A radio frequency ablation catheter and radio frequency ablation apparatus

Abstract

The application discloses a radio frequency ablation catheter and radio frequency ablation equipment, which is characterized in that a protection module is arranged between the catheter heating unit and the catheter body in the heating area. The protection module specifically comprises at least two parallel arranged conductive components which are separated by a temperature sensitive insulation layer. The physical state and / or chemical state of the temperature sensitive insulation layer can change when reaching or exceeding a preset temperature threshold, thereby destroying the electrical insulation state between the adjacent conductive components to form a detectable electrical state change. The control unit can execute the protection operation of reducing or cutting off the radio frequency energy output according to the electrical signal formed by the electrical state change. The protection module of the embodiment is equivalent to arranging countless potential overheating sensors in the whole heating area. No matter where the overheating occurs, it can be immediately sensed as long as the trigger temperature is reached. Moreover, the trigger of the protection mechanism is the direct result of the physical and / or chemical process, and the response speed is extremely fast.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular relates to a radiofrequency ablation catheter and radiofrequency ablation device. Background Technology

[0002] Radiofrequency ablation is a common method for treating cardiovascular diseases such as tachyarrhythmias. Its principle is to release radiofrequency energy through an electrode (usually a heating wire made of a metal coil) at the tip of a catheter, causing controlled thermal damage to the local myocardial tissue, thereby blocking the conduction of abnormal electrical signals.

[0003] Currently, mainstream radiofrequency ablation catheters typically use a spiral coil as the heating element, with only one thermocouple temperature measurement point located near the proximal or central end of the heating element for monitoring and controlling the ablation temperature. However, this structure has significant drawbacks:

[0004] 1. Limitations of single-point temperature measurement: When the catheter is operated within a tortuous blood vessel, the spiral heating wire may not make complete and uniform contact with the vessel wall. The portion of the heating wire that is not in contact or has poor contact will experience a sharp increase in temperature in that localized area, far exceeding the temperature measured by a single-point thermocouple, because the heat cannot be effectively dissipated through the blood flow or tissue.

[0005] 2. Overheating risk: This localized overheating (often called "hot spots") can easily lead to two serious consequences: First, the polymer coating on the catheter surface can be charred, carbonized, or even melted, damaging the catheter; second, it may cause accidental burns, perforations, or thrombosis of the blood vessel wall, causing serious harm to the patient.

[0006] 3. Feedback delay: Existing single-point temperature feedback systems cannot detect this local overheating. They only react when the heat is conducted to the temperature measurement point, by which time overheating damage may have already occurred. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a radiofrequency ablation catheter and radiofrequency ablation device to solve the problem that existing radiofrequency ablation catheters are difficult to accurately detect local overheating.

[0008] To solve the above problems, the technical solution of the present invention is as follows:

[0009] A radiofrequency ablation catheter of the present invention comprises:

[0010] The catheter body has a heating area of ​​a preset length.

[0011] A catheter heating unit is arranged in the heating area to convert current into heat energy under the action of radio frequency energy and conduct heat to the target tissue.

[0012] A temperature measuring unit is arranged in the heating unit of the conduit and forms one or more temperature measuring points for detecting the temperature of the heating area;

[0013] A protection module is arranged in the heating area corresponding to the catheter heating unit and located between the catheter heating unit and the catheter body; the protection module includes at least two conductive components arranged in parallel and separated by a temperature-sensitive insulating layer, wherein the temperature-sensitive insulating layer is configured to change its physical and / or chemical state when a preset temperature threshold is reached or exceeded, resulting in the destruction of the electrical insulation state between at least two of the conductive components and forming a detectable change in electrical state;

[0014] The control unit is electrically connected to the catheter heating unit, the temperature measuring unit, and the protection module, respectively. The control unit is configured to control the radio frequency energy output of the catheter heating unit according to the temperature data of the temperature measuring point, and the control unit is configured to perform protection operations according to the electrical signals formed by the changes in the electrical state.

[0015] The protection operation involves cutting off or reducing the radio frequency energy output of the catheter heating unit.

[0016] In the radiofrequency ablation catheter of the present invention, the temperature-sensitive insulating layer is an insulating coating applied to or covered on the surface of the conductive component.

[0017] The radiofrequency ablation catheter of the present invention has an insulating coating that is a polyester insulating varnish, a polyurethane insulating varnish, or a ceramic insulating varnish.

[0018] The radiofrequency ablation catheter of the present invention has a conductive component that is a metal wire arranged axially in the heating area, with two metal wires arranged parallel to each other and spaced apart.

[0019] In the radiofrequency ablation catheter of the present invention, the change in electrical state is that the resistance between the at least two conductive components changes from a high resistance state to a low resistance state or a conductive state;

[0020] Alternatively, the electrical state change is the thermoelectric potential generated by the contact of the at least two conductive components to form a protective junction.

[0021] The radiofrequency ablation catheter of the present invention has a preset temperature threshold ranging from 100°C to 200°C.

[0022] The radiofrequency ablation catheter of the present invention includes a heating unit comprising a heating wire wound around the heating area and a radiofrequency generator connected to both ends of the heating wire, wherein the radiofrequency generator is electrically connected to the control unit.

[0023] In the radiofrequency ablation catheter of the present invention, the temperature measuring unit is a thermocouple arranged in the winding gap of the heating wire and / or a thermocouple arranged between the heating wire and the catheter body.

[0024] The radiofrequency ablation catheter of the present invention has a first through hole at the proximal end of the catheter body that avoids the heating area, and the conductive component is configured to be arranged axially in the heating area, and the end of the conductive component extends into the inner cavity of the catheter body through the first through hole and protrudes from the proximal opening of the catheter body.

[0025] The present invention provides a radiofrequency ablation device, comprising the radiofrequency ablation catheter described in any one of the above claims.

[0026] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art:

[0027] In one embodiment of the radiofrequency ablation catheter of the present invention, a catheter heating unit is provided in the heating area of ​​the catheter body, and a temperature measuring unit is arranged at the heating unit to form one or more temperature measuring points. The control unit controls the radiofrequency energy output of the heating unit based on the temperature information fed back from each temperature measuring point. Further, a protection module is provided in the heating area between the heating unit and the catheter body. The protection module specifically includes at least two conductive components arranged in parallel and separated by a temperature-sensitive insulating layer. The physical and / or chemical state of the temperature-sensitive insulating layer can change when a preset temperature threshold is reached or exceeded, thereby disrupting the electrical insulation between adjacent conductive components to form a detectable electrical state change. The control unit can then perform a protection operation of reducing or cutting off the radiofrequency energy output based on the electrical signal formed by the electrical state change. The protection module of this embodiment is equivalent to deploying numerous potential overheat sensors throughout the heating area. Regardless of where overheating occurs, it can be immediately sensed once the trigger temperature is reached. Furthermore, the protection mechanism is triggered as a direct result of physical and / or chemical processes, with an extremely fast response speed, far superior to traditional methods that analyze temperature trends through software algorithms. This avoids electronic system delays and solves the problem that existing radiofrequency ablation catheters cannot accurately detect local overheating. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the distal portion of the radiofrequency ablation catheter of the present invention;

[0029] Figure 2 This is an exploded view of the distal portion of the radiofrequency ablation catheter of the present invention;

[0030] Figure 3 for Figure 1 A magnified view of a portion of the image;

[0031] Figure 4 This is a schematic cross-sectional view of the radiofrequency ablation catheter of the present invention;

[0032] Figure 5 for Figure 4 A magnified view of a portion of the image;

[0033] Figure 6 This is a schematic diagram illustrating the working principle of the radiofrequency ablation catheter of the present invention.

[0034] Explanation of reference numerals in the attached diagram: 1. Conduit body; 2. Heating wire; 3. Thermocouple; 4. Metal wire; 5. First through hole; 6. Control unit; 7. Radio frequency generator; 8. Protective junction; 9. Second through hole. Detailed Implementation

[0035] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a radiofrequency ablation catheter and radiofrequency ablation device according to the present invention. The advantages and features of the present invention will become clearer from the following description and claims.

[0036] Example 1

[0037] See Figures 1 to 6 In one embodiment, a radiofrequency ablation catheter includes a catheter body 1, a catheter heating unit, a temperature measuring unit, a protection module, and a control unit 6.

[0038] The catheter body 1 has a heating region of a preset length. A catheter heating unit is arranged within the heating region to convert current into heat energy under the influence of radio frequency energy, which is then conducted to the target tissue. A temperature measuring unit is arranged within the catheter heating unit, forming one or more temperature measuring points for detecting the temperature of the heating region. Specifically, the heating region may be an annular region located at the distal end of the catheter body 1. The catheter heating unit may be spirally wound or wrapped around this annular region, and the temperature measuring unit may be arranged in the gaps between the catheter heating units to form one or more temperature measuring points corresponding to the heating region.

[0039] The protection module is arranged in the heating area corresponding to the conduit heating unit and is located between the conduit heating unit and the conduit body 1. The protection module includes at least two conductive components arranged in parallel and separated by a temperature-sensitive insulating layer (the conductive components and the temperature-sensitive insulating layer can also be arranged along the length direction on the outer surface of the conduit body 1, located inside the conduit heating unit, and matched with the conduit heating unit in the length direction to ensure temperature measurement protection for the conduit heating unit at each position). The temperature-sensitive insulating layer is configured to change its physical and / or chemical state when a preset temperature threshold is reached or exceeded, resulting in the destruction of the electrical insulation state between at least two conductive components and forming a detectable change in electrical state.

[0040] The control unit 6 is electrically connected to the conduit heating unit, the temperature measuring unit, and the protection module. The control unit 6 is configured to control the radio frequency energy output of the conduit heating unit based on temperature data from several temperature measuring points, and to perform protection operations based on electrical signals generated by changes in the electrical state. The protection operation involves cutting off or reducing the radio frequency energy output of the conduit heating unit.

[0041] In this embodiment of the radiofrequency ablation catheter, a heating unit is provided in the heating area of ​​the catheter body 1, and a number of temperature measuring units are arranged within the catheter body 1 to form temperature measuring points. The control unit 6 controls the radiofrequency energy output of the heating unit based on the temperature information fed back from each temperature measuring point. Furthermore, a protection module is provided within the heating area between the heating unit and the catheter body 1. The protection module specifically includes at least two parallel conductive components separated by a temperature-sensitive insulating layer. The physical and / or chemical state of the temperature-sensitive insulating layer can change when a preset temperature threshold is reached or exceeded, thereby disrupting the electrical insulation between adjacent conductive components and forming a detectable electrical state change. The control unit 6 can then perform a protection operation to reduce or cut off the radiofrequency energy output based on the electrical signal generated by this electrical state change. The protection module in this embodiment is equivalent to deploying numerous potential overheat sensors throughout the heating area. Regardless of where overheating occurs, it can be immediately sensed once the trigger temperature is reached. Furthermore, the protection mechanism is triggered as a direct result of physical and / or chemical processes, with an extremely fast response speed, far superior to traditional methods that analyze temperature trends through software algorithms. This avoids electronic system delays and solves the problem that existing radiofrequency ablation catheters cannot accurately detect local overheating.

[0042] The specific structure of the radiofrequency ablation catheter in this embodiment will be further described below:

[0043] In this embodiment, the aforementioned temperature-sensitive insulating layer can specifically be an insulating coating applied to or covering the surface of the conductive component. This insulating coating is a polyester-based, polyurethane-based, or ceramic-based insulating varnish, allowing for adjustment of the preset temperature threshold within the range of 100°C to 200°C, preferably between 130°C and 170°C, by selecting the appropriate type of insulating varnish.

[0044] In this embodiment, the conductive component can specifically be a metal wire 4 arranged axially in the heating area, with two metal wires 4 arranged parallel to each other and spaced apart (i.e., side-by-side), and the ends of both metal wires 4 connected to the control unit 6. Further, an axially extending receiving groove can be formed on the surface of the conduit body 1 to accommodate the corresponding metal wire 4.

[0045] In this embodiment, the above-mentioned electrical state change is the change in resistance between at least two conductive components from a high resistance state to a low resistance state or a conducting state; or, the electrical state change is the thermoelectric potential generated by at least two conductive components contacting to form a protective junction 8.

[0046] In this embodiment, the catheter heating unit may specifically include a heating wire 2 wound around the heating area (and wound around a conductive component, i.e., wound around a combination of a conductive component and a catheter body 1) and a radio frequency generator 7 connected to both ends of the heating wire 2. The radio frequency generator 7 is electrically connected to the control unit 6, i.e., the control unit 6 controls the radio frequency energy (current) output from the radio frequency generator 7 toward the heating wire 2.

[0047] In this embodiment, the proximal end of the catheter body 1 is provided with a first through hole 5 that avoids the heating area (i.e., located outside the heating area). The conductive component (a metal wire 4 with insulating varnish) is configured to be arranged axially in the heating area, and the end of the conductive component extends into the inner cavity of the catheter body 1 through the first through hole 5 and protrudes from the proximal opening of the catheter body 1 to connect to the control unit 6.

[0048] Furthermore, the temperature measuring unit can be a thermocouple 3 arranged in the winding gap of the heating wire 2 and attached to the surface of the conduit body 1. It can enter the cavity of the conduit body 1 through the second through hole 9 opened in the heating area and extend from the proximal opening of the conduit body 1 to be electrically connected to the control unit 6.

[0049] In other embodiments, the temperature measuring unit may further include a thermocouple 3 disposed between the heating wire 2 and the conduit body 1. Alternatively, the thermocouple 3 may be disposed only between the heating wire 2 and the conduit body 1.

[0050] In this embodiment, the control unit 6 may specifically be a radiofrequency ablation host.

[0051] In this embodiment, under normal operating conditions, the temperature of the heating wire 2 is controlled within a safe range (e.g., 50-70°C) by the thermocouple 3, the insulating varnish of the metal wire 4 is intact, and the system does not operate.

[0052] See Figure 6When local overheating occurs (e.g., when any local area of ​​the spiral heating wire 2 overheats due to poor contact), causing the temperature of the metal wire 4 with insulating varnish below to rise to the preset melting temperature of the insulating varnish (e.g., 150°C, which is higher than the normal ablation temperature but far below the temperature threshold for catheter burnout and severe tissue damage), the insulating varnish at that point melts, and the two metal wires 4 come into contact to form a protective junction 8, generating a thermoelectric potential corresponding to the overheating temperature. This signal is sent to the control unit 6 (since this signal appears outside the expected thermocouple 3 circuit, the system can immediately identify it as a "local overheating" alarm signal). After recognizing this abnormal signal, the control unit 6 immediately sends a command to the radio frequency generator 7 to cut off the power output, thus achieving protection.

[0053] The core of the radiofrequency ablation catheter in this embodiment is to pre-embed a section of parallel laid metal wire 4 with insulating varnish below the spiral heating wire 2 (i.e., on the side close to the axis of the catheter body 1). It does not rely on complex active circuits and is a "fail-safe" design. It is only activated when abnormal overheating actually occurs, which has high reliability and simple structure.

[0054] Furthermore, the radiofrequency ablation catheter of this embodiment can effectively prevent damage. By intervening at a temperature far below the ablation temperature (e.g., 150°C), it can effectively prevent damage to the catheter itself and excessive ablation of the blood vessel wall, significantly improving surgical safety. Moreover, the structure is simple and easy to implement, requiring only an additional step in the existing catheter manufacturing process to lay a metal wire 4 with a temperature-sensitive insulating layer. This requires no major modifications to the overall catheter structure and control unit, resulting in limited cost increases.

[0055] Example 2

[0056] This embodiment provides a radiofrequency ablation device, including the radiofrequency ablation catheter described in Embodiment 1 above. It further incorporates a protection module located between the catheter heating unit and the catheter body 1 within the heating area. This protection module specifically includes at least two parallel conductive components separated by a temperature-sensitive insulating layer. The physical and / or chemical state of the temperature-sensitive insulating layer changes when a preset temperature threshold is reached or exceeded, thereby disrupting the electrical insulation between adjacent conductive components and creating a detectable electrical state change. The control unit 6 can then perform a protection operation to reduce or cut off the radiofrequency energy output based on the electrical signal generated by this electrical state change. The protection module in this embodiment is equivalent to deploying numerous potential overheat sensors throughout the heating area. Regardless of where overheating occurs, it can be immediately sensed once the trigger temperature is reached. Furthermore, the triggering of the protection mechanism is a direct result of physical and / or chemical processes, resulting in an extremely fast response speed, far superior to traditional methods that analyze temperature trends through software algorithms. This avoids electronic system delays and solves the problem of existing radiofrequency ablation catheters' inability to accurately detect localized overheating.

[0057] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A radiofrequency ablation catheter, characterized in that, include: The catheter body has a heating area of ​​a preset length. A catheter heating unit is arranged in the heating area to convert current into heat energy under the action of radio frequency energy and conduct heat to the target tissue. A temperature measuring unit is arranged in the heating unit of the conduit and forms one or more temperature measuring points for detecting the temperature of the heating area; A protection module is arranged in the heating area corresponding to the catheter heating unit and located between the catheter heating unit and the catheter body; the protection module includes at least two conductive components arranged in parallel and separated by a temperature-sensitive insulating layer, wherein the temperature-sensitive insulating layer is configured to change its physical and / or chemical state when a preset temperature threshold is reached or exceeded, resulting in the destruction of the electrical insulation state between at least two of the conductive components and forming a detectable change in electrical state; The control unit is electrically connected to the catheter heating unit, the temperature measuring unit, and the protection module, respectively. The control unit is configured to control the radio frequency energy output of the catheter heating unit according to the temperature data of the temperature measuring point, and the control unit is configured to perform protection operations according to the electrical signals formed by the changes in the electrical state. The protection operation involves cutting off or reducing the radio frequency energy output of the catheter heating unit.

2. The radiofrequency ablation catheter as described in claim 1, characterized in that, The temperature-sensitive insulating layer is an insulating coating applied to or covered on the surface of the conductive component.

3. The radiofrequency ablation catheter as described in claim 2, characterized in that, The insulating coating is a polyester insulating varnish, a polyurethane insulating varnish, or a ceramic insulating varnish.

4. The radiofrequency ablation catheter as described in claim 1, characterized in that, The conductive component is a metal wire arranged axially in the heating area, with two metal wires arranged parallel to each other and spaced apart.

5. The radiofrequency ablation catheter as described in claim 1, characterized in that, The electrical state change is that the resistance between at least two of the conductive components changes from a high resistance state to a low resistance state or a conducting state. Alternatively, the electrical state change is such that at least two of the conductive components come into contact to form a protective junction, thereby generating a thermoelectric potential.

6. The radiofrequency ablation catheter as described in claim 1, characterized in that, The preset temperature threshold ranges from 100°C to 200°C.

7. The radiofrequency ablation catheter as described in claim 1, characterized in that, The conduit heating unit includes a heating wire wound around the heating area and a radio frequency generator connected to both ends of the heating wire. The radio frequency generator is electrically connected to the control unit.

8. The radiofrequency ablation catheter as described in claim 7, characterized in that, The temperature measuring unit is a thermocouple arranged in the gap between the heating wire and / or a thermocouple arranged between the heating wire and the conduit body.

9. The radiofrequency ablation catheter as described in claim 1, characterized in that, The proximal end of the catheter body is provided with a first through hole that avoids the heating area. The conductive component is configured to be arranged axially in the heating area, and the end of the conductive component extends into the inner cavity of the catheter body through the first through hole and protrudes from the proximal opening of the catheter body.

10. A radiofrequency ablation device, characterized in that, Includes the radiofrequency ablation catheter as described in any one of claims 1 to 9.

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