CN111529008A

CN111529008A - Chemical ablation device

Info

Publication number: CN111529008A
Application number: CN202010435112.5A
Authority: CN
Inventors: 罗小平; 张明芳; 毛俊
Original assignee: Shenzhen Sainuosi Medical Technology Co ltd
Current assignee: Suzhou Sainasi Medical Technology Co ltd
Priority date: 2020-05-21
Filing date: 2020-05-21
Publication date: 2020-08-14

Abstract

The invention discloses a chemical ablation device, which comprises a clamping component and a microneedle component; the clamping and closing assembly comprises a clamp body and a clamp head which is arranged on the clamp body and consists of a pair of clamp mouths, and the clamp head can clamp or release target ablation tissues through the relative movement of the two clamp mouths; the microneedle assembly is arranged in the forceps mouth and comprises at least one microneedle; the forceps jaws comprise forceps jaw seats, at least one microneedle is arranged on at least one forceps jaw seat, a protection pad capable of being elastically restored is arranged on each forceps jaw seat, the protection pad covers the microneedle, the microneedle can penetrate through the protection pad to penetrate into target ablation tissues when the two forceps jaws move relatively, and at least one elastic component or a non-elastic supporting piece is arranged between the protection pad and the forceps jaw seats. The invention applies a chemical ablation method to obtain complete ablation of the annular pulmonary vein vestibule, can ensure that the surrounding tissues are not damaged in the ablation process, and has safe and efficient use and simple structural design.

Description

Chemical ablation device

Technical Field

The invention relates to the technical field of medical instruments, in particular to a chemical ablation device for treating arrhythmia.

Background

Arrhythmia is a series of diseases caused by various reasons, wherein the heart beats to lose the intrinsic rhythm, and has high morbidity and great harm to health. For example, the most common type of persistent arrhythmia in clinic is atrial fibrillation (referred to as atrial fibrillation), which is caused by abnormal changes in the electrophysiological properties of atrial myocytes due to various pathogenic factors, and causes rapid and irregular contraction of atria and ventricles, so that patients have uncomfortable symptoms such as palpitation, shortness of breath, weakness and the like, and the incidence rate of adverse events such as heart failure, thromboembolism, death and the like is increased. With the aging of the current society, the incidence of atrial fibrillation is increasingly higher, which seriously affects the health level of the nation. For example, ventricular tachycardia (ventricular tachycardia) and ventricular fibrillation (ventricular fibrillation) are abnormal electrical activity of local part of a ventricle caused by ventricular myocyte pathological changes, so that the ventricular contraction frequency is too high, normal blood pressure cannot be maintained, even sudden cardiac death is caused, and due to the sudden nature and severity of the attack, the sudden cardiac death causes great harm to the life health of people.

In recent years, with the growing awareness of the pathogenesis of atrial fibrillation, most of the atrial fibrillation has been found to be associated with abnormal electrical activity originating in the pulmonary veins. The junction of the pulmonary vein and the left atrium (also known as the vestibulum of the pulmonary vein) is intervened by various means, so that coagulative necrosis is caused to the junction, and the pulmonary vein and the left atrium are electrically isolated, so that most atrial fibrillation can be stopped or can not recur. The radiofrequency energy is used for ablating the pulmonary vein vestibule through the epicardium through a surgical operation, and a good treatment effect is also obtained. Also, electrical isolation of ventricular myocytes local to the lesion by various means can prevent the onset of ventricular tachycardia and ventricular fibrillation.

However, after the bipolar radiofrequency ablation forceps used in the current surgical operation are clamped in the pulmonary vein vestibule, atrial tissues at the electrode contact part on the forceps mouth can be ablated, but partial atrial tissues at the opening of the forceps mouth and between the bottoms of the forceps mouths on two sides cannot contact the electrode, so that the pulmonary vein vestibule cannot be continuously and completely ablated, and a potential basis of electrical isolation 'gaps' and new atrial arrhythmia after the radiofrequency ablation exists. The existing bipolar radiofrequency ablation forceps are attached to the epicardium to release radiofrequency energy, so that a transmural lesion is difficult to form on a thicker ventricular wall, and the treatment effect on ventricular arrhythmia is very small. In addition, the existing bipolar radiofrequency ablation forceps cannot map whether the ablation part forms a continuous and complete ablation radial line or not after ablation is completed, and whether a gap exists or not, so that the operation effect cannot be verified in the operation, and certain hidden trouble is left for the recurrence of arrhythmia. In addition, the bipolar radiofrequency ablation forceps used at present are imported, have complex structures and high manufacturing cost, and need a series of matched equipment such as a radiofrequency energy generator and the like, so that the surgical operation treatment cost of atrial fibrillation is considerable, and a part of hospitals cannot carry out the treatment.

Chinese patent 201110429592.5 discloses a chemical ablation device for treating atrial fibrillation, but in practice, during the process of placing and clamping an ablation clamp at a target ablation site, an injection needle on the ablation clamp may damage surrounding tissues, even the wall of an atrium or a pulmonary vein, and cause bleeding.

Chinese patent applications 201610959301.6 and 201910952628.4 disclose a chemical ablation device having a cushion on the jaw to prevent the injection needle from damaging surrounding tissue. However, due to the friction between the soft pad and the injection needle or the influence of other factors such as the material of the soft pad itself, the soft pad sometimes cannot be timely returned to the initial state or completely returned to the initial state after the forceps mouth clamps the target ablation tissue. In this case, the needle tip of the injection needle is inevitably exposed to the pericardium or other tissues, and there is still a problem in that surrounding tissues may be damaged, thereby prolonging the recovery time of the patient or inducing complications.

Therefore, the inventors of the present application have made an intensive study on how to design a chemical ablation apparatus that can solve the above-described problems.

Disclosure of Invention

The invention aims to provide a chemical ablation device, which is used for obtaining complete ablation of the annular pulmonary vein vestibule by applying a chemical ablation method, can ensure that peripheral tissues are not damaged in the ablation process, and is safe and efficient to use and simple in structural design.

In order to achieve the above object, the present invention provides a chemical ablation apparatus comprising a clamping assembly and a microneedle assembly;

the clamping assembly comprises a clamp body and a clamp head which is arranged on the clamp body and consists of a pair of clamp mouths, and the clamp head can clamp or release target ablation tissues through the relative movement of the two clamp mouths;

the microneedle assembly is arranged in the forceps mouth and comprises at least one microneedle used for injecting an ablation agent to target ablation tissues;

the forceps mouth comprises a forceps mouth seat, at least one microneedle is arranged on at least one forceps mouth seat, a protective pad capable of being compressed and recovered is arranged on the forceps mouth seat, when the forceps mouth is not clamped, the protective pad covers the microneedle, when the forceps mouth clamps a target to ablate tissues, the microneedle can penetrate through the protective pad to pierce the target to ablate tissues, and at least one elastic component or non-elastic supporting piece is arranged between the protective pad and the forceps mouth seat.

Preferably, the top of the jaw seat is provided with an open slot, the bottom of the open slot is provided with at least one mounting hole along the axial extension direction of the jaw seat, the mounting hole is used for mounting the microneedle, and the open slot of the jaw seat is connected with the protection pad.

Preferably, the forceps mouth further comprises a forceps mouth cover, the forceps mouth cover is connected to the bottom of the forceps mouth seat, a containing cavity is formed between the forceps mouth seat and the forceps mouth cover, and when the microneedle is installed on the installation hole, the tail of the microneedle is located in the containing cavity.

Preferably, the jaw seat and the jaw cover are fixedly connected together through a concave-convex matching structure.

Preferably, the micro-needle comprises a needle head and a sleeve fixed outside the needle head, and the sleeve is fixed in the mounting hole.

Preferably, 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.

Preferably, the distal end of the first bore is provided with a funnel-shaped open slot.

Preferably, the elastic component is sleeved outside each microneedle, an upward convex containing groove is arranged on the protective pad corresponding to the part of each microneedle, and each containing groove covers one microneedle and the elastic component sleeved outside the microneedle.

Preferably, the protection pad comprises a plurality of pad bodies, and the pad bodies are respectively provided with the accommodating grooves protruding upwards.

Preferably, the cross section of the protection pad is in an inverted U shape, the protection pad comprises support parts at two sides, and the protection pad is connected with the open slot of the jaw seat through the support parts.

Preferably, at least one of the support portions is hollowed out.

Preferably, the supporting part and the open slot of the jaw seat are fixedly connected together in an adhesion mode, an interference fit mode, a pin or screw penetrating mode and a clamping mode.

Preferably, the protective pad is made of a thermosetting elastomer or a thermoplastic elastomer.

Preferably, the hardness of one side of the protective pad facing the microneedles is greater than the hardness of the other side of the protective pad.

Preferably, the surface of the side of the protective pad facing the microneedles has a pad having a hardness greater than that of the protective pad, and the pad has small holes through which the microneedles pass at positions corresponding to the microneedles.

Preferably, the pre-stress of the elastic component is greater than or equal to the sum of the friction force between the micro-needle and the protection pad and the gravity of the protection pad.

Preferably, the elastic component is a spring or a shrapnel or a corrugated sheet or other elastic bodies with elastic functions, and the elastic component is sleeved outside the microneedles or arranged between the microneedles.

Preferably, both ends of the elastic component are fixed on the jaw seat and the protective pad by means of bonding or welding.

Preferably, the inelastic supporting piece is of a cylinder structure and is arranged on the bottom surface of an open groove of the jaw seat, and the height of the inelastic supporting piece is smaller than that of the microneedle above the bottom of the open groove.

After the scheme is adopted, the chemical ablation device has the following beneficial effects:

1. by installing the micro-needle assembly in at least one of the two forceps mouths, when the two forceps mouths clamp a target ablation tissue, an ablation agent enters the target ablation tissue through the micro-needle, continuous and complete damage of a pulmonary vein vestibular ablation radial line and transmural damage is obtained, complete ablation of a required part is realized, and the micro-needle assembly can be applied to ablation of atrial fibrillation. The protective pad is connected to the jaw seat with the micro-needle, and the protective pad covers the head of the micro-needle, so that when the two forceps mouths do not clamp the target ablation tissue, the far ends (namely needle point positions) of the micro-needles are positioned below the protective pad or embedded in the protective pad, and when the device is operated, the micro-needles on the forceps mouths can be prevented from stabbing the surrounding tissue when the forceps mouths move in the body; when the two forceps mouths are placed at the target ablation tissue to be clamped, the protective pad is compressed due to the two forceps mouths and the target ablation tissue positioned between the two forceps mouths, and the micro-needle extends out of the protective pad to penetrate into the target ablation tissue; and the micro-needle of the part of the forceps mouth which is not contacted with the myocardial tissue is still positioned below or in the protective pad, at the moment, when the chemical ablation agent is injected, the micro-needle which is penetrated into the target ablation tissue can release the chemical ablation agent, and the other micro-needles cannot release the chemical ablation agent to the target tissue. Therefore, the micro-needle head which cannot penetrate into the myocardial tissue at two sides of the forceps head is prevented from being exposed in the pericardium or the mediastinum lacuna and being in a relatively low-pressure area when injecting the chemical ablation agent, so that part of the chemical ablation agent leaks out, the release amount of the chemical agent in a target ablation area is reduced, and surrounding tissues are prevented from being damaged. When the ablation is finished, the two forceps mouths are released, the protection pad returns to the initial state due to the lack of the extrusion of the two forceps mouths and the myocardial tissue, and the microneedle is protected by the protection pad, so that the device is safe and efficient to use and has a simple structural design;

2. the protective pad is made of a thermosetting elastomer or a thermoplastic elastomer, has the characteristics of compressibility and easiness in puncturing the micro-needle, also has the characteristic of elastic recovery, has the characteristics of no toxicity, no chemical inertia, no pathogenicity, no damage to adjacent tissues, no allergy and the like, and is safe and reliable to use;

3. the forceps mouth is designed to be formed by connecting a forceps mouth seat and a forceps mouth cover through a concave-convex matching structure, the forceps mouth seat and the forceps mouth cover are both of U-shaped groove body structures, a plurality of mounting holes are formed in the forceps mouth seat and used for mounting a plurality of micro-needles, a pipeline assembly for delivering an ablation agent is arranged in a containing cavity formed by the forceps mouth cover and the forceps mouth seat, and the tail parts of the micro-needles penetrate into the pipeline assembly to form liquid communication;

4. the microneedle is designed to be connected and formed by the existing needle head and the sleeve fixed on the outer surface of the needle head, and is connected and fixed with the mounting hole on the fixing seat as a whole, so that the microneedle is easier to mount and fix on the jaw seat than the existing thin needle head, and the connection force between the microneedle and the jaw seat is stronger. The micro-needle can be positioned through the upper end surface and the lower end surface of the sleeve, namely, the size of the head part of the needle head exposed out of the upper end surface of the sleeve can be determined when the micro-needle is processed, the required length of the needle head can be obtained more accurately, the sleeve and the needle head are taken as a whole, the upper end surface and the lower end surface of the sleeve are fixed in the mounting hole when the micro-needle is positioned, and compared with the prior art that the needle head with smooth outer surface is directly mounted in the mounting hole, the micro-needle can be prevented from sliding axially, so that the mounting is more convenient and stable, the mounting size is more accurate, the structural design is simple, and the processing efficiency of a chemical ablation;

5. by installing at least one elastic part or non-elastic supporting piece between the jaw seat and the protective pad, stable and controllable resilience can be provided for the protective pad, the problem that the protective pad cannot return to the initial position or does not return to the position due to friction between the microneedle and the protective pad or other reasons is avoided, and the protective pad returns to the initial position as soon as possible after the compression is removed, so that surrounding tissues are prevented from being damaged;

6. the resilience of the protective pad in the present invention is derived from the resilience provided by the protective pad side walls (support) and the resilience provided by the elastic member or inelastic support. The resilience provided by the elastic member or the inelastic support member is more stable and controllable than the resilience provided by the side walls. The resilience provided by the side walls to the protective pad is mainly affected by the resilience of the side walls themselves and the contact area of the side walls with the jaw seat. Therefore, through the hollow structure arranged on the side wall of the protective pad, the resilience force provided by the side wall per se is reduced and/or the contact area between the side wall and the jaw seat is reduced. In this case, the side wall largely provides only the function of fixing the protection pad, and the resilience of the protection pad is largely dependent on the elastic member or the inelastic support, thereby enabling a more stable and controllable resilience to be provided by the elastic member or the inelastic support.

Drawings

FIG. 1 is a schematic view of the pulmonary veins and surrounding atrial tissue;

FIG. 2 is a schematic view of a conventional RF ablation clamp creating a "notch" when a pulmonary vein is occluded;

FIG. 3 is a schematic diagram showing the variation in the length of the pulmonary vein before and after it is clamped;

FIG. 4 is a schematic structural diagram of a first chemical ablation device in accordance with an embodiment of the present invention;

FIG. 5 is a partially enlarged view of a connection structure between a forceps mouth and a protection pad according to a first embodiment of the chemical ablation apparatus of the present invention;

FIG. 6 is a partially enlarged schematic view of a connection structure between a forceps mouth and a microneedle according to a first embodiment of the chemical ablation apparatus of the present invention;

FIG. 7 is a schematic perspective view of a protective pad according to a first embodiment of the chemical ablation apparatus of the present invention;

fig. 8 is a schematic view of a cross-sectional three-dimensional structure of a coronal plane of a connection between a jaw seat and a microneedle of a second embodiment of the chemical ablation apparatus of the present invention;

FIG. 9 is a schematic structural view of a third embodiment of the chemical ablation apparatus of the present invention;

FIG. 10 is a schematic perspective view of a third embodiment of a chemical ablation apparatus according to the present invention;

fig. 11 is a schematic view of a cross-sectional three-dimensional structure of a coronary surface of a forceps mouth, a microneedle and a protection pad of a fourth embodiment of the chemical ablation apparatus of the present invention;

fig. 12 is a schematic perspective view of a protective pad according to a fifth embodiment of the chemical ablation apparatus of the present invention;

fig. 13 is a schematic perspective view of a protective pad according to a sixth embodiment of the chemical ablation device of the present invention;

FIG. 14 is a schematic view of a crown connection structure of a protective pad, a needle and an elastic member of a seventh embodiment of the chemical ablation apparatus of the present invention;

fig. 15 is a perspective view of a protective pad of the chemical ablation device of the present invention.

Detailed Description

Defining:

distal: in this specification, when describing the device of the invention with reference to "distal", the term refers to the side which is relatively remote from the user.

Proximal: in this specification, when describing the device of the invention with reference to "proximal", the term refers to the side which is relatively close to the user.

A far end: in this specification, when describing the device of the present invention with reference to "distal end", the term generally refers to the end that is relatively remote from the user or the end that is relatively remote from the body (e.g., the handles or bodies) of the device of the present invention.

Proximal end: in this specification, when describing the device of the present invention with reference to "proximal end", the term generally refers to the end that is relatively close to the user or the end that is relatively close to the body (e.g., the handles or bodies) of the device of the present invention.

Sagittal plane: the plane through the vertical and longitudinal axes of the body (or other object) (i.e., the median sagittal plane) and all planes parallel thereto are referred to as the sagittal plane, i.e., the body or object is divided into left and right halves.

Coronal plane: the plane through the body (or other object) perpendicular to the transverse axis and all planes parallel thereto are referred to as coronal planes, i.e., the planes divide the body or object into anterior and posterior portions.

Chemical ablative agent: the chemical agent or combination of agents can cause myocardial tissue coagulative necrosis, such as anhydrous ethanol, anhydrous propanol, glycerol, iopromide mixture, or their mixture.

Vestibule of pulmonary vein: the junction of the pulmonary vein and the left atrium is shown at 4 in FIG. 1.

In the present invention, the covering of the protection pad on the microneedles refers to a case where the distal ends of the microneedles do not pierce the protection pad, including a case where the distal ends of the microneedles are located below the protection pad or are buried in the protection pad.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings, and it will be understood by those skilled in the art that the embodiments or examples described below with reference to the drawings are only illustrative of the best modes for carrying out the invention, and do not limit the scope of the invention to these embodiments. The present invention may be modified and varied in many ways based on the embodiments described below. Such modifications and variations are intended to be included within the scope of the present invention.

Fig. 1 is a schematic view of the pulmonary veins and the surrounding atrial tissue, in which reference numeral 1 is the left atrium, 2 is the left pulmonary vein, 3 is the right pulmonary vein, and 4 is the vestibule of the pulmonary veins on both sides, i.e., the part clamped by the clamping assembly of the chemical ablation device of the present invention and injected with the chemical ablation agent.

Fig. 2 is a schematic diagram showing a gap formed by the existing radio frequency ablation forceps when the pulmonary vein is clamped, wherein the left and right parts are two forceps mouths 5 of the clamping assembly, the vestibule 6 of the pulmonary vein is clamped between the two forceps mouths 5, this figure shows a sagittal plane cross-sectional view of the pulmonary vein vestibule 6, the portion between the distal ends (or tips) of the two forceps mouths 5 being the pulmonary vein vestibule portion 7 which is not in contact with the forceps mouths, and the portion between the proximal ends (or bottoms) of the two forceps mouths 5 being the pulmonary vein vestibule portion 8 which is not in contact with the forceps mouths, when using a conventional bipolar radiofrequency ablation forceps, because the atrial tissues at the two positions of the

vestibular parts

7 and 8 of the pulmonary veins which are not contacted with the forceps mouth can not contact with the ablation electrodes on the clamping assembly, the coagulative necrosis of the atrial tissues at the two positions can not be caused, thus causing the presence of a "gap" in the pulmonary vein isolation with the potential risk of post-operative atrial arrhythmia. In the chemical ablation device of the invention, the micro-needle (as shown in fig. 4) is arranged on the forceps mouth of the device and can be inserted into the vestibular tissue of the pulmonary vein, so that the forceps mouth can not contact with two myocardial tissues of 7 and 8 positions, but the micro-needle can reach the two positions. And the micro-needle is injected with the chemical ablation agent to cause approximately spherical coagulative necrosis in the target ablation tissue, and the complete isolation of the pulmonary vein can be obtained by adjusting the distance between the micro-needles and the dosage of the injected chemical ablation agent, and the generation of a gap is avoided.

As shown in fig. 3, it is a schematic view of a sagittal plane cross section of the pulmonary vein vestibule 9 in a natural state, and 10 is a schematic view of a sagittal plane cross section of the pulmonary vein vestibule clamped by the chemical ablation device, and it can be seen that the form of the pulmonary vein vestibule is changed after the pulmonary vein vestibule is clamped, but the circumference of the sagittal plane cross section is not changed. Therefore, in order to obtain better ablation effect and reduce the occurrence rate of 'gaps', the left atrium and pulmonary vein enhanced CT or other imaging technologies can be used for imaging or three-dimensional reconstruction of pulmonary vein and atrial tissues needing ablation before operation, and the circumference of the sagittal plane section of the pulmonary vein vestibule is measured and calculated through computer data processing software or other measuring methods, so that the approximate length of the clamped pulmonary vein vestibule is obtained. In addition, the pre-clamping can be used for accurate measurement during operation, and in this case, a chemical ablation device without a microneedle and with scales can be used, so that the length needing clamping can be accurately determined. As shown in the figure, after the pulmonary venous vestibule is clamped and closed by the forceps mouth, the length of the clamped pulmonary venous vestibule can be measured by using the first scale 52 on the forceps mouth, so that the arrangement length of the needed microneedle can be determined, the thickness of the clamped pulmonary venous vestibule can be measured by using the second scale 53 on the forceps handle, so that the penetration depth of the needed microneedle, namely the length of the needed microneedle can be determined, and then a certain number of microneedles and a certain length of microneedles are installed according to the predicted length and thickness.

As shown in fig. 4, the chemical ablation apparatus of the present invention comprises a clamping assembly, a microneedle assembly and a conduit assembly;

the clamping and closing assembly comprises a clamp body 11 and a clamp head which is arranged on the clamp body 11 and consists of a pair of clamp mouths 12, and the clamp head can clamp or release target ablation tissues through the relative movement of the two clamp mouths 12;

the micro-needle assembly is arranged in the two forceps mouths 12;

the tubing assembly includes an ablative agent delivery tubing in fluid communication with the microneedle assembly for delivering an ablative agent, and in this embodiment the tubing assembly includes a first tubing 24 and a second tubing 25.

Referring to fig. 4, the proximal end of the forceps handle 13 is provided with a closure locking device 14 and an ablative agent supply device 15; a push rod 16 is mounted in the jaw handle 13 and extends in the jaw handle 13 along the axis of the jaw handle 13, is connected to the closure lock 14 at the proximal end of the jaw handle 13, and is connected to a resilient assembly 17 at the distal end of the jaw handle 13; the forceps body 11 extends out from the distal end of the forceps handle 13, and the distal end of the forceps body 11 extends to form a connector 19. The two jaws 12 are a distal jaw 12a and a proximal jaw 12b, respectively, and the distal end of the connecting head 19 is connected to the distal jaw 12 a. 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 forming a lumen such that the inner shaft 21 can reciprocate therein along the inner groove 22 under the action of the push rod 16, wherein a proximal end of the inner shaft 21 is connected to a distal end of the push rod 16 via the elastic member 17, and a distal end thereof protrudes beyond a distal end of the forceps handle 13 without being pushed by the push rod 16. The connecting head 19 is formed by extending a part of the forceps body 11, which forms an inner groove 22, to the distal end of the ablation device, and the inner groove 22 extends in the connecting head 19 to form a sliding groove 23; distal jaw 12a is disposed at the distal end of connector 19; a proximal jaw 12b is arranged at the distal end of the inner shaft 21, the proximal jaw 12b being slidable along the slide channel 23 towards the distal jaw 12a by movement of the inner shaft 21 under the force of the push rod 16;

a first tube 24 extends through the forceps handle 13, the push rod 16, the inner shaft 21 and the proximal forceps mouth 12b in this order, and the proximal end of the first tube 24 is connected to an ablative agent supply 15 disposed outside the forceps handle 13, and the distal end thereof reaches the distal end of the proximal forceps mouth 12 b; a second conduit 25 extends through the handle 13, body 11 and distal jaw 12a in that order, the proximal end of the second conduit 25 being connected to an ablative agent supply 15 disposed on the exterior of the handle 13, the distal end of which reaches the distal end of the distal jaw 12 a. The first and second conduits 24, 25 merge into a common conduit within the proximal end of the handle 13 leading to an ablative agent supply. In addition, the first and second conduits 24 and 25 may be connected to an ablative agent supply to provide different ablative agents, or to provide ablative agents at different flow rates or quantities, respectively.

Referring to fig. 5, the forceps nozzle 12 of the present embodiment includes a forceps nozzle base 26 and a forceps nozzle cover 27, the forceps nozzle cover 27 is connected to a bottom of the forceps nozzle base 26, the forceps nozzle base 26 is an arc-shaped body, a first opening groove 28 is formed at a top of the forceps nozzle base 26, at least one mounting hole 29 is respectively formed on opposite surfaces of the forceps nozzle bases 26 of the two forceps nozzles 12, and the present embodiment employs a plurality of mounting holes 29, that is, a plurality of mounting holes 29 are respectively formed at a bottom of the first opening groove 28 on the two forceps nozzle bases 26 along an axial extension direction of the forceps nozzle base 26.

The microneedle assembly mounted in the two jaws 12 includes a plurality of microneedles 30 for injecting an ablative agent into targeted ablation tissue.

Referring to fig. 6 and 11, a plurality of microneedles 30 are mounted on the mounting holes 29, a receiving cavity is formed between the jaw base 26 and the jaw cover 27, the distal end of the first tube 24 or the second tube 25 is located in the receiving cavity, and the tail portion of the microneedle 30 pierces the tube located in the receiving cavity to form a liquid circulation. The first opening grooves 28 of the two jaw holders 26 to which the microneedles 30 are mounted are respectively connected with a protection pad 31.

The protection pad 31 is made of a thermosetting elastomer such as a silicone material or a rubber material or a thermoplastic elastomer such as polyether urethane, polyester urethane, styrene-butadiene-styrene block copolymer (SBS), has a hardness of 20A to 90A, has not only a compressible property that allows microneedles to easily pierce, but also an elastic recovery property, and has the characteristics of being nontoxic, chemically inert, non-pathogenic, non-damaging adjacent tissues, non-allergic, and the like, and is safe and reliable to use.

In addition, the protection pad 31 may be made of a single material or may have a composite structure. For other purposes such as preventing the elastic member from piercing the protective pad 31 and prolonging the service life, the hardness of one surface of the protective pad 31 facing the microneedles 30 may be set to be greater than the hardness of the other surface of the protective pad 31. The above-mentioned protective pad may be prepared by using materials having different hardness. A pad having a hardness greater than that of the protective pad body, such as a metal sheet or a plastic sheet with a suitable hardness, may be disposed on the side of the protective pad 31 facing the microneedles 30, and the pad may be disposed on the protective pad 31 by secondary injection molding or encapsulation. In this case, in order to make the microneedles 30 not affected by the spacer, small holes through which the microneedles 30 pass are provided at positions of the spacer corresponding to the microneedles 30.

Referring to fig. 7, the protection pad 31 of the present embodiment is an arc-shaped body with an inverted U-shaped cross section, and the protection pad 31 includes support portions 32 on two sides. The protection pad 31 is connected and fixed with the first open slot 28 on the jaw seat 26 through the bottoms of the two support portions 32, and the support portions 32 and the first open slot 28 can be connected and fixed together in an adhesion mode, an interference fit mode, a pin penetrating or screw fixing mode, a clamping mode and the like.

The protective pad 31 covers the head of the micro-needle 30, when the two forceps mouths 12 move relatively to clamp and close the target ablation tissue, the micro-needle 30 can penetrate through the protective pad 31 to penetrate into the target ablation tissue, at least one elastic component is arranged between the protective pad 31 and the forceps mouth seat 26, and the number of the elastic components can be 1-20. When the two forceps mouths do not clamp the target tissue, the elastic part is in a pre-compression state, and the pre-pressure of the elastic part is greater than or equal to the sum of the friction force between the micro needle 30 and the protection pad 31 and the gravity of the protection pad 31, preferably the pre-pressure is 0-5N.

The elastic component may be a spring or a leaf spring or a wave-shaped sheet or other elastic body with elastic function, and as shown in fig. 6, this embodiment uses a plurality of springs 33, and the plurality of springs 33 are respectively sleeved outside the plurality of microneedles 30. The spring 33 may be a common spring, or may be a variable pitch spring, a variable diameter spring, or a wave spring. The spring 33 may be merely placed around the microneedle 30 without further fixing to the jaw housing 26, or may be fixed to the jaw housing 26 by gluing or welding. One end of each spring 33 contacting the protection pad 31 is embedded in the protection pad 31. The spring 33 can be directly embedded in the protection pad 31 by using encapsulation, secondary injection molding, screwing, pressing, hot melting and the like. From the viewpoint of preventing the spring 33 from piercing the protection pad 31 and increasing the service life, the spring 33 may be connected with a spacer at an end thereof contacting the protection pad 31, and the spacer may be embedded in the protection pad 31 in various manners as mentioned above. In this case, a small hole is provided in a portion of the pad corresponding to the microneedle 30 so that the microneedle 30 can move freely without being affected by the pad. The elastic member may also be disposed between adjacent microneedles 30. The two ends of the elastic member may be fixed to the jaw seat 26 and the protection pad 31 by, for example, bonding or welding.

At least one non-elastic support may also be provided between the protection pad 31 and the jaw seat 26 instead of an elastic member. The inelastic support is disposed between adjacent microneedles 30 and may take the form of a cylinder, cone or block structure, and the inelastic support may be a solid or hollow structure. The inelastic supporting piece is arranged at the groove bottom of the first open groove 28 of the jaw seat 26, the height of the inelastic supporting piece is smaller than the height of the microneedle 30 above the groove bottom of the first open groove 28, the number of the inelastic supporting piece is 1-20, and the height can be 1-20 mm.

As shown in fig. 8, a schematic sectional three-dimensional structure of a coronal plane of a jaw seat of a chemical ablation device of the present invention connected to a microneedle is shown, most of the structure of the chemical ablation device of this embodiment is the same as that of the embodiment described in fig. 4, and the same parts are not repeated, but the differences are: the microneedle 30 of the present embodiment includes a needle 34 and a sleeve 35 fixed outside the needle 34, two ends of the needle 34 penetrate out of the sleeve 35, and the needle 34 and the sleeve 35 of the present embodiment are connected and fixed by a glue dispensing bonding method, can also be connected and fixed by a crimping method, and can also be connected and fixed together by a welding method. The connection mode here is various and is not limited here. When the microneedle of the present embodiment is manufactured, the dimension of the needle 34 exposed out of the upper end surface of the sleeve 35 can be adjusted as required, and the mounting dimension of the microneedle 34 of the present embodiment is easier to be controlled accurately than the mounting dimension of the microneedle in the prior art. In addition, the needle head in the prior art has smooth surface and small diameter, and is easy to axially slide when being installed. In the microneedle of the embodiment, the needle 34 and the sleeve 35 form a whole, the sleeve 35 forms a boss around the needle 34, so that the microneedle can be prevented from sliding by the fixed connection between the sleeve 35 and the mounting hole 29, and the axial positioning is accurate.

The sleeve 35 is fixedly mounted on the mounting hole 29. The mounting hole 29 is a stepped hole formed by a cylindrical first hole 36 and a cylindrical second hole 37, the aperture of the first hole 36 is larger than that of the second hole 37, the sleeve 35 is fixed in the first hole 36, the sleeve 35 is fixed in the inner cavity of the first hole 36 by glue, and the two holes can be connected and fixed in a welding mode or an interference fit mode. The stepped bore design may serve to position the microneedles 30. The tail of needle 34 passes through second aperture 37. In the present embodiment, the upper end surface of the sleeve 35 is fixed on the top of the first hole 36, the lower end surface is fixed on 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 mounting size of the microneedle is more accurate. The distal end of the first hole 36 is provided with a funnel-shaped second opening groove 38, the second opening groove 38 is provided to facilitate installation of the microneedle 30, and the second opening groove 38 is provided as a funnel body, on one hand, when glue is dispensed, the glue can flow into a gap between the sleeve 35 and the jaw base 26, so that the bonding firmness is increased, that is, a part of glue flows into the gap between the first hole 36 and the sleeve 35, and another part of glue covers the upper part of the sleeve 35 of the microneedle 30, that is, the second opening groove 38. The design can be achieved by bonding the glue on the outer surface of the sleeve 35 and the inner wall of the first hole 36 of the jaw base 26, and at the same time, the glue covering the top of the sleeve 35 can form a cap-like effect in the second open slot 38 after being cured, so as to increase the connection force between the microneedle 30 and the jaw base 26.

As shown in fig. 9, a schematic structural diagram of a third chemical ablation device embodiment of the present invention is shown, and most of the structure of the third chemical ablation device embodiment of the present invention is the same as the structure of the embodiment described in fig. 4, and the description of the same parts is omitted, except that: referring to fig. 10, in the embodiment of the binding clip, a plurality of microneedles 30 are mounted on the jaw base 26 of one jaw 12, and microneedles are not mounted on the jaw base 26 of the other jaw 12. The embodiment can be used for continuous, complete and transmural damage to the radial line of local tissues of the pulmonary vein vestibule, and complete ablation of a required part is realized, meanwhile, a pipeline assembly of the device only comprises a first pipeline 24, the first pipeline 24 extends to sequentially penetrate through the forceps handle 13, the push rod 16, the inner shaft 21 and the proximal forceps mouth 12, the proximal end of the first pipeline 24 is connected with an ablative agent supply device 15 arranged outside the forceps handle 13, and the distal end of the first pipeline is communicated with a microneedle on the proximal forceps mouth 12. In addition, in the chemical ablation device having only one forceps mouth 12 with the microneedle 30 mounted on the jaw base 26, a second pipeline 25 other than the first pipeline 24 may be further included, and local tissue ablation may be achieved by other means such as closing the mounting hole on the jaw base to which the microneedle 30 is not mounted, or not delivering a chemical ablation agent to the second pipeline 25.

Fig. 11 is a schematic cross-sectional three-dimensional structure diagram of a coronal plane of a forceps mouth, a microneedle and a protection pad of a fourth embodiment of the chemical ablation apparatus of the present invention, and most of the structure of this embodiment is the same as the structure of the embodiment described in fig. 8, and the same parts are not repeated, except that: in the embodiment, the groove 39 is respectively formed at the positions, close to the two side walls, of the groove bottoms of the first open grooves 28 on the jaw seats 26 of the two jaws 12, and the two support portions 32 at the two sides of the protection pad 31 are inserted into the two grooves 39 and are connected and fixed together in an adhesion manner, or fixed together in an interference fit manner, a pin or screw fixing manner, a clamping manner, and the like. The two supporting portions 32 of the present embodiment are respectively provided with a hollow structure. The hollow structure can be at least one of a through hole, a blind hole, and an open slot, and the support portion 32 of the present embodiment is provided with a through hole, which refers to any structure that penetrates through the sagittal plane of the support portion 32 and reduces the volume of the support portion 32 compared to before the through hole is not provided. Referring to fig. 12, the through-holes of this embodiment are a plurality of rectangular holes 40 arranged in the axial direction. The supporting portion 32 on both sides of the protection pad 31 may further have a plurality of third opening grooves 41 formed at the lower end thereof as shown in fig. 13, such that the plurality of third opening grooves 41 form a zigzag shape, where an opening groove refers to any structure that is located at the bottom of the supporting portion 32 near the first opening groove 28 and passes through the sagittal plane of the supporting portion 32, and that reduces the volume of the supporting portion 32 compared to before the opening groove is not formed. Furthermore, the support portion 32 may also be provided with a blind hole, which refers to any structure that does not extend through the sagittal plane of the support portion 32, reducing the volume of the support portion 32 compared to before the blind hole is not provided. When the supporting portion 32 has an hollowed structure, the contact area of the supporting portion 32 with the first opening groove 28 is reduced and/or the resilience provided by the supporting portion 32 itself is reduced. After the target ablation tissue is ablated, the forceps mouths on the two sides release the target ablation tissue, the resilience force of the protection pad 31 is mostly dependent on the elastic component or the non-elastic support, and the resilience force can be more stably and controllably provided through the elastic component or the non-elastic support, so that the protection pad 31 can be more easily rebounded. The bottom of the jaw base 26 and the jaw cover 27 of this embodiment are connected and fixed together through a concave-convex matching structure, specifically, two protruding ribs 42 are disposed at the bottom of the groove wall of the first opening groove 28 at the bottom of the jaw base 26, a fourth opening groove 43 is disposed at the top of the jaw cover 27, fifth opening grooves 44 are respectively disposed at the outer ends of the top of the two groove walls of the fourth opening groove 43, and the jaw cover 27 and the jaw base 26 are connected together through the two fifth opening grooves 44 and the two protruding ribs 42 in a buckling manner. The jaw base 26 and the jaw cover 27 are covered to form a containing cavity 45, and after the microneedle is installed, the tail part of the needle 34 is located in the containing cavity 45.

As shown in fig. 14, a schematic perspective view of a protection pad according to a seventh embodiment of the chemical ablation apparatus of the present invention is provided, in which a protection pad 31 is connected to a jaw seat 26 on which microneedles 30 are mounted, a position of the protection pad 31 corresponding to each microneedle 30 is provided with an upward protruding receiving groove 46, and the upward protruding receiving groove 46 is a hollow cone structure. The needle point of the needle 34 penetrates into the protection pad 31 in each accommodation groove 46 or the needle point of the needle 34 is located below the protection pad 31 but does not pass through the protection pad 31, and the spring 33 disposed between the groove bottom of the first open groove 28 of the jaw seat 26 and the protection pad 31 is sleeved outside the needle 34 and connected to the protection pad 31. In the present embodiment, the accommodating groove 46 is formed by bending a protection pad 31 at a position corresponding to each microneedle 30, and is connected and fixed to the first open groove 28 through bottoms of two ends of the protection pad 31 and bottoms of the accommodating groove 46. As shown in fig. 15, the protection pad 31 may also include a plurality of pad bodies, each pad body is provided with a receiving groove 46, and each pad body is connected and fixed with the first open slot 28 through the bottom of each receiving groove 46. The receiving groove 46 may also be a hollow platform structure or a hollow column structure.

According to the invention, the micro-needle assembly is arranged in at least one of the two forceps mouths 12, when the two forceps mouths 12 clamp the target ablation tissue, the ablation agent enters the target ablation tissue through the micro-needle 30, so that continuous and complete transmural injury of the ablation radial line of the vestibule of the pulmonary vein is obtained, and complete ablation of a required part is realized. When the two forceps mouths 12 do not clamp the target ablation tissue, the head of the microneedle 30 is positioned below the protective pad 31 or is embedded into the protective pad 31, and when the device is operated, the forceps mouths 12 can move in the body to prevent the microneedle 30 on the forceps mouths 12 from stabbing the surrounding tissue; when the two forceps mouths 12 are placed at the target ablation tissue to be clamped, the protective pad 31 is compressed due to the two forceps mouths 12 and the target ablation tissue between the two forceps mouths 12, and the micro-needle 30 extends out of the protective pad 31 to penetrate into the target ablation tissue; while the micro-needle 30 of the part of the forceps mouth 12 which is not contacted with the myocardial tissue is still under the protective pad 31 or in the protective pad 31, when the chemical ablation agent is injected, the micro-needle 30 which is penetrated into the target ablation tissue can release the chemical ablation agent, and the rest micro-needles 30 can not release the chemical ablation agent to the target tissue. Therefore, the micro-needle which cannot penetrate into the myocardial tissue at two sides of the forceps head is prevented from being exposed in the pericardium or the mediastinum lacuna and being in a relatively low-pressure area when injecting the chemical ablation agent, so that part of the chemical ablation agent leaks out, the release amount of the chemical agent in a target ablation area is reduced, and surrounding tissues are damaged. When the ablation is finished, the two forceps mouths 12 are released, the protection pad 31 returns to the initial state due to the lack of the extrusion of the two forceps mouths and the myocardial tissue, and the microneedle 30 is protected by the protection pad 31, so that the device is safe and efficient to use and has a simple structural design; the protective pad 31 is made of a thermosetting elastomer or a thermoplastic elastomer, has the characteristics of compressibility and easiness in puncturing the microneedles, also has the characteristic of elastic recovery, has the characteristics of no toxicity, chemical inertness, no pathogenicity, no damage to adjacent tissues, no allergy and the like, and is safe and reliable to use; the forceps mouth 12 is designed to be formed by connecting a jaw base 26 and a jaw cover 27 through a concave-convex matching structure, the jaw base 26 and the jaw cover 27 are both in a U-shaped groove structure, a plurality of mounting holes 29 are formed in the jaw base 26 and used for mounting a plurality of micro-needles 30, a pipeline assembly used for delivering an ablation agent is arranged in a containing cavity 45 formed by the jaw cover 27 and the jaw base 26, and the tail portions of the micro-needles 30 penetrate into the pipeline assembly. The clamp mouth 12 is simple to process and manufacture, easy to install and capable of saving cost; the micro-needle 30 is designed to be connected and formed by connecting the existing needle 34 and the sleeve 35 fixed on the outer surface of the needle 34, and is connected and fixed with the mounting hole 29 on the jaw seat 26 as a whole, so that the micro-needle is easier to mount and fix on the jaw seat 26 compared with the existing thin needle, and the connection force between the micro-needle 30 and the jaw seat 26 is stronger. The micro-needle 30 can be positioned through the upper end surface and the lower end surface of the sleeve 35, namely, when the micro-needle 30 is processed, the size of the head part of the needle head 34 exposed out of the upper end surface of the sleeve 35 can be determined, the required length of the needle head 34 can be obtained more accurately, the sleeve 35 and the needle head 34 are taken as a whole, when the micro-needle 30 is positioned, the upper end surface and the lower end surface of the sleeve 35 are fixed in the mounting hole 29, and compared with the prior art that the needle head with smooth outer surface is directly mounted in the mounting hole, the micro-needle can be prevented from sliding axially, so that the mounting is more convenient and stable, the mounting size is more accurate, the structural design is simple, and the processing efficiency of the chemical; by installing at least one elastic component or non-elastic support piece between the jaw seat 26 and the protection pad 31, a stable and controllable resilience can be provided for the protection pad 31, so that the problem that the protection pad 31 cannot return to the initial position or does not return to the position due to friction between the microneedle 30 and the protection pad 31 or other reasons is avoided, and the protection pad 31 returns to the initial position as soon as possible after the compression is removed, so as to avoid damaging surrounding tissues; the resilience of the protection pad 31 in the present invention is derived from the resilience provided by the side walls (support portions 32) of the protection pad 31 and the resilience provided by the elastic member or the inelastic support member. The resilience provided by the elastic member or the inelastic support member is more stable and controllable than the resilience provided by the side walls. Since the resilience provided by the side walls to the protection pad 31 is mainly affected by the resilience of the side walls and the contact area between the side walls and the jaw seat 26, by providing the hollowed-out structures on the side walls of the protection pad 31, the resilience provided by the side walls itself is reduced and/or the contact area between the side walls and the jaw seat 26 is reduced. In this case, the side wall largely provides only the function of fixing the protection pad 31, and the resilience of the protection pad 31 largely depends on the elastic member or the inelastic support, thereby enabling more stable and controllable resilience to be provided by the elastic member or the inelastic support.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It is to be understood that the present invention is not limited to the embodiment methods, structures, and precise structures shown in the drawings, which have been described above, and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1. A chemical ablation device comprising a clamping assembly and a microneedle assembly;

2. The chemical ablation device according to claim 1, wherein an open slot is formed in the top of the jaw seat, at least one mounting hole is formed in the bottom of the open slot along the axial extension direction of the jaw seat, the mounting hole is used for mounting the microneedle, and the protective pad is connected to the open slot of the jaw seat.

3. The chemical ablation device according to claim 2, wherein the forceps nozzle further comprises a forceps mouth cover, the forceps mouth cover is connected to the bottom of the forceps mouth seat, a containing cavity is formed between the forceps mouth seat and the forceps mouth cover, and when the microneedle is mounted on the mounting hole, the tail of the microneedle is located in the containing cavity.

4. The chemical ablation device according to claim 3, wherein the jaw seat and the jaw cover are fixedly connected together by a male-female fit structure.

5. The chemical ablation device of claim 2, wherein the micro-needle comprises a needle and a sleeve fixed outside the needle, the sleeve being fixed in the mounting hole.

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

7. The chemical ablation device of claim 6, wherein the distal end of the first aperture is provided with a funnel-shaped open slot.

8. The chemical ablation device according to claim 1, wherein the elastic component is sleeved outside each microneedle, a position on the protective pad corresponding to each microneedle is provided with an upward convex accommodating groove, and each accommodating groove covers one microneedle and the elastic component sleeved outside the microneedle.

9. The chemical ablation device according to claim 8, wherein the protective pad comprises a plurality of pads, and each pad is provided with the receiving groove protruding upwards.

10. The chemical ablation device according to claim 2, wherein the cross section of the protective pad is in an inverted U shape, the protective pad comprises support parts on two sides, and the protective pad is connected with the open slot of the jaw seat through the support parts.

11. The chemical ablation device of claim 10, wherein at least one of the support portions is hollowed out.

12. The chemical ablation device according to claim 10, wherein the supporting portion is fixedly connected with the open slot of the jaw seat by means of adhesion, interference fit, pin or screw fixation, and clamping.

13. The chemical ablation device of claim 1, wherein the protective pad is made of a thermoset elastomer or a thermoplastic elastomer.

14. The chemical ablation device of claim 1, wherein a side of the protective pad facing the microneedles has a hardness greater than a hardness of another side of the protective pad.

15. The chemical ablation device according to claim 1, wherein a surface of a side of the protective pad facing the microneedles has a pad having a hardness greater than that of the protective pad, and the pad has small holes through which the microneedles pass at portions corresponding to the microneedles.

16. The chemical ablation device according to claim 1, wherein the pre-stress of the elastic component is greater than or equal to the sum of the friction between the microneedle and the protective pad and the gravity of the protective pad.

17. The chemical ablation device according to claim 1, wherein the elastic component is a spring or a leaf spring or a wave-shaped sheet or other elastic body with elastic function, and the elastic component is sleeved outside the microneedles or arranged between the adjacent microneedles.

18. The chemical ablation device of claim 17, wherein the two ends of the elastic member are fixed to the jaw seat and the protective pad by bonding or welding.

19. The chemical ablation device according to claim 2, wherein the inelastic supporting member is a column structure and is disposed at the bottom of the open slot of the jaw seat, and the inelastic supporting member has a height smaller than the height of the microneedle above the bottom of the open slot.