Ultrasonic ablation catheter with positioning function and ablation method

Abstract

The invention discloses an ultrasonic ablation catheter with a positioning function and an ablation method, and relates to the technical field of medical instruments, and the ultrasonic ablation catheter comprises a positioning transmitting unit which comprises at least one row of sensor transmitting groups uniformly distributed along the circumferential direction and is used for transmitting position measurement ultrasound; the positioning receiving unit comprises at least one row of sensor receiving groups which are uniformly distributed along the circumferential direction and is used for receiving the position measuring ultrasound transmitted by the positioning transmitting unit; the energy generation unit is used for outputting ultrasonic ablation energy; the positioning transmitting unit, the positioning receiving unit and the energy generating unit are coaxially fixed to the catheter in the axial direction and located in the cavity of the balloon, the positions of the positioning transmitting unit and the positioning receiving unit do not need to be adjusted in the operation, operation is more convenient, and the positioning transmitting unit, the positioning receiving unit and the energy generating unit are independently arranged, so that operation is more convenient. The inner cavity of the catheter does not need to additionally penetrate through equipment for adjusting the angle of the energy generation unit, and the structural design of the catheter is simpler.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a positioning ultrasonic ablation catheter and ablation method. Background Technology

[0002] When using an ultrasound ablation catheter, first push the guide wire to the vicinity of the intended ablation vessel, then pass the end of the guide wire through the guide wire lumen of the catheter, and push the catheter along the guide wire to the target location.

[0003] Chinese patent discloses an ultrasound ablation device (publication number: CN115252062A), comprising: a balloon with an internal component inside; a tip located at the distal end of the balloon; a catheter located at the proximal end of the balloon; and a transducer comprising a cylindrical tube and a dematching layer. The cylindrical tube is made of piezoelectric material, and the dematching layer is rigid and conductive. The inner surface of the cylindrical tube is fitted with the dematching layer, which is then fitted with the internal component of the balloon. The rigidity of the dematching layer, combined with the rigidity of the cylindrical tube, provides support and protection for the cylindrical tube. The dematching layer also limits the mechanical vibration energy transmitted through the cylindrical tube and reduces the heat generated by ultrasound propagation on the inner surface of the dematching layer, allowing the ultrasound waves to be primarily output from the outer surface of the cylindrical tube. This eliminates the need for cooling the inner surface of the dematching layer. The dematching layer is directly fitted with the internal component of the balloon. The simple structure and manufacturing process allow for a very small transducer size, facilitating access to smaller blood vessels.

[0004] Chinese patent discloses an ultrasound therapy device and control method (Publication No.: CN116099136A). The ultrasound therapy device includes: a catheter; an expandable ultrasound component formed at the end of the catheter and introduced into a patient's blood vessel; and an operating handle connected to the catheter and used to control the expansion or contraction of the expandable ultrasound component. The expandable ultrasound component includes: an elastic capsule conforming to the blood vessel wall; a base formed within the elastic capsule; and a positioning unit and an energy generating unit circumferentially separated along the base. The positioning unit is used to detect the distance between the energy generating unit and the blood vessel wall, or the distance between the sidewall of the elastic capsule conforming to the blood vessel wall and the energy generating unit. The operating handle controls the expansion of the elastic capsule. This application achieves the fixation of the position of the ultrasound transducer in different blood vessel diameters, preventing changes in the focal position of the ultrasound field and avoiding ablation misalignment.

[0005] Chinese patent discloses an automatic method and system for judging the adhesion of an ultrasound ablation balloon to the vessel wall (Publication No.: CN117179853 A). The method includes the following steps: setting relevant operating parameters; injecting saline solution after the balloon is moved to the target ablation area; detecting the pressure inside the balloon and the external impedance value, and feeding this data back to the control system; and determining whether the balloon is well-adhered to the vessel wall. This invention employs a technical solution that simultaneously detects the pressure inside the balloon and the external impedance, comparing them with their set values ​​and a set range of variation. This achieves accurate and automatic judgment of the adhesion between the ultrasound ablation balloon and the vessel wall, ensuring that the ultrasound ablation balloon achieves good adhesion before ablation begins, greatly improving ultrasound transmission efficiency and the effectiveness of the ablation procedure.

[0006] Taking pulmonary artery ablation as an example, the guidewire tip reaches a branch of the pulmonary artery. Maintaining the guidewire's position, the catheter is advanced along the guidewire to the pulmonary artery. Due to anatomical limitations, the guidewire is usually not in the middle of the vessel, but rather against one side. This causes the ultrasound ablation catheter, when advanced along the guidewire, to naturally also lean towards the vessel side upon reaching the target location. Figure 6 As shown. Currently, most piezoelectric transducers used in interventional ultrasound ablation are cylindrical transducers with relatively uniform ablation radii in the circumferential direction. When the balloon is filled with an initial predetermined volume of fluid, if the balloon and the vessel wall are not perfectly matched in size, adverse effects may occur during ultrasound ablation due to the mismatch between distance and energy. For example, insufficient energy at a long distance may prevent energy from being transmitted to the target area, resulting in ablation failure and no therapeutic effect; while excessive energy at a short distance may cause damage to the vessel wall, inducing problems such as thrombosis and vasospasm.

[0007] Ultrasonic ablation requires the output of ablation energy based on the distance between the transducer and the vessel wall. Since vascular structures vary considerably, a single balloon size may not be able to conform circumferentially to the vessel wall, leading to inaccurate positioning and ablation. CN116099136A uses a positioning unit to measure the distance between the energy generating unit and the vessel wall to adjust the balloon inflation. However, in actual operation, because the catheter is pushed along the guidewire to the ablation position, it will generally be close to one side of the vessel. For vessels like the pulmonary artery and its branches, which are larger, the energy generating unit and positioning unit, coaxial with the catheter, cannot be located in the middle of the vessel. The distance between the generating unit and the vessel wall monitored by the positioning unit is prone to significant errors, and the balloon diameter calculated using this method may also have large errors, resulting in a mismatch between the balloon size and the vessel. Furthermore, for large-diameter vessels like the pulmonary artery, the matching balloon diameter is also relatively large, requiring a longer time to complete balloon inflation and deflation when changing ablation positions. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a positioning ultrasound ablation catheter, comprising a positioning transmitting unit including at least one row of sensor transmitting groups evenly distributed circumferentially for transmitting positioning ultrasound; a positioning receiving unit including at least one row of sensor receiving groups evenly distributed circumferentially for receiving the positioning ultrasound transmitted by the positioning transmitting unit; and an energy generating unit for outputting ultrasound ablation energy; the positioning transmitting unit, positioning receiving unit, and energy generating unit are coaxially fixed to the catheter and located within the cavity of the balloon, with the energy generating unit positioned between the positioning transmitting unit and the positioning receiving unit; the sensor transmitting groups and the sensor receiving groups are aligned axially upwards, and the ultrasound waves emitted by the sensor transmitting groups are reflected by the blood vessel wall and received by the corresponding sensor receiving groups to obtain the spatial position of the energy generating unit relative to the blood vessel.

[0009] Preferably, each of the sensor transmitting groups contains at least two transmitting sensors that are circumferentially evenly distributed.

[0010] Preferably, each of the sensor receiving groups comprises at least two receiving sensors that are circumferentially evenly distributed; The individual transmitting sensors of the sensor transmitting group and the individual receiving sensors of the sensor receiving group are aligned axially upwards. The ultrasonic waves emitted by the transmitting sensors are reflected by the blood vessel wall and then received by the corresponding receiving sensors. Preferably, in the positioning and transmitting unit, the transmitting surface of the transmitting sensor has a preset angle relative to the central axis of the balloon, the transmitting surface faces the receiving sensor, and the transmitting sensor emits ultrasonic waves at a preset angle which are received by the receiving sensor.

[0011] Preferably, the receiving surfaces of all the receiving sensors in the positioning receiving unit are parallel to the central axis of the balloon or form another preset angle with the central axis of the balloon, and the receiving surfaces of the receiving sensors face the transmitting surface to receive the ultrasonic waves emitted by the transmitting sensors.

[0012] Preferably, the positioning transmitting unit, positioning receiving unit, and energy generating unit are all made of materials with piezoelectric effect.

[0013] Preferably, the catheter is a multi-lumen tube extruded from a polymer material or a multi-lumen tube made of multiple layers of material.

[0014] Preferably, the catheter has at least four cavities, each of which communicates with the interior of the balloon. The cavities include a guidewire cavity located at the axis of the catheter, an outlet cavity on one side of the guidewire cavity that communicates with the balloon, and an inlet cavity on the other side of the guidewire cavity that communicates with the balloon. The outlet cavity and the inlet cavity are symmetrically arranged along the axial direction of the catheter.

[0015] Preferably, the energy generating unit is a group of multiple transducers evenly distributed circumferentially, and a single transducer is a plate transducer or a fan-shaped transducer. Based on the distance to the vessel wall detected by the single or multiple transducers closest to it in the axial direction, the single or multiple transducers release corresponding ultrasonic energy to ablate the nerves in the vessel wall corresponding to them in the radial direction.

[0016] An ablation method using a positioning ultrasonic ablation catheter includes the following steps: The positioning transmitting unit and the positioning receiving unit measure the actual distance from the energy generating unit to the target ablation area; Based on this actual distance, select one or more energy generating units that are closest to the target ablation region in the circumferential direction; One or more energy generating units release corresponding ultrasonic energy to ablate the nerves in the corresponding blood vessel wall in its radial direction.

[0017] The technical effects and advantages of this invention are as follows: 1. This ultrasound ablation catheter can accurately measure the distance between the energy generating unit and the blood vessel wall, and output matching energy according to the actual distance to achieve precise positioning and ablation, reduce damage to the vascular intima, reduce the risk of vascular stenosis after ablation, and improve surgical safety and treatment effect.

[0018] 2. In this invention, the positioning transmitter unit and the positioning receiver unit are coaxially fixedly installed with the energy generating unit. There is no need to adjust the position of the positioning transmitter unit and the positioning receiver unit during the operation, making the operation more convenient. Furthermore, the positioning transmitter unit and the positioning receiver unit are set independently from the energy generating unit, so the inner lumen of the catheter does not need to pass through the device for adjusting the angle of the energy generating unit. The structure design of the catheter is simpler, and the overall radial installation size is reduced, so a balloon with a relatively small diameter can be selected. The radial size of the balloon after inflation is small, which on the one hand reduces damage to the vascular access and improves the positioning performance of the device. On the other hand, the distance between the energy generating unit and the blood vessel wall is closer, which also improves the ablation accuracy.

[0019] 3. Based on the distance to the blood vessel wall detected by the single transducer closest to it in the axial direction, the single transducer releases corresponding ultrasonic energy to ablate the nerve in the blood vessel wall corresponding to it in the radial direction. This invention can realize the operation of ablation by multiple transducers in the axial direction, either separately or simultaneously. For relatively safe areas, multiple transducers can be selected to work at the same time. For known dangerous areas, the transducer corresponding to that area can be deactivated, while the transducers in other areas continue to work normally, thus improving the safety of operation.

[0020] 4. This ablation method improves ablation accuracy by releasing ultrasonic energy only from the transducer closest to the ablation area. This avoids energy superposition and offset issues caused by multiple transducers working simultaneously, allowing ultrasonic energy to be precisely applied to the target ablation area. This effectively controls the ablation range and reduces the impact on surrounding non-target areas. Furthermore, it is energy-efficient, as non-target transducers do not start throughout the process, eliminating the need for energy output and equipment standby. This significantly reduces the overall energy consumption of the system, achieving energy conservation. It also reduces losses caused by ineffective equipment operation and extends the service life of the transducers and the entire system. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the internal structure of the balloon in the ultrasound ablation catheter with positioning provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the ultrasound ablation catheter with positioning provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the ultrasonic ablation catheter with positioning provided in the embodiments of this application; Figure 4 This is a schematic diagram of the energy generation unit in a positioning ultrasonic ablation catheter provided in one embodiment of this application; Figure 5 This is a schematic diagram of the energy generation unit in a positioning ultrasonic ablation catheter provided in another embodiment of this application.

[0022] Figure 6 This is a schematic diagram of a positioning ultrasound ablation catheter entering the pulmonary artery, as provided in an embodiment of this application. In the diagram: 1. Positioning transmitter unit; 2. Positioning receiver unit; 3. Energy generator unit; 31. Piezoelectric transducer; 4. Balloon; 5. Conduit; 51. Guide wire cavity; 52. Cable cavity; 53. Water outlet cavity; 54. Water inlet cavity; 6. Conduit handle; 61. Handle housing; 62. Conduit fixing seat; 621. Water inlet pipe; 622. Water outlet pipe; 63. Handle cable. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

[0024] Please see Figure 1As shown, this embodiment provides an ultrasonic ablation catheter with positioning, including a positioning transmitting unit 1 for transmitting positioning ultrasound; and a positioning receiving unit 2 arranged along the axial direction of the positioning transmitting unit 1 for receiving the positioning ultrasound transmitted by the positioning transmitting unit 1.

[0025] It also includes an energy generating unit 3, which is used to output ultrasound ablation energy. The energy generating unit 3 is located between the positioning transmitting unit 1 and the positioning receiving unit 2. The actual distance from the energy generating unit 3 to the blood vessel wall is measured by the positioning transmitting unit 1 and the positioning receiving unit 2, and the corresponding ablation energy is output according to the actual distance.

[0026] Using this ultrasound ablation catheter, the distance between the energy generating unit 3 and the blood vessel wall can be accurately measured. The energy output can be matched according to the actual distance to achieve precise positioning and ablation, reduce damage to the vascular endothelium, reduce the risk of vascular stenosis after ablation, and improve the safety and treatment effect of the operation. Furthermore, the positioning transmitting unit 1 and the positioning receiving unit 2 are coaxially installed with the energy generating unit 3, which significantly reduces the installation size. The balloon 4 can be selected with a smaller size accordingly, which further improves the accuracy of ablation.

[0027] If the positioning transmitter unit 1 and the positioning receiver unit 2 are staggered with the energy generator unit 3 in the axial direction, the overall installation size in the radial direction will increase. It is necessary to select a balloon with a relatively large diameter to install the positioning transmitter unit 1, the positioning receiver unit 2 and the energy generator unit 3 inside. After the balloon is inflated, the distance between the energy generator unit 3 and the blood vessel wall will be relatively far, which will affect the accuracy of ablation.

[0028] It is understood that in this invention, the positioning transmitter unit 1 and the positioning receiver unit 2 are coaxially fixedly installed with the energy generating unit 3. During the operation, there is no need to adjust the position of the positioning transmitter unit and the positioning receiver unit, making the operation more convenient. Furthermore, the positioning transmitter unit and the positioning receiver unit are set independently from the energy generating unit, reducing the overall radial installation size. This allows for the selection of a balloon with a relatively small diameter. The smaller radial size of the balloon after inflation reduces damage to the vascular access and improves the positioning performance of the device. On the other hand, the closer distance between the energy generating unit and the blood vessel wall also improves the accuracy of ablation.

[0029] In this invention, the energy generating unit 3 outputs energy that matches the distance to the blood vessel wall for ablation. This can be achieved through limited experimental methods in the prior art. Furthermore, the experimental data can be compiled into a parameter table that matches the distance and energy, releasing different energies according to different distances. This will not be elaborated here.

[0030] It also includes a catheter 5, with a balloon 4 at the distal end of the catheter 5. The balloon 4 is a sac that is connected to the sealing edges of the catheter 5 at both ends, providing a water-filled sealed space. The catheter 5 is used to deliver the balloon 4 to the treatment site of the blood vessel.

[0031] Furthermore, the positioning transmitter unit 1, the positioning receiver unit 2, and the energy generator unit 3 are located inside the cavity of the balloon 4. The positioning transmitter unit 1, the positioning receiver unit 2, and the energy generator unit 3 are fixed axially and coaxially on the catheter 5. With this design, compared with the prior art, which requires an axially rotating mechanism to drive the energy generator unit to ablate different areas, the energy generator unit 3 is fixed in this solution. Ablation of different target ablation areas can be achieved without additional operation. Moreover, there is no need to consider the insertion of other interventional devices into the catheter 5. The diameters of the balloon 4 and the catheter 5 can be designed to be smaller, and the structural design of the balloon 4 and the catheter 5 is simpler.

[0032] Furthermore, the energy generating unit 3 employs a piezoelectric transducer 31, which realizes the mutual conversion of electrical energy and mechanical energy based on the piezoelectric effect and the inverse piezoelectric effect, and is used to provide ultrasonic ablation energy.

[0033] Furthermore, the positioning and transmitting unit 1 employs an ultrasonic transmitter, using materials with piezoelectric or magnetostrictive effects. It converts the input high-frequency electrical signal into ultrasonic waves of a specific frequency and intensity through piezoelectric or magnetostrictive effects and radiates them into the medium, transmitting positioning ultrasound to measure the position of the blood vessel wall.

[0034] Furthermore, the positioning receiving unit 2 adopts an ultrasonic receiver, which uses a material with piezoelectric or magnetostrictive effects to convert the received ultrasonic waves back into electrical signals through opposite material effects (piezoelectricity, magnetostriction), and receive the positioning ultrasonic waves for subsequent processing and analysis.

[0035] Furthermore, the sensor transmitting group and the sensor receiving group are aligned axially upwards, and the ultrasonic waves emitted by the sensor transmitting group are received by the corresponding sensor receiving group after being reflected by the blood vessel wall.

[0036] Specifically, the positioning and transmitting unit 1 includes at least one row of sensor transmitting groups evenly distributed circumferentially, and each sensor transmitting group contains at least two transmitting sensors evenly distributed circumferentially.

[0037] The positioning receiving unit 2 includes at least one row of sensor receiving groups evenly distributed circumferentially, and each sensor receiving group contains at least two receiving sensors evenly distributed circumferentially.

[0038] The single transmitting sensor of the sensor transmitting group and the single receiving sensor of the sensor receiving group are aligned axially upwards, so that the ultrasonic waves emitted by the transmitting sensor are reflected by the blood vessel wall and received by the corresponding receiving sensor. Multiple matched sensors simultaneously or separately measure the distance of the energy generating unit 3 relative to the blood vessel wall, and the spatial position of the energy generating unit 3 relative to the blood vessel can be obtained.

[0039] See Figure 2As shown, in this embodiment, the catheter 5 is provided with at least four cavities, each of which is connected to the inside of the balloon 4. Each cavity includes a guidewire cavity 51 located at the axis of the catheter 5, and a cable cavity 52 is provided on one side of the guidewire cavity 51. The cable cavity 52 is used to pass through the cable connecting the positioning transmitter unit 1, the positioning receiver unit 2 and the energy generator unit 3.

[0040] A water outlet chamber 53 is provided on one side of the guidewire lumen 51, which is connected to the balloon 4. A water inlet chamber 54 is provided on the other side of the guidewire lumen 51, which is connected to the balloon 4. Physiological saline enters the balloon 4 through the water inlet chamber 54 and then flows out of the balloon 4 through the water outlet chamber 53.

[0041] Preferably, the outlet chamber 53 and the inlet chamber 54 are symmetrically arranged along the axial direction of the catheter 5, and the cross-sectional sizes of the outlet chamber 53 and the inlet chamber 54 are the same. When physiological saline passes through, the pressure in the outlet chamber 53 and the inlet chamber 54 is basically the same, avoiding displacement of the catheter 5 due to pressure difference. The control lines in the remaining cavities are respectively connected to the energy generation unit, the positioning transmission unit, and the positioning receiving unit to control energy transmission and signal reception and transmission, without affecting the stability of the catheter 5.

[0042] See Figure 3 As shown, in this embodiment, a conduit handle 6 is also provided. The conduit handle 6 includes a handle housing 61 and a conduit fixing seat 62 installed in the handle housing 61 for fixing the proximal end of the conduit 5. The conduit fixing seat 62 has an inlet and an outlet. The inlet is connected to an inlet pipe 621 and the outlet is connected to an outlet pipe 622. Both the inlet pipe 621 and the outlet pipe 622 extend through the handle housing 61 to the outside.

[0043] The conduit handle 6 is also provided with a handle cable 63, which is used to provide power and signal transmission to the positioning transmitter unit 1, the positioning receiver unit 2 and the energy generator unit 3.

[0044] The catheter fixation seat 62 is provided with a guidewire cavity along the axial direction, and the guidewire cavity is connected to the catheter 5.

[0045] Specifically, the conduit fixing seat 62 is connected to the conduit 5, and the conduit cable is connected to the handle cable 63 to realize signal and power transmission. The conduit fixing seat 62 and the handle cable 63 are both located in the handle housing 61.

[0046] Furthermore, the inlet of the conduit fixing seat 62 is connected to the inlet chamber 54 of the conduit 5, and the outlet of the conduit fixing seat 62 is connected to the outlet chamber 53 of the conduit 5.

[0047] The catheter fixation seat 62 has a fixation seat guide wire cavity along the axial direction, and the fixation seat guide wire cavity is coaxially connected with the guide wire cavity 51 of the catheter 5.

[0048] In this embodiment, the catheter 5 can be a multi-lumen tube extruded from a polymer material, including but not limited to PEBAX, TPU, etc.

[0049] It can also be a multi-layered, multi-cavity tube with at least three layers. Preferably, the inner layer is an extruded tube, the middle layer is a metal layer, and the outer layer is a polymer layer.

[0050] The metal layer material includes, but is not limited to, stainless steel, nickel-titanium, etc., and its structure is a braided mesh structure or a spring tube formed by winding or cutting, or a multi-degree-of-freedom metal tube formed by cutting tubes.

[0051] Preferably, the material of the balloon 4 includes, but is not limited to, nylon, Pebax, etc.

[0052] Preferably, the positioning transmitter unit 1, the positioning receiver unit 2, and the energy generator unit 3 are all made of materials with piezoelectric effect. Materials with piezoelectric effect include, but are not limited to, lead zirconate titanate (PZT), relaxor ferroelectric single crystal (PMN-PT, PIN-PMN-PT), piezoelectric polymer (PVDF, PVDF-TrFE), piezoelectric ceramic composite material (PZT-polymer composite material), etc.

[0053] In one specific embodiment, the emitting surfaces of all the emitting sensors in the positioning emitting unit 1 are at a certain angle relative to the central axis of the balloon 4, with the angle ranging from 5° to 85°. The emitting surfaces face the receiving surfaces of the receiving sensors, so that the emitting sensors can emit ultrasonic waves at different angles that are received by the receiving surfaces of the receiving sensors.

[0054] Specifically, if the angle between the emitting surface and the central axis of the balloon 4 is 5°, the emitted ultrasonic wave will also form an angle of 5° with the central axis of the balloon 4. If the angle between the emitting surface and the central axis of the balloon 4 is 85°, the emitted ultrasonic wave will also form an angle of 85° with the central axis of the balloon 4. Different ultrasonic waves with different emitting angles can be selected according to actual needs, so that the ultrasonic waves emitted by the emitting sensor can be received by the receiving surface of the receiving sensor.

[0055] In the positioning receiving unit 2, the receiving surfaces of all the receiving sensors are parallel to the central axis of the balloon 4 or form a certain angle with the central axis of the balloon 4, with the angle ranging from 0° to 90°. The receiving surfaces of the receiving sensors face the transmitting surface and are used to receive the ultrasonic waves emitted by the transmitting sensors.

[0056] It is understandable that when the angle between the receiving surface and the central axis of the balloon 4 is 0°, the receiving surface is parallel to the central axis of the balloon 4; when the angle between the receiving surface and the central axis of the balloon 4 is 90°, the receiving surface is perpendicular to the central axis of the balloon 4. The angle between the receiving surface and the central axis of the balloon 4 can also be adjusted according to the actual situation so that the receiving surface can receive the ultrasonic waves emitted by the transmitting surface.

[0057] See Figure 3 As shown, in this embodiment, the positioning receiving unit 2 is a multi-row sensor receiving group. Each sensor receiving group includes multiple receiving sensors. The multiple receiving sensors are evenly distributed around the circumference of the conduit 5. Each receiving sensor is arranged radially along the conduit 5. Each row of receiving sensors is correspondingly arranged with the transmitting sensor in the positioning transmitting unit 1, so that a row of transmitting sensors receives the ultrasonic waves emitted by the corresponding single transmitting sensor in the positioning transmitting unit 1.

[0058] When the distance between the blood vessel wall and the energy generating unit 3 is different, the distance between the receiving sensor on each row and the blood vessel wall is different. Thus, the distance between the blood vessel wall and the energy generating unit 3 can be calculated based on the assembly position of the transmitting sensor of the positioning transmitting unit 1 and the receiving sensor of the positioning receiving unit 2.

[0059] The following describes how to measure the actual distance from the energy generating unit 3 to the blood vessel wall using the positioning transmitting unit 1 and the positioning receiving unit 2: The ultrasonic wave emitted by a single transmitting sensor in positioning transmitting unit 1 is received by the receiving sensor in positioning receiving unit 2. Based on the ultrasonic wave propagation time T, the distance the ultrasonic wave travels can be calculated. The basic formula for ultrasonic ranging is: L = C × T; L: The total distance from the transmitter to the receiver.

[0060] C: The speed at which ultrasound waves propagate.

[0061] T: The time required for the ultrasound to travel from emission to reception.

[0062] In the positioning transmitter unit 1, all the transmitting sensors, the receiving sensors of the positioning receiver unit 2, and the point where the ultrasound is reflected from the blood vessel wall form a triangular structure. The transmitting surface angle of the transmitting sensor is known, and the distances between the transmitting sensor, the receiving sensor, and the energy generating unit 3 are also known. After obtaining the distance L from which the ultrasound propagates, which is the sum of the two sides of the triangle, the distance between the energy generating unit 3 and the blood vessel wall is obtained through mathematical calculations.

[0063] In another embodiment, see Figure 4As shown, the energy generating unit 3 is a group of multiple transducers evenly distributed circumferentially. Each transducer is a sheet-shaped transducer or a fan-shaped transducer. Based on the distance of the blood vessel wall detected by the single transducer closest to the blood vessel wall in the axial direction, the single transducer releases corresponding ultrasonic energy to ablate the nerve in the blood vessel wall corresponding to it in the radial direction. This allows for the operation of ablation by multiple transducers in the axial direction, either separately or simultaneously. For relatively safe areas, multiple transducers can be selected to work simultaneously. For known dangerous areas, the transducers corresponding to those areas can be deactivated, while the transducers in other areas continue to work normally. This design enables precise positioning of the area to be ablated, improving operational safety.

[0064] Specifically, the energy generating unit 3 includes multiple piezoelectric transducers 31, which are evenly distributed along the axial direction of the catheter 5. The distance between each piezoelectric transducer 31 and the blood vessel wall may be different. Each piezoelectric transducer 31 provides different ultrasound ablation energy according to its actual distance from the blood vessel wall, or some piezoelectric transducers 31 work while others do not, thereby improving the safety of the operation.

[0065] Specifically, as shown in Figure 4, when the detected distance to the blood vessel wall is h1, the single or multiple transducers closest to that blood vessel wall release ultrasonic energy to ablate the nerves within the blood vessel wall corresponding to h1; when the detected distance to the blood vessel wall is h2, the single or multiple transducers closest to that blood vessel wall release ultrasonic energy to ablate the nerves within the blood vessel wall corresponding to h2, and so on, to complete all ultrasonic ablation.

[0066] Understandably, when the target ablation area is large, multiple transducers can be selected to release ultrasound energy. Each transducer releases different amounts of energy, and each transducer releases corresponding energy based on its actual distance from the blood vessel wall.

[0067] In another embodiment, see Figure 5 As shown, the positioning transmitting unit 1 is a multi-row sensor transmitting array, with each row of sensor transmitting groups having the same angle relative to the central axis of the balloon 4. The positioning receiving unit 2 is a sensor receiving group with at least one row. The multiple rows of sensor transmitting groups in the positioning transmitting unit 1 emit ultrasonic waves sequentially in chronological order. If the receiving sensor of the positioning receiving unit 2 does not receive a signal within a certain time (this time is much longer than the ultrasonic propagation time for detecting the diameter of the blood vessel), it will emit the signal of the next row until the positioning receiving unit 2 receives the ultrasonic signal. Thus, the distance of the blood vessel wall relative to the energy generating unit 3 can be calculated based on the assembly position of the transmitting and receiving sensors.

[0068] Understandably, in actual use, by using the positioning transmitter unit 1 and the positioning receiver unit 2 to obtain the spatial position of the energy generating unit 3 relative to the blood vessel wall, a variety of methods can be used to achieve a better ablation effect.

[0069] In another embodiment, the balloon 4 is a non-compliant balloon. The circumference of the blood vessel wall is calculated based on the distance from the circumferential energy generating unit 3 to the blood vessel wall. The target diameter of the balloon 4 is adjusted according to the circumference. The diameter of the balloon 4 is adjusted to be the same as the blood vessel diameter by adjusting the flow rate of the inlet water, and then the corresponding ablation energy is output.

[0070] In another embodiment, based on the above embodiments, an ablation method for a positioning ultrasonic ablation catheter is also provided, comprising the following steps: The positioning transmitter unit 1 and the positioning receiver unit 2 measure the actual distance from the energy generator unit 3 to the target ablation area; Based on this actual distance, select one or more energy generating units 3 that are closest to the target ablation region in the circumferential direction; One or more energy generating units 3 release corresponding ultrasonic energy to ablate the nerves in the corresponding blood vessel wall in the radial direction.

[0071] In the above method, the energy generating unit 3 is a group of multiple transducers evenly distributed circumferentially. Each transducer is a sheet transducer or a fan-shaped transducer. Based on the distance of the blood vessel wall detected by the single transducer closest to the blood vessel wall in the axial direction, the single transducer releases corresponding ultrasonic energy to ablate the nerve in the blood vessel wall corresponding to it in the radial direction. This can realize the operation of ablation by multiple transducers in the axial direction separately or simultaneously. For relatively safe areas, multiple transducers can be selected to work at the same time. For known dangerous areas, the transducer corresponding to that area can not work, while the transducers in other areas still work normally. This design can achieve precise positioning of the area to be ablated and improve the safety of operation.

[0072] In other words, in this ablation method, if the target ablation area is small, the transducer closest to the ablation area is selected and activated, releasing ultrasound energy of the corresponding power according to preset parameters. If the target ablation area is large, multiple transducers closest to the ablation area are selected and activated. Each transducer releases different amounts of energy, releasing corresponding energy based on its actual distance from the vessel wall, releasing ultrasound energy of the corresponding power according to preset parameters. The remaining transducers remain in a dormant state, only triggering an activation command when the ablation area position is dynamically adjusted and re-selected as the closest transducer. During the procedure, there is no need to adjust the angle of the energy generating unit 3, the positioning transmitting unit 1, or the positioning receiving unit 2, making the operation more convenient for doctors and saving surgical time. This ablation method improves ablation accuracy by releasing ultrasonic energy only from the transducer closest to the ablation area, avoiding the energy superposition and offset problems caused by multiple transducers working simultaneously. This allows the ultrasonic energy to be precisely applied to the target ablation area, effectively controlling the ablation range and reducing the impact on surrounding non-target areas. Furthermore, it utilizes energy efficiently, with non-target transducers remaining inactive throughout the entire process. This eliminates the need for energy output and equipment standby, significantly reducing overall system energy consumption and achieving energy savings. It also reduces losses caused by ineffective equipment operation, extending the service life of the transducers and the entire system.

[0073] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A positioning ultrasonic ablation catheter, comprising a catheter (5) and a balloon (4) connected to the distal end of the catheter (5), characterized in that, It includes a positioning and transmitting unit (1), which includes at least one row of sensor transmitting groups evenly distributed circumferentially for transmitting positioning ultrasound; The positioning receiving unit (2) includes at least one row of sensor receiving groups evenly distributed along the circumference for receiving the positioning ultrasound emitted by the positioning transmitting unit (1); It also includes an energy generation unit (3) for outputting ultrasonic ablation energy; The positioning transmitter (1), positioning receiver (2) and energy generator (3) are coaxially fixed on the catheter (5) and located in the cavity of the balloon (4), with the energy generator (3) located between the positioning transmitter (1) and the positioning receiver (2). The sensor transmitting group and the sensor receiving group are aligned axially upwards. The ultrasonic waves emitted by the sensor transmitting group are reflected by the blood vessel wall and received by the corresponding sensor receiving group to obtain the spatial position of the energy generating unit (3) relative to the blood vessel.

2. The ultrasonic ablation catheter with positioning function according to claim 1, characterized in that, Each of the sensor emission groups contains at least two emission sensors that are circumferentially evenly distributed.

3. The ultrasonic ablation catheter with positioning capability according to claim 1, characterized in that, Each of the sensor receiving groups contains at least two receiving sensors that are circumferentially evenly distributed; The individual transmitting sensors of the sensor transmitting group and the individual receiving sensors of the sensor receiving group are aligned axially upwards. The ultrasonic waves emitted by the transmitting sensors are reflected by the blood vessel wall and then received by the corresponding receiving sensors.

4. The ultrasonic ablation catheter with positioning capability according to claim 3, characterized in that, The emitting surface of the emitting sensor in the positioning emitting unit (1) has a preset angle relative to the central axis of the balloon (4), and the emitting surface faces the receiving sensor. The emitting sensor emits ultrasonic waves at a preset angle, which are received by the receiving sensor.

5. The ultrasonic ablation catheter with positioning capability according to claim 2, characterized in that, The receiving surfaces of all the receiving sensors in the positioning receiving unit (2) are parallel to the central axis of the balloon (4) or form another preset angle with the central axis of the balloon (4). The receiving surfaces of the receiving sensors face the transmitting surface and are used to receive the ultrasonic waves emitted by the transmitting sensors.

6. The ultrasonic ablation catheter with positioning capability according to claim 2, characterized in that, The positioning transmitter (1), positioning receiver (2), and energy generator (3) are all made of materials with piezoelectric effect.

7. The ultrasonic ablation catheter with positioning capability according to claim 1, characterized in that, The catheter (5) is a multi-lumen tube made of polymer material extrusion or a multi-lumen tube made of multi-layer material.

8. The ultrasonic ablation catheter with positioning function according to claim 2, characterized in that, The catheter (5) is provided with at least four cavities, each of which is connected to the interior of the balloon (4). Each cavity includes a guidewire cavity (51) located at the axis of the catheter (5). A water outlet cavity (53) is provided on one side of the guidewire cavity (51) and is connected to the balloon (4). A water inlet cavity (54) is provided on the other side of the guidewire cavity (51) and is connected to the balloon (4). The water outlet cavity (53) and the water inlet cavity (54) are symmetrically arranged along the axis of the catheter (5).

9. The ultrasonic ablation catheter with positioning capability according to claim 1, characterized in that, The energy generating unit (3) is a group of multiple transducers evenly distributed circumferentially, and each transducer is a sheet transducer or a fan-shaped transducer. Based on the distance to the vessel wall detected by the single or multiple transducers closest to it in the axial direction, the single or multiple transducers release corresponding ultrasonic energy to ablate the nerves in the vessel wall corresponding to them in the radial direction.

10. The ablation method using a positioning ultrasonic ablation catheter according to any one of claims 1-9, characterized in that, Includes the following steps: The positioning transmitting unit and the positioning receiving unit measure the actual distance from the energy generating unit to the target ablation area; Based on this actual distance, select one or more energy generating units that are closest to the target ablation region in the circumferential direction; One or more energy generating units release corresponding ultrasonic energy to ablate the nerves in the corresponding blood vessel wall in its radial direction.

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