Energy converter and ultrasonic scalpel
By employing a rapid curve design for the transition section of the amplitude transformer in the ultrasonic transducer, the problems of stress concentration and frequency deviation in stepped amplitude transformers are solved, resulting in more stable vibration and better cutting and hemostasis, thus improving the safety and efficiency of the surgery.
Patent Information
- Application Number
- CN202422891342.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-26
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-11-26
AI Technical Summary
The stepped amplitude transformer of existing ultrasonic transducers is subjected to high stress at the shape change points, which leads to reduced service life and resonant frequency deviation, affecting the ability to cut and stop bleeding.
The fastest curve is used as the transition curve of the amplitude transformer. Combined with the design of prestressed bolts and cover plates, stress concentration is reduced and the resonance frequency is corrected to ensure that the longitudinal vibration frequency is close to the ideal frequency of 55.5KHz.
It improves the cutting and hemostasis effect and vibration stability of ultrasonic scalpels, reduces the risk of structural damage, and enhances the safety and efficiency of surgery.
Smart Images
Figure CN223530786U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of medical device technology, specifically a transducer and an ultrasonic surgical scalpel. Background Technology
[0002] An ultrasonic transducer is a device that converts electrical energy into mechanical vibration energy. A medical ultrasonic scalpel consists of a main ultrasonic generator, a transducer, a scalpel head, a foot switch, and other main components. The transducer, with an alloy shell, converts the high-frequency electrical energy provided by the main generator into ultrasonic mechanical kinetic energy and transmits it to the scalpel head, generating high-frequency mechanical resonance. This mechanical vibration energy (i.e., ultrasonic vibration) produces mechanical, temperature, and cavitation effects on the human tissue it contacts. High-power ultrasound can cause the water in the tissue cells in contact with the scalpel head to vaporize instantly, break protein hydrogen bonds, and disintegrate the cells, thereby cutting the tissue. The frictional heat energy caused by mechanical vibration can coagulate and stop bleeding while cutting the tissue. It is the combined effect of this series of functions that achieves hemostasis, cutting, or coagulation of the tissue.
[0003] When the amplitude transformer of an ultrasonic transducer is connected to a piezoelectric ceramic, the vibration displacement amplitude of the piezoelectric ceramic can be amplified from a few micrometers to tens of micrometers to meet the needs of tissue cutting during surgery. The transducer amplitude transformer can also be used as a mechanical impedance transformer to perform impedance matching between the transducer and the load, so that the ultrasonic vibration energy can be transmitted more effectively from the piezoelectric ceramic to the load. The amplitude transformer of the ultrasonic scalpel transducer is a longitudinal vibration amplitude transformer. The cutting and coagulation effect is best when the resonant frequency is 55.5KHz. The stepped amplitude transformer is the theoretical type of amplitude transformer, which is convenient for calculating the resonant frequency and amplitude ratio of the amplitude transformer. Since no transition curve is used, the maximum amplitude ratio can be obtained.
[0004] However, due to the sudden change in shape, the stepped section of the stepped amplitude bar also bears high stress. This not only reduces the service life of the stepped amplitude bar, but may also lead to structural damage. Stress concentration will also affect the resonant frequency of the amplitude bar. Amplitude bars using transition curves generally have the optimal circular arc curve and catenary curve. Amplitude bars using these two transition curves have a large deviation between the actual value of the resonant frequency and the theoretical value of 55.5KHz, which leads to a reduction in the ability to stop bleeding during cutting. Utility Model Content
[0005] The purpose of this invention is to provide a transducer to solve at least one aspect of the problems and defects mentioned in the background art.
[0006] A transducer includes a prestressed bolt, a front cover plate, and an amplitude transformer. The amplitude transformer is divided into a large end and a small end. The prestressed bolt passes through a rear cover plate and a piezoelectric ceramic crystal stack in sequence, and is screwed to one end of the front cover plate. The other end of the front cover plate is connected to the large end of the amplitude transformer. A transition section is connected to the end of the large end of the amplitude transformer away from the front cover plate. The end of the transition section away from the large end of the amplitude transformer is connected to the small end of the amplitude transformer. The radius of the transition section gradually decreases from the large end to the small end of the amplitude transformer to form an arc surface. The curve of the arc surface of the transition section is the steepest curve.
[0007] Furthermore, an amplitude rod flange is provided on the large end of the amplitude rod.
[0008] Furthermore, the length of the transition section is 3mm-4mm.
[0009] Furthermore, a bolt assembly hole is provided on the side of the small end of the amplitude rod away from the transition section.
[0010] Furthermore, the radius of the cycloid circle corresponding to the fastest curve is 1 mm.
[0011] Furthermore, the amplitude coefficient of the amplitude transformer ranges from 1.25 to 1.75.
[0012] Furthermore, the amplitude coefficient of the amplitude lever is 1.25, 1.5, or 1.75.
[0013] Furthermore, the transducer's vibration frequency range is 45-65KHz.
[0014] Furthermore, the modal frequency of the transducer is 55.515KHz-55.583KHz.
[0015] Furthermore, an ultrasonic surgical scalpel includes the transducer described in any of the above claims.
[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0017] This solution uses a design that uses the steepest curve as the transition curve. Compared to the stepped transition section of the existing technology, the steepest curve is used as the transition curve in the transition section of the amplitude transformer to correct the resonant frequency and reduce the stress concentration at the abrupt cross section. It also makes the longitudinal vibration frequency of the ultrasonic scalpel transducer closer to the ideal frequency, resulting in more stable vibration and improved hemostasis during surgery. Attached Figure Description
[0018] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.
[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0020] Figure 2 This is a schematic diagram of the arc surface forming of the transition section in the overall structure of this utility model;
[0021] Figure 3 This is a schematic diagram showing the dimensions and specifications of each part of the ultrasonic surgical scalpel transducer of this utility model;
[0022] Figure 4 A schematic diagram showing the typical dimensions and specifications of an ultrasonic surgical scalpel transducer.
[0023] Figure 5 This is a diagram showing the mesh division result of the ultrasonic surgical scalpel transducer of this utility model.
[0024] In the diagram: 1. Prestressed bolt; 2. Rear cover plate; 3. Piezoelectric ceramic crystal stack; 4. Front cover plate; 5. Large end of the amplitude transformer; 6. Amplitude transformer flange; 7. Transition section; 8. Small end of the amplitude transformer; 9. Preset point. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model; that is, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The components of the embodiments of the present utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0027] Please see Figure 1-5As shown in the embodiment of this utility model, a transducer applicable to an ultrasonic surgical scalpel includes a prestressed bolt 1, a front cover plate 4, and an amplitude transformer. The amplitude transformer is divided into a large end 5 and a small end 8. The prestressed bolt 1 passes through the rear cover plate 2 and the piezoelectric ceramic crystal stack 3 in sequence, and is screwed to one end of the front cover plate 4. The other end of the front cover plate 4 is connected to the large end 5 of the amplitude transformer. The end of the large end 5 of the amplitude transformer away from the front cover plate 4 is connected to a transition section 7. The end of the transition section 7 away from the large end 5 of the amplitude transformer is connected to the small end 8 of the amplitude transformer. The radius of the transition section 7 gradually decreases from the large end 5 of the amplitude transformer to the small end 8 of the amplitude transformer, forming an arc surface. The curve of the arc surface of the transition section 7 is the steepest curve. The piezoelectric ceramic crystal stack 3 is pressed onto the front cover plate 4 by the rear cover plate 2 and locked in place by the prestressed bolts 1. The piezoelectric ceramic crystal stack 3 can convert electrical energy into mechanical energy to provide mechanical vibration energy. The transition section 7 adopts the steepest curve as the arc surface curve. This design can reduce the concentration of stress at the abrupt cross section and correct the resonance frequency, so that the longitudinal vibration frequency of the ultrasonic scalpel transducer is closer to the ideal frequency of 55.5KHz, making the vibration more stable and improving the cutting and hemostasis effect during surgery.
[0028] In some embodiments, the large end 5 of the amplitude transformer is provided with an amplitude transformer flange 6, which can be used to firmly fix the amplitude transformer in the required position to prevent it from moving or loosening during operation, so as to maintain the stability and accuracy of the ultrasonic equipment.
[0029] In some embodiments, the length of the transition section 7 is 3mm-4mm. The transition section 7 within this length range, combined with the fastest curve, can make the transducer longitudinal vibration frequency closer to the ideal frequency of 55.5KHz, thereby improving the stability of vibration.
[0030] In some embodiments, the small end 8 of the amplitude transformer is provided with a bolt assembly hole (not shown in the figure) on the side away from the transition section 7. The bolt assembly hole can be used to connect other equipment structures more conveniently with bolts.
[0031] In some embodiments, please refer to Figure 2 As shown, the radius of the cycloidal circle corresponding to the fastest curve is 1 mm. This cycloidal circle rolls from the end of the transition section 7 near the large end 5 of the amplitude transformer to the end of the transition section 7 near the small end 8 of the amplitude transformer. A preset point 9 is set on the arc of the cycloidal circle. When the cycloidal circle rolls, the trajectory of the preset point 9 is the trajectory of the fastest curve. The trajectory of the fastest curve can be easily measured by the virtual cycloidal circle, making it more convenient to process the arc surface of the fastest curve on the transition section 7.
[0032] In some embodiments, when the amplitude coefficient of the amplitude transformer is 1.25-1.75, a total of 6 vibration modes are set, and the transducer vibration frequency range is 45-65KHz. Among them, when it is in the 4th vibration mode, the frequency is 55.515KHz-55.583KHz, which is closest to the ideal frequency of 55.5KHz.
[0033] Specifically, to better illustrate the differences between the fastest curve amplitude transformer, the optimal circular curve amplitude transformer, and the catenary curve amplitude transformer, the following is a comparison of the performance data of the three curve transition section amplitude transformers when the natural frequency is set to 55.5 kHz and the amplitude coefficients are 1.25, 1.5, and 1.75:
[0034]
[0035] As can be seen from the data table above, the fastest curve amplitude transformer of this scheme has a better frequency correction effect than the optimal circular curve amplitude transformer and the catenary curve amplitude transformer when the amplitude coefficient N is 1.25, 1.5 and 1.75.
[0036] To evaluate its practical effectiveness, three types of amplitude transformers with an amplitude coefficient N of 1.75 were fabricated. The principal amplitude at the tip of the three different amplitude transformers was measured using a laser vibrometer. The measurement results are shown in the table below:
[0037]
[0038] As can be seen from the data in the table above, the optimized fastest curve amplitude transformer of this invention can obtain the maximum tip principal amplitude, making the ultrasonic energy more concentrated and able to cut biological tissue more effectively. This helps doctors to more accurately control the cutting depth and range of the scalpel, thereby reducing damage to surrounding tissues, improving the safety of the operation, and significantly shortening the operation time, reducing patient pain and postoperative recovery time.
[0039] In some embodiments, the ultrasonic scalpel transducer designed in this invention operates at a frequency of 55.5 kHz. Therefore, the modal extraction range is set to 45-65 kHz. Vibration modal simulation is used to obtain all frequencies and mode shapes of the ultrasonic scalpel transducer within the 45-65 kHz frequency range, and the Block Lancoz method is employed for solution. The transducer designed in this invention contains six vibration modes within the 45-65 kHz frequency range, which can be classified into longitudinal, torsional, and bending vibration modes according to their mode shapes. The fourth longitudinal vibration mode frequency is 55.570 kHz, deviating from the design target value of 55.5 kHz by only 0.126%, as shown in the table below. Simulation results demonstrate the rationality of this structural design.
[0040]
[0041]
[0042] The dimensions and specifications of each part of the ultrasonic surgical scalpel transducer in this solution are as follows: Figure 3 As shown, where:
[0043] L1 is the thickness of the rear cover plate (preload bolts and rear cover plate), L1 = 9mm; L2 is the thickness of the piezoelectric ceramic crystal stack, L2 = 10mm; L3 is the thickness of the large end of the front cover plate, L3 = 2.5mm; L4 is the length of the transition section of the large end of the front cover plate, L4 = 6mm; L5 is the length of the small end of the front cover plate, L5 = 13.6mm; L6 is the length of the large end of the luffing rod, L6 = 21.5mm; L7 is the length of the transition section of the luffing rod, L7 = 7mm; L8 is the length of the small end of the luffing rod, L8 = 15.5mm. R1 is the diameter of the rear cover plate (the rear cover plate, piezoelectric ceramic crystal stack, and front cover plate have the same diameter), R1 = 16mm; R2 is the diameter of the large end of the luffing rod, R2 = 10mm; R3 is the diameter of the small end of the luffing rod, R3 = 6.5mm.
[0044] Typical dimensions of an ultrasonic scalpel transducer are as follows: Figure 4 As shown.
[0045] Based on the dimensions of each part of the ultrasonic surgical scalpel transducer, parametric modeling was performed using SolidWorks software and the model was imported into ANSYS. The GLUE command was used to connect the transducer parts, ignoring details such as threaded structures, electrode plates, and adhesives. The ultrasonic surgical scalpel transducer was then meshed. The mesh size was preferably less than 1 / 8 of the wavelength of the element material to ensure high computational accuracy in a short computation time. Based on the transducer dimensions of this invention, a mesh size of 1.5 mm was chosen. The piezoelectric crystal stack was meshed using SOILD226 hexahedral elements with a swept meshing method, while the remaining parts were meshed using SOILD187 general-purpose tetrahedral elements with a free meshing method. The meshing results are shown below. Figure 5 As shown, it contains a total of 36,429 nodes and 19,655 elements.
[0046] The above description is merely an example and illustration of the structure of this utility model. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of this utility model.
Claims
1. A transducer, characterized in that, The system includes a prestressed bolt (1), a front cover plate (4), and an amplitude transformer. The amplitude transformer is divided into a large end (5) and a small end (8). The prestressed bolt (1) passes through the rear cover plate (2) and the piezoelectric ceramic crystal stack (3) in sequence, and is screwed to one end of the front cover plate (4). The other end of the front cover plate (4) is connected to the large end (5) of the amplitude transformer. The end of the large end (5) of the amplitude transformer away from the front cover plate (4) is connected to a transition section (7). The end of the transition section (7) away from the large end (5) of the amplitude transformer is connected to the small end (8) of the amplitude transformer. The radius of the transition section (7) gradually decreases from the large end (5) of the amplitude transformer to the small end (8) of the amplitude transformer to form an arc surface. The curve of the arc surface of the transition section (7) is the steepest curve.
2. The transducer according to claim 1, characterized in that, The large end (5) of the amplitude transformer is provided with an amplitude transformer flange (6).
3. A transducer according to claim 1, characterized in that, The length of the transition section (7) is 3mm-4mm.
4. A transducer according to claim 1, characterized in that, The small end (8) of the amplitude transformer has a bolt assembly hole on the side away from the transition section (7).
5. A transducer according to claim 1, characterized in that, The radius of the cycloid circle corresponding to the fastest curve is 1 mm.
6. A transducer according to claim 1, characterized in that, The amplitude coefficient of the amplitude transformer ranges from 1.25 to 1.
75.
7. A transducer according to claim 6, characterized in that, The amplitude coefficient of the amplitude transformer is 1.25, 1.5 or 1.
75.
8. A transducer according to claim 1, characterized in that, The transducer's vibration frequency range is 45-65KHz.
9. A transducer according to claim 8, characterized in that, The modal frequencies of the transducer are 55.515 kHz to 55.583 kHz.
10. An ultrasonic surgical scalpel, characterized in that, Includes the transducer as described in any one of claims 1 to 9.