CN115363745B

CN115363745B - Ablation catheter

Info

Publication number: CN115363745B
Application number: CN202211322767.7A
Authority: CN
Inventors: 董潇男; 唐闽; 刘成
Original assignee: Hangzhou Dinova EP Technology Co Ltd
Current assignee: Hangzhou Dinova EP Technology Co Ltd
Priority date: 2022-10-27
Filing date: 2022-10-27
Publication date: 2023-03-24
Anticipated expiration: 2042-10-27
Also published as: CN115363745A

Abstract

The invention provides an ablation catheter which comprises a catheter body and a head electrode, wherein the near end of the head electrode is connected with the far end of the catheter body, the head electrode is of a hollow mesh structure and has elasticity, and the head electrode can be connected with an energy output device so as to transmit ablation energy output by the energy output device to a target tissue region for ablation isolation. According to the ablation catheter provided by the embodiment of the invention, the head electrode adopts the hollowed-out net structure, so that the head electrode has elasticity and flexibility compared with a common solid electrode, the head electrode can be more suitable for the requirement of ablation of the attached tissue based on the better elasticity and flexibility brought by the hollowed-out net structure, the effect of attaching the head electrode to the tissue is good, and the head electrode can more thoroughly ablate the target tissue under the condition of receiving the energy transmitted by the energy output device.

Description

Ablation catheter

Technical Field

The invention relates to the technical field of medical instruments, in particular to an ablation catheter.

Background

Atrial fibrillation (atrial fibrillation) is one of the most common clinical arrhythmias characterized by loss of ordered electrical activity under sinus rhythm control by the atria, replacement with rapidly disorganized fibrillation waves, consequent loss of effective contraction and relaxation of the atria, deterioration or loss of pumping function, and resulting in extremely irregular ventricular responses, and is one of the leading causes of sudden cardiac death.

The effective treatment means of atrial fibrillation is aimed at recovering sinus rhythm and mainly comprises two main categories of drug treatment and non-drug treatment; the drug therapy is mainly suitable for first-diagnosis patients with atrial fibrillation and paroxysmal atrial fibrillation without related contraindications, and the heart rate of the ventricles can be controlled mainly through the drug therapy to ensure the basic functions of the heart, such as beta receptor blockers, amiodarone, digitalis and the like; non-drug therapies include anticoagulation, electrical cardioversion, surgical maze procedures, and catheter ablation.

For catheter ablation, radio frequency ablation and cryoablation are relatively mature in the market at present, abnormal myocardial cells are killed by controlling the temperature through an intervention means, the whole trauma is small, the recovery period is short, but normal cells are killed without difference by the temperature, and other complications are easily caused. The pulse ablation technology which is developed at present also belongs to one of catheter ablation, and has the purposes of selectively enabling abnormal myocardial cells to generate irreversible electroporation by applying a certain pulse electric field and further recovering normal sinus rhythm. However, for the above various catheter ablation techniques, many ablation catheters on the market at present cannot realize good adhesion with body tissues, and are easy to cause the tissues to be ablated insufficiently.

Disclosure of Invention

In order to solve the problem that the tissue is ablated incompletely because the traditional ablation catheter cannot be well attached to the body tissue, the invention discloses an ablation catheter which is suitable for the requirement of ablation of attached tissue.

According to one aspect of the invention, the ablation catheter comprises a catheter body and a head electrode, wherein the proximal end of the head electrode is connected with the distal end of the catheter body, the head electrode is of a hollow mesh structure and has elasticity, and the head electrode can be connected with an energy output device so as to transmit ablation energy output by the energy output device to a target tissue area for ablation isolation.

According to the technical scheme, the embodiment of the invention at least has the following advantages and positive effects:

according to the ablation catheter provided by the embodiment of the invention, the head electrode adopts the hollowed-out net structure, so that the head electrode has elasticity and flexibility compared with a common solid electrode, the head electrode can bring better elasticity and flexibility based on the hollowed-out net structure, so that the head electrode is more suitable for the requirement of ablation on tissue, the effect of the head electrode on the tissue is good, and the head electrode can ablate target tissue more thoroughly under the condition of receiving energy transmitted by the energy output device. In addition, the head electrode can realize the selection of the energy in the ablation process, improve the flexibility of the ablation process, greatly reduce the complexity of the operation, increase the operability of the operation, effectively shorten the operation time and reduce the risk of the operation process. For example, the head electrodes may use pulsed electrical discharges during ablation to reduce muscle stimulation to the patient.

Drawings

FIG. 1 is a schematic structural view of an ablation catheter in accordance with a first embodiment of the present invention;

FIG. 2 is a schematic structural view of a distal portion of the ablation catheter of FIG. 1;

FIG. 3 is a schematic structural view of a distal portion of a second embodiment ablation catheter;

FIG. 4 is an enlarged schematic view of the structure at A in FIG. 3;

FIG. 5 is a schematic view showing a third embodiment of an ablation catheter with a balloon in a deflated state;

FIG. 6 is a schematic view of a balloon of a third embodiment ablation catheter in an inflated state;

FIG. 7 is a schematic view of a balloon of a third embodiment ablation catheter in an inflated state;

FIG. 8 is a first schematic view illustrating operation of the ablation catheter of the third embodiment;

FIG. 9 is a second schematic operational view of the third embodiment ablation catheter;

fig. 10 is a schematic structural view of a balloon of the fourth embodiment ablation catheter in a deflated state;

FIG. 11 is a schematic view of a fourth embodiment ablation catheter with a balloon in an inflated state;

FIG. 12 is a schematic structural view of a fifth embodiment ablation catheter;

FIG. 13 is a schematic structural view of a support frame of a sixth embodiment of an ablation catheter in a collapsed state;

FIG. 14 is a schematic structural view of a support frame of a sixth embodiment of an ablation catheter in an expanded state;

fig. 15 is a schematic structural view of a support frame in an expanded state in an ablation catheter of the seventh embodiment.

The reference numerals are explained below:

100. an ablation catheter; 1. a tube body; 11. an inner tube; 12. an outer tube; 13. an inner sheath core; 131. a micro-orifice; 2. a head electrode; 21. a curved surface; 3. a handle assembly; 31. a handle body; 32. a bending adjusting module; 4. a tube electrode group; 41. a first tube electrode; 42. a second tube electrode; 5. an ablation assembly; 51. a support body; 511. a balloon; 512. a support framework; 513. a carrier bar; 52. an ablation electrode; 53. a route of contact; 6. a drive tube; 7. a scope module; 71. an endoscope; 72. an illuminating lamp.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

For convenience of expression, in the context of endoluminal interventions, proximal refers to the end of the instrument that is closer to the operator after the intervention and distal refers to the end of the instrument that is further from the operator after the intervention.

First embodiment

Referring to fig. 1, an embodiment of the present invention provides an ablation catheter 100, wherein the ablation catheter 100 is capable of ablation isolation of a target tissue region. The target tissue region may be located in the heart, including but not limited to the mitral isthmus, the tricuspid isthmus, the left atrial apex, the pulmonary veins, or trigger foci incorporating typical atrial flutter, non-pulmonary vein origin (e.g., left atrial appendage, superior vena cava, coronary sinus ostium), and the like. It is understood that the target tissue region is not limited to being located in the heart, and may be located in other body tissues, and the invention is not limited thereto.

Referring to fig. 1 and 2, an ablation catheter 100 includes a catheter body 1 and a tip electrode 2. The head electrode 2 is arranged at the far end of the tube body 1, and the tube body 1 is used for driving the head electrode 2 arranged at the far end of the tube body to intervene in a target tissue area so as to be used for ablation and isolation of the target tissue area. Fig. 1 illustrates that the ablation catheter 100 further comprises a handle assembly 3 and a pulling device (not shown), the pulling device can be a pulling wire, the distal end of the pulling device is connected with the bendable section of the tube body 1, the proximal end of the pulling device is connected with the handle assembly 3, the proximal end of the tube body 1 is connected with the handle assembly 3, and the handle assembly 3 can control the pulling device to adjust the position and the direction of the distal end of the tube body 1. That is, the handle assembly 3 can bend the distal end of the tube body 1 to change its shape according to personalized differences of specific human lumen anatomical structures, so that the tube body 1 can carry the head electrode 2 to reach a target tissue region of a human blood vessel to complete ablation.

In this embodiment, the tube 1 is linear and can be bent to match the function of the tube 1, and the tube 1 can carry the head electrode 2 at the distal end of the tube 1 to reach each tissue of the heart, so as to adapt to various focus positions. The body 1 is preferably constructed of PEBAX (block polyether amide resin) material so that the body 1 is resistant to the high voltage energy released by the electrodes. Of course, other materials, such as PEEK (polyetheretherketone), may be used for the tube body 1.

For ease of understanding, fig. 1 illustrates that the handle assembly 3 includes a handle body 31 and a bending adjustment module 32, the bending adjustment module 32 is disposed at the proximal end of the tube 1 and connected to the handle body 31, the bending adjustment module 32 may be a bending adjustment knob, and the bending adjustment module 32 can be driven to drive the distal end of the tube 1 to bend through a traction device, so as to guide the head electrode 2 to approach the target tissue region. It should be noted that the bending structure of the handle assembly 3 may take any one of the forms known in the market, and the present invention is not limited thereto. In addition, the bending structure of the handle assembly 3 is not necessary, i.e., the ablation catheter 100 may not have the bending function.

The near-end of head electrode 2 is connected with the distal end of body 1, and head electrode 2 is the network structure of fretwork, and head electrode 2 is including accomplishing at least one of heat setting's wire woven mesh and the metal pipe net of accomplishing heat setting after the cutting, and the wire woven mesh is preferably nickel titanium wire woven mesh, and the metal pipe net is preferably nickel titanium pipe net. It should be understood that the head electrode 2 may be a metal wire mesh, or the head electrode 2 may be formed by joining a metal wire mesh and a metal wire mesh.

The mesh structure of head electrode 2 based on the fretwork has more general solid electrode structure better elasticity and flexibility, and better elasticity and the pliability that head electrode 2 can bring based on the mesh structure of its fretwork make it more be fit for melting and lean on the needs of tissue, and head electrode 2 is leaned on tissue effect good, and head electrode 2 can be more thoroughly ablated to the target tissue under the energy of receiving energy output device transmission. The shape of the head electrode 2 may be a capsule type, a cylinder type, or a sphere type to ensure that the distal end of the head electrode 2 has a smooth curved surface, thereby ensuring that the head electrode 2 is maximally attached to the tissue. In one embodiment, the radial dimension of the curved surface 21 of the distal end of the head electrode 2 is gradually increased in the direction from the distal end to the proximal end of the head electrode 2, so as to further increase the contact area of the head electrode 2 with the tissue.

It has been described hereinbefore that the head electrode 2 is capable of receiving energy delivered by an energy output device for ablating a target tissue region, which energy output device may be referred to herein as a radio frequency ablator for delivering high frequency electrical current to the ablation catheter 100, for example to the head electrode 2. The energy output device may also be a pulse generator for delivering a pulsed current to the ablation catheter 100, for example to the head-electrode 2, or an energy integration device capable of selectively emitting radiofrequency energy and pulsed energy.

In order to connect the head electrode 2 with the energy output device, the handle assembly 3 comprises a connector, the connector is located at the proximal end of the handle body 31, a lead channel is further arranged inside the tube body 1, and a lead of the head electrode 2 passes through the lead channel and then is connected with the connector arranged at the proximal end of the handle body 31, so that the head electrode 2 is connected with the energy output device.

The ablation catheter 100 can provide a variety of electrical discharge patterns to select the appropriate energy output for discharge based on the ablation site, and the ablation catheter 100 can use both radiofrequency energy ablation and pulsed electric field ablation. Therefore, the ablation catheter 100 of the embodiment can realize free energy switching in the ablation process, that is, in the ablation process, an operator can select a more suitable energy mode to perform ablation according to the complexity of the surgical site, the actual situation of a patient or the experience of a doctor, so that the flexibility of the ablation process is improved, the complexity of the operation is greatly reduced, the operability of the operation is increased, the operation time is effectively shortened, and the risk in the operation process is reduced.

The head electrode 2 may be selected to deliver radiofrequency current or pulsed current to the myocardial tissue to form monopolar radiofrequency ablation or monopolar pulsed ablation. In this case, the energy output device is also connected to at least one reference electrode, which can be placed on the back or on the chest of the patient. When the head electrode 2 is selected to perform monopolar radiofrequency ablation or monopolar pulse ablation, the polarity of the head electrode 2 is opposite to that of the reference electrode, for example, when the polarity of the head electrode 2 is positive, the polarity of the reference electrode is negative.

The ablation catheter 100 further includes a tube electrode assembly 4, the tube electrode assembly 4 being attached to the outer wall of the body 1 and disposed near the proximal end of the tip electrode 2. The tube electrode group 4 comprises at least one tube electrode, and the tube electrode can be made of medical metal materials such as platinum-iridium alloy, gold or other platinum alloys. The head electrode 2, in combination with different tube electrodes, can map myocardial signals over different ranges. In addition to the head electrode 2 emitting RF energy or pulse energy alone as described above, the head electrode 2 may be combined with a tube electrode to generate a pulsed electric field for bipolar pulse ablation of a target tissue region, and the head electrode 2 may be combined with a tube electrode to generate a high frequency current for bipolar RF ablation of a target tissue region.

In this embodiment, the tube electrode group 4 includes a first tube electrode 41 and a second tube electrode 42, the first tube electrode 41 and the second tube electrode 42 are arranged at intervals from the distal end to the proximal end of the tube body 1 along the axial direction of the tube body 1, and the first tube electrode 41, the second tube electrode 42 and the head electrode 2 are insulated from each other. The first tube electrode 41 and the second tube electrode 42 are respectively connected with a connector arranged at the proximal end of the handle assembly 3 through a lead wire to obtain ablation energy. Fig. 2 illustrates the first tube electrode 41 and the second tube electrode 42 as ring electrodes, it being understood that in other embodiments, at least one of the first tube electrode 41 and the second tube electrode 42 may also be a sheet electrode or a ball electrode.

When at least one of the head electrode 2, the first tube electrode 41, and the second tube electrode 42 is selected for monopolar radiofrequency ablation or monopolar pulse ablation, the polarity of the selected electrode is opposite to that of the reference electrode. In other embodiments, the head electrode 2 and at least one of the first tube electrode 41 and the second tube electrode 42 can be selected for bipolar pulse ablation, compared with unipolar pulse ablation, bipolar ablation does not need an external negative plate to form a current loop, most of the current only exists near the electrode and does not flow through skeletal muscles in the back and other areas, so that the bipolar pulse ablation has less stimulation on muscles, and the ablation energy is more concentrated around the electrode. Here, it should be understood that the polarities of the electrodes are opposite to each other in the bipolar pulse ablation to form a positive-negative circuit, for example, if the head electrode 2 and the first tube electrode 41 are selected for the bipolar pulse ablation, the polarities of the head electrode 2 and the first tube electrode 41 are opposite, specifically, the head electrode 2 may be a positive electrode, and the first tube electrode 41 may be a negative electrode, or vice versa. In other embodiments, the tip electrode 2 and at least one of the first and

second tube electrodes

41, 42 may also be selected for bipolar radiofrequency ablation.

The distance L1 between the first tube electrode 41 and the head electrode 2 is 1mm to 5mm, and the distance L2 between the second tube electrode 42 and the first tube electrode 41 is 2mm to 8mm. In one embodiment, the distance L1 between the first tube electrode 41 and the head electrode 2 is preferably 1mm, and the distance L2 between the second tube electrode 42 and the first tube electrode 41 is preferably 4mm. Because the distance between the head electrode 2 and the first tube electrode 41 is relatively close, during discharge ablation, the head electrode 2 and the first tube electrode 41 can be regarded as integral local ablation, the ablation depth is increased along with the increase of the applied voltage amplitude, the polarities of the head electrode 2 and the first tube electrode 41 can be set to be opposite, and at the moment, a local bipolar pulse electric field generated between the head electrode 2 and the first tube electrode 41 can be used for specifically ablating a focus area, so that the surrounding healthy tissues are prevented from being damaged. It should be noted that the axial dimension of each tube electrode may preferably be 1mm.

The ablation catheter 100 of this embodiment, head electrode 2 adopts the capsule type, the cylinder type, perhaps spherical fretwork network structure design, the needs of pasting target tissue when both having ensured to melt, the head electrode 2 of fretwork is more flexible and pliability than general solid electrode simultaneously, more be fit for melting and paste the needs of pasting the tissue, it is better to paste the effect, can make target tissue melt more thoroughly, can realize the selection of melting process energy simultaneously, promote the flexibility of melting process, and the complexity of the significantly reduced operation, increase the maneuverability of operation, effectively shorten the operating time, reduce the risk among the operation process. The ablation catheter 100 can selectively use radio frequency discharge or pulse discharge for different target tissue regions during ablation to improve ablation safety.

Second embodiment

Referring to fig. 3 and 4, wherein fig. 3 illustrates a schematic structural view of a distal portion of an ablation catheter 100 in a second embodiment, fig. 4 illustrates an enlarged schematic structural view at a of the ablation catheter 100 shown in fig. 3.

The ablation catheter 100 of the present embodiment is substantially similar in structure to the first embodiment, except that the present embodiment can be understood as further defining the ablation catheter 100 of the first embodiment. The ablation catheter 100 of the embodiment further includes an inner sheath core 13, the material of the inner sheath core 13 may be at least one selected from a polymer material or a stainless steel tube, and the inner sheath core 13 is disposed through the tube body 1 and exposed from the distal end of the tube body 1. The inner sheath core 13 is provided with a perfusion channel extending to the proximal end of the tube body 1, and a microflow hole 131 is further arranged on the portion of the inner sheath core 13 between the proximal end of the head electrode 2 and the distal end of the head electrode 2, and the microflow hole 131 is communicated with the perfusion channel. The proximal end of the irrigation channel may be perfused with saline, which after perfusion can be directed through the orific-holes 131 to complete irrigation of the tip electrode 2 with saline. The saline infusion during the ablation can also prevent the thrombosis of the device, reduce the thrombosis risk during the ablation process and ensure the treatment effect. It should be noted that the number of the microfluidic holes 131 may be one or more, and when the number of the microfluidic holes 131 is plural, the plurality of microfluidic holes 131 may be uniformly arranged along the circumferential surface of the inner sheath core 13 to ensure that the saline flowing out from the microfluidic holes 131 is more uniform.

The distal end of inner sheath core 13 can be connected with the distal end fixed connection of head electrode 2, and the proximal end of inner sheath core 13 can be connected with handle component 3, and handle component 3 can drive inner sheath core 13 along axial displacement to inner sheath core 13 can also drive head electrode 2 radial expansion and shrink when the axial displacement along body 1 to change head electrode 2 shape.

Third embodiment

Referring to fig. 5-7, fig. 5-7 illustrate a structural schematic view of a third embodiment ablation catheter 100.

The ablation catheter 100 of the present embodiment is substantially similar in structure to the first embodiment, except that the present embodiment can be understood as further defining the ablation catheter 100 of the first embodiment. The ablation catheter 100 of the present embodiment further includes an ablation assembly 5, the ablation assembly 5 is sleeved on the tube body 1 and is close to the proximal end of the head electrode 2, and more specifically, the ablation assembly 5 is disposed close to the proximal end of the tube electrode assembly 4. The ablation assembly 5 includes a support body 51 and an ablation electrode 52 disposed on the support body 51, the ablation assembly 5 being capable of radial contraction and expansion. Wherein radial contraction and expansion of the ablation assembly 5 of the present invention refers to radial contraction and expansion of the support body 51.

The number of the ablation electrodes 52 is multiple, the multiple ablation electrodes 52 are arranged at intervals and enclose to form a ring-shaped ablation array, the ring-shaped ablation array is used for ring-shaped ablation isolation of a target tissue area after the ablation assembly 5 is radially expanded, for example, the radially expanded and expanded ablation assembly 5 can perform ring-shaped ablation isolation of the tissue area on a pulmonary vein orifice, for example, so as to prevent abnormal electricity from spreading and/or destroy abnormal electricity conduction through heart tissue, treat arrhythmia and reduce the risk of a plurality of potentially fatal complications. The ablation assembly 5 can be expanded radially to be expanded, which is explained in various ways, for example, the ablation catheter 100 is provided with a sheath (not shown) sleeved outside the catheter body 1, the sheath is used for radially compressing the ablation assembly 5, so that the radially compressed ablation assembly 5 is accommodated in an inner channel of the sheath, and the radially compressed ablation assembly 5 can be delivered to a target tissue region in the sheath, that is, the ablation assembly 5 is accommodated in the sheath before being released. When the target tissue area is reached, the ablation assembly 5 can be extended out of the sheath and naturally expanded to expand.

The ability of the ablation assembly 5 to expand radially to distract may also be achieved by the embodiments shown in fig. 5-7. In this embodiment, the support 51 includes a balloon 511, the balloon 511 is preferably a compliant balloon, the size of the balloon 511 can vary with the filling pressure, and the balloon 511 can be cylindrical, spherical, heart-shaped, or other irregular shapes. The material of the balloon 511 may be polyether block polyamide (pebax), thermoplastic polyurethane rubber (TPU), or polyamide material (PA), and TPU is preferred in this embodiment. Balloon 511 can be filled with a fluid to radially expand, and balloon 511 can also release the fluid to radially contract. The fluid can be selected to be a cold saline circulation or a liquid nitrogen circulation so as to avoid bubbles generated during ablation, create good tissue contact and enhance the ablation effect. Of course, the fluid may alternatively be other liquid or gaseous media.

In this embodiment, both the proximal end and the distal end of the balloon 511 are seamlessly connected to the outer wall of the tube 1, a filling cavity (not shown) is formed between the balloon 511 and the tube 1, the tube 1 is provided with a channel (not shown) extending to the proximal end of the tube 1, the tube 1 is further provided with an opening (not shown) communicating with the filling cavity and the channel, the channel can allow fluid to pass through so that the fluid enters the filling cavity through the opening, and the fluid entering the filling cavity can prop open the balloon 511, so that the balloon 511 can be switched from the contracted state shown in fig. 5 to the expanded state shown in fig. 6. The fluid in the balloon 511 can also flow reversely to the channel of the tube 1 through the opening under the action of the negative pressure device and be drawn out through the proximal end of the tube 1, and the balloon 511 can be switched from the expanded state shown in fig. 6 to the contracted state shown in fig. 5.

While the plurality of ablation electrodes 52 are arranged at intervals and enclosed to form the annular ablation array, fig. 7 illustrates that when the balloon 511 is attached to the target tissue region, a part of the ablation electrodes 52 arranged on the outer surface of the balloon 511 is attached to the target tissue region, and another part of the ablation electrodes 52 is not attached to the target tissue region. Fig. 7 illustrates a virtual contact path 53 connecting two adjacent ablation electrodes 52, and the ablation electrodes 52 on the virtual contact path 53 can perform discharge ablation on the target tissue. It should be noted that the ablation electrode 52 may be a flexible electrode sheet, and in this case, the ablation assembly 5 includes a plurality of spaced and insulated flexible electrode sheets, which can be deformed to increase the contact area with the tissue, and can release micro-current to complete the impedance detection. It is understood that in other embodiments, the ablation electrode 52 may also be in the form of a wire electrode or an electrode pad, and the wire electrode has good flexibility to facilitate the release and sheath retraction of the ablation catheter 100.

The ablation electrodes 52 are arranged in various ways, and the ablation electrodes 52 may be arranged perpendicular to the central axis of the balloon 511, or the array of the ablation electrodes 52 is coplanar with the central axis of the balloon 511, such as a plurality of rows of aligned and evenly-distributed arrangements or a plurality of rows of staggered arrangements, etc., in this embodiment, five rows of aligned arrangements are preferred, and the distribution position is the entire outer surface of the balloon 511. A small hole for passing a lead is formed at the position of the surface of the balloon 511 where the ablation electrode 52 is arranged, and the lead passes through the small hole to connect the ablation electrode 52 with the connector. The ablation electrode 52 may be looped with a reference electrode for monopolar radiofrequency ablation or monopolar pulse ablation. Meanwhile, the plurality of ablation electrodes 52 disposed on the outer surface of the balloon 511 can be divided into two sets of electrode groups with opposite polarities for bipolar radiofrequency ablation or bipolar pulse ablation.

The present invention will be described in detail with respect to the operational steps for performing surgery on the ablation catheter 100. Referring to fig. 8, when balloon 511 is not inflated, the distal end of tube 1 may be steered by handle assembly 3, atrial point-to-point focal ablation using head electrode 2 at the distal end of tube 1, or atrial point-to-point focal ablation using at least one of head electrode 2 at the distal end of tube 1 and tube electrode set 4 at the distal end of tube 1 in cooperation. If ablation of the pulmonary vein is desired, referring to fig. 9, fluid can be filled into balloon 511 to inflate balloon 511, the inflated balloon 511 radially expanding and conforming to the ostium of the pulmonary vein. At this time, all ablation electrodes 52 on the surface of the balloon 511 can be detected by impedance through the micro-current distribution, so as to determine the adhesion condition of all ablation electrodes 52 to the pulmonary veins, so that a user can selectively connect the ablation electrodes 52 contacting with the target tissue into a loop to complete ablation, and the ablation electrodes 52 connected into the loop form a continuous loop or a partial loop. At the same time, ablation electrodes 52 that are not in contact with the target tissue may be selectively disconnected.

Specifically, all ablation electrodes 52 on the surface of balloon 511 are used to connect to a controller, which may include a processing chip integrated into the energy output device or separately externally connected to the energy output device, the controller being capable of energizing ablation electrodes 52 within a predetermined range of impedance values based on the impedance values detected by ablation electrodes 52, and the controller being further capable of de-energizing ablation electrodes 52 outside the predetermined range of impedance values. It should be explained that the preset impedance value range may be data for pre-storing in a memory, and when the ablation electrode 52 is in full contact with the target tissue region, the impedance value detected by the ablation electrode 52 will be within a certain range interval a. When the ablation electrode is in contact with the target tissue region portion, the impedance value detected by the ablation electrode 52 will be within a range interval B. When the ablation electrode 52 is not in contact with the target tissue region, the impedance value detected by the ablation electrode 52 is within a certain range interval C. The controller may set the preset impedance value range to a so that all ablation electrodes 52 located within interval a are energized and other portions are de-energized according to the detected impedance value. It is to be understood that in other embodiments, the determination of the state of the ablation electrode 52 in contact with the target tissue is not limited to the above-described impedance detection method, and the ablation electrode 52 in contact with the target tissue may be selected to discharge in other manners, for example, using the results of observation by the endoscope 71 described below.

The significance of the zone discharge is that different ablation electrodes 52 are different in the sticking degree with the myocardial tissue, the ablation electrode 52 which is not well stuck in the close state can save the ablation energy, the utilization rate of the energy is increased, the dissipation of the energy in the blood is reduced, meanwhile, the air discharge is avoided, and unnecessary bubbles generated by the electrolysis of the blood are reduced. Ablation energy can be targeted to the tissue to be ablated to avoid damaging unintended tissue to be ablated. When the regional discharge is carried out, all the ablation electrodes 52 do not need to be electrified, the total current during the ablation is reduced, the possible body stimulation is reduced, the short circuit or electric arc caused by too many ablation electrodes 52 can be reduced, and the safety is improved. It should be noted that the ablation zone can be marked on a three-dimensional system, and the non-ablated area can also be marked, so that the marking result can be used for guiding the next ablation.

Increase in this embodiment and melt subassembly 5, make and melt catheter 100 not only can be used for the local ablation, can also carry out the continuous ablation of ring pulmonary vein through melting subassembly 5 (for example sacculus 511), increased ablation catheter 100's adaptation disease scope, have better application prospect, sacculus 511 can realize leaning on with pulmonary vein's effective simultaneously, and sacculus 511 is better with pulmonary vein's the subsides nature, has improved ablation catheter 100's ablation efficiency greatly.

Fourth embodiment

Referring to fig. 10 and 11, fig. 10 and 11 illustrate a schematic structural view of a fourth embodiment ablation catheter 100. The ablation catheter 100 of this embodiment is substantially similar in structure to the third embodiment, except that the balloon 511 of this embodiment is configured and arranged in a manner to accomplish radial expansion and contraction. In this embodiment, the tube body 1 includes an inner tube 11 and an outer tube 12, the proximal end of the head electrode 2 is connected to the distal end of the inner tube 11, the distal end of the balloon 511 is connected to the distal end of the inner tube 11, and the proximal end of the balloon 511 is connected to the distal end of the outer tube 12. The outer tube 12 is sleeved on the inner tube 11, a channel 13 for passing through fluid is formed between the outer tube 12 and the inner tube 11 at an interval, and the outer tube 12 can move axially relative to the inner tube 11 to drive the proximal end and the distal end of the balloon 511 to approach and depart from each other. When the proximal and distal ends of balloon 511 are brought closer together, balloon 511 expands radially under fluid inflation. When the proximal and distal ends of balloon 511 are moved away from each other, balloon 511 contracts radially and compresses the fluid.

The proximal end of the outer tube 12 is connected to a handle assembly 3, and the handle assembly 3 is used to pull the outer tube 12 for axial movement relative to the inner tube 11, thereby adjusting the size of the balloon 511. The size of balloon 511 can be achieved by the following specific procedure: when the outer tube 12 moves towards the head electrode 2 relative to the inner tube 11, the balloon 511 is inflated slowly by the gas or liquid inside the balloon 511 under the external pressure, and the shape of the balloon 511 changes from the shuttle shape to the spherical shape and finally changes to the oblate spherical shape. When the outer tube 12 moves away from the head electrode 2 relative to the inner tube 11, the balloon 511 presses the gas or liquid inside, so that the liquid or gas flows back into the external gas or liquid collecting device, and the shape of the balloon 511 is gradually changed from a flat sphere to a round sphere and finally changed into a shuttle shape.

Compared with the third embodiment of the ablation catheter 100, the ablation catheter 100 of the present embodiment can not only adjust the size of the balloon 511 to meet the ablation of pulmonary veins with different sizes and shapes, but also perform ablation in the vestibular of the pulmonary veins or in the ostium of the pulmonary veins. Because the balloon 511 is a compliant balloon, the balloon 511 has better forming capability, the balloon 511 can be well attached to myocardial tissues, and a leak point or insufficient ablation depth caused by poor attachment of the ablation electrode 52 arranged on the balloon 511 to the target tissues can be avoided.

Fifth embodiment

Referring to fig. 12, fig. 12 illustrates a schematic structural view of a fifth embodiment ablation catheter 100. The ablation catheter 100 of the present embodiment is substantially similar in structure to the third or fourth embodiment, except that the present embodiment may be understood as further defining the ablation catheter 100 of the third or fourth embodiment.

In this embodiment, the ablation catheter 100 further includes a driving tube 6 and a scope module 7, the driving tube 6 is inserted into the catheter body 1, and specifically, for the fourth embodiment, the driving tube 6 is inserted into the inner tube 11. The sight glass module 7 is arranged at the far end of the driving tube 6, the sight glass module 7 is arranged opposite to the balloon 511, the sight glass module 7 comprises an endoscope 71 and a lighting lamp 72, the near end of the driving tube 6 is connected with the handle assembly 3, the handle assembly 3 can control the driving tube 6 to rotate, and then the driving tube 6 can drive the sight glass module 7 to rotate circumferentially, so that the endoscope 71 can observe a plurality of ablation electrodes through the tube body 1 under the lighting and light supplementing effects of the lighting lamp 72.

In the third embodiment, the tube 1 includes a transparent material at least in a region facing the scope module 7 so that the endoscope can image the ablation electrode 52 on the balloon 511. In the fourth embodiment, the inner tube 11 is made of a transparent material at least in a region facing the scope module 7. The illuminating lamps 72 may be LED lamps, the number of the illuminating lamps 72 may be two as illustrated in fig. 12, two illuminating lamps 72 are disposed at the proximal end and the distal end of the endoscope 71, and of course, the number of the illuminating lamps 72 may also be one. The illuminating lamp 72 mainly provides a light source for the endoscope 71 to observe the heart cavity condition, so that the contact and sticking condition of the ablation electrode 52 on the balloon 511 and the myocardial tissue can be visually observed, the ablation catheter 100 is guaranteed to be stably stuck to a target tissue area, and the dependence on X-ray perspective and three-dimensional system building is reduced. In addition, the driving tube 6 can also move relative to the tube body 1 along the axial direction of the tube body 1 so as to adjust the axial position of the sight glass module 7 relative to the balloon 511, and the axial movement and the circumferential rotation of the sight glass module 7 are more favorable for the visual observation of the attaching condition of the target tissue area.

Sixth embodiment

Referring to fig. 13 and 14, fig. 13 and 14 illustrate a schematic structural view of a sixth embodiment ablation catheter 100. The ablation catheter 100 of the present embodiment is substantially similar in structure to the third embodiment, except that the support body 51 of the present embodiment is different from the support body 51 of the third embodiment, i.e., the support body 51 of the present embodiment does not include the balloon 511. In this embodiment, the supporting body 51 includes a supporting frame 512, and the supporting frame 512 is made of a material with a shape memory function to keep radially expanding in a natural state. Specifically, the supporting framework 512 comprises a plurality of carrying rods 513 arranged at intervals along the circumferential direction of the pipe body 1, the number of the carrying rods 513 can be any suitable value from 3 to 12, the specific number of the carrying rods 513 is not limited in the invention, and each carrying rod 513 is provided with an ablation electrode 52. In the embodiment where the tube body 1 comprises an inner tube 11 and an outer tube 12, the proximal end of each support rod 513 is connected to the distal end of the outer tube 12, and the distal end of each support rod 513 is connected to the outer wall of the inner tube 11 adjacent to the distal end thereof, such as welding, soldering, gluing, etc.

The outer tube 12 is sleeved on the inner tube 11 and can move axially relative to the inner tube 11 to drive the proximal ends and the distal ends of the respective support rods 513 to approach and separate from each other, when the proximal ends and the distal ends of the respective support rods 513 (i.e., the support frames 513) approach each other, the respective support rods 513 (i.e., the support frames 512) are radially expanded, and when the proximal ends and the distal ends of the respective support rods 512 (i.e., the support frames 512) separate from each other, the respective support rods 513 are radially contracted.

It will be appreciated that the support framework 512 is radially expandable and contractible, and that the radially expandable support framework 512 is capable of providing circumferential ablative isolation of, for example, the ostium of a pulmonary vein to inhibit the propagation of abnormal electricity and/or disrupt the conduction of abnormal electricity through the heart tissue, thereby treating cardiac arrhythmias with a reduced risk of many potentially fatal complications. Radial expansion of the support frame 512 in this embodiment is achieved by controlling the axial movement of the outer tube 12 relative to the inner tube 11. Specifically, by controlling the outer tube 12 to move distally, the axial dimension of the support frame 512 is reduced, the radial dimension is increased, and the support frame 512 is expanded. By controlling the outer tube 12 to move towards the proximal end, the axial dimension of the support framework 512 is increased, the radial dimension is decreased, and the support framework 512 contracts in the radial direction.

The number of the ablation electrodes 52 provided on each carrier rod 513 may be one or more. Ablation electrodes 52 disposed on carrier rod 513 can be used to provide ablation energy for tissue ablation, as well as for electrophysiological signal mapping. In this embodiment, each of the supporting rods 513 is provided with four ring electrodes along the axial direction thereof, and the supporting frame 512 is formed with four rings of electrode sets. The inner wall of each ablation electrode 52 is welded with a conducting wire with an insulating layer, the bearing rod 513 comprises a rod body and an insulating sleeve sleeved outside the rod body, the insulating sleeve is made of a pebax pipe or other high-polymer insulating materials, and the insulating property between the ablation electrode 52 and the rod body is guaranteed. The insulating sleeve may be one layer, two layers or multiple layers, and is not limited herein. The cross-sectional shape of the rod body may be circular, semicircular, round drum or other shapes, which are not limited herein. In this embodiment, the rod body is made of nickel titanium sheet, so that the rod body has excellent elastic property and strength to be well attached to the target tissue. It will be appreciated that the shaft body may also be made of other materials, such as stainless steel or a polymeric material.

The ablation electrodes 52 are sleeved on the insulating sleeve, so that the insulation between the ablation electrodes 52 and the nickel-titanium sheet is ensured, the insulating lead is arranged between the rod body and the insulating sleeve, namely, the inner surface of each ablation electrode 52 passes through the surface of the insulating sleeve through the lead, is connected to a connector on the handle assembly 3 along the rod body and the outer tube 12, is electrically connected with the energy output device through the connector, and is connected between the ablation electrodes 52 and the lead through welding or other special processes.

In an embodiment, the polarities of the two adjacent ablation electrodes 52 on the same carrier bar 513 are opposite, and the polarities of the adjacent ablation electrodes 52 on the two adjacent carrier bars 513 are opposite, so that when a pulsed electric field is formed, the plurality of ablation electrodes 52 on the support framework 512 surround a plurality of rings on the longitudinal axis of the inner tube 11, the plurality of ablation electrodes 52 on each ring form an electric field in a ring shape, the adjacent ablation electrodes 52 on each carrier bar 513 are coupled with each other to form an electric field in a radial direction, the electric field generated by the whole ablation assembly 5 is distributed in the circumferential direction and the radial direction to form a 3D spatial electric field, and the ablation range is large. In other embodiments, all ablation electrodes 52 on the same carrier bar 513 have the same polarity, and adjacent ablation electrodes 52 on two adjacent carrier bars 513 have opposite polarities.

For the ablation assembly 5 of the present embodiment, by controlling the relative position relationship between the inner tube 11 and the outer tube 12, the axial length of the supporting framework 512 can be changed, so as to adjust the diameter of the supporting framework 512, so that the diameter of the supporting framework 512 can be matched with the annular size of the ostium of the pulmonary vein, so as to adapt to pulmonary veins of different anatomical structures, thereby improving the adaptability and the attaching stability of the ablation catheter 100 to different target ablation region forms, facilitating the ablation operation of the ablation catheter 100, and ensuring the effect of the ablation operation.

Seventh embodiment

Referring to fig. 15, fig. 15 illustrates a schematic structural view of a seventh embodiment ablation catheter 100. The ablation catheter 100 of the present embodiment is substantially similar in structure to that of the sixth embodiment, except for the structure of the support frame 512. In this embodiment, the supporting framework 512 includes at least one of a woven metal wire mesh subjected to heat setting and a woven metal pipe mesh subjected to cutting and heat setting, the woven metal wire mesh is preferably a woven nickel-titanium wire mesh, and the woven metal pipe mesh is preferably a woven nickel-titanium pipe mesh. It should be understood that the supporting framework 512 may be made of a woven metal wire mesh, or a woven metal pipe mesh, or the supporting framework 512 may be made of a woven metal wire mesh and a woven metal pipe mesh, and the portions of the mesh may be welded or fixed to each other through an intermediate connecting member. In this embodiment, the supporting frame 512 is woven from elastic metal wires. It should be noted that the supporting framework 512 of the mesh structure of the present embodiment can further increase the contact area between the supporting framework 512 and the target tissue, so as to optimize the discharging effect of the ablation electrode 52 disposed on the supporting framework 512.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An ablation catheter is characterized by comprising a bendable catheter body, a head electrode, a catheter electrode group and an ablation assembly, wherein the near end of the head electrode is connected with the far end of the catheter body, the head electrode is of a hollow mesh structure and has elasticity, the catheter electrode group is arranged on the outer wall of the catheter body and is close to the near end of the head electrode, the ablation assembly is sleeved on the catheter body and is positioned at the near end of the catheter electrode group, the ablation assembly comprises a support body and an ablation electrode arranged on the support body, and the support body can contract and expand in the radial direction;

the head electrode is connected with an energy output device, or the head electrode is matched with the tube electrode group and is connected with the energy output device so as to transmit ablation energy output by the energy output device to a target tissue area for ablation isolation; the ablation electrode is connected with the energy output device so as to transmit ablation energy output by the energy output device to a target tissue area for ablation isolation.

2. The ablation catheter of claim 1, wherein the tip electrode comprises at least one of a heat-set woven wire mesh and a heat-set cut metal wire mesh.

3. The ablation catheter of claim 1, wherein the distal end of the tip electrode has a curved surface with a progressively larger radial dimension in a direction from the distal end to the proximal end of the tip electrode.

4. The ablation catheter of claim 1, wherein the set of tube electrodes includes a first tube electrode and a second tube electrode, the first tube electrode and the second tube electrode being spaced apart from each other from a distal end to a proximal end of the tube body in an axial direction of the tube body, the first tube electrode and the second tube electrode being insulated from each other.

5. The ablation catheter of claim 1, further comprising an inner sheath core disposed through the tube and exposed from the distal end of the tube; the inner sheath core is provided with a perfusion channel extending to the near end of the tube body, a micro-flow hole is further formed in the part, between the near end of the head electrode and the far end of the head electrode, of the inner sheath core, and the micro-flow hole is communicated with the perfusion channel.

6. The ablation catheter of claim 1, wherein the number of the ablation electrodes is plural, and the plural ablation electrodes are arranged at intervals and enclose to form an annular ablation array, and the annular ablation array is used for annular ablation isolation of the target tissue region after the support body is radially expanded.

7. The ablation catheter of claim 1, wherein said ablation electrode is a plurality of flexible electrode pads, and wherein when some of said plurality of flexible electrode pads are in contact with said target tissue region, said electrically conductive contact of said selected ones of said plurality of flexible electrode pads is selected to deliver said ablation energy to said target tissue region.

8. The ablation catheter of claim 1, wherein the support comprises a balloon that is fillable with a fluid for radial expansion and is further capable of releasing the fluid for radial contraction.

9. The ablation catheter of claim 8, wherein the balloon is connected at both a proximal end and a distal end to an outer wall of the tube, the balloon and the tube forming a fill lumen therebetween; the body is provided with a passageway that extends to the body proximal end, the body still is provided with fill the chamber with the trompil of passageway intercommunication, the passageway can supply fluid to pass so that fluid passes through the trompil gets into fill the chamber.

10. The ablation catheter of claim 8, wherein the tube body comprises an inner tube and an outer tube, the proximal end of the head electrode being connected to the distal end of the inner tube, the distal end of the balloon being connected to the distal end of the inner tube, the proximal end of the balloon being connected to the distal end of the outer tube; the outer tube is sleeved on the inner tube, a channel for fluid to pass through is formed between the outer tube and the inner tube at intervals, and the outer tube can move axially relative to the inner tube so as to drive the near end and the far end of the balloon to approach and depart from each other.

11. The ablation catheter as claimed in claim 8, further comprising a driving tube and a scope module, wherein the driving tube is disposed in the tube body, the scope module is disposed at a distal end of the driving tube, and the scope module is disposed opposite to the balloon, the scope module comprises an endoscope and an illuminating lamp, the driving tube can drive the scope module to rotate circumferentially, so that the endoscope can observe the attaching state of the ablation electrode and the target tissue region through the tube body under the illumination effect of the illuminating lamp.

12. The ablation catheter of claim 11, wherein the drive tube is further movable relative to the tube in an axial direction of the tube to adjust a position of the speculum module relative to the balloon.

13. The ablation catheter of claim 1, wherein the support body comprises a support frame made of a shape memory material to maintain radial expansion in a natural state.

14. The ablation catheter of claim 13, wherein the support frame comprises a plurality of carrier bars spaced circumferentially around the tubular body, each carrier bar being provided with the ablation electrode.

15. The ablation catheter of claim 13, wherein said support frame comprises at least one of a heat-set woven mesh of wires and a cut and heat-set mesh of wires.

16. The ablation catheter of claim 13, wherein the tube body comprises an inner tube and an outer tube, the proximal end of the head electrode being connected to the distal end of the inner tube, the distal end of the support frame being connected to the distal end of the inner tube, the proximal end of the support frame being connected to the distal end of the outer tube; the outer pipe is sleeved on the inner pipe and can move axially relative to the inner pipe so as to drive the near end and the far end of the support framework to approach and depart from each other; when the near-end and the distal end of supporting framework are close to each other, the supporting framework radially struts, and when the near-end and the distal end of supporting framework are kept away from each other, the supporting framework radially contracts.

17. The ablation catheter of any one of claims 1-16, further comprising a handle assembly coupled to the proximal end of the tube, and a pulling device disposed within the interior of the tube and coupled to the adjustable bend section of the tube, wherein the handle assembly is configured to control the pulling device to adjust the position and orientation of the distal end of the tube.