Ultrasonic transducer capable of generating two-dimensional complex vibration and design method therefor

Abstract

The present invention relates to an ultrasonic transducer capable of generating two-dimensional complex vibration and a design method therefor. The sizes of piezoelectric elements in the ultrasonic transducer satisfy that: when each piezoelectric element is excited, the resonant frequencies of the piezoelectric element in the thickness direction and the width direction can be coupled to be a same frequency, so as to generate two-dimensional complex vibration in the thickness direction and the width direction, and this two-dimensional complex vibration can enable ultrasonic waves emitted by the ultrasonic transducer to be propagated in a plurality of directions, thereby achieving a wider coverage range and more efficient energy transfer, and significantly improving an ultrasonic-assisted thrombolysis treatment effect. By means of the design method, the sizes of the corresponding piezoelectric elements can be obtained only by acquiring initial performance parameters and target performance parameters; under the sizes, the piezoelectric elements can achieve two-dimensional complex vibration in the thickness direction and the width direction, the coupling effect of the piezoelectric elements in the length direction can be avoided, and unnecessary consumption of energy outputted by the ultrasonic transducer can be avoided.

Description

A two-dimensional composite vibration ultrasonic transducer and its design method Technical Field

[0001] This invention relates to the field of interventional medical device technology, and in particular to a two-dimensional composite vibration ultrasonic transducer and its design method. Background Technology

[0002] Thrombotic diseases are common and frequently occurring in clinical practice. In my country, millions of people are diagnosed with thrombotic disorders each year. Thrombi are composed of insoluble fibrin, deposited platelets, accumulated white blood cells, and trapped red blood cells. Once a thrombus forms in a blood vessel, it obstructs normal blood flow, leading to ischemia or even necrosis of local tissues or organs.

[0003] There are currently several treatment options for venous thromboembolism, one of which is ultrasound-assisted thrombolysis. In ultrasound-assisted thrombolysis, an ultrasound corer is guided to the location of the embolism within the blood vessel lumen, radiating ultrasound waves into the thrombus. Simultaneously, thrombolytic drugs are injected into the thrombus. The mechanical vibration and cavitation effect of the ultrasound waves loosen the dense fibrin structure within the thrombus, promoting the delivery of thrombolytic drugs and thus improving the thrombolytic efficiency.

[0004] In existing technologies, ultrasonic transducers can only emit ultrasonic waves in two directions, resulting in uneven distribution of ultrasonic energy. In some directions, insufficient ultrasonic energy leads to unsatisfactory thrombolysis effects. Therefore, designing an ultrasonic transducer capable of generating two-dimensional composite vibrations has become a pressing technical problem to be solved.

[0005] Summary of the Invention

[0006] This invention discloses a two-dimensional composite vibration ultrasonic transducer and its design method, which is used to solve the problems existing in the prior art.

[0007] In a first aspect, embodiments of the present invention provide a two-dimensional composite vibration ultrasonic transducer, including at least one ultrasonic transmitting unit, wherein the ultrasonic transmitting unit includes a first electrode wire, a second electrode wire, and a piezoelectric element;

[0008] The first electrode wire is located at the central axis, and two piezoelectric elements are electrically connected to the two sides of the first electrode wire respectively. The two piezoelectric elements are configured as rectangular blocks of the same size. The two second electrode wires are electrically connected to the two piezoelectric elements respectively and extend along the axial direction.

[0009] The dimensions of the piezoelectric element satisfy the following condition: when the piezoelectric element is excited, the resonant frequencies of the piezoelectric element in the thickness direction and the width direction can be coupled to the same frequency, generating two-dimensional composite vibration in the thickness direction and the width direction.

[0010] As a preferred technical solution, the dimensions of the piezoelectric element further satisfy the requirement that no coupling effect occurs in the length direction of the piezoelectric element.

[0011] As a preferred technical solution, the ratio of the width to the thickness of the piezoelectric element is negatively correlated with the thickness frequency constant of the piezoelectric element.

[0012] As a preferred technical solution, the thickness frequency constant is negatively correlated with the material density of the piezoelectric element.

[0013] As a preferred technical solution, the width-to-thickness ratio of the piezoelectric element is configured to be 0.3-3, and the length of the piezoelectric element is configured to be more than 3 times the thickness and / or width.

[0014] As a preferred technical solution, the thickness direction of the piezoelectric element is the polarization direction, the length direction of the piezoelectric element is parallel to the axis of the first electrode wire, and the width direction of the piezoelectric element is another direction perpendicular to the thickness and length directions.

[0015] Secondly, embodiments of the present invention provide a design method for a two-dimensional composite vibration ultrasonic transducer. The design method is used to design a two-dimensional composite vibration ultrasonic transducer as described in any of the preceding claims, comprising:

[0016] Obtain the initial and target performance parameters of the piezoelectric element;

[0017] Calculation models for the apparent compliance constant of piezoelectric elements in the width and thickness directions are constructed respectively;

[0018] Construct a resonant frequency model for a piezoelectric element when it undergoes two-dimensional fundamental frequency resonance;

[0019] Based on the apparent compliance constant calculation model and the resonant frequency model, a correlation model between the width-to-thickness ratio and the thickness frequency constant of the piezoelectric element is constructed.

[0020] Based on the initial and target performance parameters, the dimensions of the piezoelectric element are determined through an association model.

[0021] As a preferred technical solution, the initial performance parameters include the material density of the piezoelectric element, multiple sets of elastic compliance constants, and stress components of the piezoelectric element in the length, width, and thickness directions. The multiple sets of elastic compliance constants include: a first elastic compliance constant in which the polarization direction is the length direction and the vibration direction is also the length direction; a second elastic compliance constant in which the polarization direction is the length direction and the vibration direction is the width direction; a third elastic compliance constant in which the polarization direction is the length direction and the vibration direction is the thickness direction; and a fourth elastic compliance constant in which the polarization direction is the thickness direction and the vibration direction is also the thickness direction.

[0022] The target performance parameters include the target resonant frequency and the target aspect ratio of the piezoelectric element.

[0023] As a preferred technical solution, the step of constructing calculation models for the apparent compliance constants of the piezoelectric element in the width and thickness directions respectively further includes:

[0024] Based on the piezoelectric equation, calculation models for strain components of a piezoelectric element in the length, width, and thickness directions are constructed respectively.

[0025] Calculate the Poisson's ratio of a piezoelectric element in multiple directions;

[0026] A calculation model for the coupling coefficient of the piezoelectric element in the thickness and width directions is constructed.

[0027] Based on the strain component calculation model, the Sompo ratio and coupling coefficient calculation model, strain component calculation models for piezoelectric elements in the width and thickness directions are constructed respectively.

[0028] As a preferred technical solution, the step of constructing a resonant frequency model of a piezoelectric element when it undergoes two-dimensional fundamental frequency resonance includes:

[0029] A first resonant frequency model and a second resonant frequency model are constructed respectively. The first resonant frequency model is related to the width of the piezoelectric element, and the second resonant frequency model is related to the thickness of the piezoelectric element.

[0030] As a preferred technical solution, the step of determining the dimensions of the piezoelectric element based on initial performance parameters and a correlation model includes:

[0031] Obtain a set of coupling coefficients for the vibration of the piezoelectric element in the thickness and width directions;

[0032] Based on the correlation model, the values ​​of several width-to-thickness ratios and thickness frequency constants were determined;

[0033] The dimensions of the piezoelectric element are determined based on the target performance parameters.

[0034] Thirdly, embodiments of the present invention provide an electronic device, including:

[0035] One or more processors;

[0036] Memory, used to store one or more programs;

[0037] When the one or more programs are executed by the one or more processors, the one or more processors implement the ultrasonic transducer design method for two-dimensional composite vibration as described in any of the preceding claims.

[0038] Fourthly, embodiments of the present invention provide a readable storage medium storing a two-dimensional composite vibration ultrasonic transducer design program. When the design program is executed by a processor, it can realize the two-dimensional composite vibration ultrasonic transducer design method as described in any of the preceding claims.

[0039] Compared with the prior art, the technical solution adopted in this invention can achieve the following beneficial effects:

[0040] In one embodiment, the present invention provides a two-dimensional composite vibration ultrasonic transducer. The dimensions of the piezoelectric element in the ultrasonic transducer are such that when the piezoelectric element is excited, the resonant frequencies of the piezoelectric element in the thickness direction and the width direction can be coupled to the same frequency to generate two-dimensional composite vibration in the thickness direction and the width direction. This two-dimensional composite vibration allows the ultrasonic waves emitted by the ultrasonic transducer to propagate in multiple directions, thereby achieving a wider coverage and more efficient energy transfer. In particular, when applied to ultrasound-assisted thrombolysis, it can significantly enhance the treatment effect and shorten the operation time.

[0041] In another embodiment of the present invention, a design method for the ultrasonic transducer with the above-mentioned two-dimensional composite vibration is also provided. Based on this design method, complex experimental operations are no longer required, simplifying the design steps. Only the initial performance parameters and target performance parameters need to be obtained to obtain the corresponding piezoelectric element size. Under this size, the piezoelectric element can realize two-dimensional composite vibration in the thickness and width directions and can avoid its coupling effect in the length direction, thus avoiding unnecessary consumption of the acoustic output energy of the ultrasonic transducer. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, forming part of the present invention. The illustrative embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0043] Figure 1 is a schematic diagram of the structure of a two-dimensional composite vibration ultrasonic transducer disclosed in Embodiment 1 of the present invention;

[0044] Figure 2 is a schematic diagram of the structure of the ultrasonic conductor disclosed in Embodiment 1 of the present invention;

[0045] Figure 3 is a schematic diagram of the structure of the ultrasonic transducer assembly disclosed in Embodiment 1 of the present invention;

[0046] Figure 4 is a graph showing the relationship between the thickness frequency constant and the width-to-thickness ratio as disclosed in Embodiment 2 of the present invention.

[0047] Explanation of reference numerals in the attached drawings: Piezoelectric element 11, first electrode wire 12, second electrode wire 13, ultrasonic transducer assembly 14, Luer connector 15, power connector 16. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of this invention, it should be noted that the term "or" is generally used to include the meaning of "and / or," unless otherwise expressly indicated.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, in the description of this application, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0050] Obviously, the described embodiments are only some, not all, of the embodiments of the present 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.

[0051] Example 1

[0052] Referring to Figure 1, in this embodiment of the invention, a two-dimensional composite vibration ultrasonic transducer is provided, which is preferably used in ultrasound-assisted thrombolysis. During treatment, it can radiate ultrasonic energy from inside the thrombus to the surrounding area, so that the thrombolytic drug can be more evenly distributed inside the thrombus to accelerate the dissolution of the thrombus.

[0053] In a preferred embodiment, the two-dimensional composite vibration ultrasonic transducer includes at least one ultrasonic transmitting unit, as shown in FIG1. ​​The ultrasonic transmitting unit includes a first electrode wire 12, a second electrode wire 13, and a piezoelectric element 11. The first electrode wire 12 is preferably configured as a negative electrode wire and is located at the central axis of the ultrasonic transmitting unit. A piezoelectric element 11 is electrically connected to each side of the first electrode wire 12. The piezoelectric elements 11 arranged on the left and right sides are configured as rectangular blocks of the same size. A second electrode wire 13 is electrically connected to the outer surface of each of the two piezoelectric elements 11. The second electrode wire 13 is preferably configured as a positive electrode wire and extends along the axial direction.

[0054] When an alternating voltage is applied to the first electrode wire 12 and the second electrode wire 13, the piezoelectric element 11 is excited and generates mechanical vibration, thereby emitting ultrasonic waves. In some embodiments, the piezoelectric element 11 may be selected from piezoelectric ceramics, polyvinylidene fluoride (PVDF) or single crystal piezoelectric materials, and piezoelectric ceramic materials are more preferably used.

[0055] Preferably, the piezoelectric element 11 has three directions: the polarization direction of the piezoelectric element 11 is defined as its thickness direction, the direction parallel to the axis of the first electrode wire 12 is defined as its length direction, and the other direction perpendicular to the thickness direction and the length direction is defined as its width direction.

[0056] In a preferred embodiment, the dimensions of the piezoelectric element 11 satisfy the following condition: when the piezoelectric element 11 is excited by an alternating voltage, the resonant frequencies of the piezoelectric element 11 in the thickness and width directions can couple to the same frequency, generating a two-dimensional composite vibration in both the thickness and width directions. This two-dimensional composite vibration allows the ultrasonic waves emitted by the ultrasonic transducer to propagate in multiple directions, thereby achieving a wider coverage and more efficient energy transfer. Especially when applied to ultrasound-assisted thrombolysis, it can significantly enhance the treatment effect and shorten the operation time.

[0057] Specifically, when the piezoelectric element 11 is excited by an alternating voltage, it vibrates at its natural frequency, which is the resonant frequency. At the resonant frequency, the piezoelectric element 11 can generate vibrations with the maximum amplitude. In this embodiment, the piezoelectric element 11 can generate resonant frequencies in both its thickness and width directions when excited, and these frequencies are coupled to the same frequency. This allows it to vibrate and emit ultrasonic waves simultaneously in both the thickness and width directions. Since the vibrations in the width direction and the thickness direction are not located in the same plane, this is called "two-dimensional composite vibration".

[0058] In a preferred embodiment, since the length direction of the piezoelectric element 11 is the same as the delivery direction of the ultrasonic transducer in the human body, the vibration of the piezoelectric element 11 in the length direction basically does not produce a therapeutic effect and will consume the energy output by the ultrasonic transducer. In order to convert electrical energy into vibration in the thickness and width directions as much as possible, the dimensions of the piezoelectric element 11 further satisfy the following: the length direction of the piezoelectric element 11 does not produce a coupling effect.

[0059] In a preferred embodiment, the width-to-thickness ratio of the piezoelectric element 11 is negatively correlated with its thickness frequency constant. Specifically, the thickness frequency constant is the product of the resonant frequency of the piezoelectric element 11 in its thickness direction and its thickness. The thickness frequency constant is negatively correlated with the material density of the piezoelectric element 11; therefore, further, the width-to-thickness ratio of the piezoelectric element 11 is negatively correlated with its material density.

[0060] In a preferred embodiment, based on the above design concept, the aspect ratio of the piezoelectric element 11 is configured to be 0.3-3, the length of the piezoelectric element 11 is configured to be more than 3 times its thickness and / or width, and the frequency is 20KHz-10MHz. Specifically, after determining the aspect ratio and thickness frequency constant of the piezoelectric element 11, the values ​​of the thickness and width of the piezoelectric element 11 can be further determined according to the relationship between the two.

[0061] Furthermore, this embodiment also provides an ultrasonic transducer core, which includes several axially electrically connected two-dimensional composite vibration ultrasonic transducers to form an ultrasonic transducer group 14, as shown in Figures 2 and 3. The outer periphery of the ultrasonic transducer group 14 is covered with encapsulating adhesive, and a Luer connector 15 and a power connector 16 are further provided at its proximal end. Preferably, a temperature sensor can be further provided between the ultrasonic transducer group 14 and the encapsulating adhesive. The specific structure and setting position of the temperature sensor can refer to any embodiment disclosed in the prior art, and are not specifically limited here.

[0062] Furthermore, this embodiment also provides an ultrasonic thrombolysis device, including the aforementioned ultrasonic core, with a thrombolysis catheter disposed outside the ultrasonic core for delivering the ultrasonic core within the body. In this embodiment, the structure and size of the thrombolysis catheter are not specifically limited, and those skilled in the art can freely choose according to actual needs.

[0063] Example 2

[0064] In this embodiment of the invention, a design method for a two-dimensional composite vibration ultrasonic transducer is provided, which is used to design the two-dimensional composite vibration ultrasonic transducer in Embodiment 1 above. The technical features already described in Embodiment 1 above are naturally inherited in this embodiment and will not be repeated.

[0065] Preferably, the above design method includes:

[0066] S210, obtain the initial performance parameters and target performance parameters of the piezoelectric element 11.

[0067] In some embodiments, the piezoelectric element 11 is a rectangular block. The polarization direction of the piezoelectric element 11 is defined as its thickness direction, and the thickness T extends along the Z-axis of the rectangular coordinate system. The direction parallel to the axis of the first electrode wire 12 is defined as its length direction, and the length L extends along the X-axis of the rectangular coordinate system. The other direction perpendicular to the thickness direction and the length direction is defined as its width direction, and the width W extends along the Y-axis of the rectangular coordinate system. The length L is much larger than the thickness T and the width W, and the dimensions of the width W and the thickness T are comparable.

[0068] In some embodiments, the initial performance parameters include the material density ρ of the piezoelectric element 11 and multiple sets of elastic compliance constants. and the stress component σ of the piezoelectric element 11 in the length direction x Stress component σ in the width direction y The stress component σ in the thickness direction z .

[0069] In some embodiments, the elastic compliance constant The subscript i represents the polarization direction of the piezoelectric element 11, and the subscript j represents the vibration direction of the piezoelectric element 11. The values ​​1 represent the X direction, 2 the Y direction, and 3 the Z direction, and the unit is (×10⁻¹⁰). -12 m 2 / N); In this embodiment, only the expansion and contraction vibration of the piezoelectric element 11 is considered. Multiple sets of elastic compliance constants Includes: the first elastic compliance constant of the piezoelectric element 11 in which the polarization direction is the length direction and the vibration direction is also the length direction. The second elastic compliance constant of the piezoelectric element 11 with the polarization direction being the length direction and the vibration direction being the width direction The third elastic compliance constant of the piezoelectric element 11 with the polarization direction being the length direction and the vibration direction being the thickness direction. The fourth elastic compliance constant of the piezoelectric element 11 in the thickness direction and the vibration direction is also in the thickness direction.

[0070] In some embodiments, the target performance parameters include the target resonant frequency f0 of the piezoelectric element 11 and the target aspect ratio.

[0071] S220, construct calculation models for the apparent compliance constant of the piezoelectric element 11 in the width and thickness directions respectively.

[0072] In some embodiments, step S220 further includes:

[0073] S221, Based on the piezoelectric equation, strain component calculation models of piezoelectric element 11 in the length direction, width direction and thickness direction are constructed respectively. The strain component calculation models are as follows (1)-(3):

[0074] Where, ε y ,ε z These are the strain components of the piezoelectric element 11 in the Y and Z directions, respectively. According to the above embodiment 1, the size of the piezoelectric element 11 satisfies that no coupling effect is generated in its length direction. Therefore, the strain component of the piezoelectric element 11 in the X direction in equation (3) is 0.

[0075] S222, calculate the Sorpoise ratio of the piezoelectric element 11 in multiple directions.

[0076] In some embodiments, Poisson's ratio V ij That is, the ratio of the strain of the piezoelectric element 11 in different directions, let:

[0077] S223, construct a coupling coefficient calculation model for the vibration of piezoelectric element 11 in the thickness and width directions.

[0078] In some embodiments, the coupling coefficient of the piezoelectric element 11 vibrating in the thickness and width directions is defined as n, and the coupling coefficient calculation model is as follows:

[0079] n = -σ z / σ y (5)

[0080] S224. Based on the strain component calculation model, the Sompo ratio and coupling coefficient calculation model, strain component calculation models of piezoelectric element 11 in the width and thickness directions are constructed respectively.

[0081] In some embodiments, from equations (1)-(5) above, the calculation models for the strain components of the piezoelectric element 11 in the width and thickness directions are respectively:

[0082] In some embodiments, the apparent compliance constant calculation model of the piezoelectric element 11 in the width and thickness directions can be further obtained according to the above equations (6) and (7):

[0083] S230, construct a resonant frequency model of the piezoelectric element 11 when it undergoes two-dimensional fundamental frequency resonance.

[0084] In some embodiments, step S230 further includes:

[0085] S231, construct a first resonant frequency model and a second resonant frequency model respectively. The first resonant frequency model is related to the width of the piezoelectric element 11, and the second resonant frequency model is related to the thickness of the piezoelectric element 11. The first resonant frequency model is as follows:

[0086] The second resonant frequency model is:

[0087] In equations (10) and (11) above, f0 is the fundamental resonant frequency of the piezoelectric element 11, and ρ is the density of the piezoelectric element 11, in units of (kg / m).

[0088] S240, based on the apparent compliance constant calculation model and the resonant frequency model, construct the correlation model between the width-to-thickness ratio and the thickness frequency constant of the piezoelectric element 11.

[0089] In some embodiments, the aspect ratio of the piezoelectric element 11 is . The thickness frequency constant is f0T. Using equations (1)-(11) above, the width-to-thickness ratio calculation model and the thickness frequency constant calculation model of the piezoelectric element 11 can be obtained. The width-to-thickness ratio calculation model is:

[0090] The thickness frequency constant calculation model is as follows:

[0091] S250, based on initial performance parameters and target performance parameters, determines the size of piezoelectric element 11 through an association model.

[0092] In some embodiments, step 250 further includes: obtaining a set of coupling coefficients n of the piezoelectric element 11 vibrating in the thickness and width directions; determining the values ​​of several width-to-thickness ratios and thickness frequency constants based on the correlation model; and determining the dimensions of the piezoelectric element 11 based on the target performance parameters.

[0093] In some embodiments, after obtaining the initial performance parameters, V 12 V 13 V 31 Since all are constants, a series of coupling coefficients n can be calculated. The values ​​of f0T and f0T are mapped onto a series of relational curves. When designing an ultrasonic transducer, the target resonant frequency f0 of the piezoelectric element 11 and the target width-to-thickness ratio are considered. Once determined, the width W and thickness T of the piezoelectric element 11 can be determined based on the above relationship curve. After determining the width W and thickness T of the piezoelectric element 11, the length L can be selected as needed. The length L preferably needs to be at least 3 times the thickness T and width W to avoid the coupling effect of the piezoelectric element 11 in the length direction.

[0094] In one embodiment, a target resonant frequency f0 of 2MHz and a target aspect ratio are designed. Taking an ultrasonic transducer with a two-dimensional composite vibration of 1.5 as an example, its initial performance parameters include: 12.3×10 -12 m 2 / N, -4.05×10 - 12 m 2 / N, -5.31×10 -12 m2 / N, 15.5×10 -12 m 2 / N, the material density ρ of the piezoelectric element 11 is 7500 kg / m³, and according to the above formula (4), V 12 =0.33, V 13 =0.43, V 31 =0.34, and then according to the above equations (12) and (13), the thickness frequency constant f0T and the width-to-thickness ratio are obtained. The relationship curve is shown in Figure 4. From Figure 4, it can be seen that when the width-to-thickness ratio... When the value is 1.5, the thickness frequency constant f0T of the piezoelectric element 11 is approximately 1070 Hz·m. At this time, the thickness T can be calculated to be approximately 0.54 mm and the width W to be approximately 0.8 mm. Then, the length L dimension is selected as needed. The length L is preferably more than 3 times the thickness T and / or the width W.

[0095] In some embodiments, the aspect ratio of the piezoelectric element 11 is configured to be 0.3-3, the length of the piezoelectric element 11 is configured to be more than 3 times its thickness and / or width, and the frequency is 20 kHz to 10 MHz.

[0096] In one embodiment of the present invention, an electronic device is also provided, the electronic device including at least one processor and a memory, the memory being used to store one or more programs, which, when executed by the processor, enable the processor to implement the ultrasonic transducer design method for two-dimensional composite vibration as described above.

[0097] In one embodiment of the present invention, a readable storage medium is also provided, on which a design program for a two-dimensional composite vibration ultrasonic transducer is stored. When the design program for the two-dimensional composite vibration ultrasonic transducer is executed by a processor, steps S210 to S250 can be implemented.

[0098] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0099] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these modifications are within the protection scope of the present invention.

Claims

1. A two-dimensional composite vibration ultrasonic transducer, characterized in that, It includes at least one ultrasonic transmitting unit, wherein the ultrasonic transmitting unit includes a first electrode wire, a second electrode wire, and a piezoelectric element; The first electrode wire is located at the central axis, and the two piezoelectric elements are electrically connected to the two sides of the first electrode wire respectively. The two piezoelectric elements are configured as rectangular blocks of the same size. The two second electrode wires are electrically connected to the two piezoelectric elements respectively and extend along the axial direction. The dimensions of the piezoelectric element satisfy the following condition: when the piezoelectric element is excited, the resonant frequencies of the piezoelectric element in the thickness direction and the width direction can be coupled to the same frequency, generating a two-dimensional composite vibration in the thickness direction and the width direction.

2. The ultrasonic transducer with two-dimensional composite vibration according to claim 1, characterized in that, The dimensions of the piezoelectric element further satisfy the requirement that no coupling effect occurs in the length direction of the piezoelectric element.

3. The ultrasonic transducer with two-dimensional composite vibration according to claim 2, characterized in that, The width-to-thickness ratio of the piezoelectric element is negatively correlated with the thickness frequency constant of the piezoelectric element.

4. The ultrasonic transducer with two-dimensional composite vibration according to claim 3, characterized in that, The thickness frequency constant is negatively correlated with the material density of the piezoelectric element.

5. The ultrasonic transducer with two-dimensional composite vibration according to claim 4, characterized in that, The width-to-thickness ratio of the piezoelectric element is configured to be 0.3-3, and the length of the piezoelectric element is configured to be more than 3 times the thickness and / or width.

6. The ultrasonic transducer with two-dimensional composite vibration according to any one of claims 1-5, characterized in that, The thickness direction of the piezoelectric element is the polarization direction, the length direction of the piezoelectric element is parallel to the axis of the first electrode wire, and the width direction of the piezoelectric element is another direction perpendicular to the thickness and length directions.

7. A design method for a two-dimensional composite vibration ultrasonic transducer, the design method being used to design a two-dimensional composite vibration ultrasonic transducer as described in any one of claims 1-6, characterized in that, include: Obtain the initial and target performance parameters of the piezoelectric element; Calculation models for the apparent compliance constant of the piezoelectric element in the width and thickness directions are constructed respectively; Construct a resonant frequency model of the piezoelectric element when it undergoes two-dimensional fundamental frequency resonance; Based on the apparent compliance constant calculation model and the resonant frequency model, a correlation model between the width-to-thickness ratio and the thickness frequency constant of the piezoelectric element is constructed. Based on the initial performance parameters and the target performance parameters, the dimensions of the piezoelectric element are determined using the correlation model.

8. The design method according to claim 7, characterized in that, The initial performance parameters include the material density of the piezoelectric element, multiple sets of elastic compliance constants, and the stress components of the piezoelectric element in the length, width, and thickness directions. The multiple sets of elastic compliance constants include: a first elastic compliance constant in which the polarization direction and vibration direction of the piezoelectric element are both in the length direction; a second elastic compliance constant in which the polarization direction and vibration direction are both in the width direction; a third elastic compliance constant in which the polarization direction and vibration direction are both in the thickness direction; and a fourth elastic compliance constant in which the polarization direction and vibration direction are both in the thickness direction. The target performance parameters include the target resonant frequency and target aspect ratio of the piezoelectric element.

9. The design method according to claim 7, characterized in that, The step of constructing the apparent compliance constant calculation model of the piezoelectric element in the width and thickness directions respectively further includes: Based on the piezoelectric equation, strain component calculation models for the piezoelectric element in the length, width, and thickness directions are constructed respectively. Calculate the Spohr ratio of the piezoelectric element in multiple directions; Construct a model for calculating the coupling coefficient of the piezoelectric element's vibration in the thickness and width directions; Based on the strain component calculation model, the Sompo ratio and the coupling coefficient calculation model, strain component calculation models for the piezoelectric element in the width and thickness directions are constructed respectively.

10. The design method according to claim 7, characterized in that, The step of constructing the resonant frequency model of the piezoelectric element when it undergoes two-dimensional fundamental frequency resonance includes: A first resonant frequency model and a second resonant frequency model are constructed respectively. The first resonant frequency model is associated with the width of the piezoelectric element, and the second resonant frequency model is associated with the thickness of the piezoelectric element.

11. The design method according to claim 7, characterized in that, The step of determining the dimensions of the piezoelectric element based on the initial performance parameters and the correlation model includes: Obtain a set of coupling coefficients for the vibration of the piezoelectric element in the thickness and width directions; Based on the aforementioned correlation model, the values ​​of several width-to-thickness ratios and thickness frequency constants are determined; The dimensions of the piezoelectric element are determined based on the target performance parameters.

12. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the ultrasonic transducer design method for two-dimensional composite vibration as described in any one of claims 7-11.

13. A readable storage medium, characterized in that, The readable storage medium stores a design program for a two-dimensional composite vibration ultrasonic transducer, which, when executed by a processor, enables the design method for a two-dimensional composite vibration ultrasonic transducer as described in any one of claims 7-11.

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