Balloon ablation catheter and balloon ablation system

Abstract

This invention provides a balloon ablation catheter and a balloon ablation system. The balloon ablation catheter includes a catheter body, a balloon, several electrodes, and temperature sensors. The balloon is disposed at the distal end of the catheter body and consists of an inner balloon and an outer balloon. The electrodes and temperature sensors are disposed on the outer surface of the outer balloon and are distributed 360° around the axis of the catheter body along the latitude of the balloon. The electrodes can be used for electrocardiogram signal mapping and / or signal capture to determine the contact status between the balloon and the target object. The temperature sensors are used to obtain the actual temperature of the balloon surface and the contact point between the balloon and the tissue. Leads are connected to the electrodes, and all leads pass through the outer balloon into the space between the inner and outer balloons, extending along the space to the catheter body and reaching the proximal end of the catheter body.

Description

Technical Field

[0001] This utility model relates to the field of medical devices, and in particular to a balloon ablation catheter and balloon ablation system. Background Technology

[0002] Patients with atrial fibrillation have a high risk of stroke. During atrial fibrillation, the atria beat irregularly and rapidly, losing their contractile function. This makes it easy for blood to stagnate in the atria, forming blood clots. If these clots break off and travel through the arteries to the brain, a stroke occurs. By using an interventional catheter to apply energy to the pulmonary veins to ablate them, the pulmonary vein potential is isolated, thus achieving a therapeutic effect for atrial fibrillation.

[0003] Cryoballoon ablation, based on anatomical considerations, utilizes the contact between the balloon and tissue for freezing, offering advantages such as single-use and continuous operation. The cryoballoon achieves cryoablation primarily through the Joule-Thomson effect, also known as the throttling expansion effect. This effect refers to the temperature drop caused by the expansion and heat absorption of a high-pressure fluid as it passes through a small capillary tube to a low-pressure region. The cryoablation device is a comprehensive control system, mainly composed of a control panel, a coolant storage container, a vacuum system, and related piping. The high-pressure refrigerant is stored in a gas cylinder isolated from the outside environment at room temperature. At the start of cryoablation, the refrigerant is pressurized and liquefied through the device's internal components, then flows through the capillary tube into the balloon. The liquefied refrigerant is ejected through small holes on the capillary surface and rapidly vaporizes and expands, quickly carrying away the internal temperature of the balloon, causing a significant drop in balloon temperature and producing the cryoablation effect.

[0004] Pulmonary vein isolation is currently considered the cornerstone of atrial fibrillation treatment. The treatment outcome depends on the quality of contact between the therapeutic element and the target tissue. Currently, during cryoablation, the degree of contact between the balloon and the pulmonary vein is typically assessed using contrast agents under X-ray guidance. This method exposes both the patient and healthcare personnel to radiation, posing health risks. Furthermore, some patients have intolerances to contrast agents (e.g., allergies to contrast agents or renal insufficiency).

[0005] In current cryoablation techniques, the temperature sensor is placed at the outlet of the expanded gas, and the actual temperature monitored is the temperature of the recovered gas, which is then used to assess the treatment effect. This method has significant limitations, as it cannot directly monitor the true temperature of the balloon surface or the tissue.

[0006] In cryoablation, the structure of pulmonary veins varies from person to person; however, cryoballoons are limited in size and structure, making them unsuitable for all pulmonary vein structures. In practice, pulmonary vein isolation cannot be achieved using cryoballoons alone. The unisolated area is usually the junction of the superior and inferior pulmonary veins. Due to structural abnormalities at this location, it is difficult to determine whether the balloon has formed an effective apposition. Poor apposition can affect the final treatment outcome and may lead to recurrence postoperatively.

[0007] In addition, cryoballoon ablation is mainly performed under the guidance of X-rays and cannot be combined with a three-dimensional mapping system, which increases the difficulty of the operation for the operator and is also detrimental to the health of both the patient and the operator. Utility Model Content

[0008] In view of this, the purpose of this utility model is to provide a balloon ablation catheter and balloon ablation system that can monitor the state of balloon-blood vessel adhesion without the use of contrast agents.

[0009] To achieve the above objectives, this utility model provides a balloon ablation catheter, comprising a catheter body, a balloon, several electrodes, and temperature sensors. The balloon is disposed at the distal end of the catheter body and consists of an inner balloon and an outer balloon. The electrodes and temperature sensors are disposed on the outer surface of the outer balloon and are distributed 360° around the axis of the catheter body along the latitude of the balloon. The electrodes can be used for electrocardiogram signal mapping and / or signal capture to determine the contact status between the balloon and the target object. The temperature sensors are used to obtain the actual temperature of the balloon surface and the contact point between the balloon and the tissue. All the wires connected to the electrodes pass through the outer balloon into the space between the inner and outer balloons and extend along the space to the catheter body, thereby reaching the proximal end of the catheter body.

[0010] In one embodiment, three or more of the electrodes and the temperature sensor are distributed 360° along the latitude direction of the balloon, and any two adjacent electrodes along the latitude direction of the balloon are used to capture the signal, and any two adjacent electrodes are arranged on the same latitude or different latitudes.

[0011] In one embodiment, one or more of the electrodes and the temperature sensor are disposed along the same meridian on the outer surface of the balloon.

[0012] In one embodiment, a flexible encapsulation structure using a polymer substrate is also included. The flexible encapsulation structure includes an electrode and temperature sensor fixing substrate and a wire fixing band. The electrode and temperature sensor fixing substrate is fixed to the outer surface of the outer balloon. The wire fixing band passes through the outer balloon, bends, enters the interlayer, and extends along the interlayer to the catheter body up to the proximal end of the catheter body. The electrode and temperature sensor are fixed on the electrode and temperature sensor fixing substrate, and the wire is fixed on the wire fixing band.

[0013] In one embodiment, the electrode fixing substrate and the temperature sensor fixing substrate have a skirt formed at the bend of the wire fixing strip, the skirt covering the seam between the wire fixing strip and the outer balloon, and the skirt is bonded to the outer balloon.

[0014] In one embodiment, the electrode and temperature sensor fixing substrate is bonded to the outer balloon with adhesive, and the wire fixing strap passes through the outer balloon and is then sealed with adhesive at the joint between the wire and the outer balloon.

[0015] In one embodiment, a plurality of electrodes and temperature sensors are disposed on the outer surface of the outer balloon along multiple meridians. All electrodes, temperature sensors and wires on the same meridian are encapsulated in the same flexible encapsulation structure, and / or all electrodes, temperature sensors and wires on the same latitude are encapsulated in the same flexible encapsulation structure.

[0016] In one embodiment, at least some of the electrodes are also used to release radio frequency energy, pulse energy, or microwave energy, and / or, some of the electrodes are disposed on the distal outer surface of the balloon.

[0017] In one embodiment, a plurality of the electrodes and the temperature sensors are arranged in a spoke-like pattern on the outer surface of the balloon, each spoke containing a plurality of the electrodes and the temperature sensors arranged along the meridian direction of the balloon.

[0018] Based on the same inventive concept, this utility model also provides a balloon ablation system, which includes a system body and any of the balloon ablation catheters described in the present invention. The system body is connected to the balloon ablation catheter and is used to provide energy to the balloon ablation catheter. It is also used to collect the signal captured by the electrode and then determine the contact status between the balloon and the target object based on the signal.

[0019] In one embodiment, a balloon ablation system includes a three-dimensional mapping system connected to a plurality of electrodes for electrocardiogram signal mapping and displaying the balloon morphology.

[0020] Compared with the prior art, the balloon ablation catheter and balloon ablation system of this invention have the following advantages:

[0021] The aforementioned balloon ablation catheter includes a catheter body, a balloon, several electrodes, and a temperature sensor. The balloon is positioned at the distal end of the catheter body. The electrodes and temperature sensor are disposed on the outer surface of the balloon, distributed 360° around the axis of the catheter body along the latitude of the balloon. The electrodes are used for ECG signal mapping, signal capture, and / or supplementary radiofrequency ablation, pulsed ablation, or microwave ablation. The temperature sensor is used to obtain the actual temperature of the balloon surface and the contact point between the balloon and the tissue. Correspondingly, the main body of the aforementioned balloon ablation system is used to provide energy to the balloon catheter and to collect the signals captured by the electrodes, thereby determining the contact status between the balloon and the target object based on the signals. Thus, the contact status between the balloon and the biological tissue can be assessed by determining whether the electrodes are in contact with biological tissue based on the signals fed back from the electrodes. Therefore, when the signal fed back from the electrodes is not a biological tissue signal, it can be determined that the target object has not been completely blocked by the balloon; while when the signal fed back from the electrodes is a biological tissue signal, it can be determined that the target object has been completely blocked by the balloon. This method avoids exposing patients and medical staff to radiation, preventing harm from contrast agents and radiation. It also addresses the issue of contrast agent intolerance in some patients, allowing more patients to receive treatment. Furthermore, even at specific vascular locations (such as the junction of the superior and inferior pulmonary veins), the signals fed back from the electrodes can determine whether the balloon has formed an effective contact, providing excellent monitoring. The balloon surface electrodes can also be integrated with a 3D mapping system for ECG signal mapping, displaying the balloon's morphology within the system. Temperature sensors can acquire the actual temperature of the balloon surface and the contact area between the balloon and tissue during cryoablation, enabling more precise assessment of treatment effectiveness.

[0022] Furthermore, in the aforementioned balloon ablation catheter, the balloon is optimized to be a double-layered balloon, allowing all leads connected to the electrodes to pass through the outer balloon and enter the interlayer between the inner and outer balloons, extending along the interlayer to the catheter body and reaching the proximal end of the catheter body. In this way, the outer balloon provides better protection for the leads, preventing damage to the leads during device use. Attached Figure Description

[0023] Those skilled in the art will understand that the accompanying drawings are provided to better understand the present invention and do not constitute any limitation on the scope of the present invention. Wherein:

[0024] Figure 1This invention provides an application scenario for the interventional treatment of arrhythmias using a balloon ablation system according to one embodiment.

[0025] Figure 2 This is a schematic diagram of the structure of a balloon ablation catheter according to an embodiment of the present invention;

[0026] Figure 3 This is a front view of an embodiment of the present invention, showing an electrode disposed on the outer surface of a balloon.

[0027] Figure 4 for Figure 3 Side view of the central balloon;

[0028] Figure 5 To adopt Figure 4 The principle of signal detection when the middle electrode is distributed;

[0029] Figure 6 This invention provides a scenario in which the pulmonary vein is completely blocked by a balloon according to one embodiment.

[0030] Figure 7 for Figure 6 The signal detection principle when the middle pulmonary vein is completely blocked by a balloon;

[0031] Figure 8 This invention provides a scenario for the use of the pulmonary vein when it is not completely blocked by the balloon, according to one embodiment.

[0032] Figure 9 for Figure 8 The signal detection principle when the middle pulmonary vein is not completely blocked by the balloon;

[0033] Figure 10 This is a schematic diagram of the structure of the electrode, temperature sensor and wire packaged based on flexible circuit board technology according to an embodiment of the present invention;

[0034] Figure 11 This is a side view of a flexible packaging structure provided according to an embodiment of the present invention;

[0035] Figure 12 This is a schematic diagram of the structure of assembling electrodes, temperature sensors and wires on a balloon based on flexible circuit board technology according to an embodiment of the present invention.

[0036] In the attached image:

[0037] 1-Balloon ablation catheter; 2-Cryotherapy equipment; 3-Control equipment; 4-Balloon; 41-Distal outer surface; 42-Inner balloon; 43-Outer balloon; 5-Pulmonary vein; 6-Handle; 7-Electrical interface; 8-Inner lumen interface; 9-Fluid interface; 10-Outer tube; 11-Catheter body; 12-Inner core; 13-Fluid delivery tube; 14-Balloon internal temperature sensor; 15-Ablation area; 16-Iconization point; 17-Soft tip; 20-Electrode and temperature sensor; 21-Biotonic tissue signal detected between adjacent electrodes in the latitudinal direction; 22-Biotonic tissue signal detected between adjacent electrodes in the longitudinal direction; 23-No biotonic tissue signal detected between adjacent electrodes in the latitudinal and longitudinal directions; 24-Electrode and temperature sensor fixation substrate; 25-Conductor fixation strap; 26-Conductor; 27-Skirt; 32-Surface electrode. Detailed Implementation

[0038] To make the objectives, advantages, and features of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the objectives of the embodiments of this utility model. Furthermore, the structures shown in the drawings are often part of the actual structure. In particular, different drawings may emphasize different aspects and sometimes use different scales.

[0039] The purpose of this invention is to provide a balloon ablation catheter and balloon ablation system to solve the problems existing in the current method of assessing the contact between the balloon and the target object using contrast agents. The "target object" referred to herein refers to the target blood vessel of a patient or individual, such as the pulmonary vein, renal artery, or other sites requiring ablation treatment.

[0040] The balloon ablation catheter and balloon ablation system provided by this utility model include, but are not limited to, pulmonary vein isolation treatment. For example, they can also be applied to renal artery ablation treatment or ablation treatment of other vascular sites. This application does not limit the scope of application.

[0041] The following description refers to the accompanying drawings.

[0042] Please refer to Figure 1 and Figure 2This utility model provides a balloon ablation system, which includes a balloon ablation catheter 1 and a system body. The system body includes a cryotherapy device 2 and a control device 3. The cryotherapy device 2 is in fluid communication with the balloon ablation catheter 1 to deliver a cryotherapy medium to the balloon ablation catheter 1. The control device 3 is electrically connected to the balloon ablation catheter 1 to provide energy to the balloon ablation catheter 1, including radio frequency, pulse, or microwave energy. The control device 3 can also collect and display signals transmitted from the balloon ablation catheter 1. The cryotherapy device 2 and the control device 3 can be set independently, or the control device 3 can be integrated with the cryotherapy device 2 in the same device. The control device 3 can also serve as the control center of the cryotherapy device 2 to monitor the ablation process in real time. However, those skilled in the art can understand how to select the cryotherapy device 2 and the control device 3 to achieve the corresponding functions and / or effects based on the disclosure of this application and common general knowledge in the field. Specifically, this application will not elaborate further. For example, the refrigeration equipment 2 can be implemented using a compressor or other refrigeration equipment, and the control equipment 3 is a control device for operation control, monitoring, regulation, data acquisition, etc., which can be any existing computer, central processing unit, processing device, microprocessor, digital signal processor, application-specific integrated circuit, or other control device.

[0043] The balloon ablation catheter 1 includes a balloon 4, a catheter body 11, and a handle 6; the balloon 4 is located at the distal end of the catheter body 11 and can be used for cryoablation; the handle 6 is located at the proximal end of the catheter body 11 and can control the rotation and bending of the entire catheter body 11. Figure 1 This is an example of pulmonary vein 5 isolation treatment. In this application scenario, cryoablation is performed by contacting balloon 4 with pulmonary vein 5. Figure 2 As shown, during cryoablation treatment, after balloon 4 is expanded, it is placed against pulmonary vein 5 to perform cryoablation on ablation area 15. During cryoablation, low-temperature cryoprotectant reaches balloon 4 through catheter 11, causing balloon 4 to cool down significantly and produce cryoablation effect, thereby achieving the purpose of treating arrhythmia.

[0044] Continue to refer to Figure 2 The catheter body 11 includes an outer tube 10 and an inner core 12; a handle 6 is disposed on the outer tube 10; the inner core 12 is a hollow structure and is movably inserted inside the outer tube 10; the distal end of the inner core 12 extends beyond the distal end of the outer tube 10. When the balloon 4 is assembled, the proximal end of the balloon 4 is connected to the distal end of the outer tube 10, and the distal end of the balloon 4 is connected to the distal end of the inner core 12.

[0045] The catheter body 11 also includes a fluid delivery tube 13. The fluid delivery tube 13 and the inner core 12 are arranged side by side inside the outer tube 10, with the fluid delivery tube 13 positioned between the inner core 12 and the outer tube 10. The distal end of the fluid delivery tube 13 is located inside the balloon 4, allowing the injection of freezing medium onto the inner surface of the balloon 4. The fluid delivery tube 13 may include a helical section and a straight section integrally connected to the helical section; the helical section has several small holes for injecting freezing medium in different directions, ensuring uniform cooling or thawing of the balloon 4. Thus, when the freezing medium in a liquid, gaseous, or mixed state leaves the small holes, it expands and / or fills the inner cavity of the balloon 4, raising the surface of the balloon 4 to the temperature required for cryoablation, and then the heat-exchanged medium is discharged through the catheter body 11. The fluid delivery tube 13 can be bonded to the outer surface of the inner core 12, such as being bonded to the inner core 12 as a whole, or only the distal spiral tube segment can be wrapped around the inner core 12 and fixed to the inner core 12.

[0046] The handle 6 is typically provided with several interfaces, preferably including: an electrical interface 7, which is directly or indirectly electrically connected to the control device 3; an internal interface 8 for other instruments to pass through, the proximal end of the inner core 12 being connected to the internal interface 8 for delivering other external instruments such as guidewires and mapping catheters; and a fluid interface 9, the proximal end of the fluid delivery tube 13 being connected to the cryo-equipment 2 via the fluid interface 9. Furthermore, a balloon internal temperature sensor 14, as a preferred structure, is located at the distal end of the catheter body 11 to collect the temperature of at least one of the catheter body 11 and the balloon 4, monitoring the ablation temperature based on the collected balloon internal temperature to avoid excessively high or low ablation temperatures. Preferably, a contrast point 16 is provided at the distal end of at least one of the inner core 12 and the outer tube 10 to facilitate intraoperative confirmation of the balloon 4's position relative to the sheath. The distal end of the inner core 12 is typically configured with a soft tip 17 to prevent damage to blood vessels or tissues.

[0047] Furthermore, to address the problems existing in current methods of assessing the contact between balloon 4 and the target object using contrast agents, the balloon ablation catheter 1 provided in this embodiment has a plurality of electrodes and temperature sensors 20 disposed on the outer surface of balloon 4. These electrodes and temperature sensors 20 are distributed 360° around the axis of the catheter body 11 along the latitude direction of balloon 4. In this way, biological tissue signals can be captured in the latitude direction of balloon 4 by the electrodes and temperature sensors 20, and the contact status between balloon 4 and the target object can be determined by the biological tissue signals captured in the latitude direction. The biological tissue signals can be myocardial tissue signals or vascular wall tissue signals; the electrodes 20 can also be combined with a three-dimensional mapping system to perform electrocardiogram signal mapping, displaying the balloon morphology in the three-dimensional mapping system. The temperature sensors 20 can obtain the actual temperature of the balloon surface and the contact area between the balloon and the tissue during cryoablation, for evaluating the treatment effect.

[0048] It should be recognized that because blood and biological tissues correspond to different impedances or bioelectrical signals, the signals corresponding to blood and biological tissues are different. Only when the captured signal is a biological tissue signal can it be determined that the target object is completely blocked by balloon 4, and that balloon 4 and the target object have formed an effective contact. If the detected signal is a blood signal, it is determined that the target object is not completely blocked by balloon 4, and that balloon 4 and the target object have not formed an effective contact.

[0049] In practice, the control device 3 can acquire the signals captured by the electrode 20, and then determine the contact status between the balloon 4 and the target object based on these signals. The signals captured by the electrode 20 can be blood signals or biological tissue signals, which are output and displayed in the form of electrical signals. However, electrical signals can be output and displayed in various forms, such as in the form of an electrocardiogram, and can directly display electrical signals of impedance or associated impedance. This application is not limited in this regard.

[0050] Taking pulmonary vein isolation therapy as an example, when two adjacent electrodes 20 on balloon 4 along the latitude direction simultaneously contact normal myocardial tissue, myocardial tissue signals will be captured. Since there is a significant difference between the impedance of blood and the impedance of myocardial tissue, the electrical signals fed back by electrodes 20 can be used to determine whether the electrodes 20, distributed 360° along the latitude direction, are in contact with the myocardial tissue, thus assessing the contact status between balloon 4 and myocardial tissue. During this process, if the signal fed back by electrodes 20 is not a myocardial tissue signal, it can be determined that the pulmonary vein 5 is not completely blocked by balloon 4, and balloon 4 has not formed an effective contact with the pulmonary vein 5; conversely, if the signal fed back by electrodes 20 is a myocardial tissue signal, it indicates that balloon 4 and pulmonary vein 5 have formed an effective contact, completely blocking the pulmonary vein 5.

[0051] It should be understood that the latitude direction of balloon 4 corresponds to the circumference of the blood vessel, and the longitude direction corresponds to the length direction of the blood vessel. If balloon 4 forms an effective contact with the target blood vessel, the target blood vessel can be completely blocked by balloon 4 in its circumference, forming a complete contact ring. In this case, the signals monitored within 360° of the latitude direction of balloon 4 are all myocardial tissue signals. However, if balloon 4 does not form an effective contact with the target blood vessel, and the target blood vessel is not completely blocked by balloon 4 in its circumference, there will be gaps between the blood vessel wall and balloon 4 that allow blood flow. A complete contact ring cannot be formed between balloon 4 and the target blood vessel, and the signals monitored within 360° of the latitude direction of balloon 4 are not all myocardial tissue signals. Therefore, the contact status between balloon 4 and the target blood vessel can be directly determined based on the feedback signals. This monitoring method is effective, reliable, and safe.

[0052] Therefore, in practical use, without the use of contrast agents, the contact status between the balloon 4 and the target object can be determined by the signal fed back from electrode 20, thereby avoiding exposure of patients and medical staff to radiation and preventing harm to human health. It also solves the problem of discomfort caused by contrast agents for some patients, allowing more patients to receive ablation treatment. Moreover, even in special vascular locations (such as the junction of the superior and inferior pulmonary veins), the signal fed back from electrode 20 can be used for assessment, resulting in good monitoring. Ultimately, this allows balloon cryoablation to be adapted to the needs of different individuals, enabling surgery at more precise ablation locations, improving treatment outcomes, and reducing the risk of postoperative recurrence.

[0053] Furthermore, at least a portion of electrode 20 can also be used to release radiofrequency energy, pulsed energy, or microwave energy for radiofrequency ablation, pulsed ablation, or microwave ablation, and as a complementary treatment to cryoablation. For example, Figure 1 As shown, the control device 3 is also connected to an integrated surface electrode 32 (as a reference electrode). When radiofrequency ablation, pulse ablation, or microwave ablation is required, the surface electrode 32 is placed on the patient's skin to form a discharge circuit with the electrode 20 on the balloon 4 to achieve radiofrequency ablation, pulse ablation, or microwave ablation.

[0054] To improve the effectiveness and accuracy of the measurements, preferably, three or more electrodes and temperature sensors 20 are distributed 360° around the axis of the catheter body 11 along the latitudinal direction of the balloon 4. This allows for monitoring of the balloon 4's contact status at more points along the latitudinal direction, minimizing blind spots and ultimately improving measurement accuracy. However, this application does not preclude the use of two electrodes and temperature sensors 20 distributed 360° along the latitudinal direction of the balloon 4; for example, by enlarging the electrodes and temperature sensors 20 to eliminate blind spots, measurement accuracy can still be guaranteed.

[0055] Regardless of the method, any two adjacent electrodes 20 along the latitudinal direction of the balloon 4 are used to capture signals. Adjacent electrodes 20 can be shared to reduce the number of electrodes 20, save materials, and reduce structural complexity. In this embodiment, three, four, five, six, or more electrodes 20 are distributed 360° along the latitudinal direction of the balloon 4. More preferably, six to ten electrodes 20 are distributed 360° along the latitudinal direction of the balloon 4. According to an illustrative embodiment of this application, six electrodes 20 are distributed 360° along the latitudinal direction of the balloon 4.

[0056] Several electrodes and temperature sensors 20 are uniformly or non-uniformly arranged around the axis of the catheter body 11 along the latitude direction of the balloon 4. In this embodiment, the electrodes and temperature sensors 20 are uniformly arranged along the latitude direction of the balloon 4. "Uniformly arranged" means arranged at equal angles along the latitude direction of the balloon 4, while "non-uniformly arranged" means arranged at different angles along the latitude direction of the balloon 4. Taking six electrodes and temperature sensors 20 as an example, one electrode and temperature sensor 20 is arranged at 60° intervals along the latitude direction of the balloon 4, or the six electrodes and temperature sensors 20 are arranged at different angles along the latitude direction of the balloon 4. Any two adjacent electrodes and temperature sensors 20 can be arranged on the same latitude line or on different latitude lines, as long as there is a certain distance between the two electrodes and temperature sensors 20 to capture signals.

[0057] Furthermore, one or more electrodes and temperature sensors 20 may be disposed along the same meridian on the outer surface of the balloon 4. Preferably, multiple electrodes and temperature sensors 20 (e.g., two or more) may be disposed along the same meridian on the outer surface of the balloon 4. This can further expand the signal detection range along the length of the blood vessel, further eliminate monitoring blind spots, and make the measurement results more accurate and effective. According to the illustrative embodiment of this application, four electrodes and temperature sensors 20 are disposed along the same meridian on the outer surface of the balloon 4, but this is not a limitation. For example, two, three, four, or more electrodes and temperature sensors 20 may be disposed along the same meridian on the outer surface of the balloon 4, specifically depending on the length of contact between the balloon 4 and the target object. For example, the length of the area occupied by the electrodes and temperature sensors 20 distributed along the meridian direction of the balloon 4 is close to the surface contour length when the balloon 4 is in complete contact with the target object.

[0058] It should be noted that when multiple electrodes and temperature sensors 20 are arranged along the same meridian on the outer surface of the balloon 4, signals can also be captured by two adjacent electrodes and temperature sensors 20 on the same meridian. This allows for further monitoring of the occlusion of the blood vessel along its length on the same meridian, avoiding the problem of directly determining that the balloon 4 has not formed an effective contact with the target blood vessel simply because a biological tissue signal is not captured at one monitoring point. In some cases, the balloon 4 may abut against the blood vessel wall in an asymmetrical manner. Although a contact ring is formed, the asymmetry of the contact position may cause some electrodes and temperature sensors 20 on the same meridian to not be in contact with the blood vessel and thus fail to capture biological tissue signals. In this case, it is necessary to capture biological tissue signals by using electrodes and temperature sensors 20 at other locations on the same meridian that are already in contact with the blood vessel, thereby more accurately assessing the degree of contact between the balloon 4 and the target object.

[0059] In practice, the electrodes and temperature sensors 20 can be arranged on the outer surface of the balloon 4 in any suitable distribution. This application does not impose any particular limitation on this, as long as the balloon 4 is provided with electrodes and temperature sensors 20 distributed 360° along the latitude direction. Based on this, the electrodes 20 can be further extended to a 360° distribution along the same or different latitudes, and more electrodes and temperature sensors 20 can be extended along the same meridian. Although this application only describes a spoke-like geometric distribution, the electrodes and temperature sensors 20 can also be distributed in, for example, a pentagonal, circular, polygonal, elliptical, or other regular or irregular patterns. An illustrative description follows.

[0060] refer to Figures 3 to 9 In one exemplary embodiment, a plurality of electrodes and temperature sensors 20 are arranged in a spoke-like pattern on the outer surface of the balloon 4. The spoke-like pattern is a plurality of spokes arranged in the meridian direction on the outer surface of the balloon 4 with the distal end of the catheter body 11 as the center. Each spoke is provided with a plurality of electrodes and temperature sensors 20. Taking 6 spokes as an example, each spoke is provided with 4 electrodes and temperature sensors 20, but the actual implementation is not limited to this.

[0061] Figure 5 This further explains the principle of electrical signal detection. Figure 5 In the diagram, double-arrow line 21 indicates that biological tissue signals are captured between adjacent electrodes 20 in the latitudinal direction of balloon 4, and another double-arrow line 22 indicates that biological tissue signals are captured between adjacent electrodes 20 in the longitudinal direction of balloon 4. On the same spoke, the control device 3 collects signals between any two adjacent electrodes and temperature sensors 20 and determines whether the signal is a blood signal or a biological tissue signal. In the latitudinal direction, the control device 3 collects signals between any two electrodes and temperature sensors 20 between any two adjacent spokes and determines whether the signal is a blood signal or a biological tissue signal.

[0062] The following section will further explain how to determine the contact status between the balloon 4 and the target object using a specific application scenario.

[0063] Figure 6 The description depicts a scenario where the pulmonary veins are completely blocked by balloon 4. Figure 7 Corresponding to Figure 6 Detection results in the given scenario. For example... Figure 6 As shown, when the ablation area 15, i.e., the pulmonary vein, is well occluded, balloon 4 can form a complete, close-fitting ring with the pulmonary vein. At this time, as... Figure 7As shown, the detected signals are as follows: at least one pair of electrodes 20 on the same spoke is a myocardial tissue signal; at least one pair of electrodes 20 between adjacent spokes in the latitudinal direction is detected as a myocardial tissue signal; and ultimately, all myocardial tissue signals in the latitudinal direction can form a complete closure, that is, the signal detected between any adjacent spokes is a myocardial tissue signal. Based on this, it can be determined that the pulmonary vein is completely blocked by the balloon 4, forming an effective contact. However, in actual use, the balloon 4 and the pulmonary vein are mostly not coaxially contacted, that is, there is a certain probability that only one electrode 20 may contact the myocardial tissue in the longitudinal direction. In this case, no myocardial tissue signal can be detected in the longitudinal direction. In this case, the detection signal in the latitudinal direction is mainly used as the standard. As long as the myocardial tissue signal detected in the latitudinal direction can form a closed loop, it can be determined that the blockage is good.

[0064] Figure 8 This describes a scenario where the pulmonary vein is incompletely blocked by balloon 4. Figure 9 Corresponding to Figure 8 Detection results in the given scenario. For example... Figure 8 As shown, when the ablation zone 15, i.e., the pulmonary vein, is not completely blocked, balloon 4 and the pulmonary vein cannot form a complete, close-fitting ring. At this time, as... Figure 9 As shown, because there will be blood flushing at the poor contact between balloon 4 and pulmonary vein, some signals detected between adjacent spokes in the latitude direction of balloon 4 are blood signals (double arrow line 23 indicates that no biological tissue signal was detected between adjacent electrodes 20 in the latitude and longitude directions). This means that not all signals in the latitude direction are myocardial tissue signals, and the myocardial tissue signal cannot form a complete closure, which indicates that the closure is incomplete.

[0065] Since balloon 4 primarily contacts the blood vessel wall via its distal outer surface 41 when in contact with the target, the electrodes and temperature sensor 20 are typically only positioned on the distal outer surface 41 of balloon 4. The electrodes and temperature sensor 20 are securely fixed to the distal outer surface 41 of balloon 4, usually using adhesive to directly or indirectly fix them thereto. Furthermore, all wires 26 connected to the electrodes and temperature sensor 20 extend from the outer surface of balloon 4 to the catheter body 11, and then along the catheter body 11 to the proximal end for connection to the electrical interface 7.

[0066] As those skilled in the art will understand, in some applications, the balloon ablation catheter 1 reaches the target ablation site (such as the pulmonary vein or renal artery) through a matching sheath. After the balloon 4 completely exits the sheath, inflation and ablation are performed. After ablation, the gas inside the balloon 4 is deflated, and it is then returned to the sheath. After repositioning, the balloon 4 exits the sheath and is inflated again for the next treatment. Thus, during treatment, the balloon 4 repeatedly enters and exits the sheath, and the sheath opening scrapes against the surface of the balloon.

[0067] To address the issue of the sheath opening scraping against the balloon surface, this application further optimizes the mounting method of the electrodes and temperature sensor 20. The mounting method of the electrodes and temperature sensor 20 will be further explained below.

[0068] Please refer to Figures 10 to 12 In a preferred embodiment, the balloon 4 is a double-layered balloon, consisting of an inner balloon 42 and an outer balloon 43, with the outer balloon 43 covering the outside of the inner balloon 42. When assembling the electrode and temperature sensor 20 and the wire 26, the electrode and temperature sensor 20 are fixed to the outer surface of the outer balloon 43. The wire 26 passes through the outer balloon 43 into the space between the inner and outer balloons 42 and extends along the space to the catheter body 11, reaching the proximal end of the catheter body 11 and connecting to the electrical interface 7. This arrangement encapsulates the wire 26 between the inner balloon 42 and the outer balloon 43, and the outer balloon 43 protects the wire 26, preventing damage during use due to scratching from the sheath opening. Therefore, when assembling the double-layer balloon, the proximal end of the double-layer balloon is connected to the distal end of the outer tube 10, and the distal end of the double-layer balloon is connected to the distal end of the inner core 12. The lead wire 26 is simply placed in the interlayer and does not need to be connected to the inner balloon 42 and the outer balloon 43 with glue, because the inner balloon 42 and the outer balloon 43 will stick tightly together during inflation to fix the lead wire 26.

[0069] Furthermore, a flexible encapsulation structure is used to mount the electrodes and temperature sensors 20 and the wires 26. The flexible encapsulation structure is made of a polymer substrate, and its principle is based on flexible printed circuit board (FPC) technology to encapsulate the electrodes and temperature sensors 20 and the wires 26. Specifically, the flexible encapsulation structure includes an electrode and temperature sensor fixing substrate 24 and a wire fixing band 25, which can be integrally formed or assembled from separate parts. The electrode and temperature sensor fixing substrate 24 is directly fixed to the outer surface of the outer balloon 43; the wire fixing band 25 passes directly through the outer balloon 43, bends, enters the interlayer of the double balloon, and extends along the interlayer to the catheter body 11 until it reaches the proximal end of the catheter body 11 and connects to the electrical interface 7. When assembling the electrodes and temperature sensors 20 and the wires 26, the electrodes and temperature sensors 20 are directly fixed to the electrode and temperature sensor fixing substrate 24, and the wires 26 are directly fixed to the wire fixing band 25. This structural design is lightweight, thin, and highly flexible, making it less prone to damage during actual use. Furthermore, the flexible encapsulation structure adapts to the expansion and contraction of the balloon 4, reducing the impact of these movements and ensuring the effectiveness and operability of signal monitoring on the balloon surface. Simultaneously, the double-layered balloon allows for good contact with the target object, improving the ablation effect. In actual fabrication, electrodes, temperature sensors 20, and wires 26 can be embedded in the polymer substrate to form a flexible, integrated, or monolithic encapsulation structure.

[0070] Reference Figure 11 As shown, the electrode and temperature sensor fixing substrate 24 and the wire fixing strap 25 are not on the same plane. The wire fixing strap 25 is bent at a certain angle relative to the electrode and temperature sensor fixing substrate 24. This arrangement makes it convenient to pass the wire fixing strap 25 through the outer balloon 43 and then into the interlayer of the double balloon, thereby facilitating the assembly of the electrode and temperature sensor 20 and the wire 26. The wire fixing strap 25 is placed between the inner balloon 42 and the outer balloon 43. The outer balloon 43 can protect the wire fixing strap 25 and prevent it from being damaged by the sheath opening during use.

[0071] Reference Figure 10As shown, a single flexible packaging structure can encapsulate multiple electrodes 20 and temperature sensors at once. Therefore, during assembly, only the flexible packaging structure needs to be installed; it is not necessary to install each electrode 20 and temperature sensor individually, making installation convenient and labor-saving. Specifically, in this embodiment, multiple electrodes and temperature sensors 20 are arranged along multiple meridians on the outer surface of the outer spherical bulb 43. That is, multiple electrodes and temperature sensors 20 are arranged on each meridian. Furthermore, in some embodiments, all electrodes and temperature sensors 20 and wires 26 on the same meridian are encapsulated on the same flexible packaging structure, and / or all electrodes and temperature sensors 20 and wires 26 on the same latitude are encapsulated on the same flexible packaging structure. This saves materials, reduces the number of parts, and lowers costs.

[0072] Furthermore, such as Figure 11 and Figure 12 As shown, the electrode and temperature sensor mounting substrate 24 has a skirt 27 formed at the bend of the wire fixing strap 25. The skirt 27 can directly cover the joint between the wire fixing strap 25 and the outer balloon 43, and then the skirt 27 is bonded to the outer balloon 43. This increases the sealing of the joint and protects the joint area through the skirt 27. Furthermore, the electrode and temperature sensor mounting substrate 24 is bonded to the outer balloon 43 with adhesive, and the wire fixing strap 25, after passing through the outer balloon 43, is also bonded and sealed to the joint between itself and the outer balloon 43 with adhesive.

[0073] Figure 12 This describes the assembly method of the electrode and temperature sensor 20 on the balloon 4 according to one embodiment. For example... Figure 12 As shown, during balloon 4 assembly, the electrode and temperature sensor fixing substrate 24 is installed on the outer surface of the outer balloon 43 (specifically, the distal outer surface 41) and tightly bonded to the outer balloon 43 with adhesive. The wire fixing strap 25 passes through the outer balloon 43 and enters the interlayer between the inner balloon 42 and the outer balloon 43, and the joint between the wire fixing strap 25 and the outer balloon 43 is sealed with adhesive. At the same time, the skirt 27 of the electrode and temperature sensor fixing substrate 24 seals the joint between the wire fixing strap 25 and the outer balloon 43. Finally, the skirt 27 is tightly bonded to the outer balloon 43 with adhesive. Meanwhile, the wire fixing strap 25 reaches the catheter body 11 along the interlayer and is finally electrically connected to the control device 3 through the electrical interface 7. Thus, before cryoablation, the control device 3 in the balloon ablation system collects the signal fed back from the electrode 20 and judges the degree of contact between the balloon 4 and the target object based on this signal. If the contact is good, cryoablation begins, and the cryoablation device 2 delivers the cryo-medium to the balloon ablation catheter 1. If the contact is not good, the catheter position is readjusted until the balloon 4 and the target object form an effective contact.

[0074] In summary, compared with existing technologies, this invention can determine whether the electrodes are in contact with biological tissue based on the signals fed back from the electrodes on the balloon ablation catheter, thereby assessing the contact status between the balloon and the biological tissue. This method avoids exposure of patients and medical staff to radiation, preventing harm from contrast agents and radiation. It also solves the problem of contrast agent intolerance in some patients, enabling more patients to receive treatment. Furthermore, even in special locations on blood vessels, the signals fed back from the electrodes can determine whether the balloon has formed an effective contact, providing excellent monitoring. Thus, the amount of contrast agents and radiation used can be effectively reduced, increasing the safety of the procedure.

[0075] Furthermore, this invention optimizes the electrode installation method by connecting the wire to the catheter through the interlayer between the inner and outer balloons. This method protects the wire from damage caused by the sheath during use by the outer balloon, enabling the electrode to work stably during normal use, reducing the risk of damage, and increasing the reliability and effectiveness of use.

[0076] Finally, it should be noted that, as discussed in this article, "patient" or "individual" can be a person or any animal. It should be understood that "animal" can be any applicable type, including but not limited to mammals, veterinary animals, livestock, or pets.

[0077] The above description is only a description of the preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the present utility model.

Claims

1. A balloon ablation catheter, characterized in that, The device includes a catheter body, a balloon, several electrodes, and a temperature sensor. The balloon is located at the distal end of the catheter body and consists of an inner balloon and an outer balloon. The electrodes and the temperature sensor are disposed on the outer surface of the outer balloon and are distributed 360° around the axis of the catheter body along the latitude of the balloon. The electrodes can be used for electrocardiogram signal mapping and / or signal capture to determine the contact status between the balloon and the target object. The temperature sensor is used to obtain the actual temperature of the balloon surface and the contact point between the balloon and the tissue. The leads are connected to the electrodes, and all the leads pass through the outer balloon into the space between the inner balloon and the outer balloon, and extend along the space to the catheter body, and then to the proximal end of the catheter body.

2. The balloon ablation catheter of claim 1, wherein, Three or more electrodes and the temperature sensor are distributed 360° along the latitude direction of the balloon. Any two adjacent electrodes along the latitude direction of the balloon are used to capture the signal, and any two adjacent electrodes are set on the same latitude or different latitudes.

3. The balloon ablation catheter of claim 1 or 2, wherein, One or more electrodes and the temperature sensor are disposed along the same meridian on the outer surface of the outer balloon.

4. The balloon ablation catheter of claim 1 or 2, wherein, It also includes a flexible encapsulation structure using a polymer substrate, the flexible encapsulation structure including an electrode and temperature sensor fixing substrate and a wire fixing band, the electrode and temperature sensor fixing substrate being fixed to the outer surface of the outer balloon, the wire fixing band passing through the outer balloon and bending into the interlayer, and extending along the interlayer to the catheter body up to the proximal end of the catheter body, the electrode and temperature sensor being fixed on the electrode and temperature sensor fixing substrate, and the wire being fixed on the wire fixing band.

5. The balloon ablation catheter of claim 4, wherein, The electrode and temperature sensor fixing substrate has a skirt formed at the bend of the wire fixing strip. The skirt covers the joint between the wire fixing strip and the outer balloon, and the skirt is bonded to the outer balloon.

6. The balloon ablation catheter of claim 5, wherein, The electrode and the temperature sensor mounting substrate are bonded to the outer balloon with adhesive. The wire fixing strap passes through the outer balloon and is then sealed with adhesive at the joint between it and the outer balloon.

7. The balloon ablation catheter of claim 4, wherein, Multiple electrodes and temperature sensors are arranged along multiple meridians on the outer surface of the outer balloon. All electrodes, temperature sensors and wires on the same meridian are encapsulated in the same flexible encapsulation structure, and / or all electrodes, temperature sensors and wires on the same latitude are encapsulated in the same flexible encapsulation structure.

8. The balloon ablation catheter of claims 1 or 2, wherein, At least some of the electrodes are also used to release radio frequency energy, pulse energy, or microwave energy, and / or, some of the electrodes are disposed on the distal outer surface of the balloon.

9. The balloon ablation catheter of claims 1 or 2, wherein, The electrodes and temperature sensors are arranged in a spoke-like pattern on the outer surface of the balloon, and each spoke contains a plurality of the electrodes and temperature sensors arranged along the meridian direction of the balloon.

10. A balloon ablation system, comprising: The system includes a main body and a balloon ablation catheter as described in any one of claims 1-9. The main body is connected to the balloon ablation catheter and is used to provide energy to the balloon ablation catheter. It is also used to collect signals captured by the electrodes and then determine the contact status between the balloon and the target object based on the signals.

11. The balloon ablation system of claim 10, wherein, It includes a three-dimensional mapping system, which is connected to several of the electrodes for mapping electrocardiogram signals and displaying the morphology of the balloon.

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