Acoustic lens focused transducer system

Abstract

The acoustic lens focusing transducer system comprises a handle, a control mechanism and a transducer, the control mechanism is installed in the handle, the handle is further provided with a treatment window, the transducer is rotatably installed in the treatment window, the control mechanism is in linkage with the transducer, and the transducer is in linkage with the control mechanism. The transducer is controlled to rotate or rotate synchronously in the circumferential direction in the projection area of the treatment window; the transducer comprises a lens, piezoelectric ceramic and a matching layer which are sequentially arranged and attached from outside to inside; wherein the structure of the lens is arranged to enable the ultrasonic waves converted by the lens to form at least one ultrasonic focus point in the treatment area of the treatment window. The device has the advantages that the overall structure is optimized, the overall structure is smaller, and handheld treatment of an operator is facilitated. Wherein the lens adopts a circular flat Fresnel acoustic lens or adopts a curved surface groove.

Description

Technical Field

[0001] The invention relates to medical equipment, in particular to an acoustic lens focusing transducer system. Background Art

[0002] Currently, a variety of non-invasive treatment effects can be achieved by using focused ultrasound therapy devices, including but not limited to: face lifting, forehead lifting, jaw lifting, eye treatment, wrinkle reduction, scar reduction, burn treatment, tattoo removal, vein removal, tightening of vaginal support tissue, etc.

[0003] There are three common focusing methods:

[0004] 1. Spherical self-focusing transducer: The transducer is directly made into a spherical crown or multiple spherical rings are combined into a spherical crown. This type of transducer can select a spherical surface of appropriate size according to different depth requirements, so it has high flexibility. Usually mechanical scanning is used. When a ring array structure is used, a combination of electronic scanning and mechanical scanning is used to perform three-dimensional scanning of large tissues.

[0005] 2 High-power multi-element ultrasonic transducer: This type of transducer arranges many piezoelectric ceramic sheets on a spherical concave surface with a diameter of several tens of centimeters, which can form a high energy density area at the center of the sphere. The focal length of this transducer is generally long. This type of product has the problem of high control difficulty, and it is impossible to accurately judge the internal tissue state and changes, which is easy to cause surgical accidents and has high costs. In addition, the phased array has many channels, complex circuits, high costs, and difficult to repair if damaged.

[0006] 3. Acoustic lens focusing transducer with acoustic matching layer: specifically refers to an acoustic redirecting entity through which acoustic energy passes and which provides effective confined direction or reshaping, for example by focusing the acoustic energy to one or more distant focal points.

[0007] The focused ultrasound therapeutic device mentioned above is usually equipped with a variety of treatment heads, each of which includes a shell and a transducer arranged in the shell, and each transducer corresponds to a fixed depth, so as to achieve the same and / or multiple depths of treatment. These treatment heads usually have a fixed focal length, and under the condition of a preset electrical energy output power, the emitting surface can emit ultrasonic energy that meets the purpose of treatment. However, such parallel treatment heads are large in size and will take up more installation space. When used in combination with the ultrasonic therapeutic device in the prior art, it is not convenient to move them by hand. In addition, since each transducer corresponds to a fixed depth, the working head needs to be replaced each time the operation is performed to adjust the surgical depth. The corresponding consumables (working heads) during the operation are frequently replaced, and the operation time is relatively long. Summary of the invention

[0008] The purpose of the present invention is to provide an acoustic lens focusing transducer system, which optimizes the overall structure, makes the overall structure more compact, and is convenient for the operator to hold the treatment in hand.

[0009] The present invention is implemented by the following technical scheme: an acoustic lens focusing transducer system, comprising a handle 1, a control mechanism 2 and a transducer 3, wherein the control mechanism 2 is installed in the handle 1, a treatment window 34 is also provided on the handle 1, and the transducer 3 is rotatably installed in the treatment window 34, and the control mechanism 2 is linked with the transducer 3 to control the transducer 3 to perform self-rotation or self-rotation synchronous circumferential motion within the projection area of ​​the treatment window 34;

[0010] The transducer 3 includes a lens 31, a piezoelectric ceramic 32 and a matching layer 33 which are arranged and bonded in sequence from the outside to the inside;

[0011] The structure of the lens 31 is configured to form at least one ultrasound focus point 35 in the treatment area of ​​the treatment window 34 with the ultrasound converted by the lens 31 .

[0012] Compared with the previous technology, the beneficial effects of the present invention are:

[0013] 1. The present invention has a compact structure and a small volume, and can be used in combination with an existing ultrasonic therapeutic apparatus, making it convenient for doctors to hold the handle of the therapeutic apparatus.

[0014] 2. In one embodiment of the present invention, the lens adopts a circular flat-plate Fresnel acoustic lens, which is thinner than a traditional spherical lens, minimizing the occupied space. At the same time, the conventional piezoelectric ceramics are transformed from arc shape to flat plate shape, which further reduces the processing difficulty.

[0015] 3. In one embodiment of the present invention, the lens adopts a curved groove; its cross section is arc-shaped, and the two ends of the arc are provided with a first arc-shaped portion and a second arc-shaped portion which are concave; thereby forming two ultrasonic focusing points; its sound energy focusing intensity is stronger than that of the Fresnel acoustic lens. In addition, traditional medical devices generally require at least three working heads for treatment to adapt to operations at different depths. Since two ultrasonic focusing points can replace two working heads, an instrument using two ultrasonic focusing points can ensure that two actions are completed in one operation, reduce the number of replacements of consumables (working heads) during the operation, and thus save the operation time.

[0016] 4. The present invention has a wide range of applications and can be applied to the fields of tumor ablation and medical aesthetics according to demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the Fresnel acoustic lens in Example 1 of the present invention;

[0018] Figure 2This is a schematic diagram of focusing of the Fresnel acoustic lens in Example 1;

[0019] Figure 3 This is a schematic diagram of focusing when the Fresnel acoustic lens of Example 1 is actually used;

[0020] Figure 4 This is a schematic diagram of the sound pressure distribution in the tissue after the transducer is turned on when using Example 1;

[0021] Figure 5 is a sound pressure level diagram of Example 1;

[0022] Figure 6 is a three-dimensional sound pressure diagram of Example 1;

[0023] Figure 7 is the three-dimensional temperature map of Example 1;

[0024] Figure 8 is the sound intensity field distribution diagram of Example 1;

[0025] Fig. 9 This is a normalized temperature / sound intensity curve diagram of Example 1;

[0026] Fig.10 is a cross-sectional view of a transducer with a bifocal lens in Example 2;

[0027] Fig.11 is a schematic diagram of a bifocal lens in Example 2;

[0028] Fig.12 is the acoustic pressure field in the tissue domain of Example 2;

[0029] Fig.13 This is the sound intensity field distribution diagram of Example 2;

[0030] Fig.14 This is a normalized temperature / sound intensity curve diagram of Example 2;

[0031] Fig.15 The first schematic diagram of lens rotation and zooming;

[0032] Fig.16 A second schematic diagram of lens rotation and zooming;

[0033] Fig.17 The third schematic diagram is a lens rotation zoom;

[0034] Fig.18 is a side cross-sectional view of the bifocal lens of Example 2;

[0035] Fig.19 is a side sectional view of the transducer of Example 3;

[0036] Fig. 20It is a cross-sectional view of the transmission structure of Example 3 combined with a bifocal lens;

[0037] Fig.21 It is a cross-sectional view of the transmission structure of Example 4 combined with the Fresnel acoustic lens;

[0038] Fig. 22 It is a cross-sectional view of the transmission structure of Example 4 combined with a bifocal lens;

[0039] Fig.23 is a cross-sectional view of Example 5;

[0040] Fig.24 is a cross-sectional view after the modification of Example 5;

[0041] Fig.25 This is a schematic diagram of the transducer described in Example 1 being attached to the body surface in combination with a coupling agent.

[0042] Explanation of reference numerals: 1 handle, 21 motor, 22 gear, 23 motor bevel gear, 24 steering bevel gear, 25 passive gear, 26 transmission gear, 27 turntable, 271 shaft, 3 transducer, 31 lens, 32 piezoelectric ceramic, 33 matching layer, 34 treatment window, 35 ultrasound focusing point, 35 guide annular tooth, 41 curved groove, 42 first arc portion, 43 second arc portion, 51 turntable, 52 tooth structure, 61 circular groove, 62 annular groove. DETAILED DESCRIPTION

[0043] The present invention is described in detail below in conjunction with the accompanying drawings:

[0044] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", etc., indicating orientations or positional relationships, are 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 cannot be understood as a limitation on the present invention.

[0045] like Figure 1 The acoustic lens focusing transducer system comprises a handle 1, a control mechanism 2 and a transducer 3, wherein the control mechanism 2 is installed in the handle 1, a treatment window 34 is also provided on the handle 1, and the transducer 3 is rotatably installed in the treatment window 34, and the control mechanism 2 is linked with the transducer 3 to control the transducer 3 to perform self-rotation or self-rotation synchronous circumferential motion in the projection area of ​​the treatment window 34;

[0046] The transducer 3 includes a lens 31, a piezoelectric ceramic 32 and a matching layer 33 which are arranged and bonded in sequence from the outside to the inside;

[0047] The structure of the lens 31 is configured to form at least one ultrasound focus point 35 in the treatment area of ​​the treatment window 34 with the ultrasound converted by the lens 31 .

[0048] According to the shape of the lens, the present invention derives the following two embodiments:

[0049] Example 1

[0050] The lens 31 is a circular flat plate-shaped Fresnel acoustic lens 31 , and a circular groove 61 having the same center as the Fresnel acoustic lens 31 and a plurality of annular grooves 62 having different radii and the same center as the Fresnel acoustic lens 31 are formed on the front side of the Fresnel acoustic lens 31 .

[0051] The circular flat Fresnel acoustic lens used here is thinner than the traditional spherical lens, which minimizes the space occupied. At the same time, the conventional piezoelectric ceramics are transformed from arc-shaped to flat-shaped, which further reduces the processing difficulty. The traditional spherical lens cannot be processed by conventional machines and can only be molded and ground.

[0052] When selecting lens materials, the following three factors need to be considered: 1. Small attenuation coefficient, 2. Good high temperature resistance, and 3. Low price.

[0053] Currently, the following materials can be used: PMP (polymethylpentene) material, acrylic resin, ABS plastic, epoxy resin and polystyrene, fluorosilicone acrylate and other plastics or sapphire as materials for lens production.

[0054] The present invention uses PMMA (polymethylmethacrylate) to process the lens, and the acoustic parameters are shown in Table 1:

[0055] Table 1 Lens acoustic parameters

[0056] Speed ​​of sound / m·s-1 Density / g·cm-3 Acoustic attenuation coefficient / dB·cm-1 2258 1.04 8.2

[0057] The present invention achieves weight reduction and volume reduction by replacing the traditional structure with a circular flat-plate Fresnel lens; compared with a spherical self-focusing transducer, it reduces production costs; compared with a high-power multi-element ultrasonic transducer, it reduces focus motion control costs.

[0058] The circular groove and the annular groove in the Fresnel acoustic lens mentioned in the present invention meet the following conditions:

[0059] The width of the annular groove is the width of the Fresnel zone;

[0060] Point F on the rotation axis of the Fresnel acoustic lens 31 is used as the ultrasound focusing point 35 .

[0061] The edge points of all annular grooves are marked from inside to outside as points 1-N, where N is a positive integer.

[0062] Then r F1 -r F2 =r F2 -r F3 ……=r F(N-1) -r FN =λ / 2, (1)

[0063] Among them, r is the sound path r of the edge point of the annular groove, and λ is the wavelength;

[0064] Counting from the center groove to both sides, when the sound wave enters the Fresnel acoustic lens 31 and passes through the odd-numbered bands,

[0065] The phase change is Δφ1, and the corresponding phase change through the even band is Δφ2, then:

[0066] Δφ2-Δφ1=π,(2)

[0067] That is, ω(d / c1-d / c2)=π; (3)

[0068] The expression of groove depth d can be obtained:

[0069] m=1,3,5…(4)

[0070] Wherein: λ1 is the wavelength of the sound wave in the air; c1 and c2 are the sound speeds in the air and in the Fresnel acoustic lens 31, respectively. As can be seen from the figure, the sound waves of two adjacent bands differ by an integer multiple of a period at point F, and the sound waves can be completely superimposed.

[0071] Diagram of sound path superposition

[0072] The sound pressure of a plane wave can be expressed as

[0073] , where k represents the wave number, represents the initial phase, p represents the sound pressure, and r represents the sound path. According to the Fresnel equation, the refractive indexes M1 and M2 of the two refractions when passing through the acoustic lens are respectively

[0074]

[0075] In formula (6), Z1 and Z2 are the characteristic impedances of air and lens respectively. Therefore, for the sound wave passing through the acoustic lens, its sound pressure can be expressed as

[0076] p t (r)=M1·M2·p(r) (7)

[0077] According to the Huygens-Fresnel principle, the total disturbance at point F is:

[0078]

[0079] The disturbance caused by the surface element dΣ on the secondary wave surface at point F is:

[0080]

[0081] Among them, θ is the direction angle of F to the secondary surface wave dΣ; r is the distance to point F; is the proportional constant. Select an annular half-wave band for analysis, take a first-order approximation for the area of ​​the band, integrate equation (9), and the total disturbance of the half-wave band to point F is obtained as:

[0082]

[0083] The sound waves transmitted by adjacent odd-numbered and even-numbered bands differ in r and θ, and only need to change 2π in the phase. Counting from the center, the sound pressure corresponding to the nth ring is

[0084] P n (F) = (1 + cosθ n )·P t ·∑ n / 2r n λ (11)

[0085] , where θn is the direction angle of the nth ring and dΣ is the area of ​​the nth ring. The radius of the first ring r0 of the Fresnel zone ring is related to the length of the nth ring rn

[0086]

[0087]

[0088] o, where f is the focal length of the acoustic lens, Figure 2 where is the distance of OF. So Σn is a constant,

[0089]

[0090] Substituting in, we get:

[0091]

[0092] According to the principle of wave superposition, the amplitude p(F) of the sound wave converged to point F through the acoustic lens can be calculated as

[0093] Efficiency of Fresnel Acoustic Lens

[0094] In practical applications, there are some factors that lead to the loss of acoustic lens efficiency, including reflection loss, absorption loss, process loss and structural loss. Among them, reflection loss plays a decisive role in the efficiency of acoustic lens.

[0095] According to the Fresnel reflection formula, the reflectivity R can be expressed as

[0096]

[0097] Where θ1 and θ2 are the incident angle and refraction angle respectively. Assuming that the reflectivity of the m-band sound at the incident interface of the i-th edge of the lens is Ri1, the reflectivity of the exit interface is Ri2, the sound absorption coefficient is Xs, the sound path from the exit surface to the incident surface is Gc, the incident angle on the incident interface is αi1, the refraction angle is αi2, the incident angle of the exit surface is βi1, and the exit angle is βi2, then the transmittance of the sound wave can be expressed as

[0098] T i =(1-R i1 )(1-R i2 )(1-X s ) Gc (18)

[0099] Among them, the expressions of Ri1 and Ri2 can be obtained from formula (17). Therefore, the total acoustic efficiency T of the Fresnel acoustic lens is the ratio of the sum of the acoustic energy transmitted by each ring to the sum of the acoustic energy incident on the lens surface, that is,

[0100] T=∑W i T i / ∑W i (19)

[0101] Among them, Wi is the energy of the sound incident on the i-th ring. When calculating the energy, because this paper designs a flat acoustic lens, the area that actually receives the sound wave is the surface area of ​​the front of the lens.

[0102] For these factors, the following methods can be used to reduce the efficiency loss of the acoustic lens:

[0103] 1. Consider the material and structure of the acoustic lens. High sound-transmitting materials and optimized structural design can be used to reduce absorption loss and structural loss. For example, the sound-transmitting performance of the acoustic lens can be improved by selecting high-sound damping materials and increasing the sound transmission coefficient.

[0104] 2. Reduce process errors. By improving the manufacturing process and reducing errors, the process loss can be reduced. For example, advanced manufacturing processes such as micro-nano manufacturing and precision injection molding can be used to reduce errors and improve manufacturing accuracy.

[0105] 3. Optimize interface design. The use of acoustic waveguide materials and / or bionic materials can reduce reflection losses. These materials can change the reflection coefficient of the interface, thereby reducing reflection losses. In addition, multi-level interface technology can be used to transition the interfaces of different media layer by layer to further reduce reflection losses.

[0106] Through the above measures, the efficiency of the acoustic lens can be effectively improved and the loss of acoustic energy can be reduced.

[0107] Regarding absorption loss: The treatment window in this case can be in direct contact with the tissue after applying gel, without the need to add a sound-conducting liquid transition like the existing solution, thereby reducing the loss caused by the sound-conducting medium.

[0108] The steady-state acoustic field in the water and tissue domains is modeled, and the acoustic intensity distribution in the tissue phantom is obtained. The absorbed acoustic energy is calculated and used as a heat source. Since the size of the acoustic focus area is much smaller than that of the tissue, the thermal simulation is performed only in the tissue domain.

[0109] The wave equation solved is the homogeneous Helmholtz equation in two-dimensional axisymmetric cylindrical coordinates:

[0110]

[0111] Where r and z are radial and axial coordinates, respectively, p is the sound pressure, and ω is the angular frequency. c and the speed of sound c c Takes a complex value representing the damping property of the material.

[0112] Based on Equation 19, assuming that acoustic wave propagation is linear and that the amplitude of shear waves in the tissue domain is much smaller than that of pressure waves, nonlinear effects and shear waves can be ignored. Given the acoustic pressure field, the acoustic intensity field can be easily obtained. In the plane wave limit, the heat source Q for thermal simulation is calculated as

[0113]

[0114] Among them, α ABS is the sound absorption coefficient, I is the sound intensity, p is the sound pressure, and v is the velocity vector of the sound particle. The acoustic volume heat source is inserted into the Pennes bioheat transfer equation as the heat transfer in the tissue phantom, and we get

[0115]

[0116] Where T is temperature, ρ is density, C P is the specific heat, k is the thermal conductivity, ρ b is the blood density, C b is the specific heat of blood, W b is the blood perfusion rate, T b is the blood temperature, Q is the heat source, Q met It is a metabolic heat source.

[0117] In this model, we assume that tissue properties do not change as temperature increases. Blood perfusion is also negligible.

[0118] Based on the above examples, the geometric structure parameters simulated in the model are as follows: a flat Fresnel lens with a focal length of 15mm and an opening diameter of 28mm is selected. The tissue phantom is a cylinder with a radius of 30mm and a length of 40mm. The tissue phantom and the transducer are coaxially arranged, so the model can be defined as two-dimensional axisymmetric. The driving frequency of the transducer is 2MHz, and the model solves the results in the tissue phantom after the transducer is turned on for 1 second. The following is a schematic diagram Figure 4 Shown: From Figure 4 The acoustic pressure field in the tissue domain can be clearly seen. Figure 4 The sound pressure distribution is depicted in Figure 2. The ultrasound beam enters the tissue and converges to the focal area. Figure 5-8 Both can display the sound energy concentrated in the focal area.

[0119] Fig. 9 is the normalized temperature / sound intensity curve, Fig. 9 It shows the shape of the heated area and the sidelobe heating effect at the maximum sound pressure position around the focal area (main lobe). The results show that due to the smoothing effect of conduction, the sidelobes in the sound intensity field are alleviated in the temperature response, which shows that the temperature change is roughly proportional to the sound intensity.

[0120] The following table 1 is the input information of organizational parameters for thermal simulation

[0121] Table 1 shows the organizational parameters

[0122] Tissue density <![CDATA[1050kg / m 3 ]]> Tissue heat capacity C 3370J / (kg·℃) Thermal conductivity κ 0.6w / (m℃) <![CDATA[Blood flow rate W b > <![CDATA[5kg / (m 3 ·s)]]> <![CDATA[Blood specific heat C b > 3770J / (kg·℃) Tissue attenuation coefficient α 25dB / m <![CDATA[Water attenuation coefficient α0]]> 0.22dB / m

[0123] When ultrasonic waves pass through the piezoelectric ceramic, they get plane waves. After phase modulation through the acoustic lens, they can also achieve the energy focusing effect of the spherical self-focusing ceramic.

[0124] Example 2

[0125] like Fig.18 As shown, the lens 31 is a bifocal lens 31, and the front side surface of the lens 31 is provided with a curved groove 41 with an arc-shaped cross-section; the two ends of the arc are provided with a concave first arc portion 42 and a second arc portion 43; the center O1 corresponding to the first arc portion 42 is located at the central axis and the center O1 forms an ultrasonic focusing point 35; the radius from the first arc portion 42 to the center O1 is R1; the center O2 corresponding to the second arc portion 43 is located at the central axis and the center O2 forms an ultrasonic focusing point 35; the radius from the second arc portion 43 to the center O2 is R2; the center O1 and the center O2 do not overlap.

[0126] The first arc portion 42 and the second arc portion 43 here each occupy an area of ​​180 degrees.

[0127] The currently designed dual-focus ultrasonic treatment head has the following dimensions: R1 = 23mm, R2 = 25mm; the opening diameter is 38mm.

[0128] Currently from Figure 10-13 Both can display the sound energy concentrated into the focal area.

[0129] from Fig.14 From the normalized temperature / sound intensity curve, it can be seen that under the same input parameters, the acoustic field side lobes under the bifocal lens are significantly more than those under the planar Fresnel lens.

[0130] The use of acoustic lenses reduces the requirements for the manufacturing process and appearance of piezoelectric ceramics, reduces costs, shortens the development and verification cycle, and the performance can be improved by adjusting the lens size after ceramic aging and loss.

[0131] The lenses here can all be rotated by a control mechanism, and the following two embodiments are derived here according to different structures of the control mechanism;

[0132] Example 3

[0133] like Figure 19-20 As shown: a rotating seat 51 is fixedly arranged on the rear side wall of the transducer 3, and the rotating seat 51 is rotatably installed in the treatment window 34, and a tooth structure 52 is arranged on the outer peripheral ring of the rotating seat 51; the control mechanism 2 is linked with the gear to drive the rotating seat 51 to rotate.

[0134] The control mechanism 2 includes a motor 21 and a motor driving gear 22. The motor 21 is installed on the handle 1. The motor driving gear 22 is installed on the output shaft of the motor 21. The axial direction of the output shaft of the motor 21 is parallel to the axial direction of the transducer 3. The motor driving gear 22 is meshed with the tooth structure 52 on the outer periphery of the rotating seat 51.

[0135] Example 4

[0136] like Figure 21-22 As shown: a rotating seat 51 is fixedly arranged on the rear side wall of the transducer 3, and the rotating seat 51 is rotatably installed in the treatment window 34, and a tooth structure 52 is arranged on the outer peripheral ring of the rotating seat 51; the control mechanism 2 is linked with the gear to drive the rotating seat 51 to rotate.

[0137] The control mechanism 2 includes a motor 21 and a motor bevel gear 23. The motor 21 is installed on the handle 1. The motor bevel gear 23 is installed on the output shaft of the motor 21. The axial direction of the output shaft of the motor 21 is perpendicular to the axial direction of the transducer 3. A steering bevel gear 24 is provided in the handle 1. The tooth structure 52 on the outer periphery of the rotating seat 51 is a helical tooth structure. A plurality of passive gears 25 meshing with the tooth structure 52 are provided in a ring array in the handle 1. Transmission gears 26 are provided between the motor bevel gear 23 and the steering bevel gear 24 and between the steering bevel gears 24 and the tooth structure 52.

[0138] The swivel seat 51 here is installed in the handle 1 for axial rotation limit, and its rotation is driven by the passive gear 25; the rotation of the motor 21 here drives the motor bevel gear 23, the transmission gear 26, the steering bevel gear 24, and the transmission gear 26 in sequence, and finally drives the swivel seat 51 to rotate axially.

[0139] The above embodiments 3 and 4 can realize their own axial rotation by controlling the rotation of the transducer.

[0140] In addition, in order to achieve the above Fig.15 , 16 Petal shape as shown or Fig.17 The spiral track shown is used to change the focus movement path according to actual needs. The present invention also designs the following embodiment structure:

[0141] Embodiment 5:

[0142] like Fig.23 , 24 As shown: the control mechanism 2 includes a motor 21 and a turntable 27, a rotating shaft 271 is eccentrically arranged on the front side of the turntable, and a rotating seat 51 is connected to the front end of the rotating shaft 271 and can rotate with the rotating shaft 271;

[0143] Among them, an eccentric mounting groove is opened on the front side of the rotating seat 51, and the transducer 3 is installed in the mounting groove; a guide ring tooth 35 is arranged on the inner side surface of the treatment window 34, and the tooth structure 52 on the outer periphery of the rotating seat 51 is engaged with the guide ring tooth 35; so that when the turntable 27 rotates, the rotating seat 51 rotates circumferentially around the guide ring tooth 35 and rotates on its own at the same time.

[0144] Here, when the motor 21 rotates, it drives the turntable 27 to rotate, and then drives the rotating seat 51 to move in a circumferential direction; because the rotating seat 51 is meshed with the guide ring gear 35, and the rotating seat 51 is rotatably connected to the turntable 27, the rotating seat 51 rotates in a circumferential direction and also realizes self-rotation. Fig.15 , 16 , 17 patterns, such as petal shapes, obtain a larger effective treatment area through simple circular trajectory movement. Compared with the sound field intensity of a single focus gradually weakening from the inside to the outside, the superposition can effectively compensate for the weaker internal sound field intensity.

[0145] The hand-held portion of the handle includes but is not limited to other structural forms considering ergonomics.

[0146] Currently, the control part can adopt existing technologies. For example, the motor can adopt a stepper motor. Specifically, you can adopt the industrial-grade products of Beijing Sitong Company. The gears can adopt common spur teeth, helical teeth, bevel teeth, gear racks, planetary teeth, fan-shaped teeth, etc., and even directly adopt belts.

[0147] like Fig.25As shown: the Fresnel acoustic lens of Example 1 is directly contacted with the skin after being coated with coupling agent, so that the coupling agent fills the circular groove and the annular groove, thereby reducing the sound attenuation.

[0148] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Acoustic lens focusing transducer system, characterized in that: The invention comprises a handle (1), a control mechanism (2) and a transducer (3), wherein the control mechanism (2) is installed in the handle (1), a treatment window (34) is also provided on the handle (1), and the transducer (3) is rotatably installed in the treatment window (34), and the control mechanism (2) and the transducer (3) are linked to control the transducer (3) to perform self-rotation or self-rotation synchronous circumferential motion in the projection area of ​​the treatment window (34); The transducer (3) comprises, from the outside to the inside, a lens (31), a piezoelectric ceramic (32), and a matching layer (33) which are arranged in sequence and bonded together; The structure of the lens (31) is configured to form at least one ultrasound focus point (35) in the treatment area of ​​the treatment window (34) with the ultrasound converted by the lens (31).

2. The acoustic lens focusing transducer system according to claim 1, characterized in that: The lens (31) is a circular flat plate-shaped Fresnel acoustic lens (31), and the front side surface of the Fresnel acoustic lens (31) is provided with a circular groove cocentric with the Fresnel acoustic lens (31) and a plurality of annular grooves cocentric with the Fresnel acoustic lens (31) and having different radii.

3. The acoustic lens focusing transducer system according to claim 1, characterized in that: The circular groove and the annular groove in the Fresnel acoustic lens (31) satisfy the following conditions: The width of the annular groove is the width of the Fresnel zone; Let point F on the rotation axis of the Fresnel acoustic lens (31) be the ultrasonic focusing point (35), The edge points of all annular grooves are marked from inside to outside as points 1-N, where N is a positive integer. Then r F1 -r F2 = r F2 -r F3 …… = r F(N-1) -r FN = λ / 2, Among them, r is the sound path r of the edge point of the annular groove, and λ is the wavelength; Counting from the center groove to both sides, when the sound wave enters the Fresnel acoustic lens (31) and passes through the odd-numbered bands, The phase change is Δφ1, and the corresponding phase change through the even band is Δφ2, then: Δφ2-Δφ1=π, That is, ω(d / c1-d / c2)=π; The expression of groove depth d can be obtained: Wherein: λ1 is the wavelength of the sound wave in the air; c1 and c2 are the sound speeds in the air and in the Fresnel acoustic lens (31), respectively.

4. The acoustic lens focusing transducer system according to claim 1, characterized in that: The lens (31) is a bifocal lens (31), and a curved groove (41) with an arc-shaped cross section is provided on the front side surface of the lens (31); a concave first arc portion (42) and a second arc portion (43) are provided at both ends of the arc; a center O1 corresponding to the first arc portion (42) is located on the central axis and the center O1 forms an ultrasonic focus point (35); a radius from the first arc portion (42) to the center O1 is R1; a center O2 corresponding to the second arc portion (43) is located on the central axis and the center O2 forms an ultrasonic focus point (35); a radius from the second arc portion (43) to the center O2 is R2; and the centers O1 and O2 do not overlap.

5. The acoustic lens focusing transducer system according to claim 1, characterized in that: A rotating seat (51) is fixedly arranged on the rear side wall of the transducer (3), and the rotating seat (51) is rotatably installed in the treatment window (34). A tooth structure (52) is arranged on the outer circumference of the rotating seat (51); the control mechanism (2) is linked with the gear to drive the rotating seat (51) to rotate.

6. The acoustic lens focusing transducer system according to claim 5, characterized in that: The control mechanism (2) comprises a motor (21) and a motor driving gear (22), wherein the motor (21) is mounted on the handle (1), and the motor driving gear (22) is mounted on the output shaft of the motor (21), wherein the axial direction of the output shaft of the motor (21) is parallel to the axial direction of the transducer (3), and the motor driving gear (22) is meshed with a tooth structure (52) on the outer periphery of the rotating seat (51).

7. The acoustic lens focusing transducer system according to claim 5, characterized in that: The control mechanism (2) comprises a motor (21) and a motor bevel gear (23). The motor (21) is mounted on the handle (1). The motor bevel gear (23) is mounted on the output shaft of the motor (21). The axial direction of the output shaft of the motor (21) is perpendicular to the axial direction of the transducer (3). A steering bevel gear (24) is arranged inside the handle (1). The tooth structure (52) on the outer periphery of the rotating seat (51) is a helical tooth structure. A plurality of passive gears (25) meshing with the tooth structures (52) are arranged in an annular array inside the handle (1). Transmission gears (26) are arranged between the motor bevel gear (23) and the steering bevel gear (24) and between the steering bevel gears (24) and the tooth structures (52).

8. The acoustic lens focusing transducer system according to claim 5, characterized in that: The control mechanism (2) comprises a motor (21) and a rotating disk (27); a rotating shaft (271) is eccentrically provided on the front side of the rotating disk; a rotating seat (51) is connected to the front end of the rotating shaft (271) and can rotate with the rotating shaft (271); An eccentric mounting groove is provided on the front side of the rotating seat (51), and the transducer (3) is installed in the mounting groove; a guide ring tooth (35) is provided on the inner side surface of the treatment window (34), and a tooth structure (52) on the outer periphery of the rotating seat (51) meshes with the guide ring tooth (35); so that when the turntable (27) rotates, the rotating seat (51) rotates around the guide ring tooth (35) and rotates on its own at the same time.

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