Method for detecting balloon catheter abutment pressure and balloon catheter ablation system

Abstract

The present invention relates to a method for detecting a balloon catheter abutment pressure and a balloon catheter ablation system. The method comprises the following steps: determining, when the balloon catheter in an inflated state abuts against a tissue of interest and is thus axially compressed and / or laterally biased, an axial distance x between a proximal end and a distal end of a balloon body in the balloon catheter and / or an included angle α between an end axis of the proximal end and an end axis of the distal end of the balloon body using a proximal magnetic sensor and a distal magnetic sensor; and acquiring, according to a first corresponding relation between the known axial distance x and an axial abutment pressure of the balloon catheter and / or a second corresponding relation between the known included angle α and a lateral abutment pressure, the actual axial abutment pressure and / or the lateral abutment pressure by mapping of the axial distance x and / or the included angle α. Correspondingly, the balloon body of the balloon electrode assembly can be compressed and deformed in the axial direction and / or compressed and biased in the lateral direction of the balloon catheter. The present invention mainly solves the technical problem of detecting the abutment pressure of a balloon catheter.

Description

Balloon catheter abutment pressure detection method and balloon catheter ablation system Technical Field

[0001] The invention relates to a balloon catheter abutment pressure detection method and a balloon catheter ablation system. Background Art

[0002] Ablation methods used to treat arrhythmias include radiofrequency ablation and pulsed electric field ablation. Pulsed electric field ablation (PFA), as a new technology for the current treatment of atrial fibrillation, refers to the application of a strong electric field in a short period of time to cause cell electroporation. Electroporation leads to cell death and can achieve a larger ablation depth and a larger ablation range. It has been successfully used as a new method for non-thermal ablation of arrhythmic heart tissue. Current research on pulsed electric field ablation is mainly focused on the "one-shot" design direction, that is, forming a ring-shaped injury at one time to achieve rapid isolation of the pulmonary veins. However, the pulmonary vein lesions that cause atrial fibrillation are complex and diverse, either the left common trunk or multiple small opening branches. The one-shot type catheter cannot achieve good ablation isolation at the anatomically variant pulmonary veins. For such situations, point-to-point ablation will be a better solution.

[0003] However, during point-to-point ablation, the balloon catheter relies on the local area of ​​the balloon electrode assembly to contact the tissue. To ensure the ablation effect, feedback on the pressure of the catheter on the tissue is required to guide the doctor in ablation. If the pulsed electric field ablation catheter uses a strain gauge pressure sensor to detect the contact pressure, it will occupy the proximal space of the catheter. However, for balloon catheters, since a filling tube is required to perfuse the balloon, there is no space for a strain gauge pressure sensor. In addition, the addition of an additional pressure sensor will increase the cost of the device and increase the financial burden on patients.

[0004] Summary of the Invention

[0005] The present invention provides a method for detecting the abutment pressure of a balloon catheter and an ablation system, which mainly solve the technical problem of detecting the abutment pressure of a balloon catheter.

[0006] In a first aspect, the present invention provides a method for detecting the abutment pressure of a balloon catheter.

[0007] A method for detecting the pressure of a balloon catheter comprises the following steps:

[0008] When the balloon catheter in a filled state is pressed against the tissue to be ablated and undergoes axial compression and / or lateral deflection, the axial distance x between the proximal end and the distal end of the balloon body in the balloon catheter and / or the angle α between the end axis of the proximal end and the end axis of the distal end of the balloon body are detected by means of a proximal magnetic sensor and a distal magnetic sensor; the proximal magnetic sensor is a magnetic positioning sensor provided at the proximal end of the balloon body of the balloon catheter, and the distal magnetic sensor is a magnetic positioning sensor provided at the distal end of the balloon body of the balloon catheter;

[0009] According to the first correspondence between the known axial spacing x and the axial abutment pressure of the balloon catheter, and / or the second correspondence between the known angle α and the lateral abutment pressure of the balloon catheter, the actual axial abutment pressure and / or lateral abutment pressure are obtained by mapping the axial spacing x and / or angle α.

[0010] In a technical solution, the first corresponding relationship is determined by a fitting formula, and / or the second corresponding relationship is determined by a fitting formula.

[0011] In one technical solution, the first corresponding relationship and / or the second corresponding relationship is determined by an average value of two or more groups of experimental data.

[0012] In one technical solution, the method further includes detecting the filling pressure of the balloon catheter, and selecting the first corresponding relationship and / or the second corresponding relationship according to different filling pressures.

[0013] In one technical solution, the filling pressure is 1±0.2 psi.

[0014] In one technical solution, the balloon catheter is inflated with liquid.

[0015] In a second aspect, the present invention provides a balloon catheter ablation system.

[0016] A balloon catheter ablation system, comprising:

[0017] A balloon catheter, comprising a tube body and a balloon electrode assembly, wherein the balloon electrode assembly is fixed at the distal end of the tube body, and the balloon electrode assembly includes a capsule body, wherein the capsule body can be deformed by compression in the axial direction of the balloon catheter and / or deflected by compression in the lateral direction of the balloon catheter; a proximal magnetic sensor is provided at the proximal end of the capsule body, and a distal magnetic sensor is provided at the distal end of the capsule body; when the capsule body is deformed by compression in the axial direction and / or deflected by compression in the lateral direction, the distal magnetic sensor can move with the distal end of the capsule body relative to the proximal magnetic sensor;

[0018] And a processing device, which is used to detect the axial distance x between the proximal end and the distal end of the balloon and / or the angle α between the end axis of the proximal end and the end axis of the distal end of the balloon based on the relative movement of the proximal magnetic sensor and the distal magnetic sensor, and according to a first correspondence between the known axial distance x and the axial abutment pressure of the balloon catheter, and / or a second correspondence between the known angle α and the lateral abutment pressure of the balloon catheter, obtain the actual axial abutment pressure and / or lateral abutment pressure by mapping the axial distance x and / or the angle α.

[0019] In one technical solution, the axis of the proximal magnetic sensor coincides with the end axis of the proximal end of the capsule.

[0020] In one technical solution, the proximal magnetic sensor is coaxially fixed to the distal end of the tube body.

[0021] In one technical solution, the proximal magnetic sensor is provided with an avoidance through-hole extending axially through the tube body, and the balloon catheter includes a filling tube for supplying filling fluid into and out of the balloon body, and the filling tube passes through the avoidance through-hole.

[0022] In one technical solution, the distal magnetic sensor includes a signal line, and the signal line passes through the avoidance through-hole or the filling tube.

[0023] In one technical solution, the axis of the distal magnetic sensor coincides with the axis of the distal end of the balloon body. When the balloon catheter is in a free state, the axis of the distal magnetic sensor coincides with the axis of the tube body.

[0024] In one technical solution, the distal magnetic sensor includes a signal line, which is a flexible line that can bend with the compression deformation and / or deflection of the capsule.

[0025] In one technical solution, a cable sheath is provided on the outside of the signal line, and an end of the cable sheath is sealed and connected to the remote magnetic sensor.

[0026] In a technical solution, a hydraulic sensor for detecting the filling pressure of the bladder is further included, and the hydraulic sensor is connected to the processing device.

[0027] In one technical solution, it also includes a handle, which is connected to the proximal end of the tube body; the inner cavity of the balloon is connected to the handle through a filling tube, the hydraulic sensor is arranged in the handle, and the hydraulic sensor is connected to the filling tube.

[0028] Beneficial effects of the present invention:

[0029] According to the above-mentioned balloon catheter abutment pressure detection method, the axial distance x between the proximal and distal ends of the balloon in the balloon catheter and / or the angle α between the end axis of the proximal end and the end axis of the distal end of the balloon can be detected by the proximal magnetic sensor and the distal magnetic sensor. At the same time, relying on the first correspondence between the axial distance x and the axial abutment pressure of the balloon catheter obtained in advance, and / or the second correspondence between the known angle α and the lateral abutment pressure of the balloon catheter, the actual axial abutment pressure and / or lateral abutment pressure value can be obtained by mapping the axial distance x and / or angle α, so that the magnetic positioning sensor that can realize the spatial position detection function of the balloon catheter can be shared, and there is no need to set up an additional sensor for detecting the abutment pressure, which also does not require additional space and increased costs.

[0030] According to the above-mentioned balloon catheter ablation system, the compliant balloon used in the balloon catheter has the characteristics of being able to deform under axial pressure along the balloon catheter and / or deflect under lateral pressure along the balloon catheter. This characteristic can cooperate with the proximal magnetic sensor and the distal magnetic sensor to produce changes in the axial spacing x and / or angle α. At the same time, the first corresponding relationship and the second corresponding relationship pre-acquired by the processing device can realize the detection of the corresponding abutment pressure, without the need to additionally set up a sensor for detecting the abutment pressure, and thus does not require additional space and increase costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1 is a perspective view of a balloon electrode assembly in one embodiment of a balloon catheter ablation system;

[0032] FIG2 is a front view of the balloon electrode assembly in FIG1 ;

[0033] FIG3 is a schematic diagram of the internal structure of the balloon electrode assembly in FIG1 ;

[0034] FIG4 is a schematic diagram of the balloon electrode assembly when it is deformed under axial compression;

[0035] FIG5 is a fitting curve diagram of the axial distance x between the proximal end and the distal end and the axial contact pressure under different filling pressures;

[0036] FIG6 is a schematic diagram of the balloon electrode assembly when it is deflected by lateral pressure along the balloon catheter;

[0037] FIG7 is a fitting curve diagram of the angle α between the end axis of the proximal end and the end axis of the distal end of the balloon and the lateral abutment pressure under different filling pressures;

[0038] FIG8 is a flowchart of abutment pressure detection in one embodiment.

[0039] List of feature names corresponding to the reference numerals in the figures:

[0040] 10. Capsule; 11. Proximal end; 12. Distal end; 13. Equatorial position;

[0041] 20. Insulating substrate; 21. First electrode sheet; 22. Second electrode sheet;

[0042] 31. First stitch; 32. Second stitch;

[0043] 40. Distal electrode;

[0044] 50. Tube body; 51. Filling tube;

[0045] 61. Proximal magnetic sensor; 62. Distal magnetic sensor; 63. Sensor protective cover; 64. Signal line; 65. Cable sheath; 66. Avoidance through hole;

[0046] 70. Heart. DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0048] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0049] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0050] The terms "proximal" and "distal" used below are commonly used in the medical field. For an instrument being operated, the proximal end is the end closest to the operator, while the distal end is the end farther from the operator. For example, in the case of an ablation catheter, the balloon electrode assembly is connected to the distal end of the catheter.

[0051] The present invention provides a balloon catheter abutment pressure detection method and a balloon catheter ablation system, which utilizes the "compliance" of the balloon catheter, that is, its deformability, and detects the axial spacing x between the proximal and distal ends of the balloon and / or the angle α between the end axis of the proximal end and the end axis of the distal end of the balloon through a proximal magnetic sensor and a distal magnetic sensor. The actual axial abutment pressure and / or lateral abutment pressure are calculated based on a first correspondence between the known axial spacing x and the axial abutment pressure of the balloon catheter, and / or a second correspondence between the known angle α and the lateral abutment pressure of the balloon catheter. This avoids the problem of large space occupation and high cost of directly using strain gauge pressure sensors to detect abutment pressure in the prior art, so that a balloon-shaped ablation catheter with a filling tube can realize abutment pressure detection, thereby meeting the needs of guiding doctors to perform ablation operations, and further relying on the novel balloon pulse electric field ablation catheter to achieve more efficient point-to-point ablation, thereby improving surgical efficiency and quality.

[0052] Embodiments of the balloon catheter ablation system of the present invention:

[0053] The balloon catheter ablation system includes a balloon catheter, a handle, and a processing device. Referring to Figures 1 to 3 , the balloon catheter includes a tube body 50 and a balloon electrode assembly. The tube body 50 is used to be inserted into the site to be ablated. The balloon electrode assembly is fixed to the distal end of the tube body 50. The balloon electrode assembly includes a capsule 10, an electrode sheet fixed to the surface of the capsule 10, a proximal magnetic sensor 61 disposed at the proximal end 11 of the capsule 10, and a distal magnetic sensor 62 disposed at the distal end 12 of the capsule 10. The capsule 10 is compliant and can be deformed by compression along the axial direction of the balloon catheter and / or deflected by compression along the lateral direction of the balloon catheter. The electrode sheet is used to generate a pulsed electric field to release ablation energy. The handle (not shown in the figure) is a common component of the ablation catheter and is connected to the proximal end 11 of the tube body 50. It is used to control the movement of the balloon catheter, such as to achieve the extension and bending of the tube body 50, and can be held by the operator to perform corresponding operations. The processing device is connected to the balloon electrode assembly and can receive corresponding detection signals. It detects the axial distance x between the proximal end 11 and the distal end 12 of the balloon 10 and / or the angle α between the end axis of the proximal end 11 and the distal end 12 of the balloon 10 according to the relative movement of the proximal magnetic sensor 61 and the distal magnetic sensor 62, and obtains the actual axial abutment pressure and / or lateral abutment pressure by mapping the axial distance x and / or the angle α according to the first corresponding relationship between the known axial distance x and the axial abutment pressure of the balloon catheter, and / or the second corresponding relationship between the known angle α and the lateral abutment pressure of the balloon catheter.

[0054] It should be noted that the balloon catheter ablation system may include an ablation host, which has a display module, an energy module for supplying power to the balloon catheter, a control module for controlling the operation of the balloon catheter, and the like, and may include the aforementioned processing device. Of course, in some other embodiments, the aforementioned processing device may exist independently of the ablation host and be used only to detect the contact pressure of the balloon catheter. In addition, since the magnetic positioning sensor is already a component of many existing three-dimensional mapping systems, the three-dimensional mapping system can also be used as a processing device to connect the magnetic positioning sensor to complete the detection process. For the balloon electrode assembly, in one embodiment, the electrode sheets on the surface of the balloon body 10 are configured to include a first electrode sheet 21 biased at the proximal side and a second electrode sheet 22 biased at the distal side. Since the first electrode sheet 21 and the second electrode sheet 22 are biased along the axial direction of the balloon body 10 and arranged crosswise along the circumference, when ablation is performed, according to the different postures of the balloon electrode assembly, the first electrode sheet 21 and the second electrode sheet 22 can be ablated separately, or can be ablated simultaneously by relying on the first electrode sheet 21 and the second electrode sheet 22 when the equatorial position 13 of the balloon electrode assembly is close to the target tissue, thereby obtaining a larger ablation range. In combination with a pulsed electric field ablation method with a larger ablation depth, a larger ablation lesion can be obtained, which is conducive to improving surgical efficiency. Specifically, the electrode sheet includes at least one first electrode sheet 21 and at least one second electrode sheet 22, the first electrode sheet 21 is biased towards the proximal side of the capsule 10, and the second electrode sheet 22 is biased towards the distal side of the capsule 10; the first electrode sheet 21 and the second electrode sheet 22 are staggered along the circumference of the capsule 10, and the circumference of the capsule 10 is the direction of the line surrounding the proximal end 11 and the distal end 12.

[0055] The balloon 10 can be filled with gas to achieve expansion, or it can be filled with liquid to achieve expansion, which is not limited in the present invention. In addition, the balloon 10 can be expanded and collapsed in an existing manner. For example, the corresponding channel in the tube body 50 can be used to transport gas or liquid to achieve expansion. Please refer to Figure 3. The corresponding channel in the tube body 50 is the filling tube 51. The filling tube 51 can supply filling fluid to and from the balloon 10. The filling fluid can be physiological saline. It should be noted that the shape of the balloon 10 after expansion is spherical. The spherical shape in the present invention can refer to a standard sphere or other similar spherical shapes, such as an ellipsoid.

[0056] In a specific embodiment, the compliant material selected for the balloon 10 may be, for example, TPU or PEBAX. It should be noted that the lateral pressure deflection along the balloon catheter is not limited to being compressed in a direction perpendicular to the axis of the balloon catheter, but may also be compressed at a certain angle to the axis of the balloon catheter, and may correspond to a position on the side of the balloon 10 deflected toward the proximal end 11 or the distal end 12. Relying on the compliant balloon material, the distal magnetic sensor 62 can form a free structure. When the balloon 10 is compressed and deformed in the axial direction and / or deflected in the lateral direction, the distal magnetic sensor 62 can move with the distal end 12 of the balloon 10 relative to the proximal magnetic sensor 61.

[0057] Unlike radiofrequency ablation, which relies on heat conduction, pulsed electric field ablation relies on pulsed electric fields. The electrode sheets fixed to the surface of the balloon body 10 of the balloon electrode assembly are used to generate the electric field. The electrode sheets can be mounted on an insulating substrate 20 to form a flexible circuit, which is then fixed to the balloon body 10. To lead out the circuit of the electrode sheets, the flexible circuit can contain metal conductors for conducting electrical energy, and the metal conductors form traces with the corresponding insulating substrate 20. In one embodiment, the balloon body 10 of the balloon electrode assembly is a small balloon body 10 with a diameter of 12 mm, and six bean sprout-shaped flexible circuits are attached to the surface of the balloon body 10.

[0058] In one embodiment, referring to Figures 1 and 2 , the first electrode sheet 21 is offset from the proximal side of the capsule 10, and the second electrode sheet 22 is offset from the distal side of the capsule 10. It should be noted that the aforementioned description of being offset from the proximal side is not intended to limit the corresponding electrode sheet to being completely located within the hemispherical range of the capsule 10 near the proximal end 11. For example, the corresponding electrode sheet may be partially located within the hemispherical range of the capsule 10 near the proximal end 11 and partially located within the hemispherical range of the capsule 10 near the distal end 12. However, overall, the overall position of the electrode sheet is offset from the hemispherical boundary of the capsule 10. The description of being offset from the distal side has a similar explanation and will not be further elaborated here.

[0059] The above-mentioned hemispherical dividing line can be considered as the equatorial position 13 of the capsule 10, that is, the position where the radial dimension of the capsule 10 is the largest in the expanded state, and this position surrounds the capsule 10 circumferentially. In one embodiment, referring to Figures 1 and 2, the side of the first electrode sheet 21 close to the distal end 12 does not exceed the equatorial position 13, and the side of the second electrode sheet 22 close to the proximal end 11 does not exceed the equatorial position 13. In summary, in one embodiment, there is no overlapping portion between the first electrode sheet 21 and the second electrode sheet 22 in the axial direction of the capsule 10. The above-mentioned structure can ensure that when the capsule 10 is ablated in a posture axially inclined to the surface of the tissue to be ablated, the first electrode sheet 21 or the second electrode sheet 22 on the side close to the tissue has a larger ablation range, thereby achieving a larger ablation surface area. Of course, in other embodiments, the first electrode sheet 21 and the second electrode sheet 22 may also have an overlapping portion along the axial direction of the capsule 10 along the circumference of the capsule 10. For example, the side of the first electrode sheet 21 close to the distal end 12 passes the equatorial position 13, and the side of the second electrode sheet 22 close to the proximal end 11 is flush with the equatorial position 13 or has a gap with the equatorial position 13. For another example, the side of the first electrode sheet 21 close to the distal end 12 is flush with the equatorial position 13 or has a gap with the equatorial position 13, and the side of the second electrode sheet 22 close to the proximal end 11 passes the equatorial position 13.

[0060] In order to further expand the ablation range, the width dimension of the first electrode sheet 21 has an increasing feature from the proximal end 11 to the distal end 12, and the width dimension of the second electrode sheet 22 has an increasing feature from the distal end 12 to the proximal end 11. The increasing feature here does not mean that the first electrode sheet 21 as a whole must be small at one end and large at the other end and gradually changes between the two ends. It is also possible that only part of the area presents a change in width dimension. Please refer to Figure 2. In one embodiment, the edge of the first electrode sheet 21 at one end away from the proximal end 11 and the edge of the end close to the proximal end 11 are arc-shaped, and the edge of the second electrode sheet 22 at one end away from the distal end 12 and the edge of the end close to the distal end 12 are arc-shaped. At the same time, the arc edges at both ends of the first electrode sheet 21 and the second electrode sheet 22 are inclined straight edges, and the width dimension gradually changes. The above-mentioned width dimension change is beneficial to the electric field distribution and is also conducive to achieving a larger ablation range.

[0061] In one embodiment, at least two first electrode sheets 21 and second electrode sheets 22 are provided; in the circumferential direction, a second electrode sheet 22 is provided in the middle of two adjacent first electrode sheets 21, and a first electrode sheet 21 is provided in the middle of two adjacent second electrode sheets 22. The above-mentioned first electrode sheets 21 and second electrode sheets 22 form a cross-arrangement structure. Please refer to Figures 3 and 4. In one embodiment, three first electrode sheets 21 and three second electrode sheets 22 are provided. It should be noted that the number of electrode sheets can be determined based on factors such as the diameter of the capsule 10, the ablation requirements, and the area of ​​each electrode sheet. The first electrode sheet 21 can have the same shape as the second electrode sheet 22, as shown in Figures 2 to 5, or it can have a different shape from the second electrode sheet 22. In addition, at least two first electrode sheets 21 can have different shapes, and / or at least two second electrode sheets 22 can have different shapes.

[0062] Based on the cross-arrangement structure of the first electrode sheet 21 and the second electrode sheet 22, in one embodiment, the balloon electrode assembly includes a first trace 31 and a second trace 32, the first trace 31 is connected to the first electrode sheet 21, the second trace 32 is connected to the second electrode sheet 22, and at least a portion of the second trace 32 is circumferentially arranged side by side with the first electrode sheet 21. The above-mentioned trace arrangement facilitates the transmission of electrical energy to the second electrode sheet 22 and has a beautiful appearance. Preferably, the first trace 31 and the first electrode sheet 21 can be arranged in the center, and the second trace 32 and the second electrode sheet 22 can be arranged in the center. The proximal end 11 of the trace can be led to the handle of the ablation catheter by a wire via the tube body 50 of the ablation catheter.

[0063] When the balloon electrode assembly performs an ablation operation, if the long axis of the ablation catheter is used as the axial direction and the surface of the tissue to be ablated is regarded as an ideal plane, the mode in which the balloon electrode assembly of the ablation catheter is attached to the tissue can be simplified to three forms, namely, the axial direction is perpendicular to the plane, the axial direction is inclined to the plane, and the axial direction is parallel to the plane. In a typical embodiment, the axial direction and the plane can be 90°, 45°, and 0°, respectively. In order to enable the electrode sheet to contact the tissue as much as possible in different modes, in one embodiment, the distal end 12 of the capsule 10 does not protrude from the spherical surface corresponding to the capsule 10, that is, the distal end 12 of the capsule 10 is not provided with a structure protruding from its smooth contour, so that there will be no problem of the protrusion of the distal end 12 of the capsule 10 affecting the posture of the balloon electrode assembly.

[0064] In one embodiment, to achieve more ablation functions, the electrode sheet includes a distal electrode 40 disposed at the distal end 12 of the capsule 10. The distal electrode 40 forms a distal cover that can close the opening formed at the distal end 12 of the capsule 10 after the capsule 10 is formed. The distal cover can be made of a metal electrode to form the distal electrode 40, which is electrically connected via a separate lead that can pass through the interior of the capsule 10. Specifically, the distal electrode 40 can be made of 316 stainless steel or a platinum-iridium alloy. Of course, in other embodiments, the distal end 12 of the capsule 10 can also be set as an insulating structure, for example, it can be sealed using epoxy resin or other plastic injection molding.

[0065] In order to prevent the distal electrode 40 from forming a protruding structure at the distal end 12 of the capsule 10 , further, in one embodiment, referring to FIG. 3 , the distal end 12 of the capsule 10 is provided with a concave structure, and the distal electrode 40 is disposed in the concave structure.

[0066] When the balloon electrode assembly is in operation, it is connected to the distal end 12 of the catheter and inserted into the body through the sheath. For localized areas requiring ablation, the balloon electrode assembly's posture can be adjusted by controlling the curvature of the catheter, allowing the assembly to contact the tissue at varying angles. Pulsed electric field ablation is then performed using the corresponding electrode pads. Because the balloon electrode assembly of the present invention can achieve a larger ablation range and depth, it is beneficial for reducing the number of ablation lesions on the heart 70, thereby improving surgical efficiency, reducing patient pain, and lowering the surgical workload for the surgeon.

[0067] The above content mainly introduces the structure of the balloon electrode assembly for achieving pulse ablation. The following will focus on how to detect the contact pressure of the balloon electrode assembly.

[0068] First, regarding the proximal magnetic sensor 61 and distal magnetic sensor 62 that implement contact pressure detection, those skilled in the art will recognize that these sensors, as magnetic positioning sensors, are commonly used positioning devices in catheter systems. These magnetic positioning sensors can be coils that, when in use, can be placed in a corresponding magnetic field space. The magnetic positioning system uses the magnetic field conditions sensed by the magnetic positioning sensors at different positions to determine the position of each magnetic positioning sensor within the magnetic field space according to a corresponding algorithm, with a position resolution generally reaching 0.5-1.0 mm. Since positioning using magnetic positioning sensors can utilize existing technologies, a detailed description thereof will not be provided here.

[0069] In a specific embodiment, the proximal magnetic sensor 61 adopts a 5DOF magnetic positioning sensor already available in the art, while the distal magnetic sensor 62 adopts a 6DOF magnetic positioning sensor already available in the art. In essence, the 6DOF magnetic positioning sensor can be formed by packaging two 5DOF magnetic positioning sensors at a certain angle (for example, 15°). Compared with the 5DOF magnetic positioning sensor, the 6DOF magnetic positioning sensor can also output the original angle information. The original angle information is not necessary for the present invention. In some other embodiments, according to the detection requirements, the proximal magnetic sensor 61 and the distal magnetic sensor 62 can both adopt 5DOF magnetic positioning sensors, or other forms of magnetic positioning sensors that can detect the axial spacing x between the proximal end 11 and the distal end 12 of the capsule 10 and / or the angle α between the end axis of the proximal end 11 of the capsule 10 and the end axis of the distal end 12.

[0070] In one embodiment, for ease of calculation, the axis of the distal magnetic sensor 62 coincides with the axis of the distal end 12 of the balloon 10. When the balloon catheter is in a free state, the axis of the distal magnetic sensor 62 coincides with the axis of the tubular body 50. In a specific embodiment, the distal magnetic sensor 62 is a solid cylinder with typical dimensions of 1.8 x 9.0 mm. It can be fixed inside the distal end cap of the balloon 10 and is coaxial with the axis of the distal end 12 of the balloon 10. Because the balloon 10 may need to be filled with liquid, a sensor protective cover 63 is provided on the outside of the distal magnetic sensor 62 to protect it. The sensor protective cover 63 completely surrounds the distal magnetic sensor 62.

[0071] In one embodiment, the distal magnetic sensor 62 includes a signal line 64, which is a flexible line that can bend with the compression deformation and / or deflection of the capsule 10. In order to protect the signal line 64 of the distal magnetic sensor 62, a cable sheath 65 can be provided on the outside of the signal line 64, and the end of the cable sheath 65 is sealed and connected to the distal magnetic sensor 62. Specifically, it can be wrapped and sealed by the sensor protection cover 63. The signal line 64 and the cable sheath 65 can both be made of flexible materials, so that the movement of the distal magnetic sensor 62 is not restricted by the signal line 64 and the cable sheath 65. Of course, in other embodiments, the distal magnetic sensor 62 can adopt a wireless signal transmission form, and the proximal magnetic sensor 61 can also adopt a wireless signal transmission form. In this case, there is no need to set the signal line 64.

[0072] Similar to the distal magnetic sensor 62, for ease of calculation, the axis of the proximal magnetic sensor 61 coincides with the axis of the proximal end 11 of the capsule 10. Furthermore, in one specific embodiment, the proximal magnetic sensor 61 is coaxially fixed to the distal end of the tube 50, which can save space within the capsule 10 and facilitate the stable placement of the proximal magnetic sensor 61. Of course, in some other embodiments, the proximal magnetic sensor 61 can also be at least partially fixed to the capsule 10, in which case it can also be located at the proximal end of the capsule 10.

[0073] In one embodiment, since the filling tube 51 must be connected to the inner cavity of the balloon body 10 to achieve expansion and collapse of the balloon body 10, to facilitate the arrangement of the filling tube 51, please refer to Figure 3. The proximal magnetic sensor 61 is a hollow cylindrical coil. The hollow structure forms an escape hole 66 on the proximal magnetic sensor 61 that extends axially through the tube body 50. The escape hole 66 is coaxial with the tube body 50, and the filling tube 51 of the balloon catheter passes through the escape hole 66. Please refer to Figure 3. The distal end 12 of the filling tube 51 is located at the proximal end 11 of the balloon body 10, and can only allow the filling fluid to enter and exit the balloon body 10. In other embodiments, the escape hole 66 can also be offset to one side of the radial direction of the tube body 50.

[0074] In one embodiment, the proximal magnetic sensor 62 may also be a miniature solid cylindrical sensor with a typical size of 0.45×6.3 mm.

[0075] 3 , the signal line 64 of the distal magnetic sensor 62 is arranged side by side with the filling tube 51 and can pass through the avoidance hole 66. In some other embodiments, the signal line 64 can also pass through the inside of the filling tube 51.

[0076] The main influencing factor of the pressure numerical fitting also includes the initial hydraulic pressure in the balloon 10. Therefore, in one embodiment, the balloon catheter ablation system further includes a hydraulic pressure sensor, which is connected to the processing device.

[0077] Due to the limited space within the balloon 10, in one embodiment, a handle is connected to the proximal end 11 of the tube 50, the inner cavity of the balloon 10 is connected to the handle via a filling tube 51, and a hydraulic sensor is disposed within the handle and connected to the filling tube 51. Of course, in some other embodiments, the hydraulic sensor may also be placed within the balloon 10.

[0078] Based on the structure of the above-mentioned balloon catheter, a method for detecting the contact pressure of the balloon catheter will be introduced below.

[0079] In summary, before performing the actual balloon catheter rest pressure test, a first correspondence between the axial spacing x and the axial rest pressure of the balloon catheter, and / or a second correspondence between the known angle α and the lateral rest pressure of the balloon catheter is first obtained through experiments. Among them, the axial spacing x and the angle α can be obtained by the magnetic positioning system through the proximal magnetic sensor 61 and the distal magnetic sensor 62, and the axial rest pressure and the lateral rest pressure can be detected by sensors, for example, temporarily arranging sensors on the tissue to be ablated, and temporarily arranging sensors on the balloon body 10, both of which can obtain the axial rest pressure and / or lateral rest pressure values. In one embodiment, in order to improve data accuracy, the first correspondence is determined by the average value of two or more sets of experimental data, and / or the second correspondence is also determined by the average value of two or more sets of experimental data, corresponding to the different samples in the table below.

[0080] For example, in the first correspondence between the axial spacing x and the axial contact pressure of the balloon catheter, the initial axial spacing x is 4.0 mm. When the balloon catheter is perpendicularly applied to the tissue, the spacing x between the two magnetic positioning sensors is compressed and reduced. By applying a series of axial contact pressures, the fitting relationship between the spacing reduction and the axial contact pressure is obtained, as shown in Table 1 and Figure 5. Of course, the axial contact pressure gradient and the number of samples during the experiment can be increased or decreased based on the required accuracy.

[0081] It should be noted that the fitting curve will be affected by the initial filling pressure. When the initial filling pressure is high, for example, 5psi, the balloon 10 requires a greater force to produce strain, and when the initial filling pressure is low, for example, 0.5psi, the balloon requires a smaller force to produce strain. When detecting the actual balloon catheter contact pressure, the corresponding fitting relationship can be selected according to the actual filling pressure. In a specific embodiment, the filling pressure is 1±0.2psi. In addition, the filling agent used to fill the balloon 10 can be a gas or a liquid. Since the gas is more compressed, the pressure required for strain can be smaller. The filling medium used in this experiment is liquid, and the filling pressure is divided into 0.5psi, 1psi, and 5psi. The corresponding experimental data are shown in Table 1 below.

[0082] Table 1

[0083] Regarding the second correspondence between angle α and the lateral contact pressure of the balloon catheter, for example, if the initial angle α is 0°, when the balloon catheter is laterally contacted with tissue, the angle α between the axis of the proximal end 11 of the balloon body 10 and the axis of the distal end 12, that is, the angle α between the two magnetic positioning sensors, increases. By applying a series of lateral contact pressures, a fitting relationship between the increase in angle α and the lateral contact pressure can be obtained, as shown in Table 2 and Figure 7. Of course, the lateral contact pressure change gradient and the number of samples during the experiment can be increased or decreased based on the accuracy requirements.

[0084] Table 2

[0085] Based on the data in Tables 1 and 2, fitting curves as shown in Figures 5 and 7 are obtained, and a fitting formula can be generated simultaneously. The fitting curve and fitting formula are stored in a processing device, such as a balloon catheter ablation system, an independent processing device, and / or a three-dimensional mapping system. Those skilled in the art will appreciate that the fitting curve and fitting formula can be generated by the system based on experimental data.

[0086] When actually detecting the abutment pressure, the balloon catheter ablation system can obviously feed back the actual axial abutment pressure and / or lateral abutment pressure to the doctor by tracking the change in the axial spacing x and / or the change in the angle α, combined with the fitting formula.

[0087] Embodiments of the balloon catheter abutment pressure detection method of the present invention:

[0088] Referring to FIG8 , the method for detecting the pressure of a balloon catheter includes the following steps:

[0089] An ablation catheter is introduced into the heart;

[0090] Inflate the bladder and detect the filling pressure;

[0091] When the inflated balloon catheter is pressed against the tissue to be ablated and undergoes axial compression and / or lateral deflection, the axial distance x between the proximal end 11 and the distal end 12 of the balloon body 10 in the balloon catheter and / or the angle α between the end axis of the proximal end 11 and the end axis of the distal end 12 of the balloon body 10 are detected by the proximal magnetic sensor 61 and the distal magnetic sensor 62; the proximal magnetic sensor 61 is a magnetic positioning sensor provided at the proximal end 11 of the balloon body 10 of the balloon catheter, and the distal magnetic sensor 62 is a magnetic positioning sensor provided at the distal end 12 of the balloon body 10 of the balloon catheter;

[0092] According to the first correspondence between the known axial spacing x and the axial abutment pressure of the balloon catheter, and / or the second correspondence between the known angle α and the lateral abutment pressure of the balloon catheter, the actual axial abutment pressure and / or lateral abutment pressure are obtained by mapping the axial spacing x and / or the angle α.

[0093] It should be noted that the above-mentioned "balloon catheter in a filled state" refers to a catheter that meets the set ablation requirements, and does not limit the filling degree of the balloon catheter's balloon body 10. For example, filling pressures of 0.5psi, 1psi, and 5psi can correspond to different filling degrees.

[0094] In some other embodiments, the axial abutment pressure can be determined solely by detecting the axial spacing x, or the lateral abutment pressure can be determined solely by detecting the angle α. If the balloon volume is fixed and the given filling agent is also a specific volume, the initial filling pressure is a fixed value, and the step of detecting the initial pressure within the balloon can be omitted, and the abutment pressure can be directly detected. Of course, in this case, the system should also match the corresponding initial pressure to map the abutment pressure of the agent.

[0095] In some other embodiments, corresponding to different embodiments of the above-mentioned balloon catheter ablation system, there may also be corresponding balloon catheter abutment pressure detection methods, for example, using different filling pressures or using different filling media.

[0096] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A method for detecting the pressure of a balloon catheter, characterized in that: The following steps are involved: When the balloon catheter in a filled state is pressed against the tissue to be ablated and undergoes axial compression and / or lateral deflection, the axial distance x between the proximal end and the distal end of the balloon body in the balloon catheter and / or the angle α between the end axis of the proximal end and the end axis of the distal end of the balloon body are detected by means of a proximal magnetic sensor and a distal magnetic sensor; the proximal magnetic sensor is a magnetic positioning sensor disposed at the proximal end of the balloon body of the balloon catheter, and the distal magnetic sensor is a magnetic positioning sensor disposed at the distal end of the balloon body of the balloon catheter; According to the first corresponding relationship between the known axial spacing x and the axial abutment pressure of the balloon catheter, and / or the second corresponding relationship between the known angle α and the lateral abutment pressure of the balloon catheter, the actual axial abutment pressure and / or lateral abutment pressure are obtained by mapping the axial spacing x and / or angle α.

2. The method for detecting the abutment pressure of a balloon catheter as claimed in claim 1, characterized in that: The first corresponding relationship is determined by a fitting formula, and / or the second corresponding relationship is determined by a fitting formula.

3. The method for detecting the abutment pressure of a balloon catheter according to claim 1 or 2, characterized in that: The first corresponding relationship and / or the second corresponding relationship is determined by an average value of more than two groups of experimental data.

4. The method for detecting the abutment pressure of a balloon catheter according to claim 1 or 2, characterized in that: The method further includes the step of detecting the filling pressure of the balloon catheter, and selecting the first corresponding relationship and / or the second corresponding relationship according to different filling pressures.

5. The method for detecting the abutment pressure of a balloon catheter as claimed in claim 4, characterized in that: The filling pressure is 1 ± 0.2 psi.

6. The method for detecting the abutment pressure of a balloon catheter according to claim 1 or 2, characterized in that: The balloon catheter is inflated with fluid.

7. A balloon catheter ablation system, characterized in that: include: A balloon catheter, the balloon catheter comprising a tube body and a balloon electrode assembly, the balloon electrode assembly being fixed at the distal end of the tube body, the balloon electrode assembly comprising a capsule body, the capsule body being compressively deformed along the axial direction of the balloon catheter and / or being deflected by compressive force along the lateral direction of the balloon catheter; a proximal magnetic sensor is provided at the proximal end of the capsule body, and a distal magnetic sensor is provided at the distal end of the capsule body, and when the capsule body is compressively deformed along the axial direction and / or is deflected by compressive force along the lateral direction, the distal magnetic sensor can move with the distal end of the capsule body relative to the proximal magnetic sensor; and a processing device, the processing device is used to detect the axial distance x between the proximal end and the distal end of the capsule and / or the end axis of the proximal end of the capsule according to the relative movement of the proximal magnetic sensor and the distal magnetic sensor. The actual axial abutment pressure and / or lateral abutment pressure are obtained by mapping the axial spacing x and / or the angle α with the axis of the distal end, and based on a first corresponding relationship between the known axial spacing x and the axial abutment pressure of the balloon catheter, and / or a second corresponding relationship between the known angle α and the lateral abutment pressure of the balloon catheter.

8. The balloon catheter ablation system according to claim 7, characterized in that: The axis of the proximal magnetic sensor coincides with the end axis of the proximal end of the capsule.

9. The balloon catheter ablation system according to claim 8, characterized in that: The proximal magnetic sensor is coaxially fixed to the distal end of the tube body.

10. The balloon catheter ablation system according to claim 8, characterized in that: The proximal magnetic sensor is provided with an avoidance through hole which penetrates the tube body axially, and the balloon catheter comprises a filling tube for filling fluid to enter and exit the balloon body, and the filling tube passes through the avoidance through hole.

11. The balloon catheter ablation system according to claim 10, characterized in that: The distal magnetic sensor includes a signal line, and the signal line passes through the avoidance through hole or the filling tube.

12. The balloon catheter ablation system according to claim 7, characterized in that: The axis of the distal magnetic sensor coincides with the axis of the distal end of the balloon body. When the balloon catheter is in a free state, the axis of the distal magnetic sensor coincides with the axis of the tube body.

13. The balloon catheter ablation system according to any one of claims 7 to 12, characterized in that: The remote magnetic sensor includes a signal line, which is a flexible line that can be bent along with the compression deformation and / or deflection of the capsule.

14. The balloon catheter ablation system according to claim 13, characterized in that: A cable sheath is arranged outside the signal line, and an end of the cable sheath is sealed and connected to the remote magnetic sensor.

15. The balloon catheter ablation system according to any one of claims 7 to 12, characterized in that: It also includes a hydraulic sensor for detecting the filling pressure of the bladder, and the hydraulic sensor is connected to the processing device.

16. The balloon catheter ablation system according to claim 15, characterized in that: It also includes a handle, which is connected to the proximal end of the tube body; the inner cavity of the balloon body is connected to the handle through a filling tube, the hydraulic sensor is arranged in the handle, and the hydraulic sensor is connected to the filling tube.

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