Medical device

Abstract

Provided is a medical device capable of inhibiting a decrease in joint strength and difficulty in assembly due to a difference between the inner diameter of a fixed portion of a stent that is assembled relative to a shaft portion and the outer diameter of the shaft portion. A medical device (10) has a stent (21) formed by a plurality of support bars (50) that extend in the axial direction and are arranged in the circumferential direction around the axial direction, and a long shaft portion (31) that is connected to a base end fixed portion (52) formed at a base end portion of the stent (21), the base end fixed portion (52) having at least one opposing portion (63) having a pair of edge portions (64) that oppose each other in a manner that allows approach and departure in the circumferential direction, the base end fixed portion (52) having a connection structure that allows the pair of opposing edge portions (64) to be connected and allows the circumferential distance between the pair of edge portions (64) to be changed in a state before being connected to the shaft portion (31).

Description

Technical Field

[0001] This invention relates to medical devices. Background Technology

[0002] To expand the perforations of biological lumens or membranes used in medical applications, an expander made of shape memory alloy is used, which can be inserted into the biological body in a constricted state and expand within the biological body (see, for example, Patent Document 1). The expander is assembled to the front end of a long strip shaft so that it can be transported to a predetermined position within the biological body. Existing technical documents Patent documents

[0003] Patent Document 1: International Publication No. 2020-0259492 Summary of the Invention

[0004] In medical devices in which an expander is assembled on the shaft, if the fixing part of the expander to the shaft is cylindrical or annular with a constant diameter, there is a possibility that the joint strength may be reduced due to the gap between the outer diameter of the shaft and the inner diameter of the fixing part.

[0005] Furthermore, when the expansion body is manufactured by cutting from the tube, the size of the fixing part depends on the size of the tube. As a result, it is difficult to assemble the fixing part and the shaft when the outer diameter of the shaft is larger than the inner diameter of the tube.

[0006] The present invention was made to solve the above-mentioned problems, and its object is to provide a medical device that can suppress the decrease in joint strength and the difficulty of assembly caused by the difference between the inner diameter of the fixing part of the expansion body assembled relative to the shaft and the outer diameter of the shaft.

[0007] The medical device of the present invention (1) that achieves the above-mentioned objective is characterized by having: an expansion body formed by a plurality of support rods extending along an axial direction and arranged circumferentially around the axial direction; and a long shaft portion connected to a fixing portion formed at the base end of the expansion body, the fixing portion having at least one opposing portion having a pair of opposing edges that are able to approach and move away in the circumferential direction, the fixing portion having a connecting structure that is able to connect the opposing pair of edges and, in a state prior to being connected to the shaft portion, allows for variation of the circumferential distance between the pair of edges. Invention Effects

[0008] The medical device described above (1) uses a connecting structure for the fixing part, which allows for proper adjustment of the circumference of the fixing part in conjunction with the outer diameter of the shaft part, thereby fixing the fixing part to the shaft part. Therefore, the medical device can suppress the reduction in joint strength and assembly difficulties caused by the difference between the inner diameter of the fixing part of the expansion body assembled relative to the shaft part and the outer diameter of the shaft part.

[0009] (2) In the medical device described in (1) above, the fixing part may also have a plurality of opposing parts spaced apart circumferentially as the opposing parts, each of the plurality of opposing parts having the pair of edges, and the connecting structure having a plurality of connecting structures in each of the plurality of opposing parts that can increase the circumferential distance between the pair of edges. Thus, the circumference of the fixing part can be adjusted more appropriately in conjunction with the outer diameter of the shaft.

[0010] (3) In the medical device described in (1) or (2) above, at least one of the plurality of connecting structures may have a connecting support rod, which has two joints that respectively engage with the pair of opposing edges, and is formed to be longer than the straight-line distance between the two joints when viewed from the radially outer side. Thus, the connecting support rod can deform to separate the two joints. Therefore, the medical device can adjust the circumference of the fixing part in accordance with the outer diameter of the shaft by deforming the connecting support rod. Therefore, even if the outer diameter of the shaft deviates, the fixing part can be well fixed to the shaft. Furthermore, since at least one of the plurality of connecting structures has a connecting support rod, the medical device can prevent the pair of edges from completely separating and easily disintegrating in all connecting structures. Therefore, the medical device can suppress the reduction in workability when fixing the fixing part to the shaft.

[0011] (4) In the medical device described in (3) above, the connecting support rod may also be of a zigzag shape. As such, the connecting support rod is easily deformable to extend the zigzag shape, thereby allowing it to easily deform to separate the two joints.

[0012] (5) In any of the medical devices described in (2) to (4) above, at least one of the plurality of interconnecting structures may have a concave-convex structure having a protrusion and a recess for the protrusion to be fitted into. The protrusion is formed at one edge of a pair of edges in a corresponding one of the plurality of opposing portions and protrudes circumferentially toward the other edge. The recess is formed at the other edge of a pair of edges in a corresponding one of the plurality of opposing portions. The protrusion has a root formed at one circumferential end and a top formed at the other circumferential end and longer in the axial direction than the root. The recess has an open top that accommodates the root of the protrusion and an open bottom that communicates with the open top and accommodates the top of the protrusion. The circumferential length of the top is shorter than the circumferential length of the open bottom. When the protrusion and the recess are fitted into each other and a circumferential gap is formed between the top of the protrusion and the open bottom of the recess, the base end of the expansion is fixed to the shaft. Therefore, the medical device allows the top of the convex portion of the expander to connect with the bottom of the opening of the concave portion, fixing the expander to the shaft. Furthermore, a circumferential gap is formed between the top of the convex portion and the bottom of the opening of the concave portion, allowing for proper adjustment of the circumference of the fixing portion in accordance with the outer diameter of the shaft. Thus, even if the outer diameter of the shaft deviates, the fixing portion can be securely fixed to the shaft. Additionally, by disengaging the convex portion from the concave portion, the medical device allows the pair of edges of the opposing portion to be completely separated. Therefore, since at least one of the multiple connecting structures has a convex and concave portion that can be completely separated, the medical device prevents the pair of edges from not being completely separated in all connecting structures. Thus, the medical device allows the opposing portion to be significantly expanded so that the fixing portion covers the shaft, improving the operability when fixing the fixing portion to the shaft.

[0013] (6) In the medical device described in (5) above, the plurality of connecting structures may also have two concave-convex structures arranged such that the fixing part can be divided into a first fixing part and a second fixing part in the circumferential direction. Thus, the medical device can divide the fixing part into two, making it easier to insert the shaft part into the fixing part.

[0014] (7) In the medical device described in (6) above, the plurality of connecting structures may also have at least one plurality of connecting support rods provided on each of the first fixing part and the second fixing part, each plurality of connecting support rods having two joints that respectively engage with a pair of edges of a corresponding opposing part of the plurality of opposing parts, and forming a length longer than the straight-line distance between the two joints when viewed from the radially outer side. Thus, since the medical device has connecting support rods on each of the divided first fixing part and the second fixing part, the shaft part is easier to insert and can be more evenly unfolded in the circumferential direction.

[0015] (8) In any of the medical devices described in (1) to (7) above, the plurality of connecting structures may be arranged approximately equally in the circumferential direction. Therefore, even if the perimeter of the fixing part changes, the medical device can maintain the cross-sectional shape of the inner circumferential surface of the fixing part in a nearly circular shape, enabling the fixing part to be firmly and tightly in contact with the shaft. Furthermore, the medical device allows the fixing part to unfold evenly in the circumferential direction, making it easy to position the fixing part appropriately relative to the shaft. Therefore, the medical device can improve the workability when fixing the fixing part to the shaft. Attached Figure Description

[0016] Figure 1 This is a side view showing the medical device of this embodiment. Figure 2 This is a side view showing the front end of a medical device. Figure 3 This is a side view of the expanded body before it is fixed to the shaft. Figure 4 This is a side view showing the front end of the expander. Figure 5 The following is a side view of the base end of the expansion body. (A) shows the part including the first connecting structure, and (B) shows the part including the second connecting structure. Figure 6 This is a front view of the expansion body viewed from the axial direction. (A) shows the expansion body of this embodiment, and (B) shows the expansion body of the modified example. Figure 7 This is a side view showing the state in which the base fixing part of the expansion body extends in circumference and covers the shaft part. (A) shows the part including the first connecting structure, and (B) shows the part including the second connecting structure. Figure 8 This is a side view showing the state in which the base fixing part of the expansion body is fixed to the shaft part. (A) shows the part including the first connecting structure, and (B) shows the part including the second connecting structure. Figure 9 This is a side view showing a variation of a medical device. Detailed Implementation

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that, for ease of explanation, the dimensions in the drawings are exaggerated and differ from the actual proportions. In addition, in this specification, the side of the medical device 10 that is inserted into the cavity of the biological body is referred to as the "front end side," and the side on which the operation is performed is referred to as the "base end side."

[0018] like Figures 1-2As shown, the medical device 10 of this embodiment is configured to dilate the puncture hole formed in the atrial septum of the patient's heart, and to perform a maintenance procedure to maintain the size of the dilated puncture hole.

[0019] The medical device 10 includes: an elongated section 20 extending from the base to the front end; an expansion body 21 provided at the front end of the elongated section 20; an electrode section 22 provided along the expansion body 21 as an energy transfer element; and a hand-held operation section 23 connected to the base end of the elongated section 20.

[0020] The elongated portion 20 has: a shaft portion 31 that holds the expansion body 21 at the front end; a front end shaft portion 34 that is fixed to the front end of the expansion body 21; an outer cylinder 30 that houses the shaft portion 31; a traction shaft 33; and a tip 35 that is fixed to the front end of the traction shaft 33.

[0021] The shaft portion 31 is an elongated tube extending from the hand-operated part 23 to at least its base end of the expander 21. The base end of the shaft portion 31 is fixed to the front end of the hand-operated part 23. The front end of the shaft portion 31 is fixed to the base end of the expander 21. Furthermore, in this embodiment, the front end of the shaft portion 31 extends to the inside of the expander 21, and the front end of the shaft portion 31 is located near the central portion in the axial direction of the expander 21. The front end shaft portion 34 is a tube fixed to the front end of the expander 21. The front end shaft portion 34 is disposed at a distance from the shaft portion 31, at a position closer to the front end than the shaft portion 31.

[0022] The outer cylinder 30 is an elongated tube covering the shaft portion 31, capable of moving axially (in the direction of the axis between the elongated portion 20 and the shaft portion 31) relative to the shaft portion 31. When the outer cylinder 30 is moved to the front end side of the elongated portion 20, it can accommodate the radially contracting expander 21 within it. It should be noted that radial direction is orthogonal to the axis of the shaft portion 31. The surgeon moves the outer cylinder 30 from the state containing the expander 21 to the base end side, thereby exposing the expander 21 from the outer cylinder 30 and allowing it to expand radially using its restorative force.

[0023] The traction shaft 33 is an elongated tube disposed inside the shaft portion 31 and the front end shaft portion 34, and is capable of axial movement relative to the shaft portion 31. The traction shaft 33 protrudes from the front end of the shaft portion 31 toward the front end side and from the front end of the expansion body 21 toward the front end side. The front end of the traction shaft 33, located on the front end side compared to the expansion body 21, is fixed to the tip 35. The base end of the traction shaft 33 extends from the hand-operated part 23 toward the base end side. A guide wire cavity is formed axially inside the traction shaft 33, allowing the guide wire to pass through. The traction shaft 33 is capable of axial movement relative to the shaft portion 31.

[0024] The tip 35 is an annular component fixed to the outer circumferential surface of the front end of the traction shaft 33, protruding radially outward from the outer circumferential surface of the traction shaft 33. The tip 35 is not fixed to the expander 21. The outer diameter of the tip 35 is larger than the inner diameter of the front end of the expander 21. Therefore, the tip 35 abuts against the front end of the expander 21 from the tip side, which can pull the expander 21 towards the base end, so that a compressive force that compresses along the axial direction of the shaft 31 is applied to the expander 21.

[0025] The expander 21 has a plurality of support rods 50 extending axially and arranged circumferentially. The support rods 50 form a mesh-like structure by branching and converging along the axial direction. Thus, the expander 21 can expand and contract radially. The plurality of support rods 50 have a plurality of front support rods 50A on the front end side of the waist 55 which is smaller than the outer diameter, and a plurality of base end support rods 50B on the base end side of the waist 55. The plurality of base end support rods 50B form a plurality of (two in this embodiment) support rod groups 50C. The plurality of base end support rods 50A included in each support rod group 50C are connected to the same separation portion 186A described later.

[0026] The expander 21 can be formed by laser cutting or similar methods on a cylindrical metal component. The expander 21 can be formed from a metallic material. Examples of suitable metallic materials include titanium-based alloys (Ti-Ni, Ti-Pd, Ti-Nb-Sn, etc.), copper alloys, stainless steel, β-titanium steel, and Co-Cr alloys. It should be noted that using a shape memory alloy with high elasticity, such as a nickel-titanium alloy, is preferable, as the expander 21 can self-expand from a contracted state to a radially expanding natural state. However, the material of the expander 21 is not limited to these, and it can also be formed from other materials. Figure 3 As shown, the expansion body 21 has a plurality of cut-in portions 62 extending from the outer peripheral surface to the inner peripheral surface, and a support rod 50 is formed between adjacent cut-in portions 62.

[0027] The expander 21 is inclined in a radially increasing manner as it approaches the center from both ends in the axial direction. Furthermore, the expander 21 has a necked shape with a sharply decreasing outer diameter at the axial center. Specifically, the expander 21 includes an annular front-end connector 51 located on the front-end side, an annular base-end connector 52 (fixed portion) located on the base-end side, a front-end side protrusion 53 located on the base-end side of the front-end connector 51 and protruding radially outward, a base-end side protrusion 54 located on the front-end side of the base-end connector 52 and protruding radially outward, and a waist portion 55 located between the front-end side protrusion 53 and the base-end side protrusion 54 with a decreasing outer diameter.

[0028] like Figures 2-4 As shown, the front-end fixing part 51 is an annular portion formed by connecting the front ends of a plurality of front-end support rods 50A arranged circumferentially. The front-end fixing part 51 is fixed to the front-end shaft part 34.

[0029] The waist portion 55 has a bottom 56 located radially innermost, a base-end side upright portion 57 extending radially outward from the base end of the bottom 56, and a front-end side upright portion 58 extending radially outward from the front end of the bottom 56. The waist portion 55 divides a receiving space 59 that can accommodate biological tissue when the expander 21 expands.

[0030] The base end fixing part 52 is an annular portion formed by connecting the base ends of a plurality of base end support rods 50B arranged circumferentially. The base end fixing part 52 is fixed to the shaft part 31.

[0031] When the traction shaft 33 slides relative to the shaft portion 31 towards the base end, applying a compressive force to the expander 21, the front end side upright portion 58 and the base end side upright portion 57 approach each other, and both are in close contact with the biological tissue contained in the receiving space 59. An electrode portion 22 is arranged along the waist portion 55 of the base end side upright portion 57, facing the receiving space 59. That is, the electrode portion 22 is provided in the middle portion along the axial direction of the expander 21. In this embodiment, 10 electrode portions 22 are provided circumferentially. It should be noted that the electrode portion 22 may also be arranged on the front end side upright portion 58.

[0032] like Figure 3 As shown in Figure 5, before the base end fixing portion 52 is fixed to the shaft portion 31, it is connected to the annular connecting portion 90 located on the base end side of the base end fixing portion 52 via the cut-off portion 91. The annular connecting portion 90 is an annular portion formed within a 360-degree range. The annular connecting portion 90 and the cut-off portion 91 are integrally cut from the same metal cylindrical component together with the expansion body 21. Furthermore, Figure 5 (A) and Figure 5 (B) shows different circumferential portions of the base fixing portion 52, for example, portions that are different by 180 degrees along the circumferential direction.

[0033] like Figure 2 , 3 As shown in (A) of 5 and 6, the base end fixing portion 52 has: two opposing portions 63, each having an edge 64 that is opposed to each other in a manner that allows them to approach and move away in the circumferential direction; a first connecting structure 65 that connects the two opposing edges 64 in one opposing portion 63; and a second connecting structure 66 that connects the two opposing edges 64 in another opposing portion 63. When the base end fixing portion 52 has multiple opposing portions 63, it is separated into multiple separating portions 67 in the circumferential direction due to the opposing portions 63. In the base end fixing portion 52, the multiple connecting structures (the first connecting structure 65 and the second connecting structure 66 in this embodiment) are preferably evenly arranged in the circumferential direction.

[0034] The first connecting structure 65 is constructed such that it enables the two opposing edges 64 to be completely separated, and also enables the separated edges 64 to be connected. In the connected state, the two edges 64 can move circumferentially only within a specified range. Figure 5 As shown in (A), the first connecting structure 65 has a T-shaped protrusion 70 and a recess 71 formed by cutting off the T-shape. The protrusion 70 is formed on one of the two edges 64 forming the opposing portion 63, and the recess 71 is formed on the other of the two edges 64. The protrusion 70 can be connected to the recess 71 by hooking, and can be completely separated from the recess 71. The protrusion 70 has: a root portion 72 formed continuously with the edge portion 64 at one circumferential end; and a top portion 73 formed at the other circumferential end, and the axial length of the expansion body 21 is longer than that of the root portion 72. The recess 71 has an open top portion 74 that accommodates the root portion 72 of the protrusion 70, and an open bottom portion 75 that communicates with the open top portion 74 and accommodates the top portion 73 of the protrusion 70. The circumferential length of the top portion 73 is shorter than the circumferential length of the open bottom portion 75. With the protrusion 70 and the recess 71 engaged, and a circumferential gap 76 formed between the top 73 of the protrusion 70 and the bottom 75 of the opening of the recess 71, the base end of the expansion body 21 is fixed to the shaft 31 (see reference). Figure 8 (A) Furthermore, in this embodiment, the top 73 protrudes towards both the front end side and the base end side relative to the root 72, but it is also possible for it to protrude only towards the front end side or the base end side relative to the root 72. In the first connecting structure 65, the root 72 is in close axial contact with the top of the opening 74 with approximately no gap, and the top 73 is in close axial contact with the bottom of the opening 75 with approximately no gap. Thus, when the protrusion 70 moves within the recess 71 in a state of connection with the recess 71, the two edges 64 are maintained in a parallel state. Therefore, it is possible to suppress the difference in circumference between the front end side and the base end side of the base end fixing portion 52, and the inner peripheral surface of the base end fixing portion 52 can easily make close contact with the outer peripheral surface of the shaft portion 31.

[0035] The second connecting structure 66 is constructed such that the two opposing edges 64 are not completely separated, allowing the two edges 64 to move circumferentially only within a specified range. For example... Figure 5As shown in (B), the second connecting structure 66 has a connecting support rod 80, which has two joints 81 that respectively engage with the two edges 64 forming the opposing portion 63. The connecting support rod 80, viewed from the radially outer side, is longer than the straight-line distance (shortest distance) between the two joints 81. As an example, the connecting support rod 80 has a zigzag construction, extending approximately parallel in a straight line (e.g., towards the front end) from the two circumferentially approaching joints 81, and connecting at their ends in the front-end direction to form a fold-back portion 82. The length of the connecting support rod 80 is the sum of the distance from one joint 81 to the fold-back portion 82 and the distance from the other joint 81 to the fold-back portion 82. The length of the connecting support rod 80 is longer than the straight-line distance between the two joints 81. Therefore, the connecting support rod 80 is easily deformed to cause the edges 64 to move away in the circumferential direction. Furthermore, the two joints 81 of the connecting support rod 80 will not separate from the two edges 64, thereby preventing the two edges 64 from completely separating. Unlike the first connecting structure 65, the second connecting structure 66, when the connecting support rod 80 can be elastically deformed, can generate a contraction force (a tightening force for the shaft 31) after expansion to reduce the inner diameter of the base end fixing part 52. In this embodiment, one second connecting structure 66 has one connecting support rod 80, but it may also have multiple connecting support rods 80. In addition, the connecting support rod 80 is not limited to a zigzag shape. For example, it may be a structure like a pantograph, in which four elongated portions are arranged in a rhomboid shape and connected, with the two ends at opposite corners serving as joints 81, and the two ends at the other two corners serving as deformable free ends.

[0036] like Figure 5 As shown, the base end fixing portion 52 has a recessed portion 68, a first hollow portion 77, and a second hollow portion 78 recessed towards the front end of the expander 21. A cut-off portion 91 is located inside the recess of the recessed portion 68 and is connected to the base end fixing portion 52. The cut-off portion 91 is formed finely from the annular connecting portion 90 towards the recessed portion 68. Therefore, the cut-off portion 91 can be cut off at a position closer to the recessed portion 68 than the annular connecting portion 90. By being cut off, the cut-off portion 91 forms a cut-off mark portion 92 inside the recess of the recessed portion 68 (see reference). Figure 7 ).

[0037] The first cutout 77 is formed from the base end of the base fixing part 52 near the first connecting structure 65 towards the front end of the expander 21. The second cutout 78 is formed from the base end of the base fixing part 52 near the second connecting structure 66 towards the front end of the expander 21. The first cutout 77 and the second cutout 78 facilitate the flow of adhesive between the base fixing part 52 and the shaft part 31.

[0038] In the first connecting structure 65 and the second connecting structure 66, the annular connecting portion 90 prevents the opposing portion 63 from expanding (the opposing edge 64 separates), properly maintaining the shape of the expander 21 before the operation of fixing the expander 21 to the shaft portion 31 begins. In particular, in the first connecting structure 65, which has an opposing portion 63 that can be completely separated from the two edge portions 64 by the protrusion 70 disengaging from the recess 71, the annular connecting portion 90 effectively prevents the opposing portion 63 from expanding excessively.

[0039] In this embodiment, the base fixing portion 52 has two connecting structures (a first connecting structure 65 and a second connecting structure 66) with different configurations. Alternatively, the base fixing portion 52 may have only one connecting structure (either a first connecting structure 65 or a second connecting structure 66). Or, the base fixing portion 52 may have three or more connecting structures. The base fixing portion 52 may have at least one first connecting structure 65 and at least one second connecting structure 66. The base fixing portion 52 may have only one or more first connecting structures 65, or only one or more second connecting structures 66. Furthermore, the base fixing portion 52 may have multiple connecting structures, at least one first connecting structure 65, or at least two first connecting structures 65. When the base fixing portion 52 has at least two first connecting structures 65, it can be significantly expanded because it has at least two completely separable opposing portions 63. Furthermore, if there are too many completely separable opposing portions 63, there is a possibility that the workability will decrease when fixing the base end fixing portion 52 to the shaft portion 31. Therefore, the base end fixing portion 52 is preferably provided with two or more connecting structures, wherein two of the connecting structures are the first connecting structure 65. As an example, in Figure 6 In the modified example shown in (B), the base fixing part 52 has two first connecting structures 65 and one second connecting structure 66. Figure 6 In other variations shown in (C), the base fixing portion 52 has two first connecting structures 65 and two second connecting structures 66 alternately in the circumferential direction. The base fixing portion 52 can be divided into a first fixing portion 52A and a second fixing portion 52B, each including a second connecting structure 66, by the two first connecting structures 65.

[0040] When the manufacturing personnel connect the expansion body 21 to the shaft 31, such as Figure 7 As shown in (A), the cut-off portion 91 is cut off, causing the annular connecting portion 90 to disconnect from the base end fixing portion 52. Then, the manufacturer disengages the protrusion 70 of the first connecting structure 65 of the base end fixing portion 52 from the recess 71, and moves it in a manner that unfolds the two opposing edges 64 of the first connecting structure 65. Next, as... Figure 7As shown in (B), the manufacturer deforms the connecting support rod 80 of the second connecting structure 66 of the base end fixing part 52 to separate the two joints 81 and move the two opposing edges 64 of the second connecting structure 66 in a manner that unfolds. The connecting support rod 80 of the second connecting structure 66 can change the separation distance between the edges 64 within a predetermined range from the state where the two joints 81 are in contact until the connecting support rod 80 is fully extended, that is, within a predetermined range from the state where the two joints 81 are in contact until the two joints 81 and the folded-back part 82 are in a straight line. The connecting support rod 80 is preferably elastically deformed, but it can also be plastically deformed. As a result, the two separating parts 67 of the base end fixing part 52 separate, and the circumference of the base end fixing part 52 increases. As a result, the manufacturer can easily cover the shaft part 31 with the base end fixing part 52. The manufacturer can insert the shaft part 31 into the base end fixing part 52.

[0041] Next, as Figure 8 As shown in (A), the manufacturer connects the protrusion 70 and the recess 71 of the first connecting structure 65. At this time, the circumferential position of the top 73 of the protrusion 70 within the opening bottom 75 of the recess 71 can be adjusted within the gap 76. Further, as... Figure 8 As shown in (B), the connecting support rod 80 of the second connecting structure 66 of the base end fixing part 52 can return to its original shape or a shape close to its original shape by its own elastic force, in a way that brings the two joint parts 81 that engage with the edge part 64 closer together. Furthermore, in the case of plastic deformation of the connecting support rod 80 during expansion, it can also shrink through plastic deformation. Therefore, as... Figure 8 As shown, even if the outer diameter of the shaft portion 31 has a deviation, the base end fixing portion 52 will, through the first connecting structure 65 and the second connecting structure 66, become an inner diameter suitable for the outer diameter of the shaft portion 31, thus making close contact with and connecting it to the shaft portion 31. Next, the manufacturer allows adhesive to flow between the base end fixing portion 52 and the shaft portion 31 to fix the base end fixing portion 52 to the shaft portion 31. At this time, adhesive can flow from the base end and front end of the base end fixing portion 52, the opposing portion 63, the first hollow portion 77, and the second hollow portion 78, etc., between the base end fixing portion 52 and the shaft portion 31. Thus, the base end fixing portion 52 and the shaft portion 31 are firmly fixed. Furthermore, the method of fixing the base end fixing portion 52 to the shaft portion 31 is not limited to bonding achieved by adhesive; for example, it can also be achieved by fastening by brazing, fusion welding, heat shrink tubing, etc.

[0042] Next, as Figure 2As shown, the manufacturer arranges multiple front-end support rods 50A on the outer peripheral surface of the front-end shaft portion 34 to form a front-end fixing portion 51, in a manner that prevents the front end of the expander 21 from unfolding due to the slit, and fixes it to the front-end shaft portion 34 using an adhesive or the like. Alternatively, the front-end support rods 50A can be fixed to the front-end shaft portion 34 before connecting the expander 21 to the shaft portion 31. Therefore, when the expander 21 is connected to the shaft portion 31, the expander 21 as a whole is difficult to disassemble, and the base-end fixing portion 52 can be easily fixed to the shaft portion 31.

[0043] Electrode 22 is disposed on conductive portion 60 of expansion body 21 and connected to an energy supply device (not shown) as an external device via conductive portion 60. A high-frequency voltage is applied from the energy supply device to the electrode pair composed of the two electrode portions 22 via conductive portion 60, thereby imparting energy between these components. In other words, electrode portion 22 is configured as a bipolar electrode.

[0044] During the expansion of the dilator 21, the electrode portion 22 is disposed on the front-facing surface of the base-side upright portion 57. Because the electrode portion 22 is located on the base-side upright portion 57, when the atrial septum is clamped by the waist portion 55, energy from the electrode portion 22 is transmitted from the right atrial side relative to the atrial septum. Furthermore, when the electrode portion 22 is located on the front-side upright portion 58, energy from the electrode portion 22 is transmitted from the left atrial side relative to the atrial septum.

[0045] like Figure 1 As shown, the hand-held operating unit 23 has a housing 40 for the surgeon to hold and an operating part 41 that allows the surgeon to move it axially along the traction shaft 33. The housing 40 is fixed to the base end of the shaft 31, and the operating part 41 is fixed to the base end of the traction shaft 33.

[0046] Medical device 10 is used to treat patients with chronic heart failure suffering from hypertrophy of the left ventricle leading to increased stiffness (rigidity) and elevated blood pressure in the left atrium. Medical device 10 inserts dilator 21 into a puncture hole in the atrial septum until the dilator 21 is halfway through. Therefore, the edge of the puncture hole formed on the atrial septum is positioned within a receiving space 59 defined by the waist portion 55. When the traction shaft 33 is pulled towards the base relative to the shaft portion 31, a compressive force is applied to the dilator 21, causing the front-side upright portion 58 and the base-side upright portion 57 to approach each other, and the electrode portion 22 positioned on the base-side upright portion 57 is pressed against the biological tissue. In this state, medical device 10 applies high-frequency energy to the edge of the puncture hole through the electrode portion 22, thereby enabling the high-frequency energy to cauterize (heat-cauterize) the edge of the puncture hole. This prevents blockage caused by the natural healing of the puncture hole and maintains its size.

[0047] As described above, the medical device 10 of this embodiment includes: an expansion body 21 formed by a plurality of support rods 50, the plurality of support rods 50 extending axially and arranged circumferentially around the axial direction; and a long shaft portion 31 connected to a base end fixing portion 52 formed at the base end of the expansion body 21. The base end fixing portion 52 has at least one opposing portion 63, the opposing portion 63 having a pair of opposing edges 64 that can approach and move away in the circumferential direction. The base end fixing portion 52 has a connecting structure that can connect the pair of opposing edges 64 and allows the circumferential distance between the pair of edges 64 to change before being connected to the shaft portion 31. Thus, by means of the connecting structure of the base end fixing portion 52, the circumference of the base end fixing portion 52 can be appropriately adjusted in conjunction with the outer diameter of the shaft portion 31, and the base end fixing portion 52 can be fixed to the shaft portion 31. Therefore, the medical device 10 can suppress the decrease in joint strength and the difficulty in assembly caused by the difference between the inner diameter of the base fixing part 52 of the expansion body 21 assembled relative to the shaft 31 and the outer diameter of the shaft 31.

[0048] The base end fixing portion 52, serving as the opposing portion 63, has a plurality of opposing portions 63 spaced apart circumferentially. Each of the plurality of opposing portions 63 has a pair of edges 64. The connecting structure has a plurality of connecting structures that can increase the circumferential distance between the pair of edges 64 in each of the plurality of opposing portions 63. As a result, the circumference of the base end fixing portion 52 can be adjusted more appropriately in conjunction with the outer diameter of the shaft portion 31.

[0049] At least one of the multiple connecting structures has a connecting support rod 80, which has two engaging portions 81 that respectively engage with a pair of opposing edges 64, and is formed to be longer than the straight-line distance between the two engaging portions 81 when viewed from the radially outer side. Thus, the connecting support rod 80 can deform to separate the two engaging portions 81. Therefore, the medical device 10 can adjust the circumference of the base fixing portion 52 by deforming the connecting support rod 80 in accordance with the outer diameter of the shaft portion 31. Therefore, even if there is a deviation in the outer diameter of the shaft portion 31, the base fixing portion 52 can be well fixed to the shaft portion 31. Furthermore, since at least one of the multiple connecting structures has a connecting support rod 80, the medical device 10 can prevent the pair of edges 64 from completely separating and easily disintegrating in all connecting structures. Therefore, the medical device 10 can suppress the reduction in operability when fixing the base fixing portion 52 to the shaft portion 31.

[0050] The connecting support rod 80 can be of a zigzag shape. As a result, the connecting support rod 80 can be easily deformed to extend the zigzag shape, thereby allowing the two joints 81 to separate.

[0051] At least one of the multiple interconnected structures includes a concave-convex structure having a protrusion 70 and a recess 71 for the protrusion 70 to fit into. The protrusion 70 is formed at one edge of a pair of edges 64 in a corresponding one of the multiple opposing portions 63 and protrudes circumferentially toward the other edge. The recess 71 is formed at the other edge of a pair of edges 64 in a corresponding one of the multiple opposing portions 63. The protrusion 70 has a root 72 formed at one circumferential end and a portion formed at the other circumferential end that is wider than the root 72. The expansion body 21 has a long top 73 in the axial direction, and a recess 71 with an open top 74 that accommodates the root 72 of the protrusion 70 and an open bottom 75 that communicates with the open top 74 and accommodates the top 73 of the protrusion 70. The circumferential length of the top 73 is shorter than the circumferential length of the open bottom 75. With the protrusion 70 and the recess 71 interlocked and a circumferential gap 76 formed between the top 73 of the protrusion 70 and the open bottom 75 of the recess 71, the base end of the expansion body 21 is fixed to the shaft portion 31. Thus, the medical device 10 can connect the top 73 of the protrusion 70 of the expansion body 21 to the open bottom 75 of the recess 71, fixing the expansion body 21 to the shaft portion 31. In addition, the circumferential gap 76 formed between the top 73 of the protrusion 70 and the open bottom 75 of the recess 71 allows for proper adjustment of the circumference of the base end fixing portion 52 in accordance with the outer diameter of the shaft portion 31. Therefore, even if the outer diameter of the shaft portion 31 has a deviation, the base fixing portion 52 can be well fixed to the shaft portion 31. Furthermore, by disengaging the protrusion 70 from the recess 71, the medical device 10 can completely separate the pair of edges 64 of the opposing portion 63. Therefore, since at least one of the multiple connecting structures has a completely separable protrusion 70 and recess 71, the medical device 10 can prevent the pair of edges 64 from not being completely separated in all connecting structures. Therefore, the medical device 10 can allow the opposing portion 63 to be significantly expanded so that the base fixing portion 52 covers the shaft portion 31, improving the operability when fixing the base fixing portion 52 to the shaft portion 31.

[0052] Alternatively, the multiple connecting structures may have two concave-convex structures arranged such that the base fixing portion 52 can be divided into a first fixing portion 52A and a second fixing portion 52B in the circumferential direction. Thus, the medical device 10 can divide the base fixing portion 52 into two, making it easier to insert the shaft portion 31 into the base fixing portion 52.

[0053] Alternatively, the multiple connecting structures may have multiple connecting support rods 80, each provided on at least one of the first fixing portion 52A and the second fixing portion 52B. Each of the multiple connecting support rods 80 has two joint portions 81 that respectively engage with a pair of edges 64 of a corresponding opposing portion 63, and are formed to be longer than the straight-line distance between the two joint portions 81 when viewed from the radial outer side. Thus, by having connecting support rods 80 on each of the divided first fixing portion 52A and the second fixing portion 52B, the medical device 10 can make it easier to insert the shaft portion 31 and can be evenly expanded in the circumferential direction.

[0054] The multiple connecting structures of the medical device 10 are evenly arranged circumferentially. Therefore, even if the perimeter of the base fixing portion 52 varies, the cross-sectional shape of the inner circumferential surface of the base fixing portion 52 can be maintained in a near-circular shape, ensuring a firm and tight contact between the base fixing portion 52 and the shaft portion 31. Furthermore, the medical device 10 allows the base fixing portion 52 to unfold evenly circumferentially, making it easy to position the base fixing portion 52 appropriately relative to the shaft portion 31. Therefore, the medical device 10 improves the operability of fixing the base fixing portion 52 to the shaft portion 31.

[0055] It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the scope of the inventive concept. For example, the connecting structure may not be formed on the base fixing portion 52, but on the front fixing portion 51. Additionally, as... Figure 9 As shown in the modified example, the expander 21 may not have a front-end fixing part. Instead of the traction shaft 33, the medical device 100 has at least one traction wire 101 connected to the operating part 41. The front end of the traction wire 101 is fixed to the waist 55. Therefore, by moving the traction wire 101 towards the base end according to the operating part 41, the diameter of the waist 55 can be adjusted.

[0056] Alternatively, the first connecting structure 65 and the second connecting structure 66 described above can be arranged axially on an opposing portion 63. That is, the first connecting structure 65 and the second connecting structure 66, which have different structures, can be combined to form a connecting structure.

[0057] It should be noted that this application is based on Japanese Patent Application No. 2024-028338, filed on February 28, 2024, the disclosure of which is referenced and incorporated herein by reference in its entirety. Explanation of reference numerals in the attached figures

[0058] 10 Medical Equipment 21. Expansion body 31 Shaft 50 support rod 51 Front-end fixing part 52. Base fixing part (fixing part) 52A First Fixing Part 52B Second Fixing Part 55 Waist 63 Opposite section 64. Edge section 65. First Connecting Structure (Connecting Structure) 66. Second Connecting Structure (Connecting Structure) 70 bulge 71 recess 72 Roots 73 Top 74 Opening top 75 Opening bottom 76 gap 80 Connecting support rod 81 Joint.

Claims

1. A medical device, characterized in that, have: An expansion body formed by multiple support rods extending along an axial direction and arranged circumferentially around the axial direction; and The long shaft portion connected to the fixing portion formed at the base end of the expansion body. The fixing part has at least one opposing part, the opposing part having a pair of edge portions that are opposed to each other in a manner that allows them to approach and move away in the circumferential direction. The fixing part has a connecting structure that can connect the opposing pair of edges and, in a state prior to being connected to the shaft part, allow the circumferential distance between the pair of edges to change.

2. The medical device according to claim 1, characterized in that, The fixing part has a plurality of opposing parts arranged at intervals along the circumference as the opposing parts, and each of the plurality of opposing parts has a pair of edge portions. The connecting structure has multiple connecting structures in each of the plurality of opposing portions that can increase the circumferential distance between the pair of edges.

3. The medical device according to claim 2, characterized in that, At least one of the plurality of connecting structures has a connecting support rod having two joints that respectively engage with the pair of opposing edges, and is formed to be longer than the straight-line distance between the two joints when viewed from the radially outer side.

4. The medical device according to claim 3, characterized in that, The connecting support rod has a zigzag structure.

5. The medical device according to any one of claims 2 to 4, characterized in that, At least one of the plurality of interconnecting structures has a concave-convex structure, the concave-convex structure having a protrusion and a recess for the protrusion to fit into, the protrusion being formed at one edge of a pair of edges in a corresponding one of the plurality of opposing portions and protruding circumferentially toward the other edge, the recess being formed at the other edge of the pair of edges in a corresponding one of the plurality of opposing portions. The protrusion has a root formed at one circumferential end and a top formed at the other circumferential end, which is longer in the axial direction than the root. The recess has an open top that receives the root of the protrusion, and an open bottom that communicates with the open top and receives the top of the protrusion. The circumferential length of the top is shorter than the circumferential length of the bottom of the opening. With the protrusion and the recess engaged, and a circumferential gap formed between the top of the protrusion and the bottom of the opening of the recess, the base end of the expansion body is fixed to the shaft.

6. The medical device according to claim 5, characterized in that, The plurality of connecting structures have two concave-convex structures arranged in such a way that the fixing part can be divided into a first fixing part and a second fixing part in the circumferential direction.

7. The medical device according to claim 6, characterized in that, The plurality of connecting structures have at least one plurality of connecting support rods provided on each of the first fixing part and the second fixing part. Each of the plurality of connecting support rods has two joints that respectively engage with a pair of edges in one of the corresponding opposing portions of the plurality of opposing portions, and is formed to be longer than the straight-line distance between the two joints when viewed from the radially outer side.

8. The medical device according to any one of claims 1 to 4, characterized in that, The multiple connecting structures are arranged approximately equally in the circumferential direction.

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