head part, the total length of the scalpel rod tail end bent part and the scalpel head part is 60-80 mm, and the included angle between the central axis of the scalpel head part and the central axis of the scalpel rod part is 5-30 degrees. The bending waveguide can work in a longitudinal vibration mode under the specific frequency, and meanwhile radial vibration caused by waveguide asymmetry is restrained, so that the flexibility of medical staff using an ultrasonic scalpel to treat target tissue hidden behind bones in an operation is effectively improved.

Description

Technical Field

[0001] The present invention relates to a technology in the field of medical equipment, in particular to an ultrasonic surgical knife with a bent end used in ultrasonic medical treatment. Background Art

[0002] Ultrasonic scalpels are widely used in clinical practice for cutting, coagulation and hemostasis of soft tissues during surgery. Compared with traditional surgical instruments, ultrasonic scalpels have the advantages of reducing bleeding, improving the accuracy of cutting and coagulation, reducing damage to surrounding tissues, no risk of electric shock, and less smoke. As more and more types of surgeries are applied to ultrasonic scalpels, in some surgical scenarios where the target tissue is hidden behind the bones, such as minimally invasive chest surgery, traditional ultrasonic scalpels need to enter the patient's body at a large angle, thus limiting the doctor's operating flexibility. Summary of the invention

[0003] In view of the problems that the existing ultrasonic scalpels are of long straight rod structure or have a small degree of curvature, and the displacement of the blade tip relative to the central axis of the blade rod is limited, the present invention proposes an ultrasonic scalpel with a curved blade end, which can realize the curved waveguide working in the longitudinal vibration mode at a specific frequency while suppressing the radial vibration caused by the asymmetry of the waveguide, thereby effectively improving the flexibility of medical staff in using the ultrasonic scalpel to treat the target tissue hidden behind the bone during surgery.

[0004] The present invention is achieved through the following technical solutions:

[0005] The present invention relates to an ultrasonic surgical knife with a bent end, which comprises a coupling part, a knife rod part, a bent end part of the knife rod and a knife head part in sequence, wherein: the total length of the bent end part of the knife rod and the knife head part is 60-80 mm, and the angle between the central axis of the knife head part and the central axis of the knife rod part is 5°-30°.

[0006] The curved part at the end of the knife rod comprises two arc waveguides connected in sequence, the central axis of the arc waveguide is an arc, and the cross section is a circle.

[0007] The coupling part is used for transition conduction and prevention of the cutter bar from breaking due to excessive stress, and specifically includes a cylindrical waveguide with a threaded hole and a catenary transition structure, wherein: the coupling part is connected to the output end of the ultrasonic vibrator to transfer the energy of the ultrasonic vibrator to the cutter bar part.

[0008] The knife bar part comprises three cylindrical waveguide sub-knife bars with successively increasing diameters, wherein a catenary structure is arranged between the first and second sub-knife bars for transition.

[0009] The cutter head is divided into a cutter head with an irregular cross section and a straight central axis to further increase the longitudinal vibration amplitude of the cutter head output point. The cutter head is connected to the bent part of the end of the cutter rod through a catenary transition.

[0010] When ultrasonic waves propagate in the tool bar, longitudinal and transverse vibrations will be generated, and the vibration speed of the particle will gradually decrease in the three tool bars, which can reduce energy loss. In addition, the larger diameter will suppress the transverse vibration of the particle. The structure will resonate at the working frequency, and the resonant energy will propagate to the tool head and generate strong longitudinal vibrations.

[0011] The transition between the coupling part and the shank part, between the second sub-shank and the third sub-shank in the shank part, and between the cutter head part and the shank bending part is made through the catenary curve, which can alleviate the stress concentration caused by the sudden change of the cross section. Technical Effects

[0012] Compared with the prior art, the scalpel of the present invention is in an almost "pure" longitudinal vibration mode when working stably at the working frequency (56.736kHz), the lateral vibration is effectively suppressed, and the stability of the scalpel bar is strong. This invention is expected to improve the flexibility of medical staff in handling target tissues hidden behind bones during surgery. The output of the ultrasonic transducer is enhanced by the amplitude of the blade head behind the scalpel bar, which improves the efficiency of electrical energy conversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the present invention;

[0014] Figure 2 It is a schematic diagram of the cutter head;

[0015] Figure 3 This is a schematic diagram of the cutter head output;

[0016] Figure 4 This is the mode shape diagram of the scalpel. DETAILED DESCRIPTION

[0017] like Figure 1 As shown, an ultrasonic surgical knife with a curved end of the knife bar involved in this embodiment includes a coupling part C, a knife bar part B, a curved end of the knife bar part A and a blade part H, wherein: the total length of the curved end of the knife bar part and the blade part is 60 to 80 mm, and the angle between the central axis of the blade part and the central axis of the knife bar part is 5° to 30°, so that the output point of the blade head deviates from the central axis of the knife bar by a certain distance, which is conducive to medical staff to more flexibly handle the target tissue hidden behind the bone during surgery. The geometric central axis of the curved end of the knife bar is a smooth arc, and this smooth transition can reduce the radial vibration caused by the asymmetry of the waveguide and help maintain the stability of the blade.

[0018] The ultrasonic surgical knife is made of TC4 alloy and is forged into an integrated structure at one time. Its operating frequency is 55kHz~57kHz, and its overall length is designed to be 250mm~270mm, that is, an integer multiple of half the wavelength of the sound wave in the TC4 material at the operating frequency (the wavelength of the sound wave in this material is 88mm).

[0019] The curved portion A at the end of the shank includes a first curved waveguide A1 and a second curved waveguide A2 in sequence.

[0020] The arc length of the center axis of the first arc waveguide A1 is 19 mm to 21 mm. It starts at a node and ends at an antinode. The tangent line of the center axis at the node coincides with the center axis of the shank part.

[0021] The central axis length of the second arc waveguide A2 is 19mm-21mm, the diameter of the second arc waveguide A2 is smaller than the diameter of the first arc waveguide A1, the second arc waveguide A2 starts at the antinode and ends at the node, and the central axis tangent at the node coincides with the central axis of the cutter head part.

[0022] The shank portion B includes a first sub-shank B1, a second sub-shank B2, a first catenary transition B3 and a third sub-shank B4 in sequence, wherein the first sub-shank B1 is connected to the second sub-shank B2 and the coupling portion C respectively, and the third sub-shank B4 is connected to the first catenary transition B3 and the first arc waveguide A1 respectively.

[0023] The diameters of the first to third sub-tool bars B1, B2 and B4 increase successively, wherein the diameter of the second sub-tool bar B2 increases by 0.1mm to 0.3mm compared with the first sub-tool bar B1, and the diameter of the third sub-tool bar B4 increases by 0.6mm to 1mm compared with the second sub-tool bar B2. This structure effectively suppresses the lateral vibration caused by the asymmetry of the waveguide, and the diameter changes occur at the wave trough or wave node. The lengths of the central axis of the three are 20mm, 20mm and 120mm respectively.

[0024] The boundary between the first sub-tool bar B1 and the second sub-tool bar B2 is at the antinode, and a smaller size change can reduce energy loss.

[0025] The bending form of the end of the shank is to guide the cylindrical waveguide to bend from the penultimate wave node through a section of circular arc as the central axis and end at the last wave node. The change of the waveguide geometry starts at the wave node and ends at the wave node, which can reduce energy loss.

[0026] The first catenary transition B3 is located at a longitudinal vibration node, wherein the axial length is determined by the length of the longitudinal vibration amplitude of -0.2 to 0.2 times the longitudinal vibration amplitude of the adjacent wave node.

[0027] The diameter of the first arc-shaped waveguide A1 is the same as the diameter of the third section of the blade rod B4.

[0028] The coupling part C is used to prevent the stress concentration caused by interface mutation when the ultrasonic vibrator is working from damaging the ultrasonic surgical knife shaft, and specifically includes: a cylindrical waveguide C1 and a second catenary transition C2, wherein: the cylindrical waveguide C1 is respectively connected to the previous ultrasonic vibrator and the second catenary transition C2, and the second catenary transition C2 is respectively connected to the second catenary transition C2 and the shaft part B.

[0029] The input end of the cylindrical waveguide C1 is designed with a threaded hole with a specification of 4#-40*5 / 8, which is connected to the upper-level ultrasonic vibrator, for example, an ultrasonic vibration system composed of a transducer and a horn.

[0030] The second catenary transition C2 is located at the longitudinal vibration node, wherein the axial length is determined by the length of the longitudinal vibration amplitude -0.2 to 0.2 times the longitudinal vibration amplitude of the adjacent wave node.

[0031] The cutter head part H comprises: a third catenary transition H1 and a cutter head H2, wherein: the third catenary transition H1 is respectively connected to the cutter head H2 and the second arc waveguide A2.

[0032] like Figure 2 As shown, the cross section of the cutter head H2 is obtained in the following manner: a circle having the same length and being concentric with the rectangle is set, and the shape of the intersection of the two is the cross section of the cutter head.

[0033] The device works in the following way: when an excitation signal with an amplitude of 25 μm and a frequency of 55 kHz to 57 kHz is added to the input end of the coupling section C1, the peak-to-peak amplitude of the output of the cutter head H2 exceeds 70 μm, such as Figure 3 shown.

[0034] When the above excitation signal is added, the ratio of the longitudinal displacement to the lateral displacement of the tool bar in the modal analysis is close to 28. Figure 4 As shown, the colors from cold to warm represent the normalized amplitude of the longitudinal vibration from small to large, the output of the cutter head is the largest, and the lateral vibration of the tool rod is significantly suppressed.

[0035] Compared with the existing straight-rod ultrasonic scalpels, the present device can obtain similar or better cutting performance and knife rod stability when the knife rod is bent: simulation shows that the present invention can work safely within a fixed frequency, and when the input end uses an excitation with an amplitude of 25μm, the peak-to-peak value of the longitudinal amplitude at the output end exceeds an amplitude of 70μm, and the ratio of the longitudinal amplitude to the lateral amplitude of the knife rod is close to 28, which effectively suppresses the lateral displacement of the knife rod while ensuring the quality of cutting and hemostasis.

[0036] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. An ultrasonic surgical knife with a curved end, characterized in that: It comprises a coupling part, a shank part, a bent part at the end of the shank part and a cutter head part in sequence, wherein: the angle between the central axis of the cutter head part and the central axis of the shank part is 5° to 30°; The curved portion at the end of the knife rod includes a first arc waveguide and a second arc waveguide in sequence; The blade part includes a first sub-blade bar, a second sub-blade bar, a first catenary transition and a third sub-blade bar in sequence, wherein the first sub-blade bar is connected to the second sub-blade bar and the coupling part respectively, and the third sub-blade bar is connected to the first catenary transition and the first arc waveguide respectively.

2. The ultrasonic surgical knife with a curved end according to claim 1, characterized in that: The arc length of the center axis of the first arc waveguide is 19 mm to 21 mm, starting from the wave node and ending at the wave antinode, and the tangent of the center axis at the wave node coincides with the center axis of the shank part; The length of the center axis of the second arc waveguide is 19mm-21mm, the diameter of the second arc waveguide is smaller than the diameter of the first arc waveguide, the second arc waveguide starts at the wave node and ends at the wave node, and the center axis tangent at the wave node coincides with the center axis of the cutter head part.

3. The ultrasonic surgical knife with a curved end according to claim 1, characterized in that: The diameters of the first to third sub-tool bars increase successively, wherein the diameter of the second sub-tool bar increases by 0.1mm to 0.3mm compared with the first sub-tool bar, and the diameter of the third sub-tool bar increases by 0.6mm to 1mm compared with the second sub-tool bar. This structure effectively suppresses the lateral vibration caused by the asymmetry of the waveguide, and the diameter changes occur at the wave trough or wave node. The lengths of the central axis of the three are 20mm, 20mm and 120mm respectively.

4. The ultrasonic surgical knife with a curved end according to claim 1 or 3, characterized in that: The boundary between the first sub-tool bar and the second sub-tool bar is at the antinode.

5. The ultrasonic surgical knife with a curved end according to claim 1, characterized in that: The coupling part includes: a cylindrical waveguide and a second catenary transition, wherein: the cylindrical waveguide is respectively connected to the upper ultrasonic vibrator and the second catenary transition, and the second catenary transition is respectively connected to the second catenary transition and the shank part; The bending form of the end of the tool rod is that the cylindrical waveguide is guided to bend through a section of circular arc as the central axis starting from the second to last wave node and ending at the last wave node.

6. The ultrasonic surgical knife with a curved end according to claim 1, characterized in that: The first catenary transition is located at the longitudinal vibration node, wherein the axis length is determined by the length of the longitudinal vibration amplitude of -0.2 to 0.2 times the longitudinal vibration amplitude of the adjacent wave node.

7. The ultrasonic surgical knife with a curved end according to claim 1, characterized in that: The diameter of the first arc-shaped waveguide is the same as the diameter of the third section of the knife rod.

8. The ultrasonic surgical knife with a curved end according to claim 1, characterized in that: The second catenary transition is located at the longitudinal vibration node, wherein the axis length is determined by the length of the longitudinal vibration amplitude -0.2 to 0.2 times the longitudinal vibration amplitude of the adjacent wave node.

9. The ultrasonic surgical knife with a curved end according to claim 1, characterized in that: The cutter head part comprises: a third catenary transition and a cutter head, wherein: the third catenary transition is respectively connected to the cutter head and the second arc waveguide; The cross section of the cutter head is obtained in the following manner: a circle having the same length as the rectangle and being concentric therewith is provided, and the shape of the intersection of the two is the cross section of the cutter head.

Images