Patch ultrasonic transducer for thyroid imaging diagnosis and preparation method thereof

Abstract

The invention relates to a patch ultrasonic transducer for thyroid imaging diagnosis and a preparation method thereof, the patch ultrasonic transducer is in two-dimensional high-density array distribution, the array element number range is 4 * 64 to 16 * 128, and each array element comprises an outer matching layer, an inner matching layer, a piezoelectric vibrator and a backing, the whole array element is in wire connection with the back common electrode through a flexible printed circuit (FPC); each array element can be excited independently, the acoustic beam direction and the focus position are adjusted through the dynamic beam forming technology, and transverse cutting, longitudinal cutting and inclined section imaging of a thyroid region is achieved; the bending radius of the FPC ranges from 10 mm to 50 mm, the system is suitable for high-resolution imaging of superficial tissues of the human body, and accurate monitoring of thyroid nodules, boundaries, volumes and dynamic changes of the thyroid nodules is achieved. Compared with the prior art, by combining flexible and rigid design, dynamic beam control and a high-density array structure, the imaging quality and diagnosis efficiency of a thyroid region are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic medical imaging, and in particular to a patch ultrasonic transducer for thyroid imaging diagnosis and a preparation method thereof. Background Art

[0002] The incidence of thyroid diseases, such as thyroid nodules, thyroiditis and dysfunction, is increasing year by year around the world. Traditional thyroid ultrasound examinations use handheld probes and are performed by professional doctors in medical institutions. The operation is complex and difficult to meet daily monitoring needs.

[0003] With the development of flexible electronic technology and high-performance ultrasonic transducers, wearable ultrasound devices are gradually being used in the medical field. Through flexible array ultrasonic transducers and dynamic beam control technology, this device can achieve real-time imaging and monitoring of superficial tissues (such as the thyroid gland), providing patients with portable and efficient health management tools.

[0004] However, existing wearable ultrasonic transducers still have the following problems:

[0005] 1. Since most devices adopt a "purely flexible" design, the ultrasound array elements are connected through flexible circuits. The relative positions of the array elements may shift due to the bending of the patch itself or the movement of the wearer, resulting in errors or even distortion of the imaging results;

[0006] 2. Insufficient imaging resolution. Traditional wearable devices mostly use lower frequencies (<7MHz), which makes it difficult to achieve high-resolution imaging of the thyroid gland;

[0007] 3. There is a lack of optimized design for the thyroid region, which cannot meet the scanning width requirements of more than 40mm in transverse section and more than 30mm in longitudinal section required for thyroid diagnosis, and cannot achieve standardized transverse and longitudinal imaging. Summary of the invention

[0008] The purpose of the present invention is to overcome the defects of the above-mentioned prior art such as insufficient resolution, limited dynamic monitoring capability and poor wearing stability, and to provide a patch ultrasonic transducer for thyroid imaging diagnosis and a preparation method thereof. By combining flexible and rigid design, dynamic beam control and high-density array structure, the imaging quality and diagnostic efficiency of the thyroid region are significantly improved, providing a new solution for non-invasive and portable medical imaging technology.

[0009] The present invention proposes a patch-type ultrasonic transducer for regular standardized imaging diagnosis of the thyroid gland. Through high-density 4×64 to 16×128 array design, line-by-line scanning technology and flexible patch design, the structural design and preparation method of the transducer are optimized to achieve high-resolution imaging and dynamic monitoring of the thyroid gland area, while solving the problem of imaging distortion caused by array element position drift in traditional flexible patches.

[0010] The present invention provides a patch ultrasonic transducer for thyroid imaging diagnosis. The patch ultrasonic transducer is a two-dimensional high-density array distribution, and the number of array elements ranges from 4×64 to 16×128. Each array element includes: an outer matching layer, an inner matching layer, a piezoelectric vibrator, and a backing. The entire array of array elements is connected to a common electrode on the back through a flexible circuit board FPC by wires; each array element can be excited individually, and the direction and focus position of the sound beam are adjusted through dynamic beamforming technology to achieve transverse, longitudinal and oblique section imaging of the thyroid region;

[0011] The bending radius of the flexible circuit board FPC ranges from 10 mm to 50 mm, which is suitable for high-resolution imaging of superficial tissues of the human body and can achieve accurate monitoring of thyroid nodules, boundaries, volumes and their dynamic changes.

[0012] Furthermore, the size of each array element is 0.2mm×0.2mm; through row-by-row and column-by-column excitation, it supports high-resolution transverse and longitudinal imaging within the range of 45mm×35mm in the thyroid region.

[0013] Furthermore, the backing material is a mixture of epoxy resin and metal powder, and the silicone rubber is polydimethylsiloxane PDMS.

[0014] Furthermore, the piezoelectric vibrator material is lead zirconate titanate PZT ceramic or 1-3 type piezoelectric ceramic composite material.

[0015] Furthermore, the patch ultrasonic transducer adopts a double-layer packaging design: the outer packaging adopts biocompatible polymer materials to enhance the waterproof, sweat-proof and durability of the device; the inner packaging protects the array elements and circuit connections to ensure structural stability when worn for a long time.

[0016] Furthermore, the outer packaging layer is a flexible packaging layer with the ability to adapt to a bending radius of 10mm to 50mm, ensuring that the device can fit closely to different neck curvatures; the inner packaging layer is a rigid base layer, which provides mechanical support for the piezoelectric vibrator, prevents the array element position from shifting, and improves imaging stability.

[0017] Furthermore, the ultrasonic transducer achieves a beam scanning angle of ±45° through dynamic beam forming, and combines electronic layer-by-layer scanning to obtain multi-directional cross-sectional images of the thyroid gland; the imaging depth covers 7-8cm, which is suitable for standardized dynamic monitoring of the thyroid gland.

[0018] Furthermore, the ultrasonic transducer can be worn for a long time and can realize real-time data transmission through wireless or wired transmission modules to meet the needs of daily dynamic monitoring and telemedicine.

[0019] The present invention also provides a method for preparing a patch ultrasonic transducer for thyroid imaging diagnosis, comprising the following steps:

[0020] S1: Connect the positive electrode of the piezoelectric vibrator to the common electrode through conductive silver glue;

[0021] S2: Fix the piezoelectric vibrator connected to the common electrode, and directly pour and cure the backing on the positive electrode surface of the piezoelectric vibrator to reduce back reflection and optimize the acoustic performance;

[0022] S3: Connect the negative electrode of the piezoelectric vibrator with the backing to the wire on the flexible circuit board to ensure the stability of signal transmission;

[0023] S4: coating an outer matching layer and an inner matching layer on the negative electrode surface of the piezoelectric vibrator, wherein the inner matching layer is made of a mixture of zirconium oxide particles and epoxy resin, and the inner matching layer is a biocompatible polymer material, which is used to optimize acoustic impedance matching;

[0024] S5: using a dicing machine to cut the transducer obtained in step S4 into array elements to form a precise high-density array structure;

[0025] S6: Repeat steps S1 to S5 to prepare a plurality of array modules, and connect the array modules using a flexible circuit so that all common electrodes are connected to each other;

[0026] S7: Encapsulation with biocompatible flexible polymers to form a complete wearable ultrasound transducer.

[0027] Furthermore, the inner matching layer is composed of a mixture of epoxy resin and nano-scale zirconium oxide, with an acoustic impedance of 4-11 MRayl; the backing is made of a mixture of epoxy resin and metal powder, with an acoustic impedance of 6 MRayl, which optimizes acoustic energy conduction and echo signal strength.

[0028] This ultrasonic transducer can simultaneously perform standardized transverse and longitudinal imaging of the thyroid region and obtain multi-directional ultrasonic echoes, providing conditions for further analysis of diagnostic information such as thyroid tissue morphology, nodule size, boundary characteristics, and volume changes.

[0029] The transducer can collect multi-directional cross-sectional images within the range of 45mm transverse section and 35mm longitudinal section of the thyroid gland, and at the same time, combined with the line-by-line scanning technology, it can generate standardized B-mode grayscale images to improve the accuracy of diagnosis.

[0030] This ultrasonic transducer can be worn on the patient's neck for a long time and is used for thyroid nodule screening, postoperative recovery monitoring and dynamic trend analysis.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] (1) High-resolution imaging: The present invention has a two-dimensional high-density array design with a lateral resolution better than 0.2 mm and a center frequency range of 7 MHz to 20 MHz, which can clearly present the boundaries and dynamic changes of thyroid nodules.

[0033] (2) Wearing comfort: The structure combines flexibility and rigidity. The flexible packaging design adapts to the curvature of the neck, and the rigid structure improves the stability of the array.

[0034] (3) Multi-scenario applicability: The present invention has dynamic beam control technology, which achieves a beam scanning angle of ±45° through dynamic beam forming, and combines electronic layer-by-layer scanning to obtain multi-directional cross-sectional images of the thyroid gland. The imaging depth covers 7-8cm, which is suitable for standardized dynamic monitoring of the thyroid gland, supports dynamic monitoring of the thyroid region, postoperative follow-up and early screening, and can also be extended to imaging of other superficial tissues (such as breast and carotid artery).

[0035] (4) Portability: The transducer can be worn for a long time and can realize real-time data transmission through wireless or wired transmission modules to meet the needs of daily dynamic monitoring and telemedicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a flow chart for preparing a high-density array patch-type ultrasonic transducer;

[0037] Figure 2 The overall and structural schematic diagram of the 8×64 array patch-type ultrasonic transducer array prepared in Example 1;

[0038] Figure 3 This is a schematic diagram of a usage scenario of the 8×64 array patch-type ultrasonic transducer prepared in Example 1;

[0039] Figure 4 This is a diagram of the element echo signal of the 8×64 array patch-type ultrasonic transducer prepared in Example 1.

[0040] Figure 5 Schematic diagram of electronic scanning of the 8×64 array patch-type ultrasonic transducer prepared in Example 1.

[0041] Figure 6 Grayscale images of the cross-section and longitudinal section of the thyroid B-mode produced by the 8×64 array patch-type ultrasonic transducer prepared in Example 1.

[0042] Figure numerals: 1-patch ultrasonic transducer; 2-array element; 3-external matching layer; 4-inner matching layer; 5-piezoelectric vibrator; 6-backing; 7-array elements in an array; 8-signal lead. DETAILED DESCRIPTION

[0043] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0044] Example 1

[0045] This embodiment provides a method for preparing a patch ultrasonic transducer for thyroid imaging diagnosis, such as Figure 1 As shown, the following steps are included:

[0046] S1. The negative electrode surface of the piezoelectric vibrator 5 with a size of 0.2 mm × 0.2 mm is attached to the flat substrate, and the positive electrode is connected to the common electrode using conductive silver glue. The common electrode uses a copper foil with a thickness of 50 μm to cover the vibrator surface to ensure electrical conduction.

[0047] S2. Seal the piezoelectric vibrator 5 and pour the backing material on the positive electrode surface. The backing 6 is made of a mixture of metal powder with a particle size of 13 μm and epoxy resin, and the acoustic impedance is 6 MRayl. The pouring thickness is controlled at 1 mm and allowed to stand for 48 hours to ensure uniform curing.

[0048] S3. Connect the negative electrode surface of the piezoelectric vibrator with the backing layer to the wire of the flexible circuit board FPC through conductive silver glue. The spacing between the wires of the flexible circuit board is 0.3mm to ensure stable signal transmission of the array element.

[0049] S4, the inner matching layer 4 and the outer matching layer 3 are sequentially coated on the negative electrode surface of the piezoelectric vibrator 5: the inner matching layer 4 is made of a mixture of epoxy resin and nanometer-sized zirconium oxide, with an acoustic impedance of 4-11 MRayl and a thickness of 1 / 4 of the ultrasonic wavelength; the outer matching layer 3 is made of a biocompatible polymer, with an acoustic impedance of 2-3 MRayl and a thickness of 50 μm. After the matching layers are evenly coated, they are cured for 12 hours.

[0050] S5. Use a dicing machine to cut the transducer with an array element spacing of 0.3 mm to form a high-density two-dimensional array of 8 rows × 64 columns. The cutting slit width is controlled within the range of 1 to 1.5 times the wavelength of the array element acoustic wave to ensure cutting accuracy and signal integrity.

[0051] S6. Repeat steps S1 to S5 to prepare multiple rows of transducers, and connect each transducer so that all common electrodes are connected to each other.

[0052] S7. The connected and conductive patch-type ultrasonic transducer array is flexibly packaged. The outer layer uses a biocompatible polyimide film with a thickness of less than 0.2 mm, and the inner layer packaging covers the array edge and circuit connection to enhance structural stability and ensure comfort for long-term wearing.

[0053] like Figure 2 As shown, a patch ultrasonic transducer 1 for thyroid imaging diagnosis is prepared by the above method. The patch ultrasonic transducer 1 is a two-dimensional high-density array distribution of 8 rows×64 columns, as shown in FIG. Figure 2 The mark 2 in the figure refers to the structure of a single array element. Each array element 2 includes: an outer matching layer 3, an inner matching layer 4, a piezoelectric vibrator 5, and a backing 6. Figure 2 The mark 7 in the figure refers to the entire row of array elements, which are connected to the common electrode on the back through the flexible circuit board FPC by wires; each array element 2 can be excited individually, and the direction and focal position of the sound beam can be adjusted through dynamic beamforming technology to achieve transverse, longitudinal and oblique section imaging of the thyroid region.

[0054] The material of the backing 6 is a mixture of epoxy resin and metal powder, and the silicone rubber adopts polydimethylsiloxane PDMS; the material of the piezoelectric vibrator 5 is lead zirconate titanate PZT ceramic or 1-3 type piezoelectric ceramic composite material.

[0055] The prepared patch ultrasonic transducer 1 for thyroid imaging diagnosis was subjected to a performance test. The instruments used in this test included an impedance analyzer (Agilent 4294A) and a pulse signal transmitter (JSR DPR300).

[0056] Acoustic performance test: pulse echo test was performed on the 64 array elements of the prepared patch ultrasonic transducer 1 using a pulse signal transmitter. The ultrasonic transducer was fixed horizontally and parallelly at a distance of 3 mm from the steel plate for pulse echo test. The pulse echo could be measured on all 64 array elements. Figure 4 Figure 3 is a representative array element pulse echo and its bandwidth diagram, indicating that the transducer has excellent ultrasonic transmission and reception performance.

[0057] Imaging performance tests, such as Figure 3 As shown, the prepared patch ultrasonic transducer 1 is attached to the right area of ​​the thyroid gland, and then laterally connected to the ultrasound instrument through the signal lead 9. The device can automatically scan at multiple angles, such as Figure 5 shown.

[0058] Two angles are selected for imaging the target thyroid gland, namely, transverse imaging and longitudinal imaging. Since ultrasound imaging is continuous, four frames are selected in this embodiment to clearly display the nodules of the target thyroid gland. Figure 6As shown in the figure, 10 is a schematic diagram of cross-section imaging, 12, 13, 14, and 15 are cross-section imaging B-ultrasound images of the thyroid gland, 11 is a schematic diagram of longitudinal imaging, and 16, 17, 18, and 19 are longitudinal imaging B-ultrasound images of the thyroid gland. In clinical diagnosis, the device collects cross-section and longitudinal images of the thyroid gland through automatic electronic scanning, which can completely cover the imaging range of the thyroid gland of 45mm×35mm. Through dynamic beam control and layer-by-layer scanning, the boundaries and internal structures of the thyroid tissue can be clearly displayed.

[0059] Cross-sectional imaging: Figure 6 As shown, the four images 12, 13, 14, and 15 are cross-sectional images of the thyroid gland. The patch-type ultrasonic transducer prepared in Example 1 activates 64 array elements in each row from top to bottom for electronic scanning. The standardized cross-sectional images of the right area of ​​the thyroid gland captured in the process are 4 images in sequence. From 12, a clear and complete thyroid gland can be seen. Continue scanning downward, and you can see an abnormal echo signal area in the thyroid tissue in 13, followed by an abnormal echo signal area shown in 14. The scan ends at 15 without abnormality. The symptoms are initially identified as thyroid nodules, and then it is necessary to switch to longitudinal imaging to confirm whether it is a thyroid nodule. The boundaries and size of the nodules are clearly displayed, providing important data support for subsequent quantitative analysis and diagnosis.

[0060] Longitudinal section imaging: Figure 6 As shown, the four images 16, 17, 18, and 19 are longitudinal images of the thyroid gland, which are four images sequentially captured from the standardized cross-sectional images of the right area of ​​the thyroid gland generated by the patch-type ultrasonic transducer prepared in Example 1, which excites 8 array elements in each column from the outside to the inside for electronic scanning. From 17, we can see the abnormal echo signal area, and then the abnormal echo signal area in 18, and then the scan in 19 returns to normal.

[0061] From the test results of the right thyroid transverse and longitudinal imaging, the abnormal echo signal area of ​​the thyroid can be clearly identified, and the thyroid nodule can be diagnosed. The experimental results show that the device can clearly display the thyroid boundary, nodules and surrounding tissue structures at an imaging depth of 7-8cm, and the scanning width can reach more than 45mm for transverse cutting and more than 35mm for longitudinal cutting, which fully meets the needs of clinical diagnosis and provides important data support for subsequent quantitative analysis and diagnosis.

[0062] Long-term wearing test: the device was attached to the necks of different subjects to test the stability and comfort of wearing for 24 hours. The results showed that the device fit well under different neck curvatures, the signal transmission was stable, and there was no obvious discomfort.

[0063] The patch-type ultrasonic transducer prepared in Example 1 can realize standardized imaging of the thyroid region when worn daily by patients, and synchronously obtain multi-section echo data in the transverse and longitudinal directions. The device has high resolution (better than 0.2mm in the transverse direction), depth coverage (7-8cm) and good signal stability, providing reliable imaging conditions for early screening of thyroid diseases, postoperative recovery and dynamic trend analysis.

[0064] The ultrasonic transducer of the present invention realizes high-resolution non-invasive monitoring of the thyroid region through high-density array design, dynamic beam control technology and flexible packaging structure, overcoming the limitations of traditional equipment in portability and imaging stability.

[0065] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0066] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A patch ultrasonic transducer for thyroid imaging diagnosis, characterized in that: The patch ultrasonic transducer (1) is a two-dimensional high-density array distribution, and the number of array elements ranges from 4×64 to 16×128. Each array element includes: an outer matching layer (3), an inner matching layer (4), a piezoelectric vibrator (5), and a backing (6). The entire array of array elements is connected to the common electrode on the back through a flexible circuit board (FPC) by wires; each array element can be excited individually, and the direction and focus position of the sound beam can be adjusted through dynamic beamforming technology to achieve transverse, longitudinal and oblique section imaging of the thyroid region; The bending radius of the flexible circuit board FPC ranges from 10 mm to 50 mm, which is suitable for high-resolution imaging of superficial tissues of the human body and can achieve accurate monitoring of thyroid nodules, boundaries, volumes and their dynamic changes.

2. A patch ultrasonic transducer for thyroid imaging diagnosis according to claim 1, characterized in that: The size of each array element is 0.2mm×0.2mm; through row-by-row and column-by-column excitation, it supports high-resolution transverse and longitudinal imaging within the range of 45mm×35mm in the thyroid area.

3. A patch ultrasonic transducer for thyroid imaging diagnosis according to claim 1, characterized in that: The backing (6) material is a mixture of epoxy resin and metal powder, and the silicone rubber is polydimethylsiloxane (PDMS).

4. A patch ultrasonic transducer for thyroid imaging diagnosis according to claim 1, characterized in that: The material of the piezoelectric vibrator (5) is lead zirconate titanate PZT ceramic or 1-3 type piezoelectric ceramic composite material.

5. The patch ultrasonic transducer for thyroid imaging diagnosis according to claim 1, characterized in that: The patch ultrasonic transducer (1) adopts a double-layer packaging design: the outer packaging adopts a biocompatible polymer material to enhance the waterproof, sweat-proof and durability of the device; the inner packaging protects the array element and the circuit connection to ensure the structural stability when worn for a long time.

6. A patch ultrasonic transducer for thyroid imaging diagnosis according to claim 5, characterized in that: The outer packaging layer is a flexible packaging layer with the ability to adapt to a bending radius of 10mm to 50mm, ensuring that the device can fit closely to different neck curvatures; the inner packaging layer is a rigid base layer, which provides mechanical support for the piezoelectric vibrator, prevents the array element position from shifting, and improves imaging stability.

7. A patch ultrasonic transducer for thyroid imaging diagnosis according to claim 1, characterized in that: The ultrasonic transducer achieves a beam scanning angle of ±45° through dynamic beam forming, and combines electronic layer-by-layer scanning to obtain multi-directional cross-sectional images of the thyroid gland; the imaging depth covers 7-8cm, which is suitable for standardized dynamic monitoring of the thyroid gland.

8. The patch ultrasonic transducer for thyroid imaging diagnosis according to claim 1, characterized in that: Ultrasonic transducers can achieve real-time data transmission through wireless or wired transmission modules to meet daily dynamic monitoring and telemedicine needs.

9. A method for preparing a patch ultrasonic transducer for thyroid imaging diagnosis according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Connecting the positive electrode of the piezoelectric vibrator (5) to the common electrode through conductive silver glue; S2: fix the piezoelectric vibrator (5) connected to the common electrode, and directly pour and cure the backing (6) on the positive electrode surface of the piezoelectric vibrator (5) to reduce back reflection and optimize acoustic performance; S3: connecting the negative electrode of the piezoelectric vibrator (5) with the backing (6) to the wire on the flexible circuit board to ensure the stability of signal transmission; S4: coating an outer matching layer (3) and an inner matching layer (4) on the negative electrode surface of the piezoelectric vibrator (5), wherein the inner matching layer (4) is made of a mixture of zirconium oxide particles and epoxy resin, and the inner matching layer (4) is a biocompatible polymer material, for optimizing acoustic impedance matching; S5: using a dicing machine to cut the transducer obtained in step S4 into array elements to form a precise high-density array structure; S6: Repeat steps S1 to S5 to prepare a plurality of array modules, and connect the array modules using a flexible circuit so that all common electrodes are connected to each other; S7: Encapsulation with biocompatible flexible polymers to form a complete wearable ultrasound transducer.

10. The method for preparing a patch ultrasonic transducer for thyroid imaging diagnosis according to claim 9, characterized in that: The inner matching layer (4) is composed of a mixture of epoxy resin and nano-scale zirconium oxide, with an acoustic impedance of 4-11 MRayl; the backing (6) is made of a mixture of epoxy resin and metal powder, with an acoustic impedance of 6 MRayl, which optimizes acoustic energy conduction and echo signal strength.

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