Multi-frequency MEMS ultrasonic endoscopy catheter and endoscopy system

Abstract

The present invention relates to a multi-frequency MEMS ultrasonic endoscopic catheter and an endoscopic system, wherein the catheter comprises a catheter body and an ultrasonic probe, wherein the ultrasonic probe comprises a frame panel, an ultrasonic transducer, and a welding pad. On the one hand, the present invention can simultaneously and synchronously receive ultrasonic signals of different frequencies of the same target, effectively overcoming the problem that the existing dual-frequency or multi-frequency solutions receive different target positions, and there is a certain time difference before and after, which may be caused by the deviation of the catheter or the transducer; on the other hand, the advantages of the miniaturization and sub-array elements of the MEMS ultrasonic transducer are utilized, which not only meets the needs of 360° scanning imaging, but also can be manufactured using CMOS technology, and can be used simultaneously and synchronously in multi-frequency ultrasonic endoscopic catheters, reducing the number of times different frequency endoscopic catheters are used, and improving the real-time, synchronization and accuracy of imaging.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a multi-frequency MEMS ultrasonic endoscopy catheter, and also relates to a multi-frequency MEMS ultrasonic endoscopy system. Background Art

[0002] High-frequency ultrasonic endoscope uses natural cavities such as the digestive tract, respiratory tract, and blood vessels to directly reach the patient's site with a catheter equipped with a 360-degree mechanically rotatable high-frequency micro-ultrasonic transducer. It can directly observe the changes in the mucosa of the digestive tract such as the esophagus, stomach, and duodenum, and can perform real-time ultrasonic scanning to observe the various levels of the digestive tract. This helps doctors detect inflammation, ulcers, tumors, and other lesions of the gastric mucosa, as well as lesions of the esophageal mucosa, such as esophagitis, esophageal ulcers, and esophageal tumors. At the same time, it can also examine lesions in the duodenal papilla, descending duodenum, horizontal part, vertical part, etc., such as duodenal polyps, duodenal obstruction, duodenal stenosis, etc.

[0003] Since the ultrasonic probe of the high-frequency ultrasonic endoscope is close to the lesion site, it can significantly improve the resolution of the lesion and detect small lesions. This allows it to be used to diagnose lesions of organs near the digestive tract, such as the pancreas, bile duct, gallbladder, liver and spleen. For example, in the diagnosis of common bile duct stones, high-frequency ultrasonic endoscopes are significantly better than B-ultrasound and CT in judging the size of stones and whether the bile duct is dilated, especially for small stones that cannot be found by B-ultrasound. However, since the attenuation of ultrasound increases exponentially with frequency, although high-frequency ultrasound can bring high resolution, its detection depth is limited. Therefore, in order to overcome the contradiction between resolution and imaging depth, people began to use catheters with dual-frequency ultrasonic transducers. By combining the characteristics of low-frequency and high-frequency ultrasound, dual-frequency ultrasonic endoscopes achieve a balance between imaging resolution and imaging depth, thereby improving the accuracy and reliability of diagnosis. Dual-frequency ultrasonic endoscopes can obtain image information at more levels and angles, which helps doctors to conduct a more comprehensive and in-depth analysis of lesions. Through dual-frequency imaging, doctors can locate the lesion more quickly, reduce unnecessary examinations and operations, and thus improve diagnostic efficiency. In interventional ultrasound examinations (such as intravascular ultrasound), dual-frequency ultrasound endoscopes can reduce the number of probe changes, reduce patient pain and examination risks. Dual-frequency ultrasound endoscopes are an important development direction for ultrasound transducers and provide new ideas for the design of high-frequency transducers. Its application in ultrasound endoscopes, IVUS imaging systems, array transducers, etc. is of great significance and can meet the needs of various ultrasound detection, diagnosis, and interventional surgery.

[0004] The MEMS (micro-electromechanical system) ultrasonic endoscopy probe is an advanced device that applies micro-electromechanical technology to the field of medical ultrasonic endoscopy. It is based on the principle of ultrasonic imaging. By integrating key components such as miniature ultrasonic transducers in the probe, the transducer can convert electrical energy into ultrasonic mechanical energy to emit ultrasonic waves. When ultrasonic waves propagate in the human body and encounter different tissue interfaces, they will produce reflections and scattering. The reflected ultrasonic signals are received by the transducer and converted back into electrical signals. After subsequent processing and analysis, the corresponding ultrasonic images are finally formed to help doctors observe the tissue conditions in the body. In short, the use of MEMS technology can make ultrasonic transducers very small, which makes the overall size of the probe small and can easily pass through the natural cavities of the human body (such as the esophagus, gastrointestinal tract, blood vessels, etc.) into the body for inspection, reducing invasiveness and discomfort to the human body. At the same time, multiple functional components can be integrated in a small space, such as transducer arrays, signal transmission lines, drive circuits (some of which may be externally matched), etc., to achieve more complex and accurate ultrasonic signal transmission and reception functions.

[0005] The current probe uses a multi-frequency ultrasonic transducer solution, such as: a high-frequency 20M transducer and a 12M transducer are back-to-back and distributed up and down, and the two share a backing. The two transducers can be excited simultaneously or successively, and the high and low frequency imaging of the same target can be achieved successively by rotating the catheter, and finally displayed simultaneously or fused. Another example: a three-frequency ultrasonic endoscope, its basic principle is to stick three transducers of different frequencies together around the direction of the catheter section.

[0006] However, although the above multi-frequency ultrasonic transducer solution can realize low-frequency and high-frequency ultrasonic imaging at the same time, it has the following defects:

[0007] 1) The transducers are arranged back to back or around the catheter. Instead of imaging the same target at the same position at the same time, they need to rotate at different angles to achieve sequential imaging of the blood vessels or digestive tract. As the ultrasound endoscope catheter rotates at high speed, the position of the probe at the center of the catheter and the position of the catheter relative to the target will drift to a certain extent, resulting in non-real-time synchronous imaging of the same target. Therefore, the deviation of catheter movement or tissue displacement cannot achieve high-precision ultrasound endoscopy imaging;

[0008] 2) The molding of the transducer is limited by the limitations of traditional processes. Even if the size of the endoscopic ultrasound transducer is very small, it is impossible to realize ultrasound endoscope probe catheters of too many frequencies. Summary of the invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an improved multi-frequency MEMS ultrasonic endoscopy catheter.

[0010] At the same time, the invention also relates to a multi-frequency MEMS ultrasonic endoscopy system.

[0011] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0012] A multi-frequency MEMS ultrasonic endoscopic catheter comprises a catheter body having a distal end and a proximal end, and an ultrasonic probe, wherein the ultrasonic probe comprises a frame panel which is in a long strip shape and can be rotated around a distal center line and is installed inside the distal end of the catheter body, ultrasonic transducers arranged in an array on the same side of the frame panel, and a welding pad formed on the frame panel near the proximal end and connecting the ultrasonic transducers, wherein the ultrasonic transducer has at least two different operating frequencies, there are multiple welding pads, and ultrasonic transducers with the same operating frequency are connected to the same welding pad, and each welding pad is connected to a host through a coaxial cable; each ultrasonic transducer is made by CMOS technology.

[0013] Preferably, the positive electrodes of ultrasonic transducers with the same operating frequency are connected to the same pad, and the negative electrodes are connected to the same ground.

[0014] Furthermore, the positive electrodes of the ultrasonic transducers connected to the same pad are connected in parallel, which can synchronously excite all ultrasonic transducers in the multi-frequency probe, and each ultrasonic transducer of the probe receives its own ultrasonic echo. Because the ultrasonic transducers of the same frequency are all connected in parallel, only one signal echo is finally formed.

[0015] According to a specific implementation and preferred aspect of the present invention, the pad is coplanar with the ultrasonic transducer, so as to facilitate the docking setting of the probe end direction, and generally in an endoscopic catheter, the pad is connected to the host through a coaxial cable in the catheter, that is, the corresponding array element distribution area corresponds to the distal end of the endoscopic tube.

[0016] According to another specific implementation and preferred aspect of the present invention, the frame panel is packaged at the distal end of the catheter body, and both sides of the frame panel are relatively close to the inner wall of the catheter body and can achieve 360° rotation around the center line of the distal end.

[0017] In some specific embodiments, the operating frequency of the ultrasonic transducer is 10-80 MHz, and the ultrasonic transducer is a piezoelectric micromachined ultrasonic transducer or a capacitive micromachined ultrasonic transducer. In short, the array element can freely combine high and low frequencies, such as 10 MHz for low frequency and 20 MHz for high frequency, or even higher 30 MHz and 50 MHz.

[0018] Preferably, the film in the piezoelectric micromachined ultrasonic transducer is made of a material with piezoelectric properties, such as aluminum nitride, scandium-doped aluminum nitride or piezoelectric ceramics, and / or the diameter of the film is 1 to 100 μm, and the thickness of the cavity is between 0.1 mm and 1 mm. Alternatively, the film in the capacitive micromachined ultrasonic transducer is made of silicon or a high molecular polymer, and the capacitive micromachined ultrasonic transducer also has a bias circuit to form a working bias voltage. The film in the piezoelectric micromachined ultrasonic transducer is made of a material with piezoelectric properties, such as aluminum nitride, scandium-doped aluminum nitride or piezoelectric ceramics; the film in the capacitive micromachined ultrasonic transducer is made of silicon or a high molecular polymer; or the capacitive micromachined ultrasonic transducer also has a bias circuit to form a working bias voltage. The array element structure of the piezoelectric micromachined ultrasonic transducer is PMUT (Piezoelectric Micromachined Ultrasonic Transducer); the array element structure of the capacitive micromachined ultrasonic transducer is CMUT (Capacitive Micromachined Ultrasonic Transducers).

[0019] According to yet another specific implementation and preferred aspect of the present invention, each ultrasonic transducer is circular or polygonal in shape.

[0020] In addition, the ultrasonic transducer has two operating frequencies and is divided into a high frequency group and a low frequency group. Both the high frequency group and the low frequency group include array element rows that are arranged side by side and spaced apart. The array element rows of the high frequency group and the low frequency group are spaced apart and staggered.

[0021] Alternatively, the ultrasonic transducer has three operating frequencies, and every three ultrasonic transducers with different operating frequencies constitute an array element monomer, and a plurality of array element monomers are arranged in rows horizontally and columns vertically at intervals on the same side of the frame panel.

[0022] Another technical solution of the present invention is: a multi-frequency MEMS ultrasonic endoscopy system, which includes a host, a display, a connecting handle and a multi-frequency MEMS ultrasonic endoscopy catheter, wherein the ultrasonic probe realizes 360° rotation scanning through a driving shaft, the connecting handle is connected to the proximal end of the catheter body, and includes a rotating motor, a high-voltage excitation module, and a rotary encoder; the host includes a data collector, a signal amplifier, a filter processor, and an imaging processor, wherein the data collector can synchronously collect and process ultrasonic echo signals of different frequencies and display them in real time separately.

[0023] Preferably, the CMOS process is used (a mature process in this field, which is an integrated circuit manufacturing process mainly used to manufacture large-scale integrated circuits. The CMOS process is developed on the basis of the PMOS and NMOS processes. The C in CMOS stands for "complementary", that is, NMOS devices and PMOS devices are simultaneously manufactured on the same silicon substrate to manufacture CMOS integrated circuits. CMOS integrated circuits have many advantages such as low power consumption, high speed, strong anti-interference ability, and high integration. The CMOS process has now become the mainstream process technology for large-scale integrated circuits, and most integrated circuits are manufactured using the CMOS process). The designed array element structure is a cavity film vibration structure, and the film in the PMUT uses a material with piezoelectric properties, such as aluminum nitride ALN, scandium-doped aluminum nitride ALscN, piezoelectric ceramics PZT, etc. The film in the CMUT uses silicon Si or a high molecular polymer.

[0024] In addition, the above real-time display can be selected as a separate frequency display or a fused frequency display.

[0025] Due to the implementation of the above technical solution, the present invention has the following advantages compared with the prior art:

[0026] In the existing multi-frequency endoscopic catheter, although low-frequency and high-frequency ultrasonic imaging can be achieved simultaneously, the transducers are back-to-back or distributed around the catheter, and the same position of the same target is not imaged at the same time, but it is necessary to rotate at different angles to achieve sequential imaging of the blood vessels or the digestive tract. Then, due to the high-speed rotation of the ultrasonic endoscope catheter, the position of the probe in the center of the catheter and the position of the catheter relative to the target will have a certain position drift, resulting in non-real-time synchronous imaging of the same target. Therefore, the deviation of catheter movement or tissue displacement cannot achieve high-precision ultrasonic endoscope imaging; in addition, the molding of the transducer is limited by the limitations of traditional processes. Even if the size of the endoscopic ultrasonic transducer is very small, it cannot achieve too many frequencies of ultrasonic endoscope probe catheters and so on. The present invention cleverly solves various deficiencies of the existing structure by overall design of the multi-frequency MEMS ultrasonic endoscope catheter structure. After adopting the endoscope catheter, the short pulse generated by the excitation module in the handle can cover all the probes. There is a working frequency of the ultrasonic transducer, and all ultrasonic transducers in the multi-frequency probe are synchronously excited. Each ultrasonic transducer of the probe receives its own ultrasonic echo, and the ultrasonic transducers of the same frequency form a signal echo. Then the ultrasonic echo signals of each frequency are transmitted to the handle through the cable and the slip ring, and are transferred to the system host through the TR switch for signal processing, and finally displayed on the screen. Therefore, on the one hand, the present invention can simultaneously and synchronously receive ultrasonic signals of different frequencies of the same target, effectively overcoming the difference that the existing dual-frequency or multi-frequency schemes receive different target positions, and there is a certain time difference before and after, which may be caused by the deviation of the catheter or the transducer; on the other hand, the advantages of the miniaturization and sub-array elements of the MEMS ultrasonic transducer are utilized, which not only meets the needs of 360° scanning imaging, but also can be manufactured using the CMOS process, and can be used simultaneously and synchronously in multi-frequency ultrasonic endoscope catheters, reducing the number of times different frequency endoscope catheters are used, and improving the real-time, synchronization and accuracy of imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the multi-frequency MEMS ultrasonic endoscopy system of the present invention;

[0028] Figure 2 for Figure 1 An enlarged schematic diagram of the structure of the mid-endoscopic catheter;

[0029] Figure 3 for Figure 2 A schematic diagram of the structure of the ultrasonic probe;

[0030] Figure 4 for Figure 2 A schematic diagram of an enlarged structure of another embodiment of an ultrasonic probe;

[0031] Figure 5 is a schematic diagram of the structure of the ultrasonic transducer of the present invention (CMUT);

[0032] Figure 6 Schematic diagram of the structure of the ultrasonic transducer of the present invention (PMUT);

[0033] Wherein: 1. host; 2. display; 3. connecting handle; 4. multi-frequency MEMS ultrasonic endoscope catheter; 40. catheter body; 40a. distal end; 40b. proximal end; 41. ultrasonic probe; 410. frame panel; 411. ultrasonic transducer; 412. welding pad; g. high frequency group; d. low frequency group; I. high frequency; II. medium frequency; III. low frequency; T. array element monomer. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0040] like Figures 1 to 6 As shown, the multi-frequency MEMS ultrasonic endoscopy system of the present embodiment includes a host 1, a display 2, a connecting handle 3 and a multi-frequency MEMS ultrasonic endoscopy catheter 4, wherein the multi-frequency MEMS ultrasonic endoscopy catheter 4 includes a catheter body 40 having a distal end 40a and a proximal end 40b, and an ultrasonic probe 41, the ultrasonic probe 41 realizes 360° rotation scanning through a driving shaft, the connecting handle 3 is connected to the proximal end 40b of the catheter body 40, and includes a rotating motor, a high-voltage excitation module, and a rotary encoder; the host 1 includes a data collector, a signal amplifier, a filtering processor, and an imaging processor, wherein the data collector can synchronously collect and process ultrasonic echo signals of different frequencies and display them in real time separately.

[0041] Specifically, the ultrasonic probe 41 includes a frame panel 410 that is in a long strip shape and can be rotated around the center line of the distal end 40a and installed inside the distal end of the catheter body 40, an ultrasonic transducer 411 arranged in an array on the same side of the frame panel 410, and a welding pad 412 formed on the frame panel 410 near the proximal end 40b and connecting the ultrasonic transducer 411, wherein the ultrasonic transducer 411 has at least two different operating frequencies, there are multiple welding pads 412, and the ultrasonic transducers 411 with the same operating frequency are connected to the same welding pad 412, and each welding pad 412 is connected to the host 1 through a coaxial cable; each ultrasonic transducer 411 is connected by a CM OS process (CMOS process is an integrated circuit manufacturing process, mainly used to manufacture large-scale integrated circuits. CMOS process is developed based on PMOS and NMOS process. The C in CMOS stands for "complementary", that is, NMOS devices and PMOS devices are made on the same silicon substrate at the same time to make CMOS integrated circuits. CMOS integrated circuits have many advantages such as low power consumption, fast speed, strong anti-interference ability and high integration. CMOS process has now become the mainstream process technology for large-scale integrated circuits, and most integrated circuits are manufactured using CMOS process).

[0042] In some specific embodiments, the frame panel 410 is encapsulated at the distal end 4a of the catheter body 40, and the two sides of the frame panel 410 are relatively close to the inner wall of the catheter body 40 and can achieve 360° rotation around the center line of the distal end. The positive electrodes of the ultrasonic transducers 411 of the same operating frequency are connected to the same pad 412, and the negative electrodes are grounded, wherein the positive electrodes of the ultrasonic transducers 411 connected to the same pad 412 are connected in parallel. It is possible to synchronously excite all ultrasonic transducers in the multi-frequency probe, and each ultrasonic transducer of the probe receives its own ultrasonic echo. Because the ultrasonic transducers of the same frequency are all connected in parallel, only one signal echo is finally formed. The pad 412 is coplanar with the ultrasonic transducer 411. In order to facilitate the docking setting of the probe end direction, generally in the endoscopic catheter, the pad is connected to the host through the coaxial cable in the catheter, that is, the corresponding array element distribution area corresponds to the distal end of the endoscope.

[0043] The operating frequency of the ultrasonic transducer 411 is 10 to 80 MHz, and the ultrasonic transducer 411 is a piezoelectric micromechanical ultrasonic transducer or a capacitive micromechanical ultrasonic transducer. In short, the ultrasonic transducer 411 can freely combine the high and low frequencies, such as 10 MHz for low frequency and 20 MHz for high frequency, or higher 30 MHz and 50 MHz. The film in the piezoelectric micromechanical ultrasonic transducer is made of a material with piezoelectric properties, such as aluminum nitride, scandium-doped aluminum nitride or piezoelectric ceramics, the diameter of the film is 1 to 100 μm, and the thickness of the cavity is between 0.1 mm and 1 mm. The film in the capacitive micromechanical ultrasonic transducer is made of silicon or a high molecular polymer, and the capacitive micromechanical ultrasonic transducer also has a bias circuit to form a working bias voltage. The film in the piezoelectric micromechanical ultrasonic transducer is made of a material with piezoelectric properties, such as aluminum nitride, scandium-doped aluminum nitride or piezoelectric ceramics. The shape of each ultrasonic transducer is circular or polygonal.

[0044] Specifically, the array element structure of the capacitive micromachined ultrasonic transducer is CMUT (Capacitive Micromachined Ultrasonic Transducers), and the thin film in the capacitive micromachined ultrasonic transducer is made of silicon or high molecular polymer; the capacitive micromachined ultrasonic transducer also has a bias circuit to form a working bias voltage. At the same time, this structure is a conventional design in the field and will not be described in detail here.

[0045] The array element structure of the piezoelectric micromachined ultrasonic transducer is PMUT (Piezoelectric Micromachined Ultrasonic Transducer). The film in the piezoelectric micromachined ultrasonic transducer is made of a material with piezoelectric properties, such as aluminum nitride (ALN), scandium-doped aluminum nitride (ALscN) or piezoelectric ceramics (PZT). At the same time, this structure is a conventional design in the field and will not be described in detail here (generally, L is 5 to 6 times of t, so that the formed film layer vibrates).

[0046] In this example, the ultrasonic transducer 411 has two operating frequencies and is divided into a high frequency group g and a low frequency group d. Both the high frequency group g and the low frequency group d include array element rows that are arranged side by side and spaced apart. The array element rows of the high frequency group g and the low frequency group d are spaced apart and staggered.

[0047] Alternatively, the ultrasonic transducer 411 has three operating frequencies (high frequency I, medium frequency II, and low frequency III), and every three ultrasonic transducers with different operating frequencies constitute an array element monomer T, and multiple array element monomers T are arranged in rows horizontally and columns vertically on the same side of the frame panel 410.

[0048] In summary, the implementation process of this embodiment is as follows:

[0049] The catheter containing the multi-frequency ultrasound probe is connected to the connecting handle, and the handle is connected to the main unit through a cable. The probe is sent to the observation site through the catheter, and the motor is started. Driven by the drive shaft, the probe rotates 360 degrees in the catheter. During operation, the short pulse generated by the excitation module in the handle can cover all the array element frequencies of the probe, synchronously excite all the array elements in the multi-frequency probe, and each array element of the probe receives its own ultrasonic echo. Because the array elements of the same frequency are connected in parallel, only one signal echo is finally formed. Then, the ultrasonic echo signals of each frequency are transmitted to the handle through the cable and slip ring, and transferred to the system main unit through the TR switch for signal processing, and finally displayed on the screen (you can choose to display a single frequency or a fused frequency display, in which the image fusion merges the low-frequency and high-frequency ultrasound endoscopy images into one screen, such as the near field uses the signal of the high-frequency array element, and the far field uses the model of the low-frequency array element).

[0050] Therefore, on the one hand, the present invention can simultaneously and synchronously receive ultrasonic signals of different frequencies of the same target, effectively overcoming the problem that the existing dual-frequency or multi-frequency solutions receive different target positions, with a certain time difference before and after, and the difference may be caused by the offset of the catheter or transducer; on the other hand, the advantages of miniaturization and sub-array elements of MEMS ultrasonic transducers are utilized, which not only meets the needs of 360° scanning imaging, but also can be manufactured using CMOS technology, and can be used simultaneously and synchronously in multi-frequency ultrasonic endoscope catheters, thereby reducing the number of times different frequency endoscope catheters are used, and improving the real-time, synchronization and accuracy of imaging.

[0051] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-frequency MEMS ultrasonic endoscopic catheter, comprising a catheter body having a distal end and a proximal end, and an ultrasonic probe, characterized in that: The ultrasonic probe includes a frame panel that is in the shape of an elongated strip and can be rotated around the distal center line and installed inside the distal end of the catheter body, ultrasonic transducers arranged in an array on the same side of the frame panel, and a welding pad formed near the proximal end of the frame panel and connecting the ultrasonic transducers, wherein the ultrasonic transducer has at least two different operating frequencies, there are multiple welding pads, and the ultrasonic transducers with the same operating frequency are connected to the same welding pad, each of the welding pads is connected to the host via a coaxial cable, and each of the ultrasonic transducers is made by CMOS technology.

2. The multi-frequency MEMS ultrasonic endoscopic catheter according to claim 1, characterized in that: The positive electrodes of the ultrasonic transducers with the same operating frequency are connected to the same welding pad, and the negative electrodes are connected to the ground.

3. The multi-frequency MEMS ultrasonic endoscopic catheter according to claim 2, characterized in that: The positive electrodes of the ultrasonic transducers connected to the same welding pad are connected in parallel.

4. The multi-frequency MEMS ultrasonic endoscopic catheter according to claim 1, characterized in that: The welding pad is coplanar with the ultrasonic transducer; and / or the frame panel is encapsulated at the distal end of the catheter body, and both sides of the frame panel are relatively close to the inner wall of the catheter body and can achieve 360° rotation around the center line of the distal end.

5. The multi-frequency MEMS ultrasonic endoscopic catheter according to claim 1, characterized in that: The working frequency of the ultrasonic transducer is 10-80 MHz, and the ultrasonic transducer is a piezoelectric micromechanical ultrasonic transducer or a capacitive micromechanical ultrasonic transducer.

6. The multi-frequency MEMS ultrasonic endoscopic catheter according to claim 5, characterized in that: The film in the piezoelectric micromechanical ultrasonic transducer is made of a material with piezoelectric properties, such as aluminum nitride, scandium-doped aluminum nitride or piezoelectric ceramics, and / or the diameter of the film is 1 to 100 μm, and the thickness of the cavity is between 0.1 mm and 1 mm.

7. The multi-frequency MEMS ultrasonic endoscopic catheter according to claim 6, characterized in that: The film in the capacitive micromechanical ultrasonic transducer is made of silicon or high molecular polymer, and the capacitive micromechanical ultrasonic transducer also has a bias circuit to form a working bias voltage.

8. The multi-frequency MEMS ultrasonic endoscopic catheter according to claim 6 or 7, characterized in that: The shape of each ultrasonic transducer is circular or polygonal.

9. The multi-frequency MEMS ultrasonic endoscopic catheter according to claim 1, characterized in that: The ultrasonic transducer has two operating frequencies and is divided into a high frequency group and a low frequency group. The high frequency group and the low frequency group both include array element rows arranged side by side and spaced apart. The array element rows of the high frequency group and the low frequency group are spaced apart and staggered. Alternatively, the ultrasonic transducer has three operating frequencies, and every three ultrasonic transducers with different operating frequencies constitute an array element monomer, and a plurality of the array element monomers are arranged in rows horizontally and columns vertically at intervals on the same side of the frame panel.

10. A multi-frequency MEMS ultrasonic endoscopy system, comprising a host, a display, a connecting handle and an endoscopy catheter, characterized in that: The endoscopic catheter is a multi-frequency MEMS ultrasonic endoscopic catheter as described in any one of claims 1 to 9, wherein the ultrasonic probe realizes 360° rotational scanning through a driving shaft, the connecting handle is connected to the proximal end of the catheter body, and includes a rotating motor, a high-voltage excitation module, and a rotary encoder; the host includes a data collector, a signal amplifier, a filter processor, and an imaging processor, wherein the data collector is capable of synchronously collecting and processing ultrasonic echo signals of different frequencies and displaying them in real time separately.

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