A spherical ablation catheter

Abstract

The present invention relates to the technical field of electrophysiological catheters, and is a spherical ablation catheter, including a balloon arranged at the head end, on which a plurality of electrodes are arranged, and after the balloon is expanded, the balloon includes a first spherical shape and a second spherical shape; the volume of the second spherical shape is larger than the volume of the first spherical shape; adjacent electrodes have a spacing in the first spherical shape or the second spherical shape; the first spherical shape is used for mapping and ablation; the second spherical shape is used for mapping and ablation. The present invention arranges a balloon that can be configured into a first spherical shape and a second spherical shape with different volumes, and arranges a plurality of electrodes on the balloon, so that there is no need to replace the ablation catheter, and the mapping and ablation of different parts can be completed by implanting the spherical ablation catheter in the body once, and the second spherical shape can be used for large-area annular ablation of pulmonary vein isolation, and the first spherical shape can be used for point ablation or large-area ablation, and precise mapping and high-efficiency ablation can be achieved at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of medical electrophysiological catheters, in particular to a spherical ablation catheter. Background Art

[0002] Multipolar catheter ablation is now more and more widely used in the treatment of atrial fibrillation due to its high ablation efficiency. Due to the realistic multi-electrode distribution and arrangement, the structure is relatively complex. Currently, multi-electrode catheters focus more on ablation, and mapping before treatment usually requires an additional mapping catheter. At present, multipolar ablation design is mainly designed for pulmonary vein ablation, which cannot simultaneously meet the requirements of local point ablation under the conditions of safety and effectiveness. However, for a surgery that requires local ablation after isolating the pulmonary vein (such as tricuspid isthmus ablation isolation, mitral isthmus ablation isolation, atrial fibrillation with ventricular arrhythmia, focal point ablation, etc.), it is often necessary to replace an additional point ablation catheter, which increases the cost and time of the surgery. Pulsed electric field ablation energy still requires good contact between the catheter and the tissue to obtain the expected ablation effect, but there is currently no design for multipolar ablation catheters that can achieve pressure monitoring functions in clinical practice.

[0003] Pulsed electric field technology is a technique that applies a short high voltage to tissues to generate a local high electric field of hundreds of volts per centimeter. The local high electric field destroys the cell membrane by creating pores in the cell membrane. The electric field applied to the membrane is greater than the cell threshold, so the pores are not closed. This electroporation is irreversible, allowing biomolecular materials to pass through the membrane for exchange, leading to cell necrosis or apoptosis. Pulse irreversible electroporation ablation is different from physical therapies based on the principle of thermal ablation, such as radiofrequency, cryotherapy, microwave, and ultrasound. The irreversible electroporation destruction of the myocardial cell membrane by microsecond pulses is a non-thermal biological effect that can effectively avoid damage to blood vessels, nerves, and esophagus. High-frequency pulsed electric fields maintain the non-thermal advantage of irreversible electroporation. Electric field pulses are expected to break through the problem of uneven internal electric field distribution caused by the cell membrane capacitance effect and the anisotropy of biological tissues. When using bipolar pulses, after the previous positive pulse train ends, a negative pulse train with the same pulse width and equal field strength is applied immediately. It is possible that the action potential induced by the positive pulse does not have time to fully generate, and the negative pulse causes the action potential to develop in the opposite direction, which will greatly reduce the electric field's stimulation of the nerves. Summary of the invention

[0004] The purpose of the present invention is to provide a spherical ablation catheter to address the problems in the prior art that the ablation and mapping of the current conventional multi-polar ablation catheters are designed independently, making it difficult to achieve both precise mapping and high-efficiency ablation at the same time. The existing multi-polar ablation design is mainly designed for pulmonary vein isolation, and cannot achieve local point ablation under the conditions of safety and effectiveness. It requires the replacement of additional point ablation catheters, which increases the cost of surgery.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A spherical ablation catheter comprises a balloon arranged at the head end, the balloon is provided with a plurality of electrodes, and the balloon comprises a first spherical shape and a second spherical shape after expansion; the volume of the second spherical shape is larger than the volume of the first spherical shape; adjacent electrodes have a spacing in the first spherical shape or the second spherical shape; the first spherical shape can be used for mapping and ablation; the second spherical shape can be used for mapping and ablation.

[0007] In this field, the distal end refers to the front end part of the electrophysiological mapping catheter, that is, the part that first enters the human body, the proximal end refers to the end of the electrophysiological mapping catheter closer to the operator, and the head end is located at the distal end of the electrophysiological mapping catheter, that is, the end that enters the human body. Therefore, those skilled in the art can clearly and unambiguously know the meaning of the head end.

[0008] By adopting the spherical ablation catheter described in the present invention, the balloon is provided and can be configured into the first spherical shape and the second spherical shape with different volumes, and a plurality of the electrodes are provided on the balloon, thereby eliminating the need to replace the ablation catheter. The mapping and ablation of different parts can be completed by implanting the spherical ablation catheter in the body once. The second spherical shape can be used for large-area annular ablation of pulmonary vein isolation, and the first spherical shape can be used for point ablation or large-area ablation, thereby realizing an integrated design of ablation and mapping of a multi-polar ablation catheter, and achieving both precise mapping and high-efficiency ablation.

[0009] As a preferred technical solution of the present invention, the distance between adjacent electrodes in the first spherical form is 0.5 mm to 3 mm.

[0010] As a preferred technical solution of the present invention, the distance between adjacent electrodes in the second spherical form is 1 mm to 4 mm.

[0011] As a preferred technical solution of the present invention, the outer diameter of the first spherical shape is 8mm~12mm; the outer diameter of the second spherical shape is 25mm~35mm.

[0012] As a further preferred technical solution of the present invention, the outer diameter of the first spherical shape is 10 mm.

[0013] As a further preferred technical solution of the present invention, the outer diameter of the second spherical shape is 28 mm.

[0014] As a preferred technical solution of the present invention, the balloon includes an outer balloon and an inner balloon; the outer balloon wraps the inner balloon; the electrode is arranged on the surface of the outer balloon; the space between the outer balloon and the inner balloon is filled with liquid; and the inner balloon is filled with gas.

[0015] With this structural setting, if the balloon is completely filled with the liquid, the balloon will become very heavy and require stronger support and operation, posing new challenges to the design and cost control of the ablation catheter so that the balloon can be easily operated in the heart; if the balloon is completely filled with the gas, if the balloon is damaged, the gas will flow into the heart, causing air embolism, posing a huge safety hazard; the design of the present application adopts a method of filling liquid between the outer balloon and the inner balloon and filling gas inside the inner balloon, which improves the safety of the use of the balloon and can also be used based on the design of some existing ablation catheters, avoiding the problem that the balloon is too heavy to control, or requires more complex support and operation, resulting in design difficulties and high costs.

[0016] As a further preferred technical solution of the present invention, the liquid is physiological saline.

[0017] As a further preferred technical solution of the present invention, the gas is nitrogen or an inert gas.

[0018] As a further preferred technical solution of the present invention, the head end includes a support component; the support component is arranged along the central axis of the outer balloon and the inner balloon, and extends into the outer balloon and the inner balloon in sequence; a liquid channel is provided on the support component between the outer balloon and the inner balloon; and a gas channel is provided on the support component within the inner balloon.

[0019] As a further preferred technical solution of the present invention, a telescopic component is provided at the distal end of the support component; the telescopic component is extended or shortened along the axial direction of the support component; and the distal end of the telescopic component is connected to the outer balloon and the inner balloon.

[0020] As a further preferred technical solution of the present invention, a first magnetic positioning sensor is provided at the distal end of the telescopic assembly; and a second magnetic positioning sensor is provided at the proximal end of the supporting assembly.

[0021] As a further preferred technical solution of the present invention, a first pressure sensor is provided on the support assembly inside the inner balloon; and a second pressure sensor is provided on the support assembly between the outer balloon and the inner balloon.

[0022] With this structural setting, the pressure of the gas in the inner balloon is detected by the first pressure sensor, and the pressure of the liquid between the outer balloon and the inner balloon is detected by the second pressure sensor; when the detected pressure value is within the preset pressure threshold interval A, the balloon corresponds to the first spherical shape; when the detected pressure value is within the preset pressure threshold interval B, the balloon corresponds to the second spherical shape.

[0023] As a further preferred technical solution of the present invention, at least one reference electrode is provided at the proximal end of the support assembly.

[0024] Effective ablation requires good contact between the electrode and tissue. Discharge in the non-contacted part is ineffective ablation, and energy often flows into the blood, causing certain damage to red blood cells. Therefore, it is hoped to reduce ineffective ablation, that is, ablation can only be performed when the electrode is effectively in contact with the tissue.

[0025] With this structural setting, during application, the reference electrode is at the bottom of the balloon. Due to its physical position, the reference electrode cannot contact the myocardial tissue but can only contact the blood. Therefore, the reference electrode can collect blood impedance (Rb) in real time; the adjacent electrodes on the balloon collect myocardial tissue impedance (Ra), and the Ra-Rb value is β. Because the impedance of myocardial tissue and other intracardiac tissues is higher than the blood impedance, the electrode does not contact the tissue when β=0, and contacts the tissue when β>0. During discharge ablation, only the electrode that contacts the tissue can be selected for discharge.

[0026] As a further preferred technical solution of the present invention, the outer balloon is a composite structure of at least two layers, and the inner balloon is a composite structure of at least two layers.

[0027] With this structural setting, by providing the outer balloon and the inner balloon with at least two layers of composite structure, the safety redundancy of the balloon is increased, and the risk of balloon damage is reduced to ensure safety.

[0028] As a preferred technical solution of the present invention, when the balloon changes, the size of the electrode does not change.

[0029] As a further preferred technical solution of the present invention, the electrode is a flexible electrode, and the electrode is bonded to the surface of the balloon.

[0030] As a further preferred technical solution of the present invention, the flexible electrode comprises several layers, the bottom layer is a polyimide layer, and the top layer is a metal layer. The polyimide layer has high insulation, flexibility, and good biological properties.

[0031] As a further preferred technical solution of the present invention, the metal layer is made of gold or copper plated with gold.

[0032] As a further preferred technical solution of the present invention, the polyimide layer is bonded to the balloon by polyurethane glue.

[0033] As a preferred technical solution of the present invention, the balloon is made of polyurethane material, which has high elasticity and stretchability, making it easy for the balloon to expand and contract, and also easy to bond.

[0034] As a further preferred technical solution of the present invention, the polyurethane material used for the balloon has a material hardness of 35D or less.

[0035] As a further preferred technical solution of the present invention, the material of the balloon also uses a filler, and the proportion of the polyurethane material used in the balloon is greater than 95%, so as to prevent the filler from affecting the elasticity and softness of the balloon.

[0036] In the above-mentioned structural arrangement, magnetic positioning sensors are respectively provided at the distal and proximal ends of the balloon, and the distance between the distal and proximal ends of the balloon can be obtained through the magnetic positioning technology. Pressure sensors are respectively provided on the inner and outer balloons, and the diameter of the balloon can be obtained through the pressure values. The size of the electrodes on the balloon does not change when the balloon is in different forms, and the spacing between the electrodes is fixed and known when the balloon is in different forms. Therefore, the balloon cooperates with the three-dimensional electrophysiological mapping system to realize the operation of the spherical ablation catheter for ablation under non-radiation conditions, thereby reducing the impact of radiation on doctors and patients' bodies.

[0037] As a preferred technical solution of the present invention, at least two layers of electrodes are sequentially arranged on the balloon from the distal pole to the equator; the number of electrodes in each layer is an even number and are evenly arranged along the circumference of the balloon.

[0038] This structural setting facilitates bipolar ablation configuration of pulsed electric field ablation.

[0039] As a further preferred technical solution of the present invention, the number of electrodes in each layer is 6 to 18.

[0040] As a further preferred technical solution of the present invention, the number of electrodes in each layer is 8 to 12.

[0041] As a further preferred technical solution of the present invention, 2 to 8 layers of electrodes are provided on the balloon.

[0042] As a further preferred technical solution of the present invention, 3 to 4 layers of electrodes are provided on the balloon.

[0043] As a further preferred technical solution of the present invention, the balloon is provided with three layers of electrodes, and the sum of the total area of ​​the first layer of electrodes and the total area of ​​the second layer of electrodes is equal to the total area of ​​the third layer of electrodes; or, the balloon is provided with four layers of electrodes, and the sum of the total area of ​​the first layer of electrodes and the total area of ​​the fourth layer of electrodes is equal to the sum of the total area of ​​the second layer of electrodes and the total area of ​​the third layer of electrodes.

[0044] With this structural setting, by arranging a reasonable area distribution of the electrodes on the surface of the balloon, arc problems caused by excessive field concentration during use can be avoided.

[0045] As a further preferred technical solution of the present invention, the number of electrodes in all layers is equal and they are arranged in rows along the meridians of the balloon, the total area of ​​the electrodes in each row is equal, and the polarities of each pair of electrodes in two adjacent rows are opposite.

[0046] With this structural setting, adjacent electrodes in the first spherical form or the second spherical form have a spacing, so that each pair of electrodes in two adjacent columns of electrodes can discharge between electrodes without the problem of arcing caused by overlapping electrodes.

[0047] As a further preferred technical solution of the present invention, the electrodes between adjacent electrode layers have opposite polarities, and discharge occurs between adjacent electrode layers.

[0048] With this structural arrangement, all the electrodes in each layer are treated as a whole electrode. Since the total area of ​​the electrodes in each layer is relatively large, the overall field strength distribution will not be overly concentrated, thereby avoiding arc problems.

[0049] As a further preferred technical solution of the present invention, the electrodes between adjacent electrode layers are arranged in a staggered distribution, and the area of ​​each electrode is equal.

[0050] This structural setting is adopted to facilitate discharge ablation between any of the electrodes. The area of ​​each electrode is equal so that the area distribution of the electrodes arranged on the surface of the balloon is reasonable, avoiding arc problems caused by excessive field concentration during use.

[0051] As a further preferred technical solution of the present invention, from the distal pole of the balloon toward the equator, the width of the electrodes in the next layer increases compared with the width of the electrodes in the previous layer, and the height of the electrodes in the next layer decreases compared with the height of the electrodes in the previous layer.

[0052] As a further preferred technical solution of the present invention, the first layer of electrodes is elliptical, and the second layer of electrodes, the third layer of electrodes, and the fourth layer of electrodes are increasingly slender.

[0053] As a preferred technical solution of the present invention, a plurality of optical fiber sensors are evenly distributed on the surface of the balloon;

[0054] A plurality of optical fibers are evenly distributed along the surface of the balloon; the optical fibers are arranged along the longitude, and each optical fiber is connected in series with at least two optical fiber sensors; the optical fiber sensors on each optical fiber are evenly distributed;

[0055] Alternatively, each of the optical fiber sensors is connected to an optical fiber, and each of the optical fibers is led out through the supporting assembly at the head end.

[0056] With this structural setting, the local displacement and deformation of the balloon can be detected by the optical fiber sensor, and the pressure value and the direction of contact of the balloon can be indirectly calculated; the pressure and direction are measured by statistical table lookup. First, when various pressures and various directions are known, different numerical matrices of each optical fiber sensor are measured (pre-calibrated and trained), and the obtained corresponding relationships are organized into a database and stored in the device. When used, the device searches the database according to the values ​​detected by the optical fiber sensor. According to the uniqueness, a set of detection values ​​can only find a corresponding force and direction in the database to match it, so that the force and contact direction of the spherical ablation catheter can be quantified.

[0057] The above-mentioned structural setting can clearly understand the contact situation of the spherical ablation catheter in the heart through the overall pressure and abutment direction monitoring of the optical fiber sensor and the precise electrode abutment monitoring involving the reference electrode, making the operation and ablation of the spherical ablation catheter safer and more effective.

[0058] As a further preferred technical solution of the present invention, 6 to 14 optical fibers are provided on the balloon.

[0059] As a preferred technical solution of the present invention, the spherical ablation catheter also includes an adjustable bend section tube body, a support tube body, and a control handle; the adjustable bend section tube body is connected to the head end; the support tube body is connected to the adjustable bend section tube body; the control handle is connected to the support tube body, and a deflection mechanism and a push-pull mechanism are provided on the control handle, the deflection mechanism controls the bending of the adjustable bend section tube body, and the push-pull mechanism controls the balloon to be configured as the first spherical shape or the second spherical shape.

[0060] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0061] 1. The spherical ablation catheter of the present invention can be configured into the first spherical shape and the second spherical shape with different volumes by providing the balloon, and multiple electrodes are provided on the balloon, so that there is no need to replace the ablation catheter, and the mapping and ablation of different parts can be completed by implanting the spherical ablation catheter in the body once, and the second spherical shape can be used for large-area annular ablation of pulmonary vein isolation, and the first spherical shape can be used for point ablation or large-area ablation, so as to realize the integrated design of ablation and mapping of multi-polar ablation catheter, and realize precise mapping and high-efficiency ablation at the same time;

[0062] 2. A preferred spherical ablation catheter of the present invention, if the balloon is fully filled with the liquid, the balloon will become very heavy and require stronger support and operation, which poses new challenges to the design and cost control of the ablation catheter, so that the balloon can be easily operated in the heart; if the balloon is fully filled with the gas, if the balloon is damaged, the gas will flow into the heart, which will cause gas embolism and pose a huge safety hazard; the design of this application adopts the method of filling the liquid between the outer balloon and the inner balloon and filling the gas inside the inner balloon, which improves the safety of the use of the balloon and can also be used on the basis of the design of some existing ablation catheters, avoiding the problem that the balloon is too heavy to be controlled, or requires more complex support and operation, resulting in design difficulties and high costs;

[0063] 3. A preferred spherical ablation catheter of the present invention has magnetic positioning sensors at the distal and proximal ends of the balloon, respectively. The distance between the distal and proximal ends of the balloon can be obtained through magnetic positioning technology. Pressure sensors are respectively provided on the inner and outer balloons, and the diameter of the balloon can be obtained through pressure values. The size of the electrode on the balloon does not change under different forms of the balloon, and the spacing between the electrodes is fixed and known under different forms of the balloon. Therefore, the balloon cooperates with a three-dimensional electrophysiological mapping system to realize non-radiation operation of the spherical ablation catheter for ablation, thereby reducing the impact of radiation on doctors and patients' bodies.

[0064] 4. A preferred spherical ablation catheter of the present invention detects the local displacement and deformation of the balloon through the optical fiber sensor, and can indirectly infer the pressure value and the sticking direction of the balloon; the pressure and direction are measured by statistical table lookup, firstly, when various pressures and various directions are known, different numerical matrices of each optical fiber sensor are measured (pre-calibrated and trained), and the obtained corresponding relationships are organized into a database and stored in the device. When used, the device searches the database according to the values ​​detected by the optical fiber sensor. According to the uniqueness, a set of detection values ​​can only find a corresponding force and direction in the database to match it, so that the force and sticking direction of the spherical ablation catheter can be quantified;

[0065] 5. A preferred spherical ablation catheter of the present invention can clearly understand the contact situation of the spherical ablation catheter in the heart through the overall pressure and abutment direction monitoring of the optical fiber sensor and the precise electrode abutment monitoring involving the reference electrode, and realize the pressure monitoring of any electrode, thereby making the operation and ablation of the spherical ablation catheter safer and more effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 is a schematic diagram of the structure of a spherical ablation catheter;

[0067] Figure 2 It is a schematic diagram of the morphological changes of the spherical head end;

[0068] Figure 3 A schematic diagram of the interior of the head end in the first spherical form;

[0069] Figure 4 A schematic diagram of the interior of the head end in the second spherical form;

[0070] Figure 5 It is a schematic diagram of the main structure of the spherical head end;

[0071] Figure 6 It is a schematic diagram of the top view of the spherical head;

[0072] Figure 7 It is a schematic diagram of the three-dimensional structure of the spherical head;

[0073] Figure 8 Schematic diagram of the polarity distribution of the ablation electrode on the spherical head surface Figure 1 ;

[0074] Fig. 9 Schematic diagram of the polarity distribution of the ablation electrode on the spherical head surface Figure 2 ;

[0075] Fig.10 Schematic diagram of the polarity distribution of the ablation electrode on the spherical head surface Figure 3 ;

[0076] Fig.11 Schematic diagram of the distribution of optical fiber sensors in the spherical head Figure 1 ;

[0077] Fig.12 Schematic diagram of the distribution of optical fiber sensors in the spherical head Figure 2 ;

[0078] Fig.13 Schematic diagram of the distribution of optical fiber sensors in the spherical head Figure 3 ;

[0079] Fig.14 This is a schematic diagram of the impedance conditions corresponding to tissues in different parts;

[0080] Fig.15 Schematic diagram of the operation of the spherical ablation catheter in the left atrium;

[0081] Fig.16 Schematic diagram of a spherical ablation catheter ablating inside a pulmonary vein;

[0082] Fig.17 Schematic diagram of a spherical ablation catheter performing ablation in the pulmonary vein vestibule.

[0083] Markings in the figure:

[0084] 1-first spherical form, 2-second spherical form, 3-reference electrode, 4-outer balloon, 5-adjustable curved tube, 6-support tube, 7-inner balloon, 8-first magnetic positioning sensor, 9-second magnetic positioning sensor;

[0085] 11-first layer electrode, 111-first layer electrode 1, 112-first layer electrode 2, 22-second layer electrode, 221-second layer electrode 1, 222-second layer electrode 2, 33-third layer electrode, 331-third layer electrode 1, 332-third layer electrode 2, 44-fourth layer electrode;

[0086] 12-liquid, 13-gas, 14-telescopic component, 15-first pressure sensor, 16-gas channel, 17-support component, 18-second pressure sensor, 19-liquid channel;

[0087] 21-fiber optic sensor, 23-deflection mechanism, 24-control handle, 25-push-pull mechanism, 26-first Luer connector, 27-second Luer connector;

[0088] 28-left atrium of the heart, 29-pulmonary vein, 30-pulmonary vein vestibule, 31-guide sheath, 32-blood impedance, 34-myocardial tissue impedance. DETAILED DESCRIPTION

[0089] The present invention is further described in detail below in conjunction with test examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0090] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0091] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0092] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0093] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0094] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0095] In the related art, conventional multipolar ablation catheters are designed independently for ablation and mapping, making it difficult to achieve both precise mapping and efficient ablation. Existing multipolar ablation designs are mainly designed for pulmonary vein isolation, and cannot simultaneously achieve local point ablation under the conditions of safety and effectiveness. However, for an operation that requires local point ablation after isolating the pulmonary veins (such as tricuspid isthmus isolation, mitral isthmus isolation, atrial fibrillation with ventricular arrhythmia, focal point ablation, etc.), it is often necessary to replace additional point ablation catheters, increasing surgical costs. Currently, pressure monitoring is achieved with a single-point ablation catheter, and there is currently no pressure monitoring design for multipolar catheters. Due to the design of multipolar catheters, it is difficult to detect the proximity of any electrode using a pressure sensor. For this reason, the technical solution of the present application was developed, and the following is combined with Figures 1 to 17 To elaborate.

[0096] Example 1

[0097] like Figures 1 to 4 As shown, a spherical ablation catheter described in the present invention includes a head end, an adjustable bend tube body 5, a support tube body 6, and a control handle 24 connected in sequence.

[0098] The head end includes a balloon and a support component 17, and a plurality of electrodes are provided on the balloon. After the balloon is expanded, the balloon includes a first spherical shape 1 and a second spherical shape 2; the volume of the second spherical shape 2 is larger than the volume of the first spherical shape 1; adjacent electrodes have a distance in the first spherical shape 1 or the second spherical shape 2; the first spherical shape 1 can be used for mapping and ablation; the second spherical shape 2 can be used for mapping and ablation; electrophysiological mapping can be performed between any two of the electrodes; the support component 17 supports the balloon.

[0099] The control handle 24 is provided with a deflection mechanism 23 and a push-pull mechanism 25; the deflection mechanism 23 controls the multi-directional bending of the adjustable curved tube 5, so as to facilitate reaching different tissue parts and improve the controllability; the push-pull mechanism 25 controls the configuration of the balloon into the first spherical shape 1 or the second spherical shape 2, such as Figure 2 shown.

[0100] In some optional embodiments, the spacing between adjacent electrodes in the first spherical form 1 is 0.5 mm to 3 mm. The spacing between adjacent electrodes in the second spherical form 2 is 1 mm to 4 mm.

[0101] In some optional embodiments, the outer diameter of the first spherical shape 1 is 8 mm to 12 mm; the outer diameter of the second spherical shape 2 is 25 mm to 35 mm. In this embodiment, the outer diameter of the first spherical shape 1 is preferably 10 mm, and the outer diameter of the second spherical shape 2 is preferably 28 mm.

[0102] In some optional embodiments, such as Figure 3 and Figure 4 As shown, the balloon includes an outer balloon 4 and an inner balloon 7; the outer balloon 4 wraps the inner balloon 7; the electrodes are arranged on the surface of the outer balloon 4; the space between the outer balloon 4 and the inner balloon 7 is filled with liquid 12; and the inner balloon 7 is filled with gas 13. In this embodiment, the liquid 12 is preferably physiological saline, and the gas 13 is preferably nitrogen or an inert gas.

[0103] For example, Figure 3 and Figure 4 As shown, the support component 17 is arranged along the central axis of the outer balloon 4 and the inner balloon 7, and extends into the outer balloon 4 and the inner balloon 7 in sequence. The proximal end of the support component 17 is connected to the distal end of the adjustable bend tube body 5. The distal end of the support component 17 is provided with a telescopic component 14, and the telescopic component 14 is sleeved in the support component 17. The telescopic component 14 can be extended or shortened along the axial direction of the support component 17. One axial end of the outer balloon 4 is fixed to the support component 17, and one axial end of the inner balloon 7 is also fixed to the support component 17. The other axial ends of the outer balloon 4 and the inner balloon 7 are fixed to the distal end of the telescopic component 14.

[0104] For example, Figure 3 and Figure 4 As shown, a liquid channel 19 is provided on the support component 17 between the outer balloon 4 and the inner balloon 7, a gas channel 16 is provided on the support component 17 inside the inner balloon 7, and a first Luer connector 26 and a second Luer connector 27 are provided at the tail end of the control handle 24. The first Luer connector 26 is connected to the gas channel 16, and the second Luer connector 27 is connected to the liquid channel 19. The gas 13 can be injected into the inner balloon 7 through the first Luer connector 26, and the liquid 12 can be injected between the outer balloon 4 and the inner balloon 7 through the second Luer connector 27; when the gas and liquid are injected so that the balloon reaches the first spherical shape 1, as shown in FIG. Figure 3 As shown, the telescopic component 14 is not extended relative to the supporting component 17; when the balloon needs to be configured into the second spherical shape 2, the push-pull mechanism 25 on the control handle 24 is manipulated, specifically, the push-pull mechanism 25 is pushed toward the distal end, so that the telescopic component 14 is extended relative to the supporting component 17, and at the same time, the gas 13 is continuously injected into the inner balloon 7, and the liquid 12 is injected between the outer balloon 4 and the inner balloon 7, as shown in FIG. Figure 4As shown, the pressure is then maintained to maintain the second spherical shape 2; on the contrary, the push-pull mechanism 25 is manipulated to be pushed toward the proximal end, so that the telescopic component 14 retracts relative to the supporting component 17, the inner balloon 7 discharges part of the gas 13, and part of the liquid 12 is discharged between the outer balloon 4 and the inner balloon 7, and the balloon switches from the second spherical shape 2 back to the first spherical shape 1. Therefore, the push-pull mechanism 25 is the switching tool for the first spherical shape 1 and the second spherical shape 2 of the balloon in this embodiment.

[0105] In some optional embodiments, the outer balloon 4 is a composite structure of at least two layers, and the inner balloon 7 is a composite structure of at least two layers. With this structural setting, by providing the outer balloon 4 and the inner balloon 7 of at least two layers of composite structure, the safety redundancy of the balloon is increased, and the risk of balloon damage is reduced to ensure safety.

[0106] In some optional embodiments, when the balloon changes, the size of the electrode does not change, the electrode is a flexible electrode, and the electrode is bonded to the surface of the balloon; the flexible electrode includes several layers, the bottom layer is a polyimide layer, and the top layer is a metal layer, and the polyimide layer has high insulation, flexibility, and good biological properties. In this embodiment, the metal layer is preferably a soft metal of gold or copper plated with gold, and the polyimide layer is bonded to the balloon by polyurethane glue.

[0107] In some optional embodiments, the balloon is made of polyurethane material, which has high elasticity and stretchability, is convenient for the balloon to expand and contract, and is also convenient for bonding; the hardness of the polyurethane material used in the balloon is 35D or less. In this embodiment, it is preferred that the material of the balloon also uses a filler, and the proportion of the polyurethane material used in the balloon is greater than 95%, so as to avoid the filler affecting the elasticity and softness of the balloon.

[0108] In some optional embodiments, the mapping is mainly performed in the first spherical form 1, when the electrode spacing is smaller and the electrophysiological signal mapping is clearer and more accurate.

[0109] The spherical ablation catheter described in this embodiment, on the one hand, by setting the balloon and being able to be configured into the first spherical shape 1 and the second spherical shape 2 of different volumes, a plurality of the electrodes are set on the balloon, so that there is no need to replace the ablation catheter, and the mapping and ablation of different parts can be completed by implanting the spherical ablation catheter once in the body. The second spherical shape 2 can be used for large-area annular ablation of pulmonary vein isolation, and the first spherical shape 1 can be used for point ablation or large-area ablation, realizing the integrated design of ablation and mapping of a multi-polar ablation catheter, and realizing precise mapping and high-efficiency ablation at the same time. On the other hand, if the balloon is completely filled with the liquid 12, the balloon It will become very heavy and require stronger support and operation, which poses new challenges to the design and cost control of the ablation catheter, so that the balloon can be easily operated in the heart; if the balloon is completely filled with the gas 13, if the balloon is damaged, the gas will flow into the heart, causing gas embolism, which poses a huge safety hazard; the design of the present application adopts a method of filling liquid 12 between the outer balloon 4 and the inner balloon 7, and filling the inner balloon 7 with gas 13, which improves the safety of the use of the balloon, and can also be used on the basis of the design of some existing ablation catheters, avoiding the problem that the balloon is too heavy to control, or requires more complex support and operation, resulting in design difficulties and high costs.

[0110] Example 2

[0111] like Figure 3 to Figure 4 As shown, a spherical ablation catheter described in the present invention is based on Example 1, and the distal end of the telescopic component 14 is provided with a first magnetic positioning sensor 8, the proximal end of the support component 17 is provided with a second magnetic positioning sensor 9, the support component 17 inside the inner balloon 7 is provided with a first pressure sensor 15, and the support component 17 between the outer balloon 4 and the inner balloon 7 is provided with a second pressure sensor 18.

[0112] The pressure of the gas 13 in the inner balloon 7 is detected by the first pressure sensor 15, and the pressure of the liquid 12 between the outer balloon 4 and the inner balloon 7 is detected by the second pressure sensor 18; when the detected pressure value is within the preset pressure threshold interval A, the balloon corresponds to the first spherical shape 1; when the detected pressure value is within the preset pressure threshold interval B, the balloon corresponds to the second spherical shape 2.

[0113] A spherical ablation catheter described in this embodiment has magnetic positioning sensors respectively provided at the distal and proximal ends of the balloon. The distance between the distal and proximal ends of the balloon can be obtained through magnetic positioning technology. Pressure sensors are respectively provided on the inner and outer balloons. The diameter of the balloon can be obtained through pressure values. The size of the electrode on the balloon does not change when the balloon is in different forms, and the spacing between the electrodes is fixed and known when the balloon is in different forms. Therefore, the balloon cooperates with a three-dimensional electrophysiological mapping system to realize non-radiation operation of the spherical ablation catheter for ablation, thereby reducing the impact of radiation on doctors and patients' bodies.

[0114] Example 3

[0115] like Figures 11 to 13 As shown, a spherical ablation catheter described in the present invention is based on Example 1 or Example 2, and a plurality of optical fiber sensors 21 are evenly distributed on the surface of the balloon.

[0116] In some optional embodiments, a plurality of optical fibers are evenly distributed along the surface of the balloon; the optical fibers are arranged along the longitude, and each optical fiber is connected in series with at least two optical fiber sensors 21; and the optical fiber sensors 21 on each optical fiber are evenly distributed.

[0117] In some optional embodiments, each of the optical fiber sensors 21 is connected to an optical fiber, and each of the optical fibers is led out through the supporting assembly 17 at the head end.

[0118] In some optional embodiments, 6 to 14 optical fibers are disposed on the balloon.

[0119] A spherical ablation catheter described in this embodiment detects the local displacement and deformation of the balloon through the optical fiber sensor 21, and can indirectly infer the pressure value and the direction of contact of the balloon; the pressure and direction are measured by statistical table lookup. First, when various pressures and various directions are known, different numerical matrices of each optical fiber sensor 21 are measured (pre-calibrated and trained), and the obtained corresponding relationships are organized into a database and stored in the device. When used, the device searches the database according to the values ​​detected by the optical fiber sensor 21. According to the uniqueness, a set of detection values ​​can only find a corresponding force and direction in the database to match it, so that the force and contact direction of the spherical ablation catheter can be quantified.

[0120] Example 4

[0121] like Figure 3 , Figure 4 , Fig.12As shown, a spherical ablation catheter described in the present invention is based on Example 3, and at least one reference electrode 3 is provided at the proximal end of the support component 17. The figure exemplarily shows the situation of providing two reference electrodes 3.

[0122] Effective ablation requires good contact between the electrode and tissue. Discharge in the non-contacted part is ineffective ablation, and energy often flows into the blood, causing certain damage to red blood cells. Therefore, it is hoped to reduce ineffective ablation, that is, ablation can only be performed when the electrode is effectively in contact with the tissue.

[0123] During application, the reference electrode 3 is at the bottom of the balloon. Due to its physical position, the reference electrode 3 cannot contact the myocardial tissue but can only contact the blood. Therefore, the reference electrode 3 can collect blood impedance 32 (Rb) in real time. The adjacent electrodes on the balloon collect myocardial tissue impedance 34 (Ra). The Ra-Rb value is β. Because the impedance of myocardial tissue and other intracardiac tissues is higher than the blood impedance 32, the electrode does not contact the tissue when β=0, and the electrode contacts the tissue when β>0. During discharge ablation, only the electrode in contact with the tissue can be selected for discharge, such as Fig.14 shown.

[0124] The spherical ablation catheter described in this embodiment can clearly understand the contact situation of the spherical ablation catheter in the heart through the overall pressure and abutment direction monitoring of the optical fiber sensor 21 and the precise electrode abutment monitoring involving the reference electrode 3, and realize the pressure monitoring of any electrode, making the operation and ablation of the spherical ablation catheter safer and more effective.

[0125] Example 5

[0126] like Figures 5 to 10 As shown, a spherical ablation catheter described in the present invention, based on any one of Examples 1 to 4, the balloon is provided with at least two layers of electrodes in sequence from the distal pole to the equator; the number of the electrodes in each layer is an even number, and are uniformly arranged along the circumference of the balloon. This structural arrangement facilitates the bipolar ablation configuration of pulsed electric field ablation.

[0127] In some optional implementations, the number of electrodes in each layer is 6 to 18. In this embodiment, the number of electrodes in each layer is preferably 8 to 12.

[0128] In some optional embodiments, the balloon is provided with 2 to 8 layers of the electrodes, and in this embodiment, the balloon is preferably provided with 3 to 4 layers of the electrodes.

[0129] For example, Figures 5 to 10As shown, the balloon is provided with three layers of electrodes, and the sum of the total area of ​​the first layer of electrodes 11 and the total area of ​​the second layer of electrodes 22 is equal to the total area of ​​the third layer of electrodes 33; by arranging a reasonable area distribution of the electrodes on the surface of the balloon, the arc problem caused by excessive field concentration during use is avoided.

[0130] Not shown in the figure, the balloon is provided with four layers of electrodes, and the sum of the total area of ​​the first layer of electrodes 11 and the total area of ​​the fourth layer of electrodes 44 is equal to the sum of the total area of ​​the second layer of electrodes 22 and the total area of ​​the third layer of electrodes 33; by arranging a reasonable area distribution of the electrodes on the surface of the balloon, the arc problem caused by excessive field concentration during use can be avoided.

[0131] In some optional embodiments, the number of electrodes in all layers is equal and they are arranged in rows along the meridians of the balloon, the total area of ​​the electrodes in each row is equal, and the polarities of each pair of electrodes in two adjacent rows are opposite. Figure 8 As shown, the polarity of the electrodes in each column is consistent, and the polarity of the electrodes in two adjacent columns is opposite. With this structural setting, the adjacent electrodes in the first spherical form 1 or the second spherical form 2 have a spacing, so that each pair of electrodes in two adjacent columns of electrodes can discharge between the electrodes, and there will be no arc problem caused by overlapping electrodes.

[0132] For example, Fig. 9 As shown, the polarities of the electrodes between adjacent electrode layers are opposite, and discharge occurs between adjacent electrode layers. With this structural arrangement, all the electrodes in each layer are treated as a whole electrode. Since the total area of ​​the electrodes in each layer is large, the overall field strength distribution is relatively not overly concentrated, thereby avoiding arc problems.

[0133] For example, Figure 5 , Figure 6 and Fig.10 As shown, the electrodes on the first layer electrode 11 are sequentially the first layer electrode 1 111, the first layer electrode 2 112, ..., the electrodes on the second layer electrode 22 are sequentially the second layer electrode 1 221, the second layer electrode 222, ..., the electrodes on the third layer electrode 33 are sequentially the third layer electrode 1 331, the third layer electrode 2 332, ...; the first layer electrode 11 and the second layer electrode 22 have the same polarity, and the third layer electrode 33 and the first layer electrode 11 have opposite polarity. Combined with the aforementioned total area of ​​the first layer electrode 11 and the total area of ​​the second layer electrode 22 being equal to the total area of ​​the third layer electrode 33, the first layer electrode 11 and the second layer electrode 22 can be regarded as a whole electrode. Similarly, the overall field strength distribution will not be overly concentrated to avoid arc problems.

[0134] Example 6

[0135] like Fig.11 and Fig.12 As shown, a spherical ablation catheter described in the present invention, based on any one of Examples 1 to 4, the balloon is provided with at least two layers of electrodes in sequence from the distal pole to the equator; the number of electrodes in each layer is an even number, and are evenly arranged along the circumference of the balloon, which is convenient for the bipolar ablation configuration of pulsed electric field ablation, and the electrodes between adjacent electrode layers are staggered and distributed, and the area of ​​each electrode is equal.

[0136] In some optional embodiments, from the distal end of the balloon toward the equator, the width of the electrodes in the next layer increases compared to the width of the electrodes in the previous layer, and the height of the electrodes in the next layer decreases compared to the height of the electrodes in the previous layer. For example, the first layer of electrodes 11 is elliptical, and the second layer of electrodes 22, the third layer of electrodes 33, and the fourth layer of electrodes 44 are increasingly elongated.

[0137] The spherical ablation catheter described in this embodiment facilitates discharge ablation between any of the electrodes. The area of ​​each electrode is equal so that the area distribution of the electrodes arranged on the surface of the balloon is reasonable, avoiding arc problems caused by excessive field concentration during use.

[0138] Example 7

[0139] like Figures 15 to 17 As shown, a method for using a spherical ablation catheter according to the present invention, taking ablation of pulmonary vein 29 as an example, the method comprises the following steps:

[0140] S1. Place the spherical ablation catheter into the left atrium 28 of the heart through the guide sheath 31, and inject the gas 13 and the liquid 12 through the first Luer connector 26 and the second Luer connector 27, so that the balloon is configured into the first spherical shape 1, which facilitates the operation of the balloon, can map the electrophysiological signals in the left atrium 28 of the heart, and construct a physical model of the left atrium 28 of the heart.

[0141] S2. Extend the balloon of the first spherical shape 1 into the pulmonary vein 29 for discharge ablation isolation, and simultaneously detect electrophysiological signals until the pulmonary vein 29 is completely isolated, and then withdraw the balloon to the left atrium 28 of the heart.

[0142] S3. Manipulate the spherical ablation catheter, configure the balloon into the second spherical shape 2, place it at the position of the pulmonary vein vestibule 30 for discharge ablation isolation, and synchronously detect electrophysiological signals until the pulmonary vein vestibule 30 is completely ablated and isolated.

[0143] S4. Release the gas 13 and the liquid 12 in the balloon, and withdraw the spherical ablation catheter.

[0144] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A spherical ablation catheter, comprising a balloon disposed at a tip end, wherein the balloon is provided with a plurality of electrodes, characterized in that: After the balloon is expanded, it includes a first spherical shape (1) and a second spherical shape (2); The volume of the second spherical form (2) is greater than the volume of the first spherical form (1); Adjacent electrodes have a spacing in the first spherical form (1) or the second spherical form (2); The first spherical shape (1) can be used for mapping and ablation; The second spherical shape (2) can be used for mapping and ablation; The balloon comprises an outer balloon (4) and an inner balloon (7); The outer balloon (4) wraps the inner balloon (7); The electrodes are arranged on the surface of the outer balloon (4); The space between the outer balloon (4) and the inner balloon (7) is filled with liquid (12); The inner balloon (7) is filled with gas (13); The head end includes a support assembly (17); The support assembly (17) is arranged along the central axis of the outer balloon (4) and the inner balloon (7), and extends into the outer balloon (4) and the inner balloon (7) in sequence; A liquid channel (19) is provided on the support assembly (17) between the outer balloon (4) and the inner balloon (7); The support assembly (17) in the inner balloon (7) is provided with a gas channel (16); A telescopic component (14) is provided at the distal end of the support component (17); The telescopic component (14) is extended or shortened along the axial direction of the supporting component (17); The distal end of the telescopic assembly (14) is connected to the outer balloon (4) and the inner balloon (7); The spherical ablation catheter also includes: An adjustable curved section pipe body (5) connected to the head end; A supporting tube body (6) connected to the adjustable bend tube body (5); A control handle (24) is connected to the support tube (6), and a deflection mechanism (23) and a push-pull mechanism (25) are provided on the control handle (24). The deflection mechanism (23) controls the bending of the adjustable bending section tube (5), and the push-pull mechanism (25) controls the extension or shortening of the telescopic component (14), so that the balloon is configured into the first spherical shape (1) or the second spherical shape (2).

2. The spherical ablation catheter according to claim 1, characterized in that: The outer diameter of the first spherical form (1) is 8 mm to 12 mm; The outer diameter of the second spherical form (2) is 25 mm to 35 mm.

3. The spherical ablation catheter according to claim 1, characterized in that: A first magnetic positioning sensor (8) is provided at the distal end of the telescopic assembly (14); A second magnetic positioning sensor (9) is provided at the proximal end of the support assembly (17).

4. The spherical ablation catheter according to claim 1, characterized in that: A first pressure sensor (15) is provided on the support assembly (17) inside the inner balloon (7); A second pressure sensor (18) is provided on the support assembly (17) between the outer balloon (4) and the inner balloon (7).

5. The spherical ablation catheter according to claim 1, characterized in that: At least one reference electrode (3) is provided at the proximal end of the support assembly (17).

6. The spherical ablation catheter according to claim 1, characterized in that: The electrode is a flexible electrode, and the electrode is bonded to the surface of the balloon.

7. The spherical ablation catheter according to claim 1, characterized in that: The balloon is provided with at least two layers of the electrodes in sequence from the distal pole to the equator; The number of the electrodes in each layer is an even number and they are evenly arranged along the circumference of the balloon.

8. The spherical ablation catheter according to claim 7, characterized in that: The balloon is provided with three layers of electrodes, and the sum of the total area of ​​the first layer of electrodes (11) and the total area of ​​the second layer of electrodes (22) is equal to the total area of ​​the third layer of electrodes (33); Alternatively, the balloon is provided with four layers of electrodes, and the sum of the total area of ​​the first layer of electrodes (11) and the total area of ​​the fourth layer of electrodes (44) is equal to the sum of the total area of ​​the second layer of electrodes (22) and the total area of ​​the third layer of electrodes (33).

9. The spherical ablation catheter according to claim 7, characterized in that: The number of electrodes in all layers is equal and they are arranged in rows along the meridians of the balloon, the total area of ​​the electrodes in each row is equal, and the polarities of each pair of electrodes in two adjacent rows are opposite; Alternatively, the polarities of the electrodes between adjacent electrode layers are opposite, and discharge occurs between the adjacent electrode layers; Alternatively, the electrodes between adjacent electrode layers are arranged in a staggered distribution, and the area of ​​each electrode is equal.

10. The spherical ablation catheter according to claim 1, characterized in that: A plurality of optical fiber sensors (21) are evenly distributed on the surface of the balloon; A plurality of optical fibers are evenly distributed along the surface of the balloon, the optical fibers are arranged along the longitude, each optical fiber is connected in series with at least two optical fiber sensors (21), and the optical fiber sensors (21) on each optical fiber are evenly distributed; Alternatively, each of the optical fiber sensors (21) is connected to an optical fiber, and each of the optical fibers is led out through the supporting assembly (17) at the head end.

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