Balloon-type electrode catheter, balloon-type electrode assembly, and flexible circuit for balloon-type electrode assembly

Abstract

The present invention relates to a balloon-type electrode catheter, and more particularly to a flexible circuit for a balloon-type electrode assembly in a balloon-type electrode catheter. The flexible circuit includes an insulating substrate attached to the balloon body of the balloon-type electrode assembly and adapted to change its degree of bending in response to the expansion and contraction of the balloon body; a plurality of electrode pads fixed on the insulating substrate for generating a pulsed electric field; and wiring located inside the insulating substrate for connecting the electrode pads to corresponding electrical circuits. The wiring includes at least one branch wiring. The branch wiring is arranged in parallel with at least one electrode pad along the extending surface of the insulating substrate and is connected to other electrode pads. The other electrode pads are electrically connected via the branch wiring. The above technical solution reduces the hardness of the flexible circuit, allowing it to more easily deform when subjected to resistance force during the process of entering and exiting a sheath, thereby avoiding significant interference with the sheath and facilitating the balloon-type electrode assembly's entry and exit from a sheath.

Description

[Technical Field]

[0001] The present invention relates to a balloon electrode catheter, and more particularly to a flexible circuit for a balloon electrode assembly in a balloon electrode catheter. [Background technology]

[0002] A balloon electrode catheter typically comprises a catheter body and a balloon electrode assembly disposed at the distal end of the catheter body. A sheath inserted into the body serves as a passageway to enter the appropriate site within the body. The balloon body at the distal end is then filled with air or liquid from the proximal end of the balloon electrode catheter, filling and expanding the balloon body. The flexible circuit disposed on the balloon body is then deployed into a desired shape, allowing the electrode pads on the flexible circuit to contact the target tissue within the body and discharge using the electrode to achieve the corresponding therapeutic objective. One typical application of balloon electrode catheters is the treatment of atrial fibrillation using pulsed electric field energy. The basic principle is to apply a high-voltage, short-duration pulse to tissue via an electrode, inducing irreversible electroporation (IRE) and causing necrosis or apoptosis of the target tissue. When used for ablation of atrial fibrillation, pulsed field ablation (PFA) offers an advantage over radiofrequency ablation (RF) in that it produces non-thermal damage. In other words, because there is almost no temperature rise during the ablation process, PFA can avoid complications such as burns, thrombosis, and pulmonary vein stenosis caused by excessive temperatures.

[0003] The flexible circuit of the balloon-type electrode assembly typically includes an insulating substrate made of an insulating material, electrode pads attached to the insulating substrate, and wiring (traces) for connecting the electrode pads to corresponding circuits. The wiring is formed inside the insulating substrate and is laminated with the electrode pads to electrically connect the electrode pads to corresponding circuits.

[0004] Although the flexible circuit is flexible and deformable, it still has a certain degree of hardness, so that after the balloon-type electrode assembly is deflated, it is not easy to move in and out of the sheath during actual use. Summary of the Invention

[0005] The technical problem that the present invention aims to solve is that conventional balloon-type electrode assemblies have difficulty entering and exiting a sheath.

[0006] In a first aspect, the present invention provides a flexible circuit for a balloon-type electrode assembly. The flexible circuit of the balloon-type electrode assembly is an insulating substrate attached to the balloon body of the balloon-type electrode assembly and used to change the degree of bending in response to the expansion and contraction of the balloon body; a plurality of electrode pads fixed on the insulating substrate and used to generate a pulsed electric field; and wiring located inside the insulating substrate and used to connect the electrode pads to corresponding electrical circuits.

[0007] The wiring includes at least one branch wiring, which is arranged in parallel with at least one of the electrode pads along the extending surface of the insulating substrate and is connected to another of the electrode pads, and is electrically connected to the other electrode pads via the branch wiring.

[0008] In one technical solution, the insulating substrate includes at least one branch portion for arranging the branch wiring therein, and at least a part of the branch portion is spaced apart from the main body portion of the insulating substrate.

[0009] In one technical solution, an oblique transition portion is formed at at least one longitudinal end of the branch portion, and the oblique transition portion forms a guide structure for guiding the branch portion into and out of the corresponding sheath.

[0010] In one technical solution, the shape of the oblique transition section is an outwardly convex arc.

[0011] In one technical solution, the thickness of the branch portion is greater than the thickness of the main body of the insulating substrate.

[0012] In one technical solution, the plurality of electrode pads include a first electrode pad, a second electrode pad, and a third electrode pad arranged in order along a direction from a proximal end to a distal end of the flexible circuit, and at least two of the branch wirings are connected to the first electrode pad on a side away from the second electrode pad, and the two branch wirings are located on opposite sides of each other in the width direction of the flexible circuit and are connected to the second electrode pad and the third electrode pad, respectively.

[0013] In one technical solution, the wiring and the electrode pads are not stacked along the thickness direction of the flexible circuit.

[0014] In a second aspect, the present invention provides a balloon-type electrode assembly. The balloon-type electrode assembly includes: an expandable and contractible balloon body; and a flexible circuit, the flexible circuit comprising: an insulating substrate attached to the balloon body of the balloon of the balloon-type electrode assembly and used to change the degree of bending in response to the expansion and contraction of the balloon body; a plurality of electrode pads fixed on the insulating substrate and used to generate a pulsed electric field; and a plurality of wirings located inside the insulating substrate and used to connect the plurality of electrode pads to corresponding electrical circuits.

[0015] The wiring includes at least one branch wiring, which is arranged in parallel with at least one of the electrode pads along the extending surface of the insulating substrate and is connected to another of the electrode pads, and is electrically connected to the other electrode pads via the branch wiring.

[0016] In one technical solution, the insulating substrate includes at least one branch portion for arranging the branch wiring therein, and at least a part of the branch portion is spaced apart from the main body portion of the insulating substrate.

[0017] In one technical solution, an oblique transition portion is formed at at least one longitudinal end of the branch portion, and the oblique transition portion forms a guide structure for guiding the branch portion into and out of the corresponding sheath.

[0018] In one technical solution, the shape of the oblique transition section is an outwardly convex arc.

[0019] In one technical solution, the thickness of the branch portion is greater than the thickness of the main body portion of the insulating substrate.

[0020] In one technical solution, the plurality of electrode pads include a first electrode pad, a second electrode pad, and a third electrode pad arranged in order along a direction from a proximal end to a distal end of the flexible circuit, and at least two of the branch wirings are connected to the first electrode pad on a side away from the second electrode pad, and the two branch wirings are located on opposite sides of each other in the width direction of the flexible circuit and are connected to the second electrode pad and the third electrode pad, respectively.

[0021] In one technical solution, the wiring and the electrode pads are not stacked along the thickness direction of the flexible circuit.

[0022] In one technical solution, the branched portion of the insulating substrate for arranging the branched wiring is fixed to the surface of the balloon body by adhesive.

[0023] In a third aspect, the present invention provides a balloon-type electrode catheter. The balloon-type electrode catheter includes: A catheter body; and a balloon-type electrode assembly connected to the distal end of the catheter body.

[0024] The balloon-type electrode assembly includes: an expandable and contractible balloon body; and a flexible circuit, the flexible circuit comprising: an insulating substrate attached to the balloon body of the balloon-type electrode assembly and used to change the degree of bending in response to the expansion and contraction of the balloon body; a plurality of electrode pads fixed on the insulating substrate and used to generate a pulsed electric field; and a plurality of wirings located inside the insulating substrate and used to connect the plurality of electrode pads to corresponding electrical circuits.

[0025] The wiring includes at least one branch wiring, which is arranged in parallel with at least one of the electrode pads along the extending surface of the insulating substrate and is connected to another of the electrode pads, and is electrically connected to the other electrode pads via the branch wiring.

[0026] In one technical solution, the insulating substrate includes at least one branch portion for arranging the branch wiring therein, and at least a part of the branch portion is spaced apart from the main body portion of the insulating substrate.

[0027] In one technical solution, an oblique transition portion is formed at at least one longitudinal end of the branch portion, and the oblique transition portion forms a guide structure for guiding the branch portion into and out of the corresponding sheath.

[0028] In one technical solution, the shape of the oblique transition section is an outwardly convex arc.

[0029] In one technical solution, the thickness of the branch portion is greater than the thickness of the main body portion of the insulating substrate.

[0030] In one technical solution, the plurality of electrode pads include a first electrode pad, a second electrode pad, and a third electrode pad arranged in order along a direction from a proximal end to a distal end of the flexible circuit, and at least two of the branch wirings are connected to the first electrode pad on a side away from the second electrode pad, and the two branch wirings are located on opposite sides of each other in the width direction of the flexible circuit and are connected to the second electrode pad and the third electrode pad, respectively.

[0031] In one technical solution, the wiring and the electrode pads are not stacked along the thickness direction of the flexible circuit.

[0032] In one technical solution, the branched portion of the insulating substrate for arranging the branched wiring is fixed to the surface of the balloon body by adhesive. [Effects of the Invention]

[0033] The flexible circuit of the balloon-type electrode assembly described above has branched wiring, which allows a corresponding electrode pad to pass beside another electrode pad in a bypass fashion using the branched wiring. This reduces the number of wires that overlap with the electrode pads in the thickness direction of the flexible circuit, or allows the wires and electrode pads to be arranged so as not to overlap along the thickness direction of the flexible circuit. This reduces the hardness of the flexible circuit, allowing the flexible circuit to more easily deform when subjected to resistance force during the process of entering and exiting the sheath. This avoids significant interference with the sheath, making it easier for the balloon-type electrode assembly to enter and exit the sheath. [Brief explanation of the drawings]

[0034] [Figure 1]1 is a schematic diagram illustrating a first embodiment of a balloon-type electrode assembly according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 1 is a schematic diagram illustrating a configuration of a balloon-type electrode assembly according to a second embodiment of the present invention. [Figure 4] FIG. 1 is a schematic diagram of a flexible circuit of a balloon-type electrode assembly before improvement. [Explanation of symbols]

[0035] 10. Catheter body 20 Balloon-type electrode assembly 21 Balloon body 22 Flexible Circuit 221 Insulating substrate 222 Electrode Pads 223 Wiring 224 Main body 225 Branch 226 Diagonal Transition 227 Branch Wiring 228 Adhesive DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention will be described in more detail below with reference to the drawings through specific embodiments. Similar components in different embodiments have the same associated component numbers. In the following detailed description, many details are described to make the present application easier to understand. However, those skilled in the art will readily understand that some features may be omitted or substituted with other components, materials, or methods under different circumstances. In some cases, some operations related to the present application are not shown or described herein to avoid obscuring the core of the present application with excessive description. However, those skilled in the art will be able to fully understand the relevant operations based on the description in the specification and general knowledge in the art without the need for detailed description of these related operations.

[0037] Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Additionally, the steps or actions in the method descriptions may be reordered or rearranged in any manner apparent to one of ordinary skill in the art. Thus, the various orders in the specification and figures are solely for the purpose of clarifying particular embodiments and do not imply a required order unless otherwise specified that a particular order must be followed.

[0038] The numbering of parts in this specification, such as "first", "second", etc., is only used to distinguish the objects described and does not have any sequential or technical meaning. "Connected" and "coupled" as used in this application include both direct and indirect connections (couplings) unless otherwise stated.

[0039] <First embodiment of the balloon-type electrode assembly according to the present invention> 1 and 2. The balloon-type electrode assembly 20 includes a balloon body 21 and a flexible circuit 22.

[0040] In a preferred embodiment, the balloon body 21 is made of a polymer material such as nylon, PEBAX®, or PET (polyethylene terephthalate). The balloon body 21 expands when filled with air and contracts when deflated. The balloon body 21 has a proximal end and a distal end, an axial direction that coincides with the direction connecting the proximal end and the distal end, and a circumferential direction that surrounds the axial direction. The terms "proximal end" and "distal end" are commonly used in the medical field. From the perspective of an instrument such as a balloon-type electrode catheter, the proximal end is the end closest to the operator of the instrument, and the distal end is the end farther from the operator of the instrument. The balloon body 21 may also be filled with other media, such as water or a medicinal solution.

[0041] In a preferred embodiment, the flexible circuit 22 includes multiple circuit strips. Each circuit strip is evenly distributed around the circumferential direction of the balloon body 21 and corresponds to a generatrix on the balloon body 21 in the expanded state. The shape of a curved surface can be considered as the locus of a moving line, and the moving line that forms the curved surface is the generatrix. For example, in a spherical surface formed by the expanded balloon body 21, the generatrix is ​​the intersection of a plane passing through the axis of the balloon body 21 and the surface of the balloon body 21. In the first embodiment, there are 12 circuit strips, but in other embodiments, the number of circuit strips can be increased or decreased as needed. Each circuit strip extends from the proximal end to the distal end of the balloon body 21, with the longitudinal ends of each circuit strip being the proximal and distal ends, respectively. To facilitate circumferential positioning of each circuit strip, the distal ends of each circuit strip are connected to the same annular circuit strip and form an integral structure with the annular circuit strip. In other embodiments, each circuit strip may be independent of the others. In other embodiments, the distal end of each circuit strip may be spaced apart from the distal end of the balloon body 21 .

[0042] Each circuit strip includes an insulating substrate 221, electrode pads 222, and wiring. The insulating substrate 221 is attached to the balloon body 21 and allows the circuit strip to change its degree of bending in response to the expansion and contraction of the balloon body 21. The insulating substrate 221 is a flexible substrate with a predetermined thickness that allows for bending and deformation. The electrode pads 222 are fixed to the outer surface of the insulating substrate 221, possibly by adhesive bonding. The surfaces of the electrode pads 222 are exposed on the circuit strip and are used to generate a pulsed electric field. The wiring is formed inside the insulating substrate 221. Copper is a common material for the wiring and electrode pads 222 to ensure effective circuit conduction. The wiring extends along the circuit strip, and after the proximal end of the wiring extends to the distal end of the corresponding catheter body 10, it may be welded to a corresponding microcable. The microcable further extends along the catheter body 10 to a handle located at the proximal end of the catheter body 10 and is welded to a connector on the handle. In another embodiment, the electrode pads 222 may be formed on the insulating substrate 221 by an etching method. The etching method is a mature method in the field of circuit board manufacturing, and therefore, a detailed description thereof will be omitted here.

[0043] In a preferred embodiment, in embodiment 1, each circuit strip includes three electrode pads 222: a first electrode pad, a second electrode pad, and a third electrode pad. The three electrode pads 222 are arranged in order from the proximal end to the distal end of the flexible circuit 22 and are located in the region of the balloon body 21 closest to the distal end. This allows the electrode pads 222 to contact target tissue in the body when the balloon electrode catheter is advanced forward. In a preferred embodiment, the electrode pads 222 are narrower in overall width toward the distal end of the balloon body 21 to accommodate different circumferential spaces on the balloon body 21 after the balloon body 21 is expanded. The width of each electrode pad 222 also gradually narrows from the proximal end to the distal end of the circuit strip. In other embodiments, the number of electrode pads 222 on a circuit strip may be increased or decreased, as long as the specific number meets the corresponding usage needs.

[0044] The wiring is located inside the insulating substrate 221 and is used to connect the electrode pads 222 to corresponding electrical circuits. In a preferred embodiment, the insulating substrate 221 includes two branch portions 225. The two branch portions 225 are drawn out from the side of the first electrode pad 222 that is farther from the second electrode pad 222 and are located on opposite sides of each other in the width direction of the flexible circuit 22. The distal ends of the two branch portions 225 are connected to the insulating substrate 221 corresponding to the second electrode pad 222 and the third electrode pad 222, respectively. The wiring also includes branch wiring 227 located within each branch portion 225. Except for the first electrode pad 222, the other two electrode pads 222 are electrically connected to the corresponding circuits via the branch wiring 227 during operation. In a preferred embodiment, the branch portions 225 are adhesively fixed to the corresponding surfaces of the balloon body 21 using adhesive 228 during assembly. The adhesive 228 may be the same as the adhesive 228 between the balloon body 21 and the main body portion 224 of the insulating substrate 221, such as an epoxy resin, an acrylic resin, or a polyurethane adhesive. By providing a branch portion and arranging the branch wiring, the width of the insulating substrate is prevented from becoming too wide, making it easier for the flexible circuit to enter the sheath. In another embodiment, when the insulating substrate 221 has three or more branch portions 225, two or more of these branch portions 225 of the insulating substrate 221 may be arranged on the same side of the main body portion 224.

[0045] In a preferred embodiment, the proximal and distal ends of the branch portion 225 each have a diagonal transition portion 226. The diagonal transition portion 226 has an outwardly convex arc shape that can guide the branch portion 225 as it enters and exits the sheath, facilitating smooth entry and exit of the balloon-type electrode assembly 20 into and out of the sheath. The outwardly convex arc shape of the diagonal transition portion 226 allows the branch wiring to bend smoothly, which is advantageous for protecting the branch wiring. In another embodiment, the diagonal transition portion 226 may have an inclined linear shape.

[0046] In a preferred embodiment, since the size of the branch portion 225 of the insulating substrate 221 is relatively small, the thickness of the branch portion 225 is set to be thicker than the thickness of the main body portion 224 of the insulating substrate 221 in order to ensure the strength of the structure and to avoid damage to the internal wiring due to excessive bending.

[0047] During use, the balloon body 21 in the balloon-type electrode assembly 20 is controlled to evacuate, causing the balloon body 21 to deflate, and the circuit strips on the balloon body 21 shrink so that they are close to each other, aligned parallel to the circumferential direction of the balloon body 21, or partially joined together. At this time, the balloon-type electrode catheter can be manipulated through the catheter body 10 to enter the corresponding sheath. After the balloon-type electrode assembly 20 protrudes from the distal end of the sheath, the balloon body 21 in the balloon-type electrode assembly 20 expands to a predetermined shape and size, simultaneously unfolding the circuit strips to a predetermined state in unison, allowing the electrode pad 222 to conform to the target tissue of the living body. This allows pulsed field ablation to be performed. After ablation is completed, the balloon body 21 in the balloon-type electrode assembly 20 is controlled to evacuate, causing the circuit strips to deflate again, allowing the assembly to be withdrawn from the sheath.

[0048] The wiring connected to the first electrode pad 222 can be directly disposed in the same electrode extension plane as the first electrode pad 222 (and therefore not shown in the cross-sectional view). The wiring connected to the second and third electrode pads 222 can also be disposed in the same electrode extension plane as the respective electrode pads 222 via the branch portion 225 of the insulating substrate 221. This eliminates the need for stacking of the wiring and the electrode pads 222 in the thickness direction of the flexible circuit 22. This effectively reduces the thickness of the insulating substrate 221 and controls the hardness of the flexible circuit 22. This allows the flexible circuit 22 to more easily deform when subjected to resistance during the process of entering and exiting the sheath, avoiding significant interference with the sheath and facilitating the balloon-type electrode assembly 20 entering and exiting the sheath. The oblique transition portions 226 at both longitudinal ends of the branch portion 225 act as guides, further facilitating the balloon-type electrode assembly 20 entering and exiting the sheath. See FIG. 4. Before the improvement, the wiring 223 corresponding to each electrode pad 222 was laminated on the electrode pad 222 along the thickness direction of the flexible circuit 22, and the insulating substrate 221 was provided with insulating protective layers located on both the top and bottom sides of the wiring 223. This made the flexible circuit 22 thick and hard, making it difficult to adapt to the external force received when entering and exiting the sheath, and making it difficult to enter and exit the sheath.

[0049] <Second embodiment of balloon-type electrode assembly according to the present invention> See Figure 3. The difference between embodiment 2 and embodiment 1 is that in embodiment 2, two electrode pads 222 are arranged on each circuit strip, whereas one electrode pad is arranged corresponding to branch portion 225, and further, the portion of branch portion 225 corresponding to the gap between the two electrode pads 222 is separated from the main body of insulating substrate 221, while the remaining portion is connected to the main body of insulating substrate 221. By employing this structure, it is easy to position branch portion 225.

[0050] In the above embodiment, none of the wiring and the electrode pads 222 overlap along the thickness direction of the flexible circuit 22. In other embodiments, except for processing the branch wiring 227 at the branch portion 225, some of the wiring and the electrode pads may overlap along the thickness direction of the flexible circuit 22. The presence of the branch wiring 227 reduces the number of wirings that overlap with the electrode pads and still serves to reduce the hardness of the portions of the flexible circuit 22 that correspond to the electrode pads, thereby making it easier for the balloon-type electrode assembly 20 to enter and exit the sheath.

[0051] <Flexible Circuit Embodiment of Balloon-Type Electrode Assembly According to the Present Invention> The structure of the flexible circuit of the balloon-type electrode assembly is the same as the structure of the flexible circuit 22 in any of the embodiments of the balloon-type electrode assembly 20 described above, and therefore will not be described here.

[0052] <Embodiments of balloon-type electrode catheter according to the present invention> As shown in Figure 3, the balloon electrode catheter comprises a catheter body 10, a balloon electrode assembly 20, and a handle (not shown). The catheter body 10 has a proximal end connected to the handle and a distal end connected to the balloon electrode assembly 20. The catheter body 10 can drive the balloon electrode assembly 20 to enter a corresponding sheath and transport the balloon electrode assembly 20 to a predetermined position in a living body. The structure of the balloon electrode assembly 20 is the same as that of the balloon electrode assemblies in any of the above-mentioned embodiments of the balloon electrode assembly, so a description thereof will be omitted here.

[0053] Although the present invention has been described in detail above using specific examples, the above description is merely for the purpose of aiding understanding of the present invention and is not intended to limit the present invention. Those skilled in the art to which the present invention pertains may make a number of simple deductions, modifications, or substitutions based on the concept of the present invention.

Claims

1. A flexible circuit for a balloon-type electrode assembly, comprising: an insulating substrate attached to the balloon body of the balloon-type electrode assembly and used to change the degree of bending in response to the expansion and contraction of the balloon body; a plurality of electrode pads fixed on the insulating substrate and used to generate a pulsed electric field; wiring located inside the insulating substrate and used to connect the plurality of electrode pads to corresponding electrical circuits; The wiring includes at least one branch wiring, which is arranged in parallel with at least one of the electrode pads along the extending surface of the insulating substrate and is connected to other of the electrode pads, and the other electrode pads are electrically connected to the branch wiring via the branch wiring.

2. 2. The flexible circuit of claim 1, wherein the insulating substrate includes at least one branch portion for arranging the branch wiring therein, and at least a portion of the branch portion is spaced apart from a main body portion of the insulating substrate.

3. 3. The flexible circuit of claim 2, wherein an oblique transition portion is formed at at least one longitudinal end of the branch portion, and the oblique transition portion forms a guide structure for guiding the branch portion as it enters and exits the corresponding sheath.

4. 4. The flexible circuit of claim 3, wherein the oblique transition portion has an outwardly convex arc shape.

5. 5. The flexible circuit of claim 2, wherein the thickness of the branched portion is greater than the thickness of the main body portion of the insulating substrate.

6. 5. The flexible circuit of claim 1, wherein the plurality of electrode pads include a first electrode pad, a second electrode pad, and a third electrode pad arranged in this order along a direction from a proximal end to a distal end of the flexible circuit, and at least two of the branch wirings are connected to a side of the first electrode pad away from the second electrode pad, and the two branch wirings are located on opposite sides of each other in the width direction of the flexible circuit and are connected to the second electrode pad and the third electrode pad, respectively.

7. The flexible circuit of a balloon-type electrode assembly according to any one of claims 1 to 4, characterized in that the wiring and the electrode pads are not stacked along the thickness direction of the flexible circuit.

8. A balloon-type electrode assembly, an expandable and contractible balloon body; A balloon-type electrode assembly comprising a flexible circuit, the flexible circuit being the flexible circuit according to any one of claims 1 to 7.

9. 9. The balloon-type electrode assembly according to claim 8, wherein the branched portion of the insulating substrate for arranging the branched wiring is fixed to the surface of the balloon body by adhesive.

10. A balloon-type electrode catheter, A catheter body; a balloon-type electrode assembly connected to the distal end of the catheter body; The balloon-type electrode assembly includes: an expandable and contractible balloon body; and a flexible circuit, wherein the flexible circuit is the flexible circuit according to any one of claims 1 to 7.

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