Chemical ablation device

Abstract

The present invention discloses a chemical ablation device, including a clamping assembly and a microneedle assembly; the clamping assembly includes a clamp body and a clamp head composed of a pair of clamp mouths installed on the clamp body, and the clamp head can clamp or release the target ablation tissue through the relative movement of the two clamp mouths; the microneedle assembly is installed in the clamp mouth, including at least one microneedle; the clamp mouth includes a clamp mouth seat, at least one microneedle is installed on at least one clamp mouth seat, and a protective pad that can be elastically restored is installed on the clamp mouth seat, and the protective pad covers the microneedle. When the two clamp mouths move relative to each other, the microneedle can penetrate the protective pad and penetrate the target ablation tissue, and at least one elastic component or non-elastic support member is provided between the protective pad and the jaw seat. The present invention uses a chemical ablation method to obtain complete ablation of the circumferential pulmonary vein vestibule, and can ensure that the surrounding tissue is not injured during the ablation process. It is safe and efficient to use, and has a simple structural design.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a chemical ablation device for treating arrhythmia. Background Art

[0002] Arrhythmia is a series of diseases caused by various reasons that cause the heart to lose its inherent rhythm. It has a high incidence rate and is extremely harmful to health. For example, the most common persistent arrhythmia in clinical practice is called atrial fibrillation (AF). It is caused by various pathogenic factors that lead to abnormal changes in the electrophysiological properties of atrial myocytes, causing rapid and irregular contractions of the atria and ventricles, which causes patients to have uncomfortable symptoms such as palpitations, shortness of breath, fatigue, and increase the incidence of adverse events such as heart failure, thromboembolism, and death. With the aging of today's society, the prevalence of atrial fibrillation is increasing, which seriously affects the health level of the people. For example, ventricular tachycardia (VT) and ventricular fibrillation (VF) are abnormal local electrical activity of the ventricles caused by ventricular myocyte lesions, causing the ventricular contraction frequency to be too fast, unable to maintain normal blood pressure, and even causing sudden cardiac death. Due to the suddenness and severity of its onset, it has caused great harm to the lives and health of the people.

[0003] In recent years, with the gradual understanding of the pathogenesis of atrial fibrillation, it has been found that most atrial fibrillation is related to abnormal electrical activity originating from the pulmonary veins. Intervening in the connection between the pulmonary vein and the left atrium (also known as the pulmonary vein vestibule) through various means, causing coagulative necrosis, and achieving electrical isolation between the pulmonary vein and the left atrium can terminate most atrial fibrillation or prevent recurrence. Surgical use of radiofrequency energy to ablate the pulmonary vein vestibule through the epicardium has also achieved good therapeutic effects. Similarly, electrical isolation of the ventricular myocytes in the local lesion through various means can prevent the occurrence of ventricular tachycardia and ventricular fibrillation.

[0004] However, the bipolar radiofrequency ablation forceps currently used in surgical operations can ablate the atrial tissue at the contact point of the electrode on the jaws of the forceps after clamping on the pulmonary vein vestibule. However, part of the atrial tissue at the jaw opening and between the bottom of the jaws on both sides cannot contact the electrode, so that the pulmonary vein vestibule cannot achieve continuous and complete ablation, which has the potential basis for the appearance of electrical isolation "gaps" and new atrial arrhythmias after radiofrequency ablation. The existing bipolar radiofrequency ablation forceps release radiofrequency energy against the epicardium, which makes it difficult to cause transmural damage to the thicker ventricular wall, and thus has little effect on the treatment of ventricular arrhythmias. In addition, the existing bipolar radiofrequency ablation forceps cannot map whether a continuous and complete ablation line is formed at the ablation site after ablation, or whether there is a gap, so it is impossible to verify the surgical effect during the operation, leaving certain hidden dangers for the recurrence of arrhythmias. In addition, the bipolar radiofrequency ablation forceps currently in use are all imported, with complex structures and high costs, and require a series of supporting equipment such as radiofrequency energy generators, making the cost of surgical treatment of atrial fibrillation considerable and preventing some hospitals from carrying out this treatment.

[0005] Chinese invention patent 201110429592.5 discloses a chemical ablation device for treating atrial fibrillation. However, in actual operation, when placing and clamping the ablation forceps at the target ablation site, the injection needle on the ablation forceps may damage surrounding tissues or even damage the atrium or pulmonary vein wall, causing bleeding.

[0006] Chinese invention patent applications 201610959301.6 and 201910952628.4 disclose a chemical ablation device, which is provided with a cushion on the jaws of the forceps to prevent the injection needle from damaging surrounding tissues. However, due to the friction between the cushion and the injection needle or other factors such as the material of the cushion itself, after the jaws of the forceps clamp the target ablation tissue, the cushion sometimes cannot return to its original state in time or cannot return to its original state completely. In this case, the needle tip of the injection needle is inevitably exposed to the pericardium or other tissues, and there is still the problem of possible damage to surrounding tissues, thereby prolonging the patient's recovery time or inducing complications.

[0007] Therefore, how to design a chemical ablation device that can solve the above problems is a subject that the inventors of the present application have devoted themselves to studying. Summary of the invention

[0008] The object of the present invention is to provide a chemical ablation device, which uses a chemical ablation method to obtain complete ablation of the circumferential pulmonary vein vestibule and can ensure that surrounding tissues are not damaged during the ablation process. It is safe and efficient to use and has a simple structural design.

[0009] In order to achieve the above-mentioned object, the present invention provides a chemical ablation device, which includes a clamping component and a microneedle component;

[0010] The clamping assembly comprises a clamp body and a clamp head composed of a pair of clamp jaws mounted on the clamp body, wherein the clamp head can clamp or release the target ablation tissue through relative movement of the two clamp jaws;

[0011] The microneedle assembly is installed in the forceps mouth and includes at least one microneedle for injecting an ablative agent into a target ablation tissue;

[0012] The jaws include a jaw seat, at least one microneedle is installed on at least one jaw seat, a compressible and recoverable protective pad is installed on the jaw seat, when the two jaws are not clamped, the protective pad covers the microneedle, when the two jaws clamp the target ablation tissue, the microneedle can pass through the protective pad and penetrate the target ablation tissue, and at least one elastic component or non-elastic support member is provided between the protective pad and the jaw seat.

[0013] Preferably, an open groove is provided on the top of the jaw seat, and at least one mounting hole is provided at the bottom of the open groove along the axial extension direction of the jaw seat, and the mounting hole is used to install the microneedle, and the protective pad is connected to the open groove of the jaw seat.

[0014] Preferably, the jaws further include a jaw cover, which is connected to the bottom of the jaw seat, and a receiving cavity is formed between the jaw seat and the jaw cover, and when the microneedle is installed on the mounting hole, the tail of the microneedle is located in the receiving cavity.

[0015] Preferably, the jaw seat and the jaw cover are connected and fixed together via a concave-convex matching structure.

[0016] Preferably, the microneedle comprises a needle head and a sleeve fixed to the outside of the needle head, and the sleeve is fixed in the mounting hole.

[0017] Preferably, the mounting hole is a stepped hole consisting of a first hole and a second hole, the aperture of the first hole is larger than the aperture of the second hole, the sleeve of the microneedle is fixed in the first hole, and the tail of the needle passes through the second hole.

[0018] Preferably, a funnel-shaped opening groove is provided at the distal end of the first hole.

[0019] Preferably, the elastic component is sleeved outside each of the microneedles, and an upwardly protruding receiving groove is provided on the protective pad at a position corresponding to each of the microneedles, and each of the receiving grooves covers one of the microneedles and the elastic component sleeved outside the microneedle.

[0020] Preferably, the protection pad comprises a plurality of pad bodies, and each of the pad bodies is provided with the accommodating groove protruding upward.

[0021] Preferably, the cross section of the protection pad is inverted U-shape, and the protection pad comprises support parts on both sides, and the protection pad is connected to the opening groove of the jaw seat through the support parts.

[0022] Preferably, at least one of the support portions is hollow.

[0023] Preferably, the support portion and the opening groove of the jaw seat are connected and fixed together by bonding, interference fit, pinning or screwing, or clamping.

[0024] Preferably, the protection pad is made of thermosetting elastomer or thermoplastic elastomer.

[0025] Preferably, the hardness of the side of the protection pad facing the microneedles is greater than the hardness of the other side of the protection pad.

[0026] Preferably, the surface of the protective pad facing the microneedle has a gasket with a harderness greater than that of the protective pad, and the gasket has a small hole for the microneedle to pass through at a position corresponding to the microneedle.

[0027] Preferably, the pre-pressure of the elastic component is greater than or equal to the sum of the friction force between the microneedle and the protection pad and the weight of the protection pad itself.

[0028] Preferably, the elastic component is a spring, a spring sheet, a corrugated sheet or other elastic body with elastic function, and the elastic component is sleeved outside the microneedle or arranged between adjacent microneedles.

[0029] Preferably, two ends of the elastic component are fixed to the jaw seat and the protection pad by bonding or welding.

[0030] Preferably, the non-elastic support member is a columnar structure, the non-elastic support member is arranged on the bottom surface of the opening groove of the jaw seat, and the height of the non-elastic support member is smaller than the height of the microneedle above the bottom of the opening groove.

[0031] After adopting the above scheme, the chemical ablation device of the present invention has the following advantageous effects:

[0032] 1. By installing a microneedle assembly in at least one of the two jaws, when the two jaws clamp the target ablation tissue, the ablative agent enters the target ablation tissue through the microneedle, thereby obtaining continuous, complete, and transmural damage to the pulmonary vein vestibule ablation line, achieving complete ablation of the required part, and it can be applied to the ablation of atrial fibrillation. By connecting a protective pad to a jaw seat with microneedles and covering the microneedle head with the protective pad, the distal end of the microneedle (i.e., the needle tip) can be located under or buried in the protective pad when the two jaws are not clamping the target ablation tissue. When operating the device, the jaws can be moved in the body to prevent the microneedles thereon from piercing surrounding tissues. When the two jaws are placed at the target ablation tissue to clamp, the protective pad is compressed due to the squeezing of the two jaws and the target ablation tissue located between the two jaws, and the microneedles extend out of the protective pad and penetrate into the target ablation tissue. The microneedles of the parts of the jaws that are not in contact with the myocardial tissue are still under or in the protective pad. At this time, when the chemical ablative agent is injected, the microneedles that penetrate into the target ablation tissue can release the chemical ablative agent, while the remaining microneedles cannot release the chemical ablative agent to the target tissue. This prevents the microneedle needles from being exposed to the pericardium or mediastinum due to the failure of the two sides of the clamp to penetrate the myocardial tissue. When the chemical ablative agent is injected, it is in a relatively low-pressure area, causing some of the chemical ablative agent to leak out, reducing the amount of chemical reagent released in the target ablation area and causing damage to surrounding tissues. When the ablation is completed, the two clamp mouths are released. Due to the lack of the two clamp mouths and the squeezing of the myocardial tissue, the protective pad returns to its initial state, and the microneedle is protected by the protective pad. The device is safe and efficient to use, and its structural design is simple;

[0033] 2. The protective pad is made of thermosetting elastomer or thermoplastic elastomer, which is not only compressible and easy to be pierced by microneedles, but also has the characteristics of elastic recovery. It is non-toxic, chemically inert, non-pathogenic, non-damaging to adjacent tissues, and non-allergenic, and is safe and reliable to use;

[0034] 3. The present invention designs the jaws to be composed of a jaw seat and a jaw cover connected by a concave-convex matching structure. Both the jaw seat and the jaw cover are U-shaped groove structures. A plurality of mounting holes are provided on the jaw seat for mounting a plurality of microneedles, and a pipeline assembly for delivering ablative agents is provided in the accommodation cavity formed by the jaw cover and the jaw seat. The tail of the microneedle pierces the pipeline assembly to form a liquid connection. The jaws are simple to manufacture, easy to install, and cost-saving.

[0035] 4. The microneedle is designed to be connected to the existing needle and the sleeve fixed on the outer surface of the needle, and connected and fixed to the mounting hole on the fixed seat as a whole, so that it is easier to install and fix on the jaw seat than the existing thin needle, and the connection force between the microneedle and the jaw seat is stronger. The microneedle can be positioned by the upper and lower end faces of the sleeve, that is, when the microneedle is processed, the size of the needle head exposed on the upper end face of the sleeve can be determined, and the required needle length can be obtained more accurately. The sleeve and the needle are as a whole. When positioning the microneedle, the upper and lower end faces of the sleeve are fixed in the mounting hole. Compared with the existing needle with a smooth outer surface directly installed in the mounting hole, it can prevent the axial sliding of the microneedle, making the installation more convenient and stable, and the installation size more accurate. The structural design is simple, which can greatly improve the processing efficiency of the chemical ablation device and the installation accuracy of the microneedle;

[0036] 5. By installing at least one elastic component or non-elastic support between the jaw seat and the protective pad, a stable and controllable resilience can be provided for the protective pad, thereby avoiding the problem that the protective pad cannot return to its original position or fails to return to its original position due to friction between the microneedle and the protective pad or other reasons, so that the protective pad can return to its original position as soon as possible after the compression is removed to avoid damage to surrounding tissues;

[0037] 6. The resilience of the protective pad in the present invention originates from the resilience provided by the side wall (support portion) of the protective pad and the resilience provided by the elastic component or the non-elastic support member. Compared with the resilience provided by the side wall, the resilience provided by the elastic component or the non-elastic support member is more stable and controllable. Since the resilience provided by the side wall to the protective pad is mainly affected by the resilience of the side wall itself and the contact area between the side wall and the jaw seat. Therefore, by providing a hollow structure on the side wall of the protective pad, the resilience provided by the side wall itself becomes smaller and / or the contact area between the side wall and the jaw seat is reduced. In this case, the side wall only provides the function of fixing the protective pad to a large extent, and the resilience of the protective pad mostly depends on the elastic component or the non-elastic support member, thereby being able to provide a more stable and controllable resilience through the elastic component or the non-elastic support member. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the pulmonary vein and its surrounding atrial tissue;

[0039] Figure 2 A schematic diagram of a "gap" created by existing radiofrequency ablation forceps when the pulmonary vein is clamped;

[0040] Figure 3 This is a schematic diagram of the change in length of the pulmonary vein before and after clamping;

[0041] Figure 4 It is a structural schematic diagram of a first embodiment of a chemical ablation device of the present invention;

[0042] Figure 5 Partial enlarged schematic view of the connection structure between the jaw and the protective pad in the first embodiment of the chemical ablation device of the present invention;

[0043] Figure 6 Partial enlarged schematic view of the connection structure between the jaw and the microneedle in the first embodiment of the chemical ablation device of the present invention;

[0044] Figure 7 Schematic perspective view of the protective pad in the first embodiment of the chemical ablation device of the present invention;

[0045] Figure 8 Schematic perspective view of the coronal section of the connection between the jaw seat and the microneedle in the second embodiment of the chemical ablation device of the present invention;

[0046] Fig. 9 Schematic view of the structure of the third embodiment of the chemical ablation device of the present invention;

[0047] Fig.10 Schematic perspective view of the jaw head in the third embodiment of the chemical ablation device of the present invention;

[0048] Fig.11 Schematic perspective view of the coronal section of the jaw, microneedle and protective pad in the fourth embodiment of the chemical ablation device of the present invention;

[0049] Fig.12 Schematic perspective view of the protective pad in the fifth embodiment of the chemical ablation device of the present invention;

[0050] Fig.13 Schematic perspective view of the protective pad in the sixth embodiment of the chemical ablation device of the present invention;

[0051] Fig.14 Schematic view of the coronal connection structure of the protective pad, needle head and elastic component in the seventh embodiment of the chemical ablation device of the present invention;

[0052] Fig.15 Schematic perspective view of the protective pad of the chemical ablation device of the present invention. Detailed implementation manners

[0053] Definition:

[0054] Distal: In this specification, when referring to "distal" in the description of the device of the present invention, this term refers to the side relatively far from the user.

[0055] Proximal: In this specification, when referring to "proximal" in the description of the device of the present invention, this term refers to the side relatively close to the user.

[0056] Distal end: In this specification, when the "distal end" is mentioned when describing the device of the present invention, the term generally refers to the end relatively far away from the user or the end relatively far away from the main body (e.g., the handle or body) of the device of the present invention.

[0057] Proximal end: In this specification, when the "proximal end" is mentioned when describing the device of the present invention, the term generally refers to the end relatively close to the user or the end relatively close to the main body (e.g., the handle or body) of the device of the present invention.

[0058] Sagittal plane: The plane passing through the vertical axis and longitudinal axis of the human body (or other objects) (i.e. the median sagittal plane) and all planes parallel to it are called sagittal planes, which divide the human body or object into left and right halves.

[0059] Coronal plane: The plane passing through the vertical axis and the horizontal axis of the human body (or other object) and all planes parallel to it are called coronal planes, that is, these planes divide the human body or object into front and back parts.

[0060] Chemical ablative agents: various chemical reagents or reagent combinations that can cause coagulative necrosis of myocardial tissue, such as anhydrous ethanol, anhydrous propyl alcohol, glycerol, iopromide mixed solution, or mixtures thereof.

[0061] Pulmonary venous vestibule: the junction of the pulmonary veins with the left atrium, seen Figure 1 The figure number 4 in.

[0062] In the present invention, the protection pad covering the microneedle refers to the situation that the distal end of the microneedle does not pierce the protection pad, including the situation that the distal end of the microneedle is located under the protection pad or buried in the protection pad.

[0063] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood by those skilled in the art that the embodiments or examples described below in conjunction with the accompanying drawings are only used to illustrate the best mode for implementing the present invention, rather than limiting the scope of the present invention to these embodiments. The present invention can make various improvements and changes based on the following embodiments. These improvements and changes are all included in the scope of the present invention.

[0064] like Figure 1 Shown is a schematic diagram of the pulmonary veins and the surrounding atrial tissues, wherein number 1 is the left atrium, 2 is the left pulmonary vein, 3 is the right pulmonary vein, and 4 is the vestibules of the pulmonary veins on both sides, which are the parts clamped by the clamping assembly of the chemical ablation device of the present invention and injected with chemical ablative agents.

[0065] Figure 2The figure shows a schematic diagram of the "gap" caused by the existing radiofrequency ablation forceps when the pulmonary veins are clamped. The left and right parts in the figure are the two jaws 5 of the clamping assembly, and the pulmonary vein vestibule 6 is clamped between the two jaws 5. The figure shows a sagittal cross-sectional view of the pulmonary vein vestibule 6. The portion between the distal ends (or tops) of the two jaws 5 is the pulmonary vein vestibule portion 7 that is not in contact with the jaws, and the portion between the proximal ends (or bottoms) of the two jaws 5 is the pulmonary vein vestibule portion 8 that is not in contact with the jaws. When using traditional bipolar radiofrequency ablation forceps, the atrial tissue at the two locations of the pulmonary vein vestibule portions 7 and 8 that are not in contact with the jaws cannot contact the ablation electrodes on the clamping assembly, so coagulative necrosis of the atrial tissue cannot be caused at these two locations, resulting in the existence of a "gap" in pulmonary vein isolation, which has a potential risk of postoperative atrial arrhythmia. When using the chemical ablation device of the present invention, since the jaws of the device are provided with microneedles (such as Figure 4 ), the microneedle can be inserted into the vestibule tissue of the pulmonary vein, so although the forceps cannot touch the myocardial tissue at 7 and 8, the microneedle can reach these two places. In addition, the injection of chemical ablative agents through microneedles can cause spherical coagulative necrosis inside the target ablation tissue. By adjusting the spacing between microneedles and the dose of injected chemical ablative agents, complete circumferential pulmonary vein isolation can be obtained and the formation of "gaps" can be avoided.

[0066] like Figure 3 10 is a schematic diagram of the sagittal section of the pulmonary vein vestibule 9 in its natural state, and 11 is a schematic diagram of the sagittal section of the pulmonary vein vestibule after being clamped by a chemical ablation device. It can be seen that the morphology of the pulmonary vein vestibule changes after being clamped, but the circumference on the sagittal section remains unchanged. Therefore, in order to obtain a better ablation effect and reduce the incidence of "gaps", the pulmonary vein and atrial tissue that need to be ablated can be imaged or three-dimensionally reconstructed using left atrial and pulmonary vein enhanced CT or other imaging techniques before surgery, and the circumference of the sagittal section of the pulmonary vein vestibule can be calculated by computer data processing software or other measurement methods to obtain the approximate length of the pulmonary vein vestibule after being clamped. In addition, it is also possible to perform pre-clamping during surgery for accurate measurement. In this case, a scaled chemical ablation device without microneedles can be used to accurately determine the length that needs to be clamped. As shown in the figure, after the pulmonary vein vestibule is clamped by the jaws of the forceps, the length of the pulmonary vein vestibule after clamping is measured using the first scale 52 on the jaws of the forceps to determine the required arrangement length of the microneedles, and the thickness of the pulmonary vein vestibule after clamping is measured using the second scale 53 on the handle of the forceps to determine the required penetration depth of the microneedles, that is, the required length of the microneedles, and then a certain number and length of microneedles are installed based on the predicted length and thickness.

[0067] like Figure 4 As shown, the chemical ablation device of the present invention includes a clamping component, a microneedle component and a pipeline component;

[0068] The clamping assembly includes a clamp body 11 and a clamp head composed of a pair of clamp mouths 12 mounted on the clamp body 11. The clamp head can clamp or release the target ablation tissue through the relative movement of the two clamp mouths 12.

[0069] The microneedle assembly is installed in the two forceps mouths 12;

[0070] The pipeline assembly includes an ablative agent delivery pipeline that is fluidically connected to the microneedle assembly to deliver the ablative agent. The pipeline assembly of this embodiment includes a first pipeline 24 and a second pipeline 25 .

[0071] refer to Figure 4 As shown in the figure, the proximal end of the clamp handle 13 is provided with a closing locking device 14 and an ablative agent supply device 15; the push rod 16 is installed in the clamp handle 13 and extends along the axis of the clamp handle 13 in the clamp handle 13, connected to the closing locking device 14 at the proximal end of the clamp handle 13, and connected to the elastic component 17 at the distal end of the clamp handle 13; the clamp body 11 passes through the distal end of the clamp handle 13, and the distal end of the clamp body 11 extends to form a connector 19. The two clamp mouths 12 are respectively a distal clamp mouth 12a and a proximal clamp mouth 12b, and the distal end of the connector 19 is connected to the distal clamp mouth 12a. The forceps body 11 includes an inner wall 20, an inner shaft 21 and an inner groove 22. The inner wall 20 and the inner groove 22 form a lumen so that the inner shaft 21 can reciprocate in the lumen along the inner groove 22 under the action of the push rod 16, wherein the proximal end of the inner shaft 21 is connected to the distal end of the push rod 16 via an elastic component 17, and its distal end protrudes beyond the distal end of the forceps handle 13 when not pushed by the push rod 16. The connector 19 is formed by the portion of the forceps body 11 where the inner groove 22 is formed, extending toward the distal end of the chemical ablation device, and the inner groove 22 extends in the connector 19 to form a slide groove 23; the distal forceps mouth 12a is arranged at the distal end of the connector 19; the proximal forceps mouth 12b is arranged at the distal end of the inner shaft 21, and under the action of the push rod 16 and through the movement of the inner shaft 21, the proximal forceps mouth 12b can slide toward the distal forceps mouth 12a along the slide groove 23;

[0072] The first pipeline 24 extends through the clamp handle 13, the push rod 16, the inner shaft 21 and the proximal clamp mouth 12b in sequence, and the proximal end of the first pipeline 24 is connected to the ablative agent supply device 15 disposed outside the clamp handle 13, and its distal end directly reaches the distal end of the proximal clamp mouth 12b; the second pipeline 25 extends through the clamp handle 13, the clamp body 11 and the distal clamp mouth 12a in sequence, and the proximal end of the second pipeline 25 is connected to the ablative agent supply device 15 disposed outside the clamp handle 13, and its distal end directly reaches the distal end of the distal clamp mouth 12a. The first pipeline 24 and the second pipeline 25 merge into a main pipeline inside the proximal end of the clamp handle 13, leading to an ablative agent supply device. In addition, the first pipeline 24 and the second pipeline 25 can also be connected to the ablative agent supply device to provide different ablative agents, or to provide ablative agents at different flow rates or dosages.

[0073] refer to Figure 5 As shown, the jaw 12 of this embodiment includes a jaw seat 26 and a jaw cover 27. The jaw cover 27 is connected to the bottom of the jaw seat 26. The jaw seat 26 is an arc-shaped body. A first opening groove 28 is provided on the top of the jaw seat 26. At least one mounting hole 29 is respectively provided on the opposite surfaces of the jaw seats 26 of the two jaws 12. This embodiment adopts multiple mounting holes 29, that is, the bottom of the first opening grooves 28 on the two jaw seats 26 are respectively provided with multiple mounting holes 29 along the axial extension direction of the jaw seat 26.

[0074] The microneedle assembly installed in the two forceps nozzles 12 includes a plurality of microneedles 30 for injecting ablative agents into target ablation tissues.

[0075] refer to Figure 6 and Fig.11 As shown, a plurality of microneedles 30 are mounted on a plurality of mounting holes 29, a receiving cavity is formed between the jaw seat 26 and the jaw cover 27, the distal end of the first pipeline 24 or the second pipeline 25 is located in the receiving cavity, and the tail of the microneedle 30 pierces the pipeline located in the receiving cavity to form liquid circulation. The first opening grooves 28 of the two jaw seats 26 on which the plurality of microneedles 30 are mounted are respectively connected to protective pads 31.

[0076] The protective pad 31 is made of thermosetting elastomers such as silicone material or rubber material or thermoplastic elastomers such as polyether polyurethane, polyester polyurethane, styrene-butadiene-styrene block copolymer (SBS), with a hardness between 20A and 90A. It is not only compressible and easy for microneedle puncture, but also has the characteristics of elastic recovery. It is non-toxic, chemically inert, non-pathogenic, non-damaging to adjacent tissues, and non-allergenic, and is safe and reliable to use.

[0077] In addition, the protective pad 31 can be made of a single material or a composite structure. In order to prevent the elastic component from piercing the protective pad 31, extend the service life and other purposes, the hardness of the side of the protective pad 31 facing the microneedle 30 can be set to be greater than the hardness of the other side of the protective pad 31. The above-mentioned protective pad can be prepared by using materials with different hardness. It is also possible to set a gasket with a hardness greater than the hardness of the material of the protective pad body on the side of the protective pad 31 facing the microneedle 30, such as a metal sheet or a plastic sheet of appropriate hardness, etc. The gasket can be set on the protective pad 31 by secondary injection molding or encapsulation. In this case, in order to prevent the microneedle 30 from being affected by the gasket, a small hole for the microneedle 30 to pass through is set at the position of the gasket corresponding to the microneedle 30.

[0078] refer to Figure 7As shown, the protection pad 31 of this embodiment is an arc-shaped body with an inverted U-shaped cross section, and the protection pad 31 includes support parts 32 on both sides. The protection pad 31 is connected and fixed to the first opening groove 28 on the jaw seat 26 through the bottom of the two support parts 32, and the support part 32 and the first opening groove 28 can be connected and fixed together by bonding, interference fit, pinning or screwing, clamping, etc.

[0079] The protective pad 31 covers the head of the microneedle 30. When the two jaws 12 move relative to each other to clamp the target ablation tissue, the microneedle 30 can penetrate the protective pad 31 and penetrate the target ablation tissue. At least one elastic component is provided between the protective pad 31 and the jaw seat 26. The number of elastic components can be 1-20. When the two jaws do not clamp the target tissue, the elastic component is in a pre-compression state. At this time, the pre-pressure of the elastic component is greater than or equal to the sum of the friction between the microneedle 30 and the protective pad 31 and the weight of the protective pad 31 itself. The preferred pre-pressure is 0-5N.

[0080] The elastic component can be a spring, a spring sheet, a corrugated sheet or other elastic body with elastic function, see Figure 6 As shown, the present embodiment uses a plurality of springs 33, and the plurality of springs 33 are respectively sleeved on the outside of the plurality of microneedles 30. The spring 33 may be an ordinary spring, or a variable pitch spring, a variable diameter spring or a wave spring. The spring 33 may be only sleeved on the outside of the microneedle 30 without further fixed connection with the jaw seat 26, or may be fixed with the jaw seat 26 by means of gluing or welding. The end of each spring 33 in contact with the protective pad 31 is embedded in the protective pad 31. The spring 33 may be directly embedded in the protective pad 31 by means of encapsulation, secondary injection molding, screwing, pressing, hot melting, etc. From the perspective of preventing the spring 33 from piercing the protective pad 31 and increasing the service life, the spring 33 may also be connected to a gasket at the end in contact with the protective pad 31, and the gasket may be embedded in the protective pad 31 by the various methods mentioned above. In this case, a small hole is provided in the portion of the gasket corresponding to the microneedle 30 so that the microneedle 30 can move freely without being affected by the gasket. The elastic component may also be provided between adjacent microneedles 30. Both ends of the elastic component can be fixed to the jaw seat 26 and the protection pad 31 by, for example, bonding or welding.

[0081] At least one inelastic support member may be provided between the protective pad 31 and the jaw seat 26 to replace the elastic member. The inelastic support member is provided between adjacent microneedles 30 and may be a column, cone or table structure. The inelastic support member may be a solid or hollow structure. The inelastic support member is provided at the bottom of the first opening groove 28 of the jaw seat 26. The height of the inelastic support member is less than the height of the microneedle 30 above the bottom of the first opening groove 28. The number of the inelastic support member is 1-20 and the height may be 1-20 mm.

[0082] like Figure 8 FIG. 1 is a schematic diagram of a coronal cross-sectional view of a three-dimensional structure of a chemical ablation device of the present invention connected to a jaw seat and a microneedle. Most of the structures of the chemical ablation device of this embodiment are similar to those of the above-mentioned Figure 4 The structures of the embodiments are the same, and the similarities are not repeated here. The differences are as follows: the microneedle 30 of the present embodiment includes a needle 34 and a sleeve 35 fixed outside the needle 34, and the two ends of the needle 34 pass through the sleeve 35. The needle 34 and the sleeve 35 of the present embodiment are connected and fixed by glue point bonding, and can also be connected and fixed by crimping, or can be connected and fixed together by welding. There are many connection methods here, which are not specifically limited here. When processing the microneedle of the present embodiment, the size of the needle 34 exposed on the upper end surface of the sleeve 35 can be adjusted as needed. Compared with the needle in the prior art, the installation size of the needle 34 of the microneedle of the present embodiment is easier to accurately control. In addition, the needle in the prior art has a smooth surface and a small diameter, and axial sliding is easy to occur during installation. In the microneedle of the present embodiment, the needle 34 and the sleeve 35 form a whole, and the sleeve 35 forms a boss around the needle 34, which can prevent the microneedle from sliding through the fixed connection between the sleeve 35 and the mounting hole 29 described below, and the axial positioning is accurate.

[0083] The sleeve 35 is installed and fixed on the mounting hole 29. The mounting hole 29 is a stepped hole composed of a cylindrical first hole 36 and a cylindrical second hole 37. The aperture of the first hole 36 is larger than the aperture of the second hole 37. The sleeve 35 is fixed in the first hole 36. In this embodiment, the sleeve 35 is fixed to the inner cavity of the first hole 36 by glue, and the two can also be connected and fixed by welding or interference fit. The design of the stepped hole can play a role in positioning the microneedle 30. The tail of the needle 34 passes through the second hole 37. In this embodiment, the upper end face of the sleeve 35 is fixed to the top of the first hole 36, and the lower end face is fixed to the bottom of the first hole 36. The boss formed by the sleeve 35 can be more stably fixed in the mounting hole 29, and the installation size of the microneedle is more accurate. A funnel-shaped second opening groove 38 is provided at the distal end of the first hole 36. The second opening groove 38 can be conveniently installed for the microneedle 30. The second opening groove 38 is set as a funnel body, on the one hand, so that when the glue is dispensed, it can be collected and flowed into the gap between the sleeve 35 and the jaw seat 26 to increase the firmness of the bonding, that is, a part of the glue flows into the gap between the first hole 36 and the sleeve 35, and the other part of the glue will cover the upper part of the sleeve 35 of the microneedle 30, that is, the second opening groove 38. This design can not only bond the outer surface of the sleeve 35 with the glue of the inner wall of the first hole 36 of the jaw seat 26, but also, after the glue covering the top of the sleeve 35 is cured, it will form a cover-like effect in the second opening groove 38, thereby increasing the connection force between the microneedle 30 and the jaw seat 26.

[0084] like Fig. 9The schematic diagram of the structure of the third embodiment of the chemical ablation device of the present invention is shown in FIG. Figure 4 The structures of the embodiments are the same, and the similarities are not repeated here. The differences are as follows: Fig.10 As shown, a plurality of microneedles 30 are installed on the jaw seat 26 of one jaw 12 of the pliers head of this embodiment, while no microneedles are installed on the jaw seat 26 of the other jaw 12. This embodiment can be used to cause continuous, complete, and transmural damage to the diameter of the local tissue of the pulmonary vein vestibule, and achieve complete ablation of the required part. At the same time, the pipeline assembly of the device only includes a first pipeline 24, which extends through the clamp handle 13, the push rod 16, the inner shaft 21 and the proximal jaw 12 in sequence. The proximal end of the first pipeline 24 is connected to the ablative agent supply device 15 arranged outside the clamp handle 13, and the distal end thereof is connected to the microneedles on the proximal jaw 12. In addition, in the chemical ablation device in which the microneedles 30 are installed on the jaw seat 26 of only one jaw 12, a second pipeline 25 other than the first pipeline 24 can also be included, and the ablation of the local tissue can be achieved by closing the mounting hole on the jaw seat where the microneedle 30 is not installed or not supplying the chemical ablative agent to the second pipeline 25 or other methods.

[0085] like Fig.11 FIG. 1 is a schematic diagram of a coronal cross-sectional view of a three-dimensional structure of a forceps nozzle, a microneedle and a protective pad of a fourth embodiment of a chemical ablation device of the present invention. Most of the structures of this embodiment are similar to those of the above-mentioned embodiment. Figure 8 The structures of the embodiments are the same, and the similarities are not repeated here. The differences are as follows: grooves 39 are respectively provided at the bottom of the first open groove 28 on the jaw seat 26 of the two jaws 12 of the embodiment near the two side walls, and the two support parts 32 on both sides of the protection pad 31 are inserted into the two grooves 39 and connected and fixed together by bonding, or by interference fit, pin or screw fixing, clamping, etc. The two support parts 32 of the embodiment are respectively provided with a hollow structure. The hollow structure can adopt at least one of a through hole, a blind hole, and an open groove. The support part 32 of the embodiment is provided with a through hole. The through hole refers to any structure that passes through the sagittal plane of the support part 32 and reduces the volume of the support part 32 compared to before the through hole is provided. Reference Fig.12 As shown in FIG. 1 , the through holes in this embodiment are a plurality of rectangular holes 40 arranged along the axial direction. The support portions 32 on both sides of the protection pad 31 can also be as shown in FIG. Fig.13As shown, a plurality of third opening grooves 41 are provided at the lower end thereof, so that the plurality of third opening grooves 41 form a sawtooth shape, wherein the opening groove here refers to any structure located at the bottom of the groove of the support portion 32 close to the first opening groove 28, penetrating the sagittal plane of the support portion 32, and reducing the volume of the support portion 32 compared with before the opening groove is provided. In addition, the support portion 32 may also be provided with a blind hole, which refers to any structure that does not penetrate the sagittal plane of the support portion 32 and reduces the volume of the support portion 32 compared with before the blind hole is provided. When the support portion 32 has a hollow structure, the contact area between the support portion 32 and the first opening groove 28 is reduced and / or the resilience provided by the support portion 32 itself becomes smaller. After the ablation of the target ablation tissue is completed, the forceps on both sides release the target ablation tissue, and the resilience of the protection pad 31 will mostly rely on the elastic component or the non-elastic support member, which can provide a more stable and controllable resilience through the elastic component or the non-elastic support member, making the protection pad 31 easier to rebound. In this embodiment, the bottom of the jaw seat 26 and the jaw cover 27 are connected and fixed together by a concave-convex matching structure. Specifically, the bottom of the jaw seat 26 is located at the bottom of the groove wall of the first opening groove 28 and is provided with two convex ridges 42. The top of the jaw cover 27 has a fourth opening groove 43. The outer ends of the top of the two groove walls located at the fourth opening groove 43 are respectively provided with fifth opening grooves 44. The jaw cover 27 and the jaw seat 26 are connected together by snapping the two fifth opening grooves 44 and the two convex ridges 42. The jaw seat 26 and the jaw cover 27 are covered to form a receiving cavity 45. After the microneedle is installed, the tail of the needle head 34 is located in the receiving cavity 45.

[0086] like Fig.14 The diagram of the three-dimensional structure of the protective pad of the seventh embodiment of the chemical ablation device of the present invention is shown. In this embodiment, the chemical ablation device is provided with a protective pad 31 connected to the jaw seat 26 on which the microneedles 30 are installed. The protective pad 31 is provided with an upwardly protruding receiving groove 46 at a position corresponding to each microneedle 30. The receiving groove 46 protrudes upward and presents a hollow cone structure. In each receiving groove 46, the needle tip of the needle 34 penetrates into the protective pad 31 or the needle tip of the needle 34 is located below the protective pad 31, but does not pass through the protective pad 31. The spring 33 disposed between the bottom of the first opening groove 28 of the jaw seat 26 and the protective pad 31 is sleeved on the outside of the needle 34 and connected to the protective pad 31. In this embodiment, the receiving groove 46 is formed by bending a protective pad 31 at the position corresponding to each microneedle 30, and is connected and fixed to the first opening groove 28 through the bottoms at both ends of the protective pad 31 and the bottom of the receiving groove 46. It can also be as follows Fig.15 As shown, the protection pad 31 includes a plurality of pad bodies, each of which is provided with a receiving groove 46, and each pad body is connected and fixed to the first opening groove 28 through the bottom of each receiving groove 46. The receiving groove 46 can also be a hollow platform structure or a hollow column structure.

[0087] The present invention installs a microneedle assembly in at least one of the two forceps jaws 12. When the two forceps jaws 12 clamp the target ablation tissue, the ablative agent enters the target ablation tissue through the microneedle 30, thereby obtaining continuous, complete, and transmural damage to the ablation line of the pulmonary vein vestibule, thereby achieving complete ablation of the required part. By connecting the protective pad 31 to the jaw seat 26 with the microneedle 30 and making the protective pad 31 cover the head of the microneedle 30, when the two jaws 12 do not clamp the target ablation tissue, the head of the microneedle 30 can be located below the protective pad 31 or buried in the protective pad 31. When the device is operated, the jaws 12 can be moved in the body to prevent the microneedles 30 thereon from piercing the surrounding tissue; when the two jaws 12 are placed at the target ablation tissue to clamp, the protective pad 31 is compressed due to the squeezing of the two jaws 12 and the target ablation tissue located between the two jaws 12, and the microneedles 30 extend out of the protective pad 31 and then penetrate into the target ablation tissue; and the microneedles 30 of the part of the jaws 12 that does not contact the myocardial tissue are still below or in the protective pad 31. At this time, when the chemical ablative agent is injected, the microneedles 30 that penetrate into the target ablation tissue can release the chemical ablative agent, and the remaining microneedles 30 cannot release the chemical ablative agent to the target tissue. This prevents the microneedles on both sides of the forceps head from being exposed to the pericardial or mediastinal cavities due to failure to penetrate the myocardial tissue, and being in a relatively low-pressure area when injecting chemical ablative agents, causing some chemical ablative agents to leak out, reducing the amount of chemical agents released in the target ablation area, and causing damage to surrounding tissues. When ablation is completed, the two jaws 12 are released. Due to the lack of squeezing of the two jaws and the myocardial tissue, the protective pad 31 returns to its initial state, and the microneedle 30 is protected by the protective pad 31. The device is safe and efficient to use, and has a simple structural design. The protective pad 31 is made of thermosetting elastomer or thermoplastic elastomer, which is not only compressible and easy for microneedle puncture, but also has the characteristics of elastic recovery. It is non-toxic and chemically inert, non-pathogenic, non-damaging to adjacent tissues, and non-allergenic, and is safe and reliable to use. The present invention designs the jaws 12 to be composed of a jaw seat 26 and a jaw cover 27 connected by a concave-convex matching structure. The jaw seat 26 and the jaw cover 27 are both U-shaped groove structures. A plurality of mounting holes 29 are provided on the jaw seat 26 for mounting a plurality of microneedles 30, and a pipeline assembly for delivering ablative agent is provided in the accommodating cavity 45 formed by the jaw cover 27 and the jaw seat 26, and the tail of the microneedle 30 pierces the pipeline assembly. The jaws 12 are simple to manufacture, easy to install, and cost-effective. The microneedle 30 is designed to be connected to a sleeve 35 fixed on the outer surface of the needle 34 through an existing needle head 34, and is connected and fixed to a mounting hole 29 on the jaw seat 26 as a whole, making it easier to install and fix on the jaw seat 26 than an existing fine needle head, and the connection force between the microneedle 30 and the jaw seat 26 is stronger.The microneedle 30 can be positioned by the upper and lower end surfaces of the sleeve 35, that is, when the microneedle 30 is processed, the size of the head of the needle 34 exposed from the upper end surface of the sleeve 35 can be determined, and the required length of the needle 34 can be obtained more accurately. The sleeve 35 and the needle 34 are used as a whole. When positioning the microneedle 30, the upper and lower end surfaces of the sleeve 35 are fixed in the mounting hole 29. Compared with the existing needle with a smooth outer surface directly mounted in the mounting hole, the axial sliding of the microneedle can be prevented, making the installation more convenient and stable, and the installation size more accurate. In addition, its structural design is simple, which can greatly improve the loading and unloading of the chemical ablation device. The invention can improve the working efficiency and the installation accuracy of the microneedle; by installing at least one elastic component or non-elastic support between the jaw seat 26 and the protective pad 31, a stable and controllable rebound force can be provided for the protective pad 31, so as to avoid the problem that the protective pad 31 cannot return to the initial position or fails to return to the initial position due to the friction between the microneedle 30 and the protective pad 31 or other reasons, so that the protective pad 31 can return to the initial position as soon as possible after the compression is removed to avoid damaging the surrounding tissue; the rebound force of the protective pad 31 in the present invention comes from the rebound force provided by the side wall (support part 32) of the protective pad 31 and the rebound force provided by the elastic component or non-elastic support. Compared with the rebound force provided by the side wall, the rebound force provided by the elastic component or non-elastic support is more stable and controllable. Since the rebound force provided by the side wall to the protective pad 31 is mainly affected by the rebound force of the side wall itself and the contact area between the side wall and the jaw seat 26, by setting a hollow structure on the side wall of the protective pad 31, the rebound force provided by the side wall itself becomes smaller and / or the contact area between the side wall and the jaw seat 26 is reduced. In this case, the side wall largely only serves to fix the protection pad 31, and the resilience of the protection pad 31 mostly depends on the elastic component or the non-elastic support member, thereby being able to provide a more stable and controllable resilience through the elastic component or the non-elastic support member.

[0088] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include undisclosed common knowledge or customary techniques in the art. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the claims.

[0089] It should be understood that the present invention is not limited to the embodiments, methods, structures, and precise structures shown in the drawings described above, and various modifications and changes can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A chemical ablation device, It is characterized in that including a clamping component and a microneedle component; The clamping assembly comprises a clamp body and a clamp head composed of a pair of clamp jaws mounted on the clamp body, wherein the clamp head can clamp or release the target ablation tissue through relative movement of the two clamp jaws; The microneedle assembly is installed in the forceps mouth and includes at least one microneedle for injecting an ablative agent into a target ablation tissue; The jaws include a jaw seat, at least one microneedle is mounted on at least one jaw seat, a compressible and restorable protective pad is mounted on the jaw seat, when the two jaws are not clamped, the protective pad covers the microneedle, when the two jaws clamp the target ablation tissue, the microneedle can penetrate the protective pad and penetrate the target ablation tissue, at least one elastic component or non-elastic support member is arranged between the protective pad and the jaw seat; An opening groove is provided on the top of the jaw seat, and the protection pad is connected to the opening groove of the jaw seat; The protection pad comprises support parts on both sides, and the protection pad is connected to the opening groove of the jaw seat through the support parts; At least one of the support portions is hollow.

2. The chemical ablation device according to claim 1, It is characterized in that At least one mounting hole is provided at the bottom of the opening groove along the extending direction of the axis of the jaw seat, and the mounting hole is used to mount the microneedle.

3. The chemical ablation device according to claim 2, It is characterized in that The jaws also include a jaw cover, which is connected to the bottom of the jaw seat. A receiving cavity is formed between the jaw seat and the jaw cover. When the microneedle is installed on the mounting hole, the tail of the microneedle is located in the receiving cavity.

4. The chemical ablation device according to claim 3, It is characterized in that The jaw seat and the jaw cover are connected and fixed together via a concave-convex matching structure.

5. The chemical ablation device according to claim 2, It is characterized in that The microneedle comprises a needle head and a sleeve fixed outside the needle head, and the sleeve is fixed in the mounting hole.

6. The chemical ablation device according to claim 5, It is characterized in that The mounting hole is a stepped hole formed by a first hole and a second hole, the aperture of the first hole is larger than the aperture of the second hole, the sleeve of the microneedle is fixed in the first hole, and the tail of the needle passes through the second hole.

7. The chemical ablation device according to claim 6, It is characterized in that A funnel-shaped opening groove is provided at the distal end of the first hole.

8. The chemical ablation device according to claim 1, It is characterized in that The elastic component is sleeved outside each of the microneedles, and an upwardly protruding receiving groove is provided on the protective pad at a position corresponding to each of the microneedles. Each of the receiving grooves covers one of the microneedles and the elastic component sleeved outside the microneedle.

9. The chemical ablation device according to claim 8, It is characterized in that The protection pad comprises a plurality of pad bodies, and each of the pad bodies is provided with the accommodating groove protruding upwards.

10. The chemical ablation device according to claim 2, It is characterized in that The cross section of the protection pad is in an inverted U shape.

11. The chemical ablation device according to claim 1, It is characterized in that The support portion and the opening groove of the jaw seat are connected and fixed together by bonding, interference fit, pinning or screwing, or clamping.

12. The chemical ablation device according to claim 1, It is characterized in that The protection pad is made of thermosetting elastomer or thermoplastic elastomer.

13. The chemical ablation device according to claim 1, It is characterized in that The hardness of one side of the protection pad facing the microneedles is greater than the hardness of the other side of the protection pad.

14. The chemical ablation device according to claim 1, It is characterized in that The surface of the protective pad facing the microneedle has a gasket with a harderness greater than that of the protective pad, and the gasket has a small hole for the microneedle to pass through at a position corresponding to the microneedle.

15. The chemical ablation device according to claim 1, It is characterized in that The pre-pressure of the elastic component is greater than or equal to the sum of the friction force between the microneedle and the protection pad and the weight of the protection pad itself.

16. The chemical ablation device according to claim 1, It is characterized in that The elastic component is a spring, a spring sheet, a corrugated sheet or other elastic body with elastic function, and the elastic component is sleeved outside the microneedle or arranged between adjacent microneedles.

17. The chemical ablation device according to claim 16, It is characterized in that The two ends of the elastic component are fixed to the jaw seat and the protection pad by bonding or welding.

18. The chemical ablation device according to claim 1, It is characterized in that The non-elastic support member is a columnar structure, and the non-elastic support member is arranged on the bottom surface of the opening groove of the jaw seat. The height of the non-elastic support member is smaller than the height of the microneedle above the bottom of the opening groove.

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