Cordless ultrasonic scalpel

Abstract

The present invention discloses a cordless ultrasonic scalpel, comprising a blade assembly, a half-wavelength transducer, a handle housing, a circuit board, and a battery. The front end of the half-wavelength transducer is threadedly connected to the blade assembly, the rear end of the half-wavelength transducer is installed in the handle housing, the half-wavelength transducer is in rolling contact with the handle housing, the circuit board and the battery are fixed in the handle housing, the battery is electrically connected to the circuit board, and a coaxial sleeve on the half-wavelength transducer is provided with a positive conductive ring and a negative conductive ring, the positive conductive ring and the negative conductive ring are respectively in elastic electrical contact with the circuit board. The half-wavelength transducer of the present invention always maintains rolling contact with the handle housing, reducing the resistance generated when the blade assembly rotates, minimizing the resistance during rotation, and improving efficiency; the positive and negative conductive rings are in elastic contact with the circuit board, always maintaining contact, ensuring work stability, and improving work efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of medical instruments, and more particularly to a cordless ultrasonic scalpel. Background Art

[0002] The principle of an ultrasonic scalpel is to generate vibrations using an ultrasonic transducer. The emitted ultrasonic waves propagate along the longitudinal axis of the blade shaft, generating amplified vibrations along the shaft along this axis, ultimately generating high-speed longitudinal mechanical motion at the blade tip. The mechanical vibrations at the blade tip are very effective in cutting soft tissue, and the heat generated by the high-frequency ultrasonic vibrations can coagulate tissue and seal blood vessels. Because the blade shaft can be easily accessed through a cannula to the surgical site, this device is particularly suitable for minimally invasive surgeries such as endoscopic and laparoscopic procedures. The key to ultrasonic scalpel control is to simultaneously control the blade tip's vibration amplitude while generating resonance along the length of the blade shaft to achieve optimal performance during surgery. However, generating effective drive signals is challenging. For example, the frequency, current, and voltage applied to the transducer must all be dynamically controlled, as these parameters vary with the load on the blade tip and the temperature differential generated by the blade shaft. These factors result in the control system for an ultrasonic scalpel being a relatively complex hybrid analog-digital circuit with a processor running real-time control software and human-computer interface software. Due to the high control system requirements, most ultrasonic scalpel products currently on the market are corded. For example, Johnson & Johnson's Harmonic series, similar to the design disclosed in U.S. Patent No. 78243, requires the scalpel to be connected to a tabletop generator. This design has the disadvantage of requiring a connecting wire, which can be cumbersome during surgery. Existing corded transducers are 92.8 mm long and weigh 40.96 g, making them cumbersome to use.

[0003] Therefore, cordless ultrasonic scalpels emerged as a necessity. These devices can operate independently without being connected to a desktop generator, freeing doctors from the hassle of wires. Cordless ultrasonic scalpels are popular for their convenience and efficiency. Because of their portability, weight, size, and efficiency are crucial considerations for cordless ultrasonic scalpels.

[0004] A cordless ultrasonic scalpel primarily consists of a transducer, blade assembly, handle housing, circuit board, and battery. These components determine its weight, size, and efficiency. However, existing cordless ultrasonic scalpels are bulky and have complex acoustic structures, which hinder portability, ease of use during surgery, and overall efficiency. Summary of the Invention

[0005] In order to solve the problems of existing cordless ultrasonic scalpels such as being bulky and having complex acoustic structures, which affect work efficiency, the present invention innovatively provides a cordless ultrasonic scalpel. The half-wavelength transducer of the cordless ultrasonic scalpel always maintains rolling contact with the handle shell, reducing the resistance generated when the scalpel head assembly rotates, minimizing the resistance during rotation and improving efficiency; the positive and negative conductive rings are in elastic contact with the circuit board and always maintain contact, ensuring work stability and improving work efficiency.

[0006] To achieve the above-mentioned technical objectives, the present invention discloses a cordless ultrasonic scalpel, comprising a blade head assembly, a half-wavelength transducer, a handle housing, a circuit board and a battery. The front end of the half-wavelength transducer is threadedly connected to the blade head assembly, the rear end of the half-wavelength transducer is installed in the handle housing, the half-wavelength transducer is in rolling contact with the handle housing, the circuit board and the battery are fixed in the handle housing, the battery is electrically connected to the circuit board, and a positive conductive ring and a negative conductive ring are coaxially sleeved on the half-wavelength transducer, and the positive conductive ring and the negative conductive ring are respectively in elastic electrical contact with the circuit board.

[0007] Furthermore, the outer peripheral surfaces of the positive conductive ring and the negative conductive ring are both arc-shaped surfaces, and the circuit board is provided with contact spherical surfaces corresponding to the positions of the positive conductive ring and the conductive ring. The two contact spherical surfaces of the circuit board are in elastic contact with the outer peripheral surfaces of the positive conductive ring and the negative conductive ring respectively.

[0008] Furthermore, the two contact spherical surfaces on the circuit board are both elastic surfaces, and the rigidity of the contact spherical surfaces is smaller than the rigidity of the positive conductive ring and the negative conductive ring.

[0009] Furthermore, the half-wavelength transducer includes a front metal block, a piezoelectric crystal stack, a rear metal block and a pre-tightening screw. The front metal block is a multi-stage variable-step structure or a stepped structure. A threaded hole is provided inside the front metal block along the axis. The rear metal block, the piezoelectric crystal stack and the front metal block are coaxially sleeved on the nail rod of the pre-tightening screw in sequence. The nail rod of the pre-tightening screw is threadedly connected to the threaded hole of the front metal block. The rear metal block and the piezoelectric crystal stack are pressed between the nail head of the pre-tightening screw and the front metal block. The end of the front metal block in contact with the piezoelectric crystal stack is a flange part, and a thread is provided on the outer peripheral surface of the straight section at the front end of the front metal block.

[0010] Furthermore, the outside of the flange portion is wrapped with a fixing piece, the outer peripheral surface of the fixing piece is an arc-shaped surface, and the outer peripheral surface of the fixing piece is in rolling contact with the handle shell.

[0011] Furthermore, a vibration isolation ring is filled between the fixing member and the flange portion, and the fixing member includes a front fixing ring and a rear fixing ring, and the front fixing ring and the rear fixing ring are connected by interference fit.

[0012] Furthermore, the front metal block includes a flange portion, a first transition section, a first straight section, a second transition section and a second straight section connected in sequence along a direction away from the piezoelectric crystal stack, the outer diameter of the first transition section and the outer diameter of the second transition section gradually decrease along the direction away from the piezoelectric crystal stack, the outer diameter of the flange portion is greater than the maximum outer diameter of the first transition section, the outer diameter of the first straight section is the same as the minimum outer diameter of the first transition section, the maximum outer diameter of the second transition section is equal to or less than the outer diameter of the first straight section, the outer diameter of the second straight section is the same as the minimum outer diameter of the second transition section, and the thread is arranged on the outer circumferential surface of the second straight section.

[0013] Furthermore, the outer peripheral surfaces of the first transition section and the second transition section are both arc-shaped surfaces, and the curvature of the arc-shaped surface of the first transition section matches the curvature of a human thumb.

[0014] Furthermore, the front metal block includes a flange portion, a first transition section, a first straight section, a second transition section, a second straight section, a third transition section, a third straight section, a fourth transition section and a fourth straight section connected in sequence along a direction away from the piezoelectric crystal stack, the outer diameter of the flange portion is greater than the maximum outer diameter of the first transition section, the outer diameter of the first transition section and the outer diameter of the second transition section gradually decrease along the direction away from the piezoelectric crystal stack, the outer diameter of the third transition section and the outer diameter of the fourth transition section gradually increase along the direction away from the piezoelectric crystal stack, the outer diameter of the first straight section is the same as the minimum outer diameter of the first transition section, the outer diameter of the second straight section, the minimum outer diameter of the second transition section and the minimum outer diameter of the third transition section are the same, the outer diameter of the third straight section is the same as the minimum outer diameter of the fourth transition section, the outer diameter of the fourth straight section is the same as the maximum outer diameter of the fourth transition section, the outer diameter of the fourth straight section is smaller than the outer diameter of the second straight section, and the thread is arranged on the outer circumferential surface of the fourth straight section.

[0015] Furthermore, the outer circumferential surfaces of the first transition section and the second transition section are arcuate surfaces, the curvature of the arcuate surface of the first transition section matches the curvature of a human thumb, and the outer circumferential surfaces of the third transition section and the fourth transition section are conical surfaces.

[0016] The beneficial effects of the present invention are:

[0017] The half-wavelength transducer of the cordless ultrasonic scalpel of the present invention always maintains rolling contact with the handle shell, reducing the resistance generated when the cutter head assembly rotates, minimizing the resistance during rotation and improving efficiency; the positive and negative conductive rings are in elastic contact with the circuit board and always maintain contact, ensuring working stability and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 2 is a schematic structural diagram of a cordless ultrasonic scalpel according to an embodiment of the present invention;

[0019] Figure 2 Schematic diagram of the connection relationship between a half-wavelength transducer, positive and negative conductive rings, and a fixing member according to an embodiment of the present invention;

[0020] Figure 3 Schematic diagram of the contact between the positive and negative conductive rings and the circuit board according to an embodiment of the present invention;

[0021] Figure 4 is a side view of a front fixing ring according to an embodiment of the present invention;

[0022] Figure 5 is an inner end view of the front fixing ring according to an embodiment of the present invention;

[0023] Figure 6 is a side view of a rear fixing ring according to an embodiment of the present invention;

[0024] Figure 7 is an inner end view of a rear fixing ring according to an embodiment of the present invention;

[0025] Figure 8 is a schematic diagram of the contact between the fixing member and the handle housing according to an embodiment of the present invention;

[0026] Figure 9 1 is a schematic structural diagram of a half-wavelength transducer according to an embodiment of the present invention;

[0027] Figure 10 FIG. 4 is a schematic structural diagram of a half-wavelength transducer according to another embodiment of the present invention.

[0028] In the figure,

[0029] 1. Cutting head assembly; 2. Half-wavelength transducer; 21. Front metal block; 211. Flange; 212. First transition section; 213. First straight section; 214. Second transition section; 215. Second straight section; 216. Third transition section; 217. Third straight section; 218. Fourth transition section; 219. Fourth straight section; 22. Piezoelectric crystal stack; 23. Rear metal block; 24. Pre-tightening screw; 25. Fixing part; 251. Front fixing ring; 252. Rear fixing ring; 26. Vibration isolation ring; 3. Handle housing; 4. Circuit board; 41. Contact sphere; 5. Battery; 6. Positive conductive ring; 7. Negative conductive ring. DETAILED DESCRIPTION

[0030] The cordless ultrasonic scalpel provided by the present invention is explained and illustrated in detail below with reference to the accompanying drawings.

[0031] This embodiment specifically discloses a cordless ultrasonic scalpel, such as Figure 1As shown, it includes a blade assembly 1, a half-wavelength transducer 2, a handle housing 3, a circuit board 4 and a battery 5. The front end of the half-wavelength transducer 2 is threadedly connected to the blade assembly 1, so that the blade assembly 1 can rotate 360 degrees, thereby allowing the blade assembly 1 to rotate axially relative to the handle housing. The rear end of the half-wavelength transducer 2 is installed in the handle housing 3, and the half-wavelength transducer 2 is in rolling contact with the handle housing 3. The circuit board 4 and battery 5 are fixed in the handle housing 3, and the battery 5 is electrically connected to the circuit board 4. Figure 2 As shown, a positive conductive ring 6 and a negative conductive ring 7 are coaxially sleeved on the half-wavelength transducer 2. The centers of the positive conductive ring 6 and the negative conductive ring 7 coincide with the axis of the half-wavelength transducer 2. The positive conductive ring 6 and the negative conductive ring 7 are respectively in elastic electrical contact with the circuit board 4. The positive conductive ring 6 and the negative conductive ring 7 receive the electrical signal input from the circuit board 4 and then transmit the electrical signal to the half-wavelength transducer 2, thereby driving the transducer to generate ultrasonic mechanical energy. A certain distance is maintained between the positive conductive ring 6 and the negative conductive ring 7 to prevent short circuits. The half-wavelength transducer 2 always maintains rolling contact with the handle housing 3, reducing the resistance generated by the rotation of the blade head assembly 1, minimizing the resistance during rotation and improving efficiency. The positive and negative conductive rings 7 are in elastic contact with the circuit board 4 and always maintain contact, ensuring stable operation and improving work efficiency.

[0032] In this embodiment, if Figure 3 As shown, the outer peripheral surfaces of the positive conductive ring 6 and the negative conductive ring 7 are both arc-shaped surfaces, and the arc-shaped surfaces of the positive conductive ring and the negative conductive ring are both convex outward. The circuit board 4 is provided with a contact spherical surface 41 corresponding to the position of the positive conductive ring 6 and the conductive ring. Figure 3 As shown, the two contact spheres 41 of the circuit board 4 are in elastic contact with the outer peripheral surfaces of the positive conductive ring 6 and the negative conductive ring 7 respectively. The surface of the contact sphere 41 is gold-plated to ensure the performance of electrical signal transmission. The two contact spheres 41 on the circuit board 4 are both elastic surfaces, and the rigidity of the contact sphere 41 is less than that of the positive conductive ring 6 and the negative conductive ring 7. After the half-wavelength transducer 2, the positive conductive ring 6 and the negative conductive ring 7 are installed in the handle housing 3, the two contact spheres 41 of the circuit board 4 are squeezed by the positive conductive ring 6 and the negative conductive ring 7 and slightly deformed, while the positive conductive ring 6 and the negative conductive ring 7 do not deform or bend. The contact sphere 41 of the circuit board 4 applies elastic force to the positive conductive ring 6 and the negative conductive ring 7, thereby achieving close contact between the positive conductive ring 6 and the negative conductive ring 7 and the circuit board 4, ensuring the stability of the contact and the stable transmission of electrical signals.

[0033] like Figure 2As shown, the half-wavelength transducer 2 includes a front metal block 21, a piezoelectric crystal stack 22, a rear metal block 23, and a pre-tightening screw 24. In this embodiment, the front metal block 21 and the rear metal block 23 are both aluminum alloy blocks, and the pre-tightening screw 24 is a titanium alloy screw, which can ensure mechanical performance while reducing the weight of the transducer. The front metal block 21 has a multi-level variable step structure or a stepped structure. The multi-level variable step structure or stepped structure of the front metal block 21 reduces the weight of the transducer while reducing the volume of the transducer, improving acoustic performance and obtaining greater gain while meeting mechanical strength requirements. A threaded hole is provided inside the front metal block 21 along the axis. The rear metal block 23, the piezoelectric crystal stack 22, and the front metal block 21 are coaxially sleeved on the nail rod of the pre-tightening screw 24 in sequence. The nail rod of the pre-tightening screw 24 is threadedly connected to the threaded hole of the front metal block 21. The rear metal block 23 and the piezoelectric crystal stack 22 are compressed between the nail head of the pre-tightening screw 24 and the front metal block 21. The end of the front metal block 21 that contacts the piezoelectric crystal stack 22 is the flange portion 211. The flange surface of the flange portion 211 better transfers pressure evenly to the piezoelectric crystal stack 22. The outer peripheral surface of the straight section at the front end of the front metal block 21 is provided with a thread. The thread at the front end of the front metal block 21 is directly connected to the thread of the cutter head assembly 1, which is simple to assemble. The outer diameter of the head of the pre-tightening screw 24 is larger than the outer diameter of the shank. The front end face of the head mates with the rear end face of the rear metal block 23, which in turn mates with the rear end face of the piezoelectric crystal stack 22. The front end face of the piezoelectric crystal stack 22 mates with the rear end face of the front metal block 21, that is, it mates with the flange surface of the front metal block 21. The head of the pre-tightening screw 24 and the front metal block 21 generate a uniform clamping force, which is evenly transmitted to the rear metal block 23 and the piezoelectric crystal stack 22. This ensures a uniform pressure distribution on the piezoelectric crystal stack 22 of the ultrasonic transducer, effectively improving the transducer's electromechanical conversion efficiency and achieving low impedance and high output performance.

[0034] The flange portion 211 is wrapped around a fixing member 25, and the outer circumference of the fixing member 25 is an arc-shaped surface. The outer circumference of the fixing member 25 is in rolling contact with the handle housing 3. The fixing member 25 wraps around the flange portion 211 and is generally cylindrical with an arc-shaped outer circumference. The center of the arc faces the axis of the flange portion 211, that is, the arc surface of the fixing member 25 is convex outward.

[0035] In this embodiment, if Figure 2 As shown, a vibration isolation ring 26 is filled between the fixing member 25 and the flange portion 211. A vibration isolation ring 26 is installed at the front and rear ends of the flange portion 211. The area of the vibration isolation ring 26 is greater than or equal to the end surface area of the flange portion 211. The vibration isolation ring 26 is made of an elastic material, preferably silicone rubber. The fixing member 25 includes a front fixing ring 251 and a rear fixing ring 252. The front fixing ring 251 is fixed in front of the vibration isolation ring 26 on the front side of the flange portion 211, and the rear fixing ring 252 is fixed behind the vibration isolation ring 26 on the rear side of the flange portion 211. Figure 4-7As shown, the front fixing ring 251 and the rear fixing ring 252 are cap-shaped, and the rear fixing ring 252 is buckled into the front fixing ring 251. The outer circumference of the front fixing ring 251 is an arcuate surface. The front fixing ring 251 and the rear fixing ring 252 are connected by an interference fit and firmly wrapped around the outside of the flange portion 211 to prevent separation due to vibration during operation of the ultrasonic scalpel. In other embodiments, the front fixing ring can also be fixed inside the rear fixing ring. In this case, the outer circumference of the rear fixing ring is an arcuate surface.

[0036] To further meet the requirement of minimizing weight, the front fixing ring 251 and the rear fixing ring 252 are both made of non-metallic high-temperature resistant materials, such as PEEK (polyetheretherketone) and PPSU (polyphenylene sulfone resin).

[0037] like Figure 4 and 5 As shown, the inner end surface of the front fixing ring 251 is provided with an annular protrusion, as shown in FIG. Figure 6 and 7 As shown, the inner end surface of the rear fixing ring 252 is provided with a plurality of protrusions evenly distributed circumferentially. The annular protrusions and the protrusions are pressed tightly against the vibration isolation ring 26 to press the vibration isolation ring 26 toward the flange portion 211 .

[0038] like Figure 8 As shown, when the half-wavelength transducer is installed in the handle housing 3, there is a certain gap between the outer peripheral surface of the fixing part and the handle housing 3. Compared with the contact between two planes, the contact area is smaller, and thus the resistance is also smaller.

[0039] In this embodiment, if Figure 9 As shown, the front metal block 21 includes a flange portion 211, a first transition section 212, a first straight section 213, a second transition section 214 and a second straight section 215 which are connected in sequence along a direction away from the piezoelectric crystal stack 22. The outer diameter of the first transition section 212 and the outer diameter of the second transition section 214 gradually decrease along a direction away from the piezoelectric crystal stack 22. The outer diameter of the flange portion 211 is greater than the maximum outer diameter of the first transition section 212. The outer diameter of the first straight section 213 is the same as the minimum outer diameter of the first transition section 212. The maximum outer diameter of the second transition section 214 is equal to or less than the outer diameter of the first straight section 213. The outer diameter of the second straight section 215 is the same as the minimum outer diameter of the second transition section 214. A thread is provided on the outer peripheral surface of the second straight section 215. The outer peripheral surfaces of the flange portion 211, the first straight section 213 and the second straight section 215 are all right cylindrical surfaces, and the first transition section 212 and the second transition section 214 realize a smooth transition, so that the diameter of the front metal block 21 is gradually reduced twice, reducing the volume and weight while ensuring the mechanical strength of the front metal block 21. At the same time, the vibration amplitude when subjected to the vibration transmitted by the piezoelectric crystal stack 22 is larger.

[0040] The outer circumferences of the first transition section 212 and the second transition section 214 are both curved, and the curvature of the first transition section 212 matches the curvature of the human thumb. When connecting the half-wavelength transducer 2 to the tool head assembly 1, the transducer flange 211 is gripped with the thumb on the curved surface of the first transition section 212. The torque wrench is used to tighten the tool head assembly 1. The curvature of the first transition section 212 matches the curvature of the thumb, providing support and adaptability for the thumb, facilitating good grip and force application.

[0041] In this embodiment, the ratio of the outer diameter of the flange portion to the maximum outer diameter of the first transition section is 7:6, the ratio of the outer diameter of the flange portion 5 to the first straight section is 2:1, and the ratio of the outer diameter of the first straight section to the second straight section is 3:2. This outer diameter ratio can fully ensure the mechanical strength and acoustic performance of the transducer.

[0042] The acoustic characteristics of the half-wavelength transducer 2 of this embodiment are compared with those of an existing corded transducer, as shown in Table 1. The length of the existing corded transducer is 92.8 mm. The outer diameters of the piezoelectric crystal stack, the rear metal block, and the pre-tightening screw head of this embodiment are identical to those of the existing corded ultrasonic transducer. The front metal block of the existing corded ultrasonic transducer is made of aluminum alloy, the rear metal block is made of stainless steel, and the pre-tightening screw is made of titanium alloy. The outer diameter of the front metal block of the existing corded ultrasonic transducer is identical to the maximum outer diameter of the first transition section of this embodiment. In this embodiment, the outer diameter of the flange is 18 mm, the maximum outer diameter of the first transition section is 15.4 mm, the outer diameter of the first straight section is 9 mm, and the outer diameter of the second straight section is 6 mm. The length of the flange is 2mm, the length of the first transition section is 2.5mm, the length of the first straight section is 10mm, the length of the second transition section is 2mm, the length of the second straight section is 14mm, the length of the piezoelectric crystal stack is 10.2mm, the length of the rear metal block is 6mm, and the length of the nail head of the pre-tightening screw is 4.7mm.

[0043] Table 1

[0044]

[0045] Comparing the data in Table 1, it can be seen that the acoustic properties of the transducer of this embodiment are improved, and the phase margin is almost doubled. The increase in the phase margin of the transducer near the resonance point will better match the transducer with the host and improve the operating efficiency of the transducer.

[0046] In another embodiment, Figure 10As shown, the front metal block 21 includes a flange portion 211, a first transition section 212, a first straight section 213, a second transition section 214, a second straight section 215, a third transition section 216, a third straight section 217, a fourth transition section 218 and a fourth straight section 219 that are sequentially connected in a direction away from the piezoelectric crystal stack 22. The outer diameter of the flange portion 211 is greater than the maximum outer diameter of the first transition section 212. The outer diameters of the first transition section 212 and the second transition section 214 gradually decrease in a direction away from the piezoelectric crystal stack 22. The outer diameters of the third transition section 216 and the fourth transition section 217 are gradually reduced. The outer diameter of 8 gradually increases in the direction away from the piezoelectric crystal stack 22, the outer diameter of the first straight section 213 is the same as the minimum outer diameter of the first transition section 212, the outer diameter of the second straight section 215, the minimum outer diameter of the second transition section 214 and the minimum outer diameter of the third transition section 216 are the same, the outer diameter of the third straight section 217 is the same as the minimum outer diameter of the fourth transition section 218, the outer diameter of the fourth straight section 219 is the same as the maximum outer diameter of the fourth transition section 218, the outer diameter of the fourth straight section 219 is smaller than the outer diameter of the second straight section 215, and the thread is arranged on the outer peripheral surface of the fourth straight section 219. The outer circumferences of the first straight section 213, the second straight section 215, the third straight section 217, and the fourth straight section 219 are all right cylindrical surfaces. The first transition section 212, the second transition section 214, the third transition section 216, and the fourth transition section 218 achieve smooth transitions. The outer diameters of the first transition section 212 and the second transition section 214 gradually decrease, reducing volume and weight while gradually increasing the vibration amplitude. Although the outer diameters of the third transition section 216 and the fourth transition section 218 gradually increase, the increase is relatively small. Overall, the outer diameter of the front metal block 21 decreases in steps from back to front, improving acoustic performance, achieving greater gain, and meeting mechanical strength requirements. Preferably, the maximum outer diameter of the third transition section 216 is smaller than the maximum outer diameter of the second transition section 214. The stepped structure of the front metal block 21 allows the diameter to be reduced multiple times, ensuring the mechanical strength of the front metal block 21, while also increasing the vibration amplitude when subjected to vibrations transmitted by the piezoelectric crystal stack 22.

[0047] The first and second straight sections are more significant to the transducer's resonant frequency and amplitude gain. Therefore, the length and diameter of the first and second straight sections are both greater than those of the third and fourth straight sections, and the diameter ratio of the first and second straight sections approximately satisfies the following: φ1 / φ2≈2. To maintain mechanical properties, the ratio of the sum of the lengths of the first transition section, the first straight section, the second transition section, and the second straight section to the overall length of the front metal block is greater than 1 / 2, and more preferably greater than 0.7.

[0048] The outer circumferences of the first transition section 212 and the second transition section 214 are curved, with the curvature of the first transition section 212 matching the curvature of the human thumb. The outer circumferences of the third transition section 216 and the fourth transition section 218 are conical. When connecting the half-wavelength transducer 2 to the tool head assembly 1, the transducer flange 211 is grasped by hand, with the thumb gripped on the curved surface of the first transition section 212. The torque wrench is used to tighten from the tool head assembly 1 end. The curved surface of the first transition section 212 matches the curvature of the thumb, providing support and adaptability for the thumb, facilitating good grip and force application. The third transition section 216 and the fourth transition section 218 are conical, increasing mechanical strength.

[0049] The acoustic characteristics of an existing corded transducer and the half-wavelength transducer of this embodiment are compared, as shown in Table 2. The length of the existing corded transducer is 92.8 mm. The outer diameters of the rear metal block, the piezoelectric crystal stack, and the pre-tightening screw head of this embodiment are the same as those of the existing corded ultrasonic transducer. The front metal block of the existing corded ultrasonic transducer is made of aluminum alloy, the rear metal block is made of stainless steel, and the pre-tightening screw is made of titanium alloy. The outer diameter of the front metal block of the existing corded ultrasonic transducer is the same as the maximum outer diameter of the first transition section of this embodiment. In this embodiment, the flange is 2.7 mm long, the first transition section is 4 mm long, the first straight section is 7 mm long, the second transition section is 1 mm long, the second straight section is 9.5 mm long, the third transition section is 1.2 mm long, the third straight section is 1 mm long, the fourth transition section is 0.4 mm long, and the fourth straight section is 5 mm long. The first and second straight sections are of greater importance to the resonant frequency and amplitude gain of the transducer. The diameter ratio of the first and second straight sections approximately satisfies the following: φ1 / φ2≈2. More preferably, the diameter ratio of the first and second straight sections is 2. In this embodiment, the maximum diameter of the flange is 15 mm, the maximum outer diameter of the first transition section is 14 mm, the diameter of the first straight section is 8 mm, the diameter of the second straight section is 4 mm, the diameter of the third straight section is 2 mm, and the outer surface of the fourth straight section is threaded, generally in accordance with 4-40 UNC. The length of the piezoelectric crystal stack is 7 mm, the length of the rear metal block is 5 mm, and the length of the nail head of the pre-tightening screw is 4 mm.

[0050] Table 2

[0051]

[0052]

[0053] Comparing the data in Table 2, it can be seen that the acoustic properties of the transducer of this embodiment are improved, and the phase margin is increased by almost 47%. By improving the structure of the front metal block 21, the mechanical strength is maintained while the acoustic properties are improved.

[0054] The edge of the rear metal block 23's end face that contacts the head of the pre-tightening screw 24 is chamfered or rounded, creating a moderately increasing diameter around the rear metal block 23, forming a roughly circular surface with a transition step. This allows the rear metal block 23 to better receive the pre-tightening force of the head of the pre-tightening screw 24, further improving the resonant characteristics of the ultrasonic transducer. The front end of the rear metal block 23, which contacts the piezoelectric crystal stack 22, is a flat circular surface.

[0055] The design mode of half-wavelength transducer 2 further reduces the size, space and weight of the ultrasonic scalpel, improves the comfort of use, and is more convenient to carry; while meeting the mechanical properties, it also improves the acoustic characteristics. The phase tolerance of the transducer at the resonance point is increased, which is more conducive to the matching of the transducer and the host, thereby improving the working efficiency of the ultrasonic scalpel.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0057] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0058] In the description of this specification, the reference terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in an appropriate manner in any at least one embodiment or example. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and simple improvements made to the essential contents of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cordless ultrasonic scalpel, characterized in that: The invention comprises a cutter head assembly (1), a half-wavelength transducer (2), a handle housing (3), a circuit board (4) and a battery (5), wherein the front end of the half-wavelength transducer (2) is threadedly connected to the cutter head assembly (1), the rear end of the half-wavelength transducer (2) is installed in the handle housing (3), the half-wavelength transducer (2) is in rolling contact with the handle housing (3), the circuit board (4) and the battery (5) are fixed in the handle housing (3), the battery (5) is electrically connected to the circuit board (4), and a positive conductive ring (6) and a negative conductive ring (7) are coaxially sleeved on the half-wavelength transducer (2), and the positive conductive ring (6) and the negative conductive ring (7) are respectively in elastic electrical contact with the circuit board (4); The half-wavelength transducer (2) comprises a front metal block (21), a piezoelectric crystal stack (22), a rear metal block (23) and a pre-tightening screw (24); the front metal block (21) is a multi-stage variable-step structure or a stepped structure; a threaded hole is provided inside the front metal block (21) along the axis; the rear metal block (23), the piezoelectric crystal stack (22) and the front metal block (21) are coaxially sleeved on the nail rod of the pre-tightening screw (24) in sequence; the nail rod of the pre-tightening screw (24) is threadedly connected to the threaded hole of the front metal block (21); the rear metal block (23) and the piezoelectric crystal stack (22) are pressed between the nail head of the pre-tightening screw (24) and the front metal block (21); the end of the front metal block (21) in contact with the piezoelectric crystal stack (22) is a flange portion (211); and a thread is provided on the outer peripheral surface of the straight section of the front end of the front metal block (21); The front metal block (21) comprises a flange portion (211), a first transition section (212), a first straight section (213), a second transition section (214), a second straight section (215), a third transition section (216), a third straight section (217), a fourth transition section (218) and a fourth straight section (219) which are sequentially connected in a direction away from the piezoelectric crystal stack (22), an outer diameter of the flange portion (211) is greater than a maximum outer diameter of the first transition section (212), an outer diameter of the first transition section (212) and an outer diameter of the second transition section (214) gradually decrease in a direction away from the piezoelectric crystal stack (22), an outer diameter of the third transition section (216) and an outer diameter of the fourth transition section (218) gradually increase in a direction away from the piezoelectric crystal stack (22), and an outer diameter of the first straight section (213) is greater than a maximum outer diameter of the first transition section (212). The diameter is the same as the minimum outer diameter of the first transition section (212), the outer diameter of the second straight section (215), the minimum outer diameter of the second transition section (214) and the minimum outer diameter of the third transition section (216) are the same, the outer diameter of the third straight section (217) is the same as the minimum outer diameter of the fourth transition section (218), the outer diameter of the fourth straight section (219) is the same as the maximum outer diameter of the fourth transition section (218), the outer diameter of the fourth straight section (219) is smaller than the outer diameter of the second straight section (215), the thread is arranged on the outer peripheral surface of the fourth straight section (219), the diameter ratio of the first straight section (213) and the second straight section (215) is 2, and the ratio of the sum of the lengths of the first transition section, the first straight section, the second transition section and the second straight section to the overall length of the front metal block is greater than 0.7; The outer peripheral surfaces of the first transition section (212) and the second transition section (214) are arcuate surfaces, the curvature of the arcuate surface of the first transition section (212) matches the curvature of a human thumb, and the outer peripheral surfaces of the third transition section (216) and the fourth transition section (218) are conical surfaces.

2. The cordless ultrasonic scalpel according to claim 1, characterized in that: The outer circumferences of the positive conductive ring (6) and the negative conductive ring (7) are both arc-shaped surfaces. The circuit board (4) is provided with contact spherical surfaces (41) corresponding to the positions of the positive conductive ring (6) and the conductive rings. The two contact spherical surfaces (41) of the circuit board (4) are in elastic contact with the outer circumferences of the positive conductive ring (6) and the negative conductive ring (7), respectively.

3. The cordless ultrasonic scalpel according to claim 2, characterized in that: The two contact spherical surfaces (41) on the circuit board (4) are both elastic surfaces, and the rigidity of the contact spherical surfaces (41) is smaller than the rigidity of the positive conductive ring (6) and the negative conductive ring (7).

4. The cordless ultrasonic scalpel according to claim 1, characterized in that: The flange portion (211) is wrapped with a fixing member (25) on the outside. The outer peripheral surface of the fixing member (25) is an arc-shaped surface. The outer peripheral surface of the fixing member (25) is in rolling contact with the handle housing (3).

5. The cordless ultrasonic scalpel according to claim 4, characterized in that: A vibration isolation ring (26) is filled between the fixing member (25) and the flange portion (211). The fixing member (25) comprises a front fixing ring (251) and a rear fixing ring (252). The front fixing ring (251) and the rear fixing ring (252) are connected by interference fit.

Images