Ablation catheter and ablation system

Abstract

The invention relates to an ablation catheter and an ablation system. The ablation catheter comprises a catheter main body, an ablation electrode and a plurality of flexible microelectrodes, the ablation electrode is arranged at the far end of the catheter main body and has a microelectrode mounting area on the outer surface; the flexible microelectrode is used for acquiring an impedance electric signal and is arranged in the microelectrode mounting area in an insulating manner, and the outer surface of the flexible microelectrode is not lower than the outer surface of the ablation electrode in the microelectrode mounting area after being subjected to attaching extrusion deformation. According to the ablation catheter and the flexible microelectrode, the sizes of the ablation catheter and the flexible microelectrode are only several millimeters at the zero point and are far smaller than the size of the ablation electrode, point monitoring can be carried out on the attaching degree of the ablation electrode instead of surface monitoring, the monitoring precision can be improved, then the ablation point closest to the focus tissue can be determined, efficient and accurate targeted ablation can be achieved, and the ablation efficiency is improved. The ablation catheter can quantitatively detect the attaching degree of the ablation electrode and the blood vessel wall in real time at a fixed point.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to an ablation catheter and an ablation system. Background Art

[0002] Vascular intervention technology can effectively treat cardiovascular and peripheral vascular diseases, with advantages such as less trauma, low reaction, and fast recovery. It also has targeted characteristics, which can effectively treat some patients who cannot tolerate surgery or have lost the opportunity for surgery or are drug-resistant. Based on the above advantages, vascular intervention technology is widely used in blood vessels such as renal arteries and pulmonary veins to treat refractory hypertension, arrhythmia and other diseases.

[0003] The ablation catheter used in vascular interventional technology usually uses the distal ablation electrode to ablate the lesion tissue. Before and during ablation, it is necessary to monitor the degree of contact between the ablation electrode and the lesion tissue to ensure the ablation effect.

[0004] The related art provides an ablation catheter, which includes an electrode portion, which is in a basket shape, and includes a traction wire and a plurality of electrode groups distributed circumferentially along the traction wire, and the electrode group includes at least two electrode bands; the electrode band includes a radio frequency transmitting electrode band and a radio frequency receiving electrode band. The degree of contact between the electrode band and the lesion tissue is determined by monitoring the impedance between the radio frequency transmitting electrode band and the radio frequency receiving electrode band. However, the ablation catheter cannot accurately feedback the contact position and contact accuracy. Summary of the invention

[0005] Based on this, it is necessary to provide an ablation catheter and an ablation system to address the technical problem that the existing ablation catheter cannot use the impedance value to accurately feedback the abutment position and abutment accuracy.

[0006] An ablation catheter, comprising: a catheter body, an ablation electrode and a plurality of flexible microelectrodes;

[0007] The ablation electrode is arranged at the distal end of the catheter body and has a micro-electrode mounting area on the outer surface;

[0008] The flexible microelectrode is used to obtain impedance electrical signals and is insulated and arranged in the microelectrode installation area. The outer surface of the flexible microelectrode is not lower than the outer surface of the ablation electrode in the microelectrode installation area after being deformed by abutment and extrusion.

[0009] In one of the embodiments, the ablation electrode has a mounting cavity in the micro-electrode mounting area, and a support body is disposed in the mounting cavity, and the support body is used to support the flexible micro-electrode.

[0010] In one of the embodiments, a groove is provided on the outer surface of the ablation electrode, the groove cavity of the groove constitutes the mounting cavity, and the groove bottom of the groove constitutes the support body.

[0011] In one embodiment, the ablation catheter further includes a temperature sensor for monitoring the contact temperature between the ablation electrode and the blood vessel wall, and the temperature sensor is disposed on one end of the flexible microelectrode close to the ablation electrode.

[0012] In one embodiment, the temperature sensor includes a first wire and a second wire, the first wire and the second wire are made of different materials, and the first wire and the second wire are connected to form a closed loop, and the first wire is used to transmit a stimulation electrical signal to the flexible microelectrode.

[0013] In one embodiment, the ablation electrode and / or the flexible microelectrode are used to obtain electrocardiographic signals, and the ablation catheter also includes a positioning sensor arranged in the ablation electrode, and the positioning sensor is used to obtain a magnetoelectric signal, wherein the magnetoelectric signal can be coordinated with the electrocardiographic signal to determine a three-dimensional model of the distal end of the ablation catheter.

[0014] In one embodiment, the ablation electrode has a circumferential surface, and a plurality of the flexible micro-electrodes are disposed on the circumferential surface.

[0015] In one embodiment, the ablation electrode further has a distal end face and a rounded surface for smoothly connecting the distal end face with the circumferential surface, the distal end face is provided with at least one flexible microelectrode, and the rounded surface is evenly provided with multiple flexible microelectrodes along the circumference of the ablation electrode.

[0016] In one embodiment, the distal end of the catheter body is in a ring structure. On the same ablation electrode, a portion of the flexible microelectrodes are arranged on a first side of the ablation electrode away from the center of the ring structure, and another portion of the flexible microelectrodes are arranged on a second side of the ablation electrode away from the proximal end of the ablation catheter. The first side is perpendicular to the horizontal plane enclosed by the ring structure, and the second side is perpendicular to the central axis of the proximal end of the ablation catheter.

[0017] An ablation system, comprising a control device and an ablation catheter as described in any one of the above items;

[0018] The control device is used to obtain the impedance electrical signal generated by the flexible microelectrode of the ablation catheter, and determine the contact position of the ablation electrode of the ablation catheter according to the impedance electrical signal.

[0019] In one of the embodiments, the control device is further used to send a stimulation electrical signal to the flexible microelectrode corresponding to the abutment site.

[0020] In the above-mentioned ablation catheter and ablation system, the flexible microelectrode has a size of only a few tenths of a millimeter, which is much smaller than the size of the ablation electrode. Therefore, the degree of contact of the ablation electrode can be monitored in a point manner, rather than in a surface manner, which can improve the monitoring accuracy and further determine the ablation point closest to the lesion tissue, thereby achieving efficient and precise targeted ablation. In addition, the impedance electrical signal obtained by the flexible microelectrode can generate an impedance value, and the degree of contact of the ablation electrode can be quantitatively determined based on the size of the impedance value, which is conducive to the adjustment of the distal position of the ablation catheter. The ablation catheter can detect the degree of contact between the ablation electrode and the blood vessel wall in real time, at a fixed point, and quantitatively. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the three-dimensional structure of the distal end of an ablation catheter adopted in an embodiment of the present application.

[0022] Figure 2 This is a distal side view of an ablation catheter adopted in an embodiment of the present application.

[0023] Figure 3 This is a schematic diagram of the operation of an ablation catheter adopted in an embodiment of the present application.

[0024] Figure 4 for Figure 1 A cross-sectional view of the tip of a tip electrode of a provided ablation catheter.

[0025] Figure 5 This is a side view of the distal end of another ablation catheter used in an embodiment of the present application.

[0026] Figure 6 A schematic diagram of an ablation catheter provided in an embodiment of the present application being parallel to a blood vessel wall.

[0027] Figure 7 A schematic diagram of an ablation catheter provided in an embodiment of the present application vertically abutting against a blood vessel wall.

[0028] Figure 8 A schematic diagram of an ablation catheter provided in an embodiment of the present application being tilted against a blood vessel wall.

[0029] Fig. 9 for Figure 1 A schematic diagram of the three-dimensional structure of a core rod of a head electrode of a provided ablation catheter.

[0030] Fig.10 This is a schematic diagram of the three-dimensional structure of the distal end of another ablation catheter adopted in an embodiment of the present application.

[0031] Fig.11This is a schematic diagram of the three-dimensional structure of the distal end of another ablation catheter adopted in an embodiment of the present application.

[0032] Fig.12 This is a schematic diagram of the three-dimensional structure of the distal end of another ablation catheter adopted in an embodiment of the present application.

[0033] Fig.13 This is a schematic diagram of the three-dimensional structure of the distal end of another ablation catheter adopted in an embodiment of the present application.

[0034] The reference numerals in the accompanying drawings are described as follows:

[0035] 10. Ablation catheter; 100. Catheter body; 110. Main body section; 120. Bendable section; 200. Ablation electrode; 200a. Mounting cavity; 200b. Circumferential surface; 200c. Distal end surface; 200d. Rounded surface; 200e. First side surface; 200f. Second side surface; 200g. Infusion hole; 210. Support body; 220. Head electrode; 220a. Saline cavity; 220b. Pull wire cavity; 220c. First guide wire cavity; 220d. Second guide wire cavity; 230. Ring electrode; 300. Flexible microelectrode; 400. Temperature sensor; 500. Handle; 600. Ablation needle; 700. Electrode belt; 20. Sheath; A. Blood vessel wall. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0037] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0038] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0041] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0042] See also Figure 1 , Figure 1A schematic diagram of the distal structure of an ablation catheter 10 in an embodiment of the present application is shown. The ablation catheter 10 provided in an embodiment of the present application includes a catheter body 100, an ablation electrode 200 and a flexible microelectrode 300; the ablation electrode 200 is arranged at the distal end of the catheter body 100, and the outer surface of the ablation electrode 200 has a microelectrode installation area; the flexible microelectrode 300 is used to obtain impedance electrical signals, and the flexible microelectrode 300 is insulated and arranged in the microelectrode installation area.

[0043] The catheter body 100 may be Figure 2 The ablation catheter 10 includes a main body section 110 and a bendable section 120 connected to each other. The main body section 110 and the bendable section 120 are arranged in sequence from the proximal end to the distal end of the ablation catheter 10. The bend of the bendable section 120 can be adjusted by Figure 3 The handle 500 at the distal end of the main body section 110 is shown to control the ablation catheter 10 to reach the lesion tissue through the sheath 20. It should be noted that in order to clearly show the structure of the ablation catheter 10, Figure 3 Only the distal portion of the sheath 20 is shown.

[0044] Optionally, the main body section 110 may be a braided tube, and may be made of insulating materials such as PEBAX, PU, ​​etc. A reinforcement portion may be provided on the main body section 110, and the reinforcement portion may enhance the support force of the main body section 110, prevent the catheter body 100 from deforming, and play a role in proportional transmission of catheter torque, etc. Among them, the reinforcement portion may be a metal wire, woven on the main body section 110.

[0045] Optionally, the distal end of the main body segment 110 may be connected to the proximal end of the bendable segment 120 by welding or bonding.

[0046] The ablation electrode 200 is one of the important components of the ablation catheter 10, and is mainly used to perform ablation treatment on the lesion tissue, and the ablation method can be energy ablation or chemical ablation. Before ablation, a three-dimensional model of the distal end of the ablation catheter 10 needs to be established to guide the placement of the distal end of the ablation catheter 10. Among them, the three-dimensional model of the distal end of the ablation catheter 10 can be established by electrical positioning or magnetic positioning.

[0047] Regarding the electrical positioning method, when the distal end of the ablation catheter 10 is delivered to the target blood vessel (such as the renal artery or pulmonary vein), the ablation electrode 200 or the flexible microelectrode 300 can be used to obtain the ECG signal, and the external control device will establish a three-dimensional model of the distal end of the ablation catheter 10 based on the ECG signal. In this method, the ablation electrode 200 or the flexible microelectrode 300 can be used in conjunction with an external patch.

[0048] With respect to the magnetic positioning method, after the distal end of the ablation catheter 10 is delivered to the target blood vessel (e.g., the renal artery or the pulmonary vein), the positioning sensor in the distal end of the ablation catheter 10 can be used to obtain a magnetoelectric signal, and the control device outside the body can establish a three-dimensional model of the distal end of the ablation catheter 10 based on the magnetoelectric signal. In this method, the ablation electrode 200 can be used in conjunction with an external magnetic field generator.

[0049] Taking into account the advantages and disadvantages of electrical positioning modeling and magnetic positioning modeling, the present application adopts a combination of electrical positioning and magnetic positioning to establish a three-dimensional model of the distal end of the ablation catheter 10, so as to improve the accuracy of the three-dimensional model, which can effectively guide the placement of the distal end of the ablation catheter 10. Specifically, in the present application, the ablation electrode 200 or the flexible microelectrode 300 is used to obtain an electrocardiographic signal, and the ablation catheter 10 also includes a positioning sensor disposed in the ablation electrode 200, and the positioning sensor is used to obtain a positioning sensor for a magnetoelectric signal, wherein the magnetoelectric signal can be matched with the electrocardiographic signal to determine the three-dimensional model of the distal end of the ablation catheter 10. At this time, the control device outside the body can perform a series of calculations on the magnetoelectric signal and the electrocardiographic signal, and then the three-dimensional model of the distal end of the ablation catheter 10 can be established according to the calculation results.

[0050] Afterwards, under the guidance of the three-dimensional model, the distal end of the ablation catheter 10 can be placed in a suitable position. The impedance electrical signal is obtained by using the flexible microelectrode 300 on the ablation electrode 200, and the control device outside the body can generate an impedance value according to the impedance electrical signal, and then evaluate the degree of contact between each flexible microelectrode 300 and the vascular wall A based on the size of the impedance value, and then determine the contact position between the ablation electrode 200 and the vascular wall A. Finally, the contact position is monopolarly stimulated or bipolarly stimulated by the flexible microelectrode 300 or the ablation electrode 200 to obtain an electrocardiogram signal, and the control device outside the body can map and determine the position of the lesion tissue according to the electrocardiogram signal. If the contact position is consistent with the position of the lesion tissue, ablation is started; if the contact position is inconsistent with the position of the lesion tissue, the position of the distal end of the ablation catheter 10 is adjusted until the contact position is consistent with the position of the lesion tissue. It should be noted that the tighter the flexible microelectrode 300 is in contact with the vascular wall A, the greater the impedance value. Once the impedance value is greater than the preset value, it can be determined that the contact area of ​​the flexible micro-electrode 300 corresponding to the impedance value is the contact point between the ablation electrode 200 and the blood vessel wall A.

[0051] During the ablation process, the contact temperature between the ablation electrode 200 and the vessel wall A needs to be monitored in real time to ensure the safety of ablation. Figure 4The end of the flexible microelectrode 300 close to the ablation electrode 200 may be provided with a temperature sensor 400 for monitoring the contact temperature between the ablation electrode 200 and the blood vessel wall A. The temperature sensor 400 can be used to monitor the contact temperature between the ablation electrode 200 and the blood vessel wall A in real time. Once the temperature is too high, relevant measures such as injecting a cooling medium (such as saline) into the lesion tissue can be taken to reduce the contact temperature between the ablation electrode 200 and the blood vessel wall A, thereby protecting the blood vessel wall A and ensuring the safety of ablation.

[0052] Specifically, the temperature sensor 400 may include a first wire and a second wire, the first wire and the second wire are made of different materials, and the first wire and the second wire are connected to form a closed loop, and the first wire is used to transmit a stimulation electrical signal to the flexible microelectrode 300. When there is a temperature difference between the two connection points of the first wire and the second wire, an electromotive force is generated between the first wire and the second wire, thereby forming a current that can characterize the temperature in the closed loop. Among them, the first wire is electrically connected to the flexible microelectrode 300, and the first wire can transmit a stimulation electrical signal to the flexible microelectrode 300, and the flexible microelectrode 300 electrically stimulates the blood vessel wall A to obtain an electrocardiogram signal, which can be used to map or establish a three-dimensional model of the distal end of the ablation catheter 10. The temperature sensor 400 of this structure can not only monitor the contact temperature between the ablation electrode 200 and the blood vessel wall A, but also transmit a stimulation electrical signal to the flexible microelectrode 300, which can simplify the internal structure of the ablation catheter 10 and avoid the distal end of the ablation catheter 10 being too large and not conducive to the delivery of the ablation catheter 10 in the body.

[0053] Since the size of the flexible microelectrode 300 is only a few tenths of a millimeter, which is much smaller than the size of the ablation electrode 200, the degree of contact of the ablation electrode 200 can be monitored in a point manner, rather than in a surface manner, which can improve the monitoring accuracy, and further determine the ablation point closest to the lesion tissue, and achieve efficient and precise targeted ablation. In addition, the impedance electrical signal obtained by the flexible microelectrode 300 can generate an impedance value, and the degree of contact of the ablation electrode 200 can be quantitatively determined based on the size of the impedance value, which is beneficial to the adjustment of the distal position of the ablation catheter 10. It can be seen that the ablation catheter 10 provided by the present application can detect the degree of contact between the ablation electrode 200 and the blood vessel wall A in real time, at a fixed point, and quantitatively.

[0054] The flexible micro-electrode 300 can be disposed in the micro-electrode installation area of ​​the ablation electrode 200 by using insulating glue (such as epoxy resin, etc.) or insulating gasket.

[0055] Considering that the blood vessel wall A is usually an irregular curved surface, the outer surface of the flexible microelectrode 300 may slightly protrude from the outer surface of the ablation electrode 200 at the microelectrode installation area to ensure that the flexible microelectrode 300 can fit tightly against the blood vessel wall A, so that the degree of contact between the ablation electrode 200 and the blood vessel wall A can be accurately monitored. If the microelectrode is made of a hard material, the microelectrode is prone to scratching the blood vessel wall A when the distal end of the ablation catheter 10 is transported in the blood vessel. In this regard, the present application sets the microelectrode as a flexible microelectrode 300, and the outer surface of the flexible microelectrode 300 is not lower than the outer surface of the ablation electrode 200 at the installation area after being deformed by contact and extrusion. The flexible microelectrode 300 has a certain degree of flexibility, and even if it protrudes from the outer surface of the ablation electrode 200, it will not cause damage to the blood vessel wall A.

[0056] The flexible microelectrode 300 may include a substrate and a flexible metal layer stacked on the substrate, wherein the substrate may be made of materials such as polyester (PET) and polyimide (PI). Such materials have high flexibility, stretchability, bendability, good biocompatibility and insulation, can fit tightly against the blood vessel wall A, and can accurately monitor the degree of contact between the ablation electrode 200 and the blood vessel wall A.

[0057] If the ablation electrode 200 is too close to the vessel wall A, the vessel wall A will apply too much pressure to the flexible microelectrode 300. Under the pressure, the flexible microelectrode 300 will be greatly deformed toward the ablation electrode 200, making the degree of contact between the flexible microelectrode 300 and the vessel wall A inconsistent with the degree of contact between the ablation electrode 200 and the vessel wall A, making it impossible to accurately monitor the degree of contact between the ablation electrode 200 and the vessel wall A. Figure 4 The ablation electrode 200 has an installation cavity 200a in the microelectrode installation area, and a support body 210 is arranged in the installation cavity 200a, and the support body 210 is used to support the flexible microelectrode 300. The support body 210 can prevent the flexible microelectrode 300 from being greatly deformed under the action of the pressing force, so as to ensure that the degree of contact between the flexible microelectrode 300 and the blood vessel wall A is consistent with the degree of contact between the ablation electrode 200 and the blood vessel wall A.

[0058] It can be understood that the base of the flexible microelectrode 300 is fixed on the support body 210 .

[0059] Specifically, the outer surface of the ablation electrode 200 is provided with a groove, the groove cavity of the groove constitutes the installation cavity 200a, and the groove bottom of the groove constitutes the support body 210. The support body 210 is formed in this way, which is convenient for the production and processing of the ablation catheter 10. In some other embodiments, the ablation electrode 200 may be provided with a channel, which extends from the inner surface of the ablation electrode 200 to the outer surface, and the support body 210 may be fixed in the channel by welding, bonding, etc.

[0060] The support body 210 has a wiring through hole communicating with the groove, and the wire in the catheter body 100 can be electrically connected to the flexible microelectrode 300 through the wiring through hole.

[0061] The position distribution of the flexible micro-electrodes 300 on the ablation electrode 200 is mainly related to the structure of the ablation electrode 200 , and the structure of the ablation electrode 200 is related to the structure of the distal end of the ablation catheter 10 .

[0062] in, Figure 2 The distal end of the ablation catheter 10 is a straight structure, and two ablation electrodes 200 are disposed at the distal end of the ablation catheter 10, respectively. Figure 5 The head electrode 220 and the ring electrode 230 are shown. The head electrode 220 includes a core rod and a head connected to each other. The core rod is used to connect the ablation electrode 200 with the catheter body 100, and the head is used to install the flexible microelectrode 300.

[0063] See also Figure 5 The head of the head electrode 220 has a distal end surface 200c, a circumferential surface 200b, and a rounded surface 200d for smoothly connecting the distal end surface 200c and the circumferential surface 200b; the distal end surface 200c, the circumferential surface 200b, and the rounded surface 200d are all provided with flexible microelectrodes 300. The flexible microelectrodes 300 are provided on the circumferential surface 200b, the distal end surface 200c, and the rounded surface 200d of the head electrode 220, which can be applied to different abutment forms of the distal end of the ablation catheter 10, such as Figure 6 The parallel abutment shown, Figure 7 The vertical abutment shown and Figure 8 The inclined abutment shown.

[0064] Specifically, at least one group of flexible microelectrodes 300 is evenly arranged on the circumferential surface 200b of the head electrode 220 along the axial direction of the ablation electrode 200, and each group of flexible microelectrodes 300 is evenly arranged around the circumference of the ablation electrode 200. By setting the position of the flexible microelectrodes 300 on the circumferential surface 200b of the head electrode 220 in this way, the degree of contact between the head electrode 220 and the blood vessel wall A can be fully monitored on the circumferential surface 200b of the head electrode 220, thereby improving the ablation accuracy. Among them, the number of groups of flexible microelectrodes 300 can be 1 group, 2 groups, 3 groups or more, which is mainly related to the axial length of the circumferential surface 200b of the head electrode 220 and the size of the flexible microelectrode 300. In order to further improve the ablation accuracy, two adjacent groups of flexible microelectrodes 300 are staggered.

[0065] The rounded surface 200d of the head electrode 220 is evenly provided with a plurality of flexible microelectrodes 300 along the circumference of the ablation electrode 200. Considering that the axial extension length of the rounded surface 200d is not large, a group of flexible microelectrodes 300 is provided along the axial direction of the head electrode 220, so that the degree of contact between the head electrode 220 and the blood vessel wall A can be fully monitored on the rounded surface 200d of the head electrode 220, thereby improving the ablation accuracy.

[0066] It should be noted that the circumferential surface 200 b of the ring electrode 230 may be provided with or without the flexible micro-electrode 300 according to specific needs.

[0067] The head electrode 220 and / or the ring electrode 230 may have Figure 1 The multiple perfusion holes 200g shown can realize the saline perfusion function, which can not only reduce the contact temperature between the ablation electrode 200 and the blood vessel wall A, prevent the blood vessel wall A from being damaged, and prevent the formation of scabs or clots, but the lower contact temperature can also allow the ablation catheter 10 to use higher power for ablation, increase the ablation depth, and thus more effectively remove the diseased tissue.

[0068] Among them, see Fig. 9 The core rod of the head electrode 220 has a pull wire cavity 220b, a saline cavity 220a, a first guide wire cavity 220c and a second guide wire cavity 220d; the pull wire cavity 220b is equipped with pull wires, springs and other related components that can realize the bending control function, wherein the proximal end of the pull wire is connected to the handle 500 on the proximal end of the catheter body 100; a saline tube is installed in the saline cavity 220a for saline perfusion; the first guide wire cavity 220c and the second guide wire cavity 220d are equipped with corresponding guide wires based on the principle of proximity, such as radio frequency wires, guide wires on the positioning sensor, temperature sensor 400, etc.

[0069] The ablation catheter 10 described above can be used for energy ablation, and can also be used as Fig.10 As shown for chemical ablation, Figure 1 The irrigation hole 200g of the ablation catheter 10 shown is not used to inject cooling medium, but to release Fig.10 The ablation needle 600 shown. Regarding the position arrangement of the flexible microelectrode 300 and the ablation needle 600, an example is given, in which a flexible microelectrode 300 and an ablation needle 600 are arranged adjacent to the distal end surface 200c of the head electrode 220, three flexible microelectrodes 300 and three ablation needles 600 are evenly and alternately arranged on the rounded surface 200d of the head electrode 220 along the circumferential direction, and six flexible microelectrodes 300 are evenly arranged on the circumferential surface 200b of the head electrode 220 along the circumferential direction.

[0070] Fig.11The distal end of the ablation catheter 10 shown is in a ring structure, and the ablation electrode 200 is a ring electrode 230 and is arranged along the ring structure. The ablation electrode 200 is a ring electrode 230 having a circumferential surface 200b, and the circumferential surface 200b is provided with a plurality of flexible microelectrodes 300.

[0071] On the same ablation electrode 200, a part of the flexible microelectrode 300 is arranged on the first side 200e of the ablation electrode 200 away from the center of the ring structure, and another part of the flexible microelectrode 300 is arranged on the second side 200f of the ablation electrode 200 away from the proximal end of the ablation catheter 10. The first side 200e is perpendicular to the horizontal plane surrounded by the ring structure, and the second side 200f is perpendicular to the central axis of the proximal end of the ablation catheter 10. The position of the flexible microelectrode 300 on the ablation electrode 200 is set in this way to adapt to the close monitoring of the blood vessel wall A in the deformed state. It should be noted that the horizontal plane surrounded by the ring structure is perpendicular to the central axis of the proximal end of the ablation catheter 10.

[0072] Among them, one or more flexible micro-electrodes 300 may be arranged on the first side 200e of the ablation electrode 200, and one or more flexible micro-electrodes 300 may be arranged on the second side 200f.

[0073] Fig.12 The distal end of the ablation catheter 10 shown is a basket structure, which has a plurality of electrode bands 700 arranged along the circumference. The electrode bands 700 can be expanded to different degrees. The ablation electrode 200 is a ring electrode 230 and is arranged along the length direction of the electrode band 700. The ring electrode 230 has a circumferential surface 200b, and the circumferential surface 200b is provided with a plurality of flexible microelectrodes 300. The position setting method of the flexible microelectrode 300 is the same as that of the ablation electrode 200. Figure 5 The position setting method of the flexible micro-electrode 300 on the head electrode 220 is the same.

[0074] Fig.13 The distal end of the ablation catheter 10 shown is a spiral structure, and the ablation electrode 200 is a ring electrode 230 and is arranged along the extension direction of the spiral structure. The ring electrode 230 has a circumferential surface 200b, and the circumferential surface 200b is provided with a plurality of flexible microelectrodes 300. The position setting method of the flexible microelectrodes 300 is the same as that of the ablation catheter 10 shown in FIG. Figure 5 The position setting method of the flexible micro-electrode 300 on the head electrode 220 is the same.

[0075] On the other hand, the present application also provides an ablation system, which includes an ablation catheter 10 and a control device; the control device is used to obtain the impedance electrical signal generated by the flexible microelectrode 300 of the ablation catheter 10, and determine the contact position of the ablation electrode 200 of the ablation catheter 10 according to the impedance electrical signal.

[0076] Since the size of the flexible microelectrode 30 is only a few tenths of a millimeter, which is much smaller than the size of the ablation electrode 200, the degree of contact of the ablation electrode 200 can be monitored in a point manner, rather than in a surface manner, which can improve the monitoring accuracy, and further determine the ablation point closest to the lesion tissue, and achieve efficient and precise targeted ablation. In addition, the impedance electrical signal obtained by the flexible microelectrode 30 can generate an impedance value, and the degree of contact of the ablation electrode 200 can be quantitatively determined based on the size of the impedance value, which is beneficial to the adjustment of the distal position of the ablation catheter 10. It can be seen that the ablation catheter 10 provided by the present application can detect the degree of contact between the ablation electrode 200 and the blood vessel wall A in real time, at a fixed point, and quantitatively.

[0077] Furthermore, the control device is also used to send a stimulation electrical signal to the flexible microelectrode 300 corresponding to the abutment site. The flexible microelectrode 300 is used to perform monopolar stimulation or bipolar stimulation on the abutment site to obtain an ECG signal, and the control device can map the ECG signal to determine the location of the lesion tissue. If the abutment site is consistent with the location of the lesion tissue, ablation is started; if the abutment site is inconsistent with the location of the lesion tissue, the position of the distal end of the ablation catheter 10 is adjusted until the abutment site is consistent with the location of the lesion tissue. In this way, the ablation accuracy can be improved.

[0078] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An ablation catheter, characterized in that: The ablation catheter comprises: a catheter body, an ablation electrode and a plurality of flexible microelectrodes; The ablation electrode is arranged at the distal end of the catheter body and has a micro-electrode mounting area on the outer surface; The flexible microelectrode is used to obtain impedance electrical signals and is insulated and arranged in the microelectrode installation area. The outer surface of the flexible microelectrode is not lower than the outer surface of the ablation electrode in the microelectrode installation area after being deformed by abutment and extrusion.

2. The ablation catheter according to claim 1, characterized in that: The ablation electrode has a mounting cavity in the micro-electrode mounting area. A support body is arranged in the mounting cavity. The support body is used to support the flexible micro-electrode.

3. The ablation catheter according to claim 2, characterized in that: The outer surface of the ablation electrode is provided with a groove, the groove cavity of the groove constitutes the installation cavity, and the groove bottom of the groove constitutes the support body.

4. The ablation catheter according to claim 1, characterized in that: The ablation catheter further comprises a temperature sensor for monitoring the contact temperature between the ablation electrode and the blood vessel wall. The temperature sensor is arranged on one end of the flexible microelectrode close to the ablation electrode.

5. The ablation catheter according to claim 4, characterized in that: The temperature sensor includes a first wire and a second wire. The first wire and the second wire are made of different materials and are connected to form a closed loop. The first wire is used to transmit a stimulation electrical signal to the flexible microelectrode.

6. The ablation catheter according to any one of claims 1 to 5, characterized in that: The ablation electrode and / or the flexible microelectrode are used to obtain electrocardiographic signals. The ablation catheter also includes a positioning sensor arranged in the ablation electrode, and the positioning sensor is used to obtain a magnetoelectric signal, wherein the magnetoelectric signal can be coordinated with the electrocardiographic signal to determine a three-dimensional model of the distal end of the ablation catheter.

7. The ablation catheter according to any one of claims 1 to 6, characterized in that: The ablation electrode has a circumferential surface, and a plurality of the flexible micro-electrodes are arranged on the circumferential surface.

8. The ablation catheter according to claim 7, characterized in that: The ablation electrode also has a distal end face and a rounded surface for smoothly connecting the distal end face with the circumferential surface, the distal end face is provided with at least one flexible microelectrode, and the rounded surface is evenly provided with a plurality of the flexible microelectrodes along the circumference of the ablation electrode.

9. The ablation catheter according to claim 7, characterized in that: The distal end of the catheter body is in a ring structure. On the same ablation electrode, a portion of the flexible microelectrodes are arranged on a first side surface of the ablation electrode away from the center of the ring structure, and another portion of the flexible microelectrodes are arranged on a second side surface of the ablation electrode away from the proximal end of the ablation catheter. The first side surface is perpendicular to the horizontal plane enclosed by the ring structure, and the second side surface is perpendicular to the central axis of the proximal end of the ablation catheter.

10. An ablation system, characterized in that: The ablation system comprises a control device and an ablation catheter as claimed in any one of claims 1 to 9; The control device is used to obtain the impedance electrical signal generated by the flexible microelectrode of the ablation catheter, and determine the contact position of the ablation electrode of the ablation catheter according to the impedance electrical signal.

11. The ablation system according to claim 10, characterized in that: The control device is also used to send a stimulation electrical signal to the flexible microelectrode corresponding to the abutment site.

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