An ablation catheter system

Abstract

The application discloses an ablation catheter system, which is composed of a handle main body, an adjusting handle and a puncture handle and has a catheter outer cylinder. An outer sheath tube is fixed in the inner part of the outer cylinder, the front end of the outer sheath tube is arranged outside the outer cylinder and is internally provided with a platinum-iridium alloy ring, and the outer sheath tube has an ultrasonic imaging function. An insulating tube is coaxially arranged in the outer sheath tube, a puncture metal needle is sleeved on the front end of the insulating tube, the insulating tube can be driven to move through an adjusting mechanism of a working section in the puncture handle, and the length of the exposed working section of the needle can be accurately adjusted. A water cooling circulation system is additionally arranged in the catheter outer cylinder, a circulating water pipeline is internally and externally nested in the insulating tube, a water tank and a puncture needle in the puncture handle are connected, and a closed water return loop is formed. The puncture handle can drive the water tank, the circulating pipeline, the insulating tube and the needle to axially move as a whole, so that the puncture depth can be adjusted. The system relies on sensors to collect temperature and contact pressure in real time, cooperates with high-frequency line transmission radio frequency energy, dynamically adjusts radio frequency ablation power through a multi-closed loop feedback logic of a host control module, and improves adaptability and ablation precision.

Description

Technical Field

[0002] This invention relates to the field of medical devices, specifically a radiofrequency ablation catheter system. Technical Background

[0004] Energy ablation requires energy provided by medical devices to inactivate and dissolve tumor tissue. Based on different working principles, it can be further divided into radiofrequency ablation, microwave ablation, cryoablation, pulsed energy ablation, ultrasound ablation, and laser ablation, among others.

[0005] Radiofrequency ablation is a physical ablation method. Its treatment principle utilizes a high-frequency current (>10kHz) to cause ions in living tissue to vibrate and rub against each other, generating heat. This leads to a tissue temperature exceeding 60°C, causing cell death and ultimately coagulating and inactivating the tumor tissue. Early radiofrequency ablation devices used monopolar needle electrodes but lacked water circulation. Later, the advent of water-cooled circulating electrodes and multipolar radiofrequency electrodes increased the ablation range, and by adjusting the extension length and direction of sub-electrodes, the ablation range became more conformal and complete.

[0006] Conventional radiofrequency ablation is guided by imaging techniques such as ultrasound or computed tomography (CT) and involves inserting an electrode needle directly into the tumor via percutaneous puncture. For example, in the case of pancreatic tumors, an ablation catheter with electrodes is required, which is inserted through the mouth or nose, through the pharynx and esophagus, into the stomach. The catheter is then used to puncture the stomach wall to reach the pancreatic tumor for radiofrequency ablation. While a simple cylindrical ablation electrode can reach the stomach through the esophagus, it cannot penetrate the stomach wall to enter the pancreatic tumor and deliver the radiofrequency field generated by the catheter to the tumor site. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention proposes a radiofrequency ablation catheter system capable of entering the human body through natural cavities to perform ablation treatment on lesions.

[0009] This invention discloses an ablation catheter system, including a working handle, an adjusting handle, a puncture handle, an outer sheath, a working section adjusting mechanism, a water cooling circulation system, a puncture metal needle, an insulating tube, a temperature sensor, a high-frequency line, a PCB adapter board, a main control module, and a radio frequency energy generation module.

[0010] The working handle includes a handle body, an outer sheath fixing sleeve, an adjusting handle, and a Luer connector; wherein, the handle body is a cylindrical structure, and the outer sheath fixing sleeve is coaxially fixed inside.

[0011] The front end of the handle body is coaxially slidably fitted with an adjustable handle that can be adjusted in axial position; the front end of the adjustable handle is equipped with a Luer connector for docking with an endoscope.

[0012] The rear end of the handle body is coaxially slidably fitted with a puncture handle whose axial position is adjustable; the puncture handle and the handle body are limited in movement by a matching annular shoulder, and the side wall of the puncture handle is provided with an internal threaded through hole with a tightening bolt to fix the position.

[0013] The ablation catheter outer tube is composed of the aforementioned handle body, adjustment handle, and puncture handle.

[0014] The outer sheath is coaxially fixed inside the outer sheath fixing sleeve, and its front end protrudes through the inner hole of the Luer connector; an ultrasonically enhanced platinum-iridium alloy ring is coaxially assembled inside the front end of the outer sheath.

[0015] The insulating tube is coaxially sleeved inside the outer sheath; the front part of the insulating tube is fitted over the outside of the puncture metal needle, and the rear part is fixed to the working section adjustment mechanism. The working section adjustment mechanism is located inside the puncture handle and has a sliding pair along the axial direction of the handle body. By controlling the movement of the working section adjustment mechanism, the length of the working section protruding from the front end of the insulating tube by the puncture metal needle is adjusted.

[0016] The water-cooled circulation system includes a water tank, an inlet pipe, a return pipe, an inner circulating water pipe, and an outer circulating water pipe. The water tank is fixed inside the puncture handle. The interior of the water tank is divided into two chambers, front and rear, by a partition, which are connected to the return pipe and the inlet pipe, respectively.

[0017] The inner and outer circulating water tubes are coaxially nested, with a return water gap between them, and are coaxially placed within an insulating layer. The end of the inner circulating water tube communicates with the rear chamber of the water tank. The end of the outer circulating water tube communicates with the front chamber, and its front end connects to the end of the puncture metal needle. The outer wall of the puncture metal needle has an ultrasonic imaging structure and is coated with a conductive, anti-adhesion coating. By moving the puncture handle, the water tank, inner circulating water tube, outer circulating water tube, insulating tube, and puncture metal needle can be moved axially as a whole, thereby adjusting the puncture depth.

[0018] The temperature sensor and pressure sensor are used to collect the temperature of the ablation area and the contact pressure between the needle and the target tissue, respectively.

[0019] The high-frequency line is electrically connected to the puncture metal needle, and all sensor signal lines and high-frequency lines are connected to the PCB adapter board.

[0020] The PCB adapter board connects the host control module and the radio frequency energy generation module via an aviation connector.

[0021] The radio frequency energy generation module is used to output radio frequency energy to the puncture metal needle.

[0022] The host control module adjusts the RF output power in real time based on multi-closed-loop feedback logic.

[0023] The advantages of this invention are:

[0024] 1. The ablation catheter system of the present invention has two independent motion mechanisms for adjusting the puncture depth and the working section length of the puncture metal needle. During application, the parameters can be finely adjusted step by step, which has a high fault tolerance rate and avoids secondary tissue damage caused by motion interference.

[0025] 2. The ablation catheter system of the present invention, through water-cooled circulation cooling combined with the conductive anti-adhesion coating on the outer wall of the puncture metal needle, can effectively solve the problem of tissue adhesion to the needle after ablation, and significantly reduce the risk of postoperative complications such as pancreatitis and burns to surrounding tissues.

[0026] 3. The ablation catheter system of the present invention can enter the human body through natural cavities to perform ablation treatment on lesions.

[0027] 4. The ablation catheter system of this invention incorporates a water-cooling circulation system, which can effectively expand the ablation range.

[0028] 5. The ablation catheter system of the present invention can adjust the length of the working section of the puncture metal needle, so as to make the ablation range more conformal, more complete and more flexible. Attached Figure Description

[0030] Figure 1 This is a structural block diagram of the ablation catheter system of the present invention;

[0031] Figure 2 This is a cross-sectional view of the overall structure of the ablation catheter portion in the ablation catheter system of the present invention;

[0032] Figure 3 This is a schematic diagram of the front insulating tube of the ablation catheter.

[0033] Figure 4 This is a schematic diagram of the working section adjustment mechanism.

[0034] Figure 5 This is a schematic diagram of the water tank structure and its internal water circulation method.

[0035] Figure 6 This is a schematic diagram of the water circulation system at the puncture site of the metal needle.

[0036] In the picture:

[0037] 1-Working handle; 2-Adjusting handle; 3-Piercing handle; 4-Outer sheath; 5-Working section adjustment mechanism; 6-Water cooling circulation system; 7-Piercing metal needle; 8-Insulating tube; 9-Protective sleeve; 10-Aviation plug; 101-Handle body; 102-Outer sheath fixing sleeve; 103-Adjusting handle; 104-Luer connector; 501-Rack; 502-Gear; 503-Knob; 601-Water tank; 602-Inlet pipe; 603-Return pipe; 604-Inner circulating water pipe; 605-Outer circulating water pipe; 606-Baffle. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings.

[0040] The ablation catheter system of this invention includes a working handle 1, an adjusting handle 2, a puncture handle 3, an outer sheath 4, a working section adjusting mechanism 5, a water cooling circulation system 6, a puncture metal needle 7, an insulating tube 8, a temperature sensor, a high-frequency line, a PCB adapter board, a main unit control module, and a radio frequency energy generation module, as shown below. Figures 1-3 As shown.

[0041] The working handle 1 includes a handle body 101, an outer sheath fixing sleeve 102, an adjusting handle 103, and a Luer connector 104. The handle body 101 is a cylindrical structure, with an outer sheath fixing sleeve 102 of equal length coaxially fixed inside. The cylindrical adjusting handle 103 is coaxially fitted onto the front end of the handle body 101, allowing the adjusting handle 103 to slide back and forth along the axis of the handle body 101. The movement of the adjusting handle 103 is limited by an annular shoulder designed on the inner wall of the end of the adjusting handle 103, which engages with an annular shoulder designed on the outer wall of the front end of the handle body 101. An internally threaded through hole is also provided on the side wall of the end of the adjusting handle 103, with a threaded connection to a tightening bolt. After the adjusting handle 103 is adjusted to its correct position, tightening the adjusting bolt causes its end to engage with the outer wall of the front end of the handle body 101, thus fixing the adjusting handle 103 in place. The front end of the adjustment handle 103 is equipped with a Luer connector 104, which is a standard medical Luer male / female interface used to connect with endoscopes such as ultrasound endoscopes.

[0042] The puncture handle 3 is a cylindrical structure, with its front end coaxially sleeved onto the rear end of the handle body 101, allowing the puncture handle 3 to slide back and forth along the end of the handle body 101. The movement of the puncture handle 3 is limited by a ring-shaped shoulder designed on the inner wall of the front end of the puncture handle 3 and a ring-shaped shoulder designed on the outer wall of the rear end of the handle body 101. An internally threaded through hole is provided on the front side wall of the puncture handle 3, with a threaded connection to a tightening bolt. After the puncture handle 3 is in position, tightening the adjusting bolt causes its end to engage with the outer wall of the rear end of the handle body 101, thus fixing the puncture handle 3 in place.

[0043] The outer sheath 4 is made of flexible tubing such as PEEK or nylon. Preferably, the outer sheath 4 is a composite tubing with an inner, middle, and outer three-layer structure, with the three layers connected by welding or bonding to accommodate transport in different curved cavities. The inner layer of the insulating tube 4 is preferably made of flexible materials such as Pebax or TPU; the middle layer of the outer sheath 4 is preferably made of stainless steel (304, 316, etc.) braided wire or spring-wound, or nickel-titanium braided wire or spring-wound. The outer layer of the outer sheath 4 is preferably made of high-temperature resistant materials such as Pebax, PTFE, or FEP. The Pebax used in the inner and outer layers of the insulating tube 4 is a modified material with enhanced lubrication.

[0044] The aforementioned outer sheath 4 is housed within the outer tube of the integral ablation catheter, which is composed of the working handle 1 and the puncture handle 3. It is coaxially fixed within the outer sheath fixing sleeve 102, with its front end protruding through the inner hole of the Luer connector of the working handle 1. A platinum-iridium alloy ring is coaxially fitted inside the front end of the outer sheath 4 for ultrasound-enhanced imaging. The platinum-iridium alloy ring can be manufactured using a forging process and fixed to the outer sheath 4 by bonding, or integrally formed during the extrusion stage of the outer sheath 4. Simultaneously, the length of the portion of the outer sheath 4 protruding from the Luer connector can be adjusted by adjusting the position of the aforementioned adjusting handle 103; and the movement distance control of the adjusting handle 103 can be visually confirmed by the scale designed along the axial direction of the front end of the handle body 101.

[0045] The insulating tube 8 is coaxially placed inside the outer sheath 4. The front part of the insulating tube 8 is fitted onto the puncture metal needle 7, and the rear part is fixed to the working section adjustment mechanism 5. The working section adjustment mechanism 5 drives the insulating tube 8 to move axially along the outer sheath 4 inside the outer sheath 4, causing the front part of the insulating tube 8 to be axially displaced relative to the puncture metal needle 7. This allows the length of the working section of the puncture metal needle 7 (the part of the puncture metal needle 7 protruding from the front end of the insulating tube 8) to be adjusted between 3mm and 20mm. In this invention, when the insulating tube 8 moves forward to its limit position, the section of the insulating tube 8 inside the outer cylinder of the ablation catheter is made of metal material to ensure the coaxiality between the insulating tube 8 and the outer cylinder of the ablation catheter during movement. At the same time, when the insulating tube 8 moves forward to its limit position, the section fitted onto the puncture metal needle 7 is made of PI material with a wall thickness of 0.02mm-0.05mm. This satisfies the requirement for mobility while avoiding unnecessary tissue damage caused by the step formed between the working section of the puncture metal needle 7 and the front end of the insulating tube 8 during puncture. The remaining parts of the insulating tube 8 are made of flexible plastic material, and the sections are coaxially connected to form an integral insulating tube 8.

[0046] The aforementioned working section adjustment mechanism 5 is located inside the puncture handle 3, in the middle position of the puncture handle 3, and includes a rack 501, a gear 502 and a knob 503.

[0047] The rack 501 has an arc-shaped bottom surface that matches the arc of the inner wall of the puncture handle 3, allowing it to fit snugly. Simultaneously, a groove is designed on the bottom surface of the rack 501 along the axial direction of the puncture handle 3. This groove slides in conjunction with a slider designed along the axial direction on the inner wall of the puncture handle 3, ensuring that the rack 501 can only slide back and forth along the axial direction of the puncture handle 3. The forward and backward sliding distance is limited by a protrusion designed on the inner wall of the puncture handle 3 and a water tank 601 installed at the rear of the puncture handle 3. A fixing hole coaxial with the puncture handle 3 is provided on the rack 501, into which the rear part of a fixing insulating tube is inserted.

[0048] The gear 502 is coaxially fixed to the inner end of the rotating shaft installed at the opening on the side wall of the puncture handle 3, and meshes with the teeth of the rack 501 arranged axially along the top surface of the rack 501. A knob 503 is fixedly installed on the outer end of the rotating shaft 503. By rotating the knob 503, the gear 502 drives the rack 501 to move axially along the puncture handle 3, and finally the rack 501 drives the insulating tube 8 to move axially along the outer sheath tube 4. At the same time, by designing the teeth on the gear 502 and the rack 501, the insulating tube 8 is moved axially by 1 mm for every tooth rotated by the gear 502.

[0049] The water-cooled circulation system 6 includes a water tank 601, an inlet pipe 602, a return pipe 603, an inner circulating water pipe 604, and an outer circulating water pipe 605. Figure 5As shown. The water tank 601 is fixedly installed inside the puncture handle 3, located at the front of the equipment compartment behind the puncture handle 3. The front and rear ends of the water tank 601 are sealed with front and rear end covers, respectively, and a partition 606 is designed in the middle to divide the interior of the water tank 601 into two chambers.

[0050] The outlet end of the water inlet pipe 602 enters the equipment compartment through an opening at the end of the equipment compartment and connects to the water inlet hole on the rear end cover of the water tank 601, thus connecting the water inlet pipe 602 with the rear chamber of the water tank 601. The inlet end of the water outlet pipe 603 passes sequentially through the through hole on the rear end cover of the water tank 601 and the front chamber of the water tank 601, and finally connects to the return water hole on the partition 606, thus connecting the water outlet pipe 602 with the front chamber of the water tank 601.

[0051] The circulating water inner pipe 604 is preferably a flexible thin-walled pipe with a wall thickness of 0.02-0.05mm. The end of the circulating water inner pipe 604 passes through the return water channel opened axially along the front end cover of the water tank 601, and is coaxially connected and fixed with the central opening of the partition 606, so that the circulating water inner pipe 604 communicates with the rear chamber; and there is a certain return water gap between the outer wall of the circulating water inner pipe 604 and the inner wall of the return water channel.

[0052] The circulating water outer pipe 605 is preferably made of a composite pipe with an inner, middle, and outer three-layer structure. The specific material selection for each layer and the connection method between each layer are the same as those for the insulating pipe 4. The circulating water outer pipe 605 is coaxially sleeved with the outer side of the circulating water inner pipe 604, and there is a return water gap between the two in the circumferential direction. The end of the circulating water outer pipe 605 is connected to the center hole of the front cover of the water tank 601, so that the circulating water outer pipe 605 communicates with the front chamber of the water tank 601.

[0053] All the above-mentioned pipes and corresponding holes are sealed in the circumferential gaps to ensure the airtightness of the entire water-cooling circulation loop and make the circulation process stable and reliable.

[0054] The end of the puncture metal needle 7 is inserted and fixed to the front end of the circulating water outer tube 605, and the two are waterproofed and sealed circumferentially. The puncture metal needle 7 can be solid prismatic, solid, hollow prismatic, or conical to meet tissue puncture requirements; the material can be a nickel-titanium alloy, titanium-niobium alloy, 304, 304l, 316, 316l, or other elastic metal materials, with nickel-titanium alloy being preferred. The outer circumference of the puncture metal needle 7 is provided with a micropillar array to achieve ultrasound-enhanced imaging; the micropillars can be triangular, concave, spiral, sandblasted, intersecting, or grid-like shapes, and can also modify the metal material for ultrasound-enhanced imaging. At the same time, the outer surface of the puncture metal needle 7 is coated with a conductive anti-adhesion coating, which is prepared by mixing conductive spraying material and anti-adhesion spraying material under specific temperature and vacuum conditions; after physical and chemical surface treatment, the puncture metal needle 7 undergoes multiple spraying operations in a vacuum furnace at 200℃-400℃.

[0055] Thus, a 500ml saline bag is connected to the inlet end of the inlet pipe 602. The saline solution flows sequentially through the inlet pipe 602, the rear chamber of the water tank 601, and the inner circulating water pipe 604 before reaching the puncture needle 7. The water circulation system can prevent tissue carbonization and rapid increase in impedance; it can expand the ablation range, making the ablation range closer to a spherical shape; it can also reduce the interference of thermal deposition. Subsequently, it flows sequentially through the return water gap between the inner circulating water pipe 604 and the outer circulating water pipe 605, the front chamber of the water tank 601, and the return water pipe 603, before flowing into the 500ml empty saline bag from the outlet end of the return water pipe 603, completing the entire water circulation. Figure 5 , Figure 6 As shown.

[0056] The outer sheath 4, the circulating water outer tube 605, and the circulating water inner tube 604 together form a flexible, bendable, and resilient ablation catheter, which can adapt to complex curved paths.

[0057] The design of the aforementioned circulating water mechanism 6 allows the puncture metal needle 7 to remain stationary during the adjustment of its working section length. Simultaneously, it enables the adjustment of the puncture depth using the puncture handle 3. When adjusting the puncture depth, the tightening bolt is rotated to unlock the puncture handle 3, which is then moved axially. At this point, the entire circulating water mechanism 6, insulating tube 8, and puncture metal needle 7 can move back and forth as a single unit, allowing for adjustment of the puncture depth while maintaining the same working section length. Furthermore, the movement distance of the puncture handle 3 can be visually confirmed via the scale designed along the axial direction at the rear end of the handle body 101, thus achieving precise control of the puncture depth. In this invention, when the puncture handle 3 moves forward to its limit position, a section of the circulating water outer tube 605 located inside the ablation catheter's outer cylinder is made of metal; the remaining portion is made of flexible plastic, reducing the risk of breakage of the circulating water outer tube 605 during puncture.

[0058] Based on the above structure, the ablation catheter is also equipped with a temperature sensor, a pressure sensor, a high-frequency line, and a PCB adapter board.

[0059] In the aforementioned temperature sensors, besides thermocouples, other types of temperature sensors can be fixed to the front end of the inner circulating water tube 604 by welding, bonding, or other methods, or embedded and fixed inside the front end of the puncture metal needle 7, to collect the temperature of the ablation area in real time, avoiding high-temperature burns to surrounding normal tissues when the ablation catheter operates at high power. The temperature sensor can also be bonded to the inner circulating water tube 604 through coating and curing, or integrally extruded with the inner circulating water tube 604, facilitating precise coaxial assembly of the temperature sensor, the inner circulating water tube 604, and the outer circulating water tube 605. If a thermocouple is used as the temperature sensor, it can be arranged inside the inner circulating water tube 604, or between the inner circulating water tube 604 and the outer circulating water tube 605. The signal lines of the aforementioned temperature sensors are routed inside the inner circulating water tube 604 to the water tank 601, and then exit through the outlet hole on the side wall of the water tank to reach the equipment compartment.

[0060] The pressure sensor is preferably a piezoelectric sensor, which is installed on the surface of the puncture metal needle 7 to detect the dynamic contact force between the needle and the target tissue in real time. The signal line of the pressure sensor is routed inside the circulating water pipe 604 to the water tank 601, and then exits through the outlet hole on the side wall of the water tank to reach the equipment compartment.

[0061] One end of the high-frequency wire is joined to the outer surface or inner surface of the piercing metal needle 7 using fusion welding, pressure welding, brazing, or laser welding processes to achieve a conductive connection. When the piercing metal needle 7 is made of nickel-titanium alloy, a crimping ring is preferred to secure the high-frequency wire to the metal needle for conductivity. The crimping section of the high-frequency wire is preferably made into a spiral structure to increase the crimping area and resistance to bending and pull-out. After crimping, additional welding can be performed to further improve the electrical connection stability and mechanical strength. When the high-frequency wire is located on the outer surface of the piercing metal needle 7, it can be routed through the inside of the insulating tube 8 to the equipment compartment. When the high-frequency wire is located on the inner surface of the piercing metal needle 7, it can be routed through the inside of the circulating water inner tube 604 or between the circulating water inner tube 604 and the circulating water outer tube 605, and then exit through the outlet hole on the side wall of the water tank to reach the equipment compartment.

[0062] Ultimately, the signal lines and high-frequency lines of all the aforementioned sensors are connected to the signal input terminals of the PCB circuit board installed inside the puncture handle 3 behind the water tank 601. Furthermore, the output cables of the PCB circuit board exit through an opening at the end of the equipment compartment and connect to an external controller, including the RF generation module and control module, via an aviation connector. A silicone protective sleeve 9 is installed at the end of the aforementioned equipment compartment to integrate the various pipes and cables, preventing bending of the cables and pipes.

[0063] The radio frequency generation module is used to output radio frequency energy, which is transmitted to the puncture metal needle 7 through a high-frequency line.

[0064] The control module is used to collect data from various sensors such as temperature, pressure, and impedance, automatically run temperature control and power adjustment algorithms, synchronously control the output of the radio frequency energy generation module, and adjust the ablation emission energy in real time. Specifically, the control module, together with the surface contact pressure, impedance, temperature, and pulse control logic of the puncture metal needle 7, forms a multi-closed-loop feedback system to prevent tissue carbonization and ensure a sufficient ablation range.

[0065] The temperature control logic employs a PID negative feedback closed-loop control, specifically as follows:

[0066] The operator sets a target temperature value T. set The host control module locks the measured temperature T(t) at the target temperature value through negative feedback, and uses a discretized incremental PID algorithm to calculate the power regulation.

[0067]

[0068] in, The power adjustment increment calculated by the temperature loop during the kth sampling period; This is the current temperature error (set value minus actual value). , , These are the proportional, integral, and differential coefficients (which need to be adjusted using clinical data); To control the sampling period of the system (e.g., 10ms or 50ms).

[0069] The impedance control logic employs a piecewise function and an adaptive limiting method, specifically as follows:

[0070] Impedance Z(t) reflects the physical state of the tissue, such as water content or degree of carbonization. Impedance control typically does not aim to "lock in" a specific value, but rather serves as a boundary constraint and mode switcher for the system.

[0071]

[0072] in, The target impedance (typically slightly higher than the initial baseline impedance, representing moderate dehydration and coagulation of the tissue). The hysteresis width (to prevent power from fluctuating frequently at the critical point). This is the attenuation function after the impedance exceeds the limit, which is usually a linear or exponentially decreasing curve. This represents the maximum power during ablation. To ensure continuous ablation power for the tissue; Set the power for the impedance control logic.

[0073] The pulse control logic is based on radio frequency duty cycle modulation. It controls the total energy (joule heat) delivered to the tissue by switching the radio frequency signal on and off at high frequency in a time-averaged manner, in order to prevent the local instantaneous boiling point from being too high.

[0074] Meanwhile, if the control module detects insufficient pressure based on the contact pressure signal sent by the pressure sensor, it can easily lead to "ineffective ablation," while excessive pressure may cause unnecessary damage. Therefore, the control module predicts the ablation effect based on changes in the contact pressure CF.

[0075] CF=kQ / d

[0076] Where k is the calibration coefficient; d is the piezoelectric constant; and Q is the weak charge induced on the surface of the piezoelectric film due to the relative displacement of the positive and negative charge centers inside after the film is subjected to external pressure.

[0077] The ablation catheter of this invention can also be equipped with a miniature electromagnetic sensor and an angle sensor, both mounted on the inner wall of the insulating layer 8 or the outer wall of the puncture metal needle 7. Their signal lines are routed through the inside of the insulating tube 8 to the device compartment and connected to the PCB circuit board. The miniature electromagnetic sensor receives the spatial magnetic field signal from the external electromagnetic positioning instrument, and the control module calculates the three-dimensional spatial coordinates of the needle tip of the puncture metal needle 7 within the cavity. The angle sensor collects real-time pitch, deflection, and rotational attitude information of the ablation catheter tip, and the control module outputs the needle insertion tilt angle and its own torsion angle. Furthermore, by binding the spatial coordinates of the platinum-iridium alloy ring on the outer sheath, the micro-pillar array on the puncture metal needle 7, and the electromagnetic sensor position with the pixel positions of the ultrasound images to establish a simulated 3D coordinate system, an AI algorithm combined with ultrasound imaging can automatically calculate a safe, shortest, and hazardous needle insertion route and monitor the entire surgical process in real time, including information such as needle insertion direction, angle, and depth.

Claims

1. An ablation catheter system, characterized in that: It includes a working handle, an adjusting handle, a puncture handle, an outer sheath, a working section adjusting mechanism, a water cooling circulation system, a puncture metal needle, an insulating tube, a temperature sensor, a high-frequency line, a PCB adapter board, a main unit control module, and a radio frequency energy generation module; The working handle includes a handle body, an outer sheath fixing sleeve, an adjusting handle, and a Luer connector; wherein, the handle body is a cylindrical structure, and the outer sheath fixing sleeve is coaxially fixed inside; The front end of the handle body is coaxially slidably fitted with an adjustable handle with adjustable axial position; the front end of the adjustable handle is equipped with a Luer connector for docking with an endoscope. The rear end of the handle body is coaxially slidably fitted with a puncture handle with adjustable axial position; the puncture handle and the handle body are limited in movement by a matching annular shoulder, and the side wall of the puncture handle is provided with an internal threaded through hole with a tightening bolt to fix the position. The ablation catheter outer tube is composed of the aforementioned handle body, adjustment handle, and puncture handle. The outer sheath is coaxially fixed inside the outer sheath fixing sleeve, and its front end protrudes through the inner hole of the Luer connector; an ultrasonic imaging-enhanced platinum-iridium alloy ring is coaxially assembled inside the front end of the outer sheath. The insulating tube is coaxially sleeved inside the outer sheath; the front part of the insulating tube is sleeved on the outside of the puncture metal needle, and the rear part is fixed to the working section adjustment mechanism; the working section adjustment mechanism is located inside the puncture handle and has a moving pair along the axial direction of the handle body; by controlling the movement of the working section adjustment mechanism, the length of the working section exposed at the front end of the insulating tube by the puncture metal needle is adjusted. The water-cooled circulation system includes a water tank, an inlet pipe, a return pipe, an inner circulating water pipe, and an outer circulating water pipe; wherein, the water tank is fixed inside the puncture handle; the interior of the water tank is divided into two chambers, front and rear, by a partition, which are respectively connected to the return pipe and the inlet pipe; The inner and outer circulating water tubes are coaxially nested with a return water gap between them and are coaxially placed within an insulating layer. The end of the inner circulating water tube is connected to the rear chamber of the water tank, and the end of the outer circulating water tube is connected to the front chamber, with its front end connected to the end of the puncture metal needle. The outer wall of the puncture metal needle is provided with an ultrasonic imaging structure and coated with a conductive anti-adhesion coating. By moving the puncture handle, the water tank, inner circulating water tube, outer circulating water tube, insulating tube, and puncture metal needle can be moved axially as a whole, thereby adjusting the puncture depth. The temperature sensor and pressure sensor are used to collect the temperature of the ablation area and the contact pressure between the needle and the target tissue, respectively. The high-frequency line is electrically connected to the puncture metal needle, and all sensor signal lines and high-frequency lines are connected to the PCB adapter board. The PCB adapter board connects the host control module and the radio frequency energy generation module via an aviation connector; The radio frequency energy generation module is used to output radio frequency energy to the puncture metal needle; The host control module adjusts the RF output power in real time based on multi-closed-loop feedback logic.

2. The ablation catheter system as described in claim 1, characterized in that: Both the outer sheath and the circulating water outer pipe are three-layer composite pipes, including an inner layer, a middle layer, and an outer layer. The three-layer structure is fixed by welding or bonding. The inner layer is made of Pebax or TPU flexible material; the middle layer is made of 304 / 316 stainless steel braided wire or coiled spring or nickel-titanium braided wire or coiled spring; the outer layer is made of Pebax, PTFE, or FEP high-temperature resistant material; the Pebax used in the inner and outer layers is lubricated modified Pebax material.

3. The ablation catheter system as described in claim 1, characterized in that: The insulating tube is a segmented coaxial integrated structure. When the insulating tube moves forward to its limit position, the part of the insulating tube inside the outer cylinder of the ablation catheter is made of metal, and the part of the insulating tube sleeved on the outside of the puncture metal needle is made of PI material with a wall thickness of 0.02mm-0.05mm; the insulating tube in other positions is made of flexible plastic material.

4. The ablation catheter system as described in claim 1, characterized in that: The working section adjustment mechanism includes a rack, a gear, a rotating shaft, and a knob. The rack is fitted against the inner wall of the puncture handle and slides along the inner wall of the puncture handle via an axial groove, allowing it to slide only along the axial direction of the puncture handle. The rack has a fixing hole and is inserted and fixed to the rear of the insulating tube. The gear is coaxially fixed to the inner end of the rotating shaft and meshes with the rack. The knob is fixed to the outer end of the rotating shaft. By rotating the knob, the gear drives the rack to move, thereby driving the insulating tube to move axially.

5. The ablation catheter system as described in claim 1, characterized in that: The specific connection method of the inner circulating water pipe, the outer circulating water pipe and the water tank is as follows: the end of the inner circulating water pipe enters the rear chamber through the through hole of the front cover of the water tank and is connected to the center opening of the partition inside the water tank; the outer circulating water pipe is connected to the center opening of the rear cover of the water tank.

6. The ablation catheter system as described in claim 1, characterized in that: The puncture metal needle has the following shape: solid prismatic, solid circular, hollow prismatic, or conical; the material is nickel-titanium alloy, titanium-niobium alloy, 304, 304L, 316, or 316L elastic metal material; the ultrasonic imaging structure of the outer wall of the puncture metal needle is a micropillar array, and the structure of the micropillar array is triangular, concave, spiral, sandblasted, intersecting, or grid-like; at the same time, the conductive anti-adhesion coating on the surface of the puncture metal needle is made by repeatedly spraying a mixture of conductive and anti-adhesion materials in a vacuum furnace at 200℃-400℃ after physical and chemical surface pretreatment.

7. The ablation catheter system as described in claim 1, characterized in that: The temperature sensor, excluding thermocouples, can be installed by welding, bonding, coating and curing, or integral extrusion molding. The installation position is at the front end of the inner tube of the circulating water or at the front end of the inner tube of the piercing metal needle. When the temperature sensor is a thermocouple, it is arranged inside the inner tube of the circulating water or between the inner tube and the outer tube of the circulating water. The pressure sensor is a piezoelectric sensor, which is installed on the surface of the piercing metal needle. The signal lines of the temperature sensor and the pressure sensor are all routed through the inner tube of the circulating water and exit through the wire outlet hole on the side wall of the water tank to connect to the PCB adapter board.

8. The ablation catheter system as described in claim 1, characterized in that: The high-frequency wire and the piercing metal needle are electrically connected by fusion welding, pressure welding, brazing or laser welding; when the piercing metal needle is made of nickel-titanium alloy, the high-frequency wire is pressed and locked by a crimping ring, and the crimping section of the high-frequency wire has a spiral structure; depending on the connection position, the high-frequency wire is routed through the inside of the insulating tube, the inside of the circulating water inner tube or the gap between the inner and outer tubes, and finally connected to the PCB adapter board.

9. The ablation catheter system as described in claim 1, characterized in that: The host control module constructs a multi-closed-loop feedback control system, including temperature PID negative feedback closed-loop control logic, impedance segmented adaptive amplitude limiting control logic, radio frequency duty cycle pulse control logic, and pressure regulation logic. The temperature control logic employs a discrete incremental PID algorithm to lock the measured ablation temperature to the set target temperature; the impedance control logic uses tissue impedance as a boundary constraint and mode switching condition, and adjusts the ablation power through a piecewise function and adaptive amplitude limiting; the pulse control logic controls the tissue thermal energy input through radio frequency signal on / off duty cycle modulation to avoid local instantaneous high temperature boiling. The pressure control logic calculates the contact pressure between the needle and the tissue using the formula CF=kQ / d, and predicts the ablation effect based on the contact pressure value; where CF is the contact pressure; k is the calibration coefficient; d is the piezoelectric constant; and Q is the weak charge induced on the surface when the positive and negative charge centers inside the piezoelectric film are relatively displaced after being compressed by external force.

10. The ablation catheter system as described in claim 1, characterized in that: It also includes a miniature electromagnetic sensor and an angle sensor, which are installed on the inner wall of the insulating tube or the outer wall of the puncture metal needle. The signal line is routed through the inside of the insulating tube and connected to the PCB adapter board. The miniature electromagnetic sensor is used to receive external magnetic field signals and calculate the three-dimensional spatial coordinates of the tip of the puncture metal needle. The angle sensor is used to collect the pitch, deflection, and rotation attitude angles of the catheter tip. The host control module combines the ultrasound image information of the platinum-iridium alloy ring and micro-pillar array with the spatial attitude information of the sensors to construct a 3D coordinate system. It automatically plans a safe needle insertion route through AI algorithms and monitors the needle insertion parameters of the puncture metal needle in real time.

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