Catheter

Abstract

To provide a catheter which holds splines at a proper interval and deforms.SOLUTION: A catheter comprises: a shaft inserted into a body; and multiple sets of splines 3, each set being formed of two splines connected to a tip side of the shaft. The two splines 3 forming the set of the splines 3 are arranged so as to sandwich therebetween at least one spline 3 belonging to another set. The mutual movements of the multiple sets of splines 3 are restricted by one restriction member.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to catheters. [Background technology]

[0002] A catheter is a type of medical device that is inserted into the body for diagnosis or treatment. As an example, a catheter is known that includes a shaft and a basket electrode assembly coupled to the tip of the shaft (see, for example, Patent Document 1). Here, the basket electrode assembly includes a plurality of splines. The basket electrode assembly is configured to deform from a contracted shape to an expanded shape by deforming the splines. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2016-507349 Summary of the Invention [Problem to be solved by the invention]

[0004] When the above-mentioned catheter is deformed with the splines in contact with tissue inside the body, there is a risk that the spacing between the splines may become too narrow or too wide.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and has an object to provide a catheter that can be deformed while maintaining splines at an appropriate interval. [Means for solving the problem]

[0006] One embodiment of the present disclosure is a catheter. The catheter includes a shaft to be inserted into a body, and multiple sets of splines, each consisting of two splines connected to the distal end side of the shaft. The two splines constituting a set of splines are arranged with at least one spline belonging to another set sandwiched between them. The movements of the multiple sets of splines are constrained relative to each other by a single restraining member, respectively.

[0007] Another aspect of the present disclosure is a catheter. The catheter includes a shaft to be inserted into a body and a plurality of splines connected to a distal end side of the shaft. The plurality of splines include a first spline and a second spline. The first spline and the second spline are disposed with at least one other spline therebetween, and the movements of the first spline and the second spline are restrained by a first restraining member.

[0008] Any combination of the above components and any conversion of the expression of the present disclosure between a method, an apparatus, a system, etc. are also valid as aspects of the present disclosure. Effect of the Invention

[0009] The catheter of the present disclosure can be modified to maintain the splines at the appropriate spacing. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view showing a schematic example of a deformed state near the tip of a catheter according to a first embodiment of the present disclosure. [Diagram 2] 13 is a perspective view showing a schematic diagram of another example of a deformed state near the tip of the catheter according to the first embodiment of the present disclosure. FIG. [Diagram 3] FIG. 2 is a perspective view of the catheter shown in FIG. 1 with the splines removed. [Figure 4] FIG. 2 is a perspective view of the catheter shown in FIG. 1 with a tip member removed. [Diagram 5] FIG. 5 is an enlarged view of the tip region shown in FIG. [Figure 6] FIG. 2 is a side view showing a schematic example of a structure near the tip of the catheter of the present embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along the line AA shown in FIG. [Figure 8] FIG. 7 is a cross-sectional view taken along line BB shown in FIG. [Figure 9] FIG. 1 is a schematic diagram showing an example of the overall structure of a catheter according to the present disclosure. [Figure 10] 7 is a cross-sectional view taken along line CC shown in FIG. 6. [Figure 11] FIG. 11 is a perspective view showing a schematic example of a deformed state near the tip of a catheter according to a second embodiment. [Figure 12] 12 is an enlarged view of the distal end region shown in FIG. 11 with the distal end member removed from among the members constituting the catheter shown in FIG. 11. [Figure 13] FIG. 12 is a schematic diagram of the catheter shown in FIG. 11, viewed from the tip side, with the tip member removed. [Figure 14] FIG. 11 is a perspective view showing a schematic example of a deformed state near the tip of a catheter according to a third embodiment. [Figure 15] 15 is an enlarged view showing a connection portion of a plurality of restraining members shown in FIG. 14. FIG. [Figure 16] 15 is a diagram showing an example in which the connecting portions of the restraining members shown in FIG. 14 are not exposed from the tip end side of the spline. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present disclosure will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, members, and processes shown in each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the scale and shape of each part shown in each drawing are set for convenience to facilitate explanation, and are not to be interpreted as being limiting unless otherwise specified. In addition, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. In addition, some of the members that are not important in explaining the embodiment in each drawing are omitted.

[0012] [First embodiment] FIG. 1 is a perspective view showing an example of a deformation state near the tip of the catheter 1 according to the first embodiment of the present disclosure. FIG. 2 is a perspective view showing another example of a deformation state near the tip of the catheter 1 according to the first embodiment of the present disclosure. As shown in FIG. 1 and FIG. 2, the catheter 1 includes a shaft 2 to be inserted into the body, a plurality of splines 3a to 3h connected to the tip side of the shaft 2, and a tip member 4 connected to the tip side of each of the plurality of splines 3a to 3h. Hereinafter, the common explanation for each of the plurality of splines 3a to 3h will be simply described as a spline 3. For other symbols with alphabets added to the end, the common explanation for those symbols will be described without adding alphabets as appropriate. Hereinafter, the side of the catheter 1 inserted into the body will be referred to as the "tip side", and the side placed outside the body will be referred to as the "base side". In addition, for each member constituting the catheter 1, the same side as the tip side of the catheter 1 will be referred to as the "tip side" of the member, and the same side as the base side of the catheter 1 will be referred to as the "base side" of the member.

[0013] The shaft 2 may be a long cylindrical member. The length of the shaft 2 is, for example, 800 mm to 1800 mm. The outer diameter of the shaft 2 is, for example, 2.0 mm to 5.0 mm. The material constituting the shaft 2 may be any material that is flexible and biocompatible. For example, the shaft 2 is made of a known resin such as polyolefin or polyamide.

[0014] The spline 3 is a member that connects the shaft 2 and the tip member 4. The spline 3 may be a cylindrical member like the shaft 2. The length of the spline 3 when extended linearly is, for example, 20 mm to 50 mm. The outer diameter of the spline 3 is, for example, 0.5 mm to 2.0 mm. The material constituting the spline 3 may be any material that is flexible and biocompatible. For example, the spline 3, like the shaft 2, is made of a known resin such as polyolefin or polyamide.

[0015] The catheter 1 according to this embodiment includes eight splines 3a to 3h. The splines 3a to 3h are arranged adjacent to each other in the following order clockwise along the circumferential direction when viewed from the distal end side. That is, the splines 3a and 3b, the splines 3b and 3c, the splines 3c and 3d, the splines 3d and 3e, the splines 3e and 3f, the splines 3f and 3g, the splines 3g and 3h, and the splines 3h and 3a are adjacent to each other. In addition, in a plane perpendicular to the central axis of the shaft 2, the splines 3 are arranged spaced apart from each other.

[0016] The spline 3 is connected to the shaft 2. As an example, a part (base end) of the spline 3 including the base end is inserted into the tip side of the shaft 2. The base end of the spline 3 and the shaft 2 are joined to each other by a known joining method such as welding or bonding with an adhesive.

[0017] The splines 3 are configured to change shape, i.e., to deform, in response to a deformation operation, which will be described later. Specifically, the shape of each spline 3 changes between a non-deployed shape or contracted shape in which the splines 3 are not deployed along the central axis of the shaft 2, and a deployed shape or expanded shape in which the splines 3 are deployed from the non-deployed shape along the central axis of the shaft 2. Details will be described later, but an example of the non-deployed shape is a "petal shape" (see FIG. 2). On the other hand, an example of the deployed shape is a "basket shape" (see FIG. 1) in which the splines 3 are deployed from the petal shape along the central axis of the shaft 2.

[0018] FIG. 3 is a perspective view of the catheter 1 shown in FIG. 1 with the spline 3 removed. FIG. 4 is a perspective view of the catheter 1 shown in FIG. 1 with the tip member 4 removed. FIG. 5 is an enlarged view of the tip region S shown in FIG. 4. As shown in FIGS. 3 to 5, the splines 3a and 3c are restrained from moving relative to each other by the restraining member 6a. Here, the restraining of the movements relative to each other means that when the splines 3a and 3c are deformed, the splines 3a and 3c are deformed while maintaining an appropriate interval between them. The interval here means the shortest distance between the tip side of the spline 3a and the tip side of the spline 3c. Therefore, even if a deformation operation is performed while the spline 3a is in contact with tissue in the body, the splines 3a and 3c are deformed while maintaining an appropriate interval between them via the restraining member 6a. Since this configuration is satisfied, the catheter 1 of this embodiment can be deformed into a desired shape, that is, a non-deployed shape or a deployed shape, while maintaining the splines 3 at an appropriate interval.

[0019] The splines 3a and 3c, whose mutual movements are restrained by the restraining member 6a, are disposed on either side of the spline 3b and are not adjacent to each other. Therefore, compared to the case where the movements of adjacent splines 3 are restrained, the movements of distant splines 3 are restrained, making processing easier. The greater the number of splines 3 provided in the catheter 1, the more precise processing is required, and therefore the above-mentioned effect of this configuration becomes more pronounced.

[0020] The above-mentioned configuration can also be expressed as follows: In other words, when the spline 3a is the first spline, the spline 3c is the second spline, and the restraining member 6a is the first restraining member, the first spline and the second spline are disposed with at least one other spline therebetween, and the mutual movements are restrained by the first restraining member.

[0021] As described above, the splines 3a and 3c constitute a pair of splines 3 whose mutual movements are constrained by one constraining member 6a. Similarly, the splines 3b and 3d constitute another pair of splines 3 whose mutual movements are constrained by one constraining member 6b. The splines 3a and 3c constituting the pair of splines 3 are disposed with one spline 3b belonging to the other pair sandwiched therebetween. As a result, in the same manner as above, the catheter 1 of this embodiment can hold the splines 3 at an appropriate interval, can be deformed into a desired shape, and can be more easily processed.

[0022] The above-mentioned configurations regarding the pair of splines 3a and 3c and the pair of splines 3b and 3d may be similar to those of other splines 3. That is, the splines 3 arranged with at least one spline between them may have their movements restrained by one restraining member 6. Specifically, the splines 3c and 3e may have their movements restrained by the restraining member 6c. The splines 3d and 3f may have their movements restrained by the restraining member 6d. The splines 3e and 3g may have their movements restrained by the restraining member 6e. The splines 3f and 3h may have their movements restrained by the restraining member 6f. The splines 3g and 3a may have their movements restrained by the restraining member 6g. The splines 3h and 3b may have their movements restrained by the restraining member 6h. In other words, the catheter 1 includes a plurality of pairs of splines 3 whose movements are restrained by one restraining member 6. Here, one set of splines 3 is made up of two splines 3. As described above, one spline 3 forms a different set with the other two splines 3. For example, spline 3a forms a set with spline 3c, and also forms a set with spline 3g.

[0023] In the present embodiment, an example has been shown in which a set of splines 3 is disposed with one spline 3 therebetween. However, it is sufficient that a set of splines 3 is disposed with at least one other spline 3 therebetween. In other words, a set of splines 3 may be disposed with two splines 3 therebetween, or may be disposed with three or more splines 3 therebetween.

[0024] The restraining member 6 may have any shape, structure, or material as long as it is a member that can restrain the mutual movement of the two splines 3 that make up one set of splines 3. As an example, the restraining member 6 is a wire. The material of the wire may be a shape memory alloy such as a nickel-titanium alloy.

[0025] The restraining member 6 may have a first end and a second end. At least a part of the first end side of the restraining member 6 may be located in one of the splines 3 constituting the set of splines 3, and at least a part of the second end side of the restraining member 6 may be located in the other of the splines 3 constituting the set of splines 3. The restraining member 6 may have a connecting portion that connects the tip of one of the splines 3 to the tip of the other of the splines 3. The connecting portion in this embodiment is a protruding portion 15 that protrudes further toward the tip side than the tip of one of the splines 3 and the tip of the other of the splines 3. Here, the at least a part of the first end side refers to a portion of the restraining member 6 that has a constant length continuing from the first end side of the protruding portion 15. The at least a part of the second end side refers to a portion of the restraining member 6 that has a constant length continuing from the second end side of the protruding portion 15. In this way, when the restraint member 6 is configured to connect the tips of a pair of splines 3 by a connecting portion, the catheter 1 of this embodiment connects the tips of non-adjacent splines 3 that are farther apart than connecting the tips of adjacent splines 3, making processing easier.

[0026] For example, at least a portion of the first end side of the restraining member 6a may be located within the spline 3a, and at least a portion of the second end side of the restraining member 6a may be located within the spline 3c. The restraining member 6a may have a protruding portion 15a that protrudes further toward the tip side than the tip of the spline 3a and the tip of the spline 3c.

[0027] The first end of the restraining member 6 may be located closer to the base end than the base end of one of the splines 3. The second end of the restraining member 6 may be located closer to the base end than the base end of the other spline 3. For example, the first end of the restraining member 6a may be located closer to the base end than the base end of the spline 3a. Also, for example, the second end of the restraining member 6a may be located closer to the base end than the base end of the spline 3c. If such a configuration is satisfied, the restraining member 6 plays the role of a skeleton that maintains the shape of the two splines 3 that constitute the set of splines 3.

[0028] When the restraining member 6 is a wire, the protruding portion 15 may be bent into a U-shape. When at least one of the pair of splines 3 restrained by the restraining member 6 is deformed, the restraining member 6 is also deformed in conjunction with it. At this time, stress generated by the deformation is concentrated in the protruding portion 15. If the protruding portion 15 is bent into a U-shape, the above-mentioned stress can be effectively alleviated, and the risk of the protruding portion 15 breaking even if it is repeatedly deformed is reduced.

[0029] FIG. 6 is a side view showing a schematic example of a structure near the tip of the catheter 1 of this embodiment. FIG. 7 is a cross-sectional view taken along line AA shown in FIG. 6. As shown in FIG. 7, the spline 3a may have a multi-lumen structure. Specifically, the spline 3a has four lumens 7 (7a1, 7b1, 7c1, 7d1) extending from the tip to the base end along the central axis of the spline 3a. Here, the lumens 7a1 and 7b1 are located closer to the central axis of the shaft 2 than the lumens 7c1 and 7d1. Also, the lumens 7b1 and 7c1 are located closer to the spline 3b than the lumens 7a1 and 7d1.

[0030] The spline 3c may have a multi-lumen structure, similar to the spline 3a. Specifically, the spline 3c has four lumens 7 (7a3, 7b3, 7c3, 7d3) extending from the tip to the base along the central axis of the spline 3c. Here, the lumens 7a3 and 7b3 are located closer to the central axis of the shaft 2 than the lumens 7c3 and 7d3. Also, the lumens 7a3 and 7d3 are located closer to the spline 3b than the lumens 7b3 and 7c3.

[0031] A first end side of the restraining member 6a may be inserted into the lumen 7c1 of the spline 3a. Meanwhile, a second end side of the restraining member 6a may be inserted into the lumen 7d3 of the spline 3c. In this manner, by inserting the restraining member 6a into the lumens 7c1, 7d3 that are located away from the central axis side of the shaft 2 and are closest to each other among the lumens 7 of the splines 3a and 3c, the splines 3a and 3c are maintained at a more appropriate interval.

[0032] In the above-described embodiment, the splines 3a, 3c, and the restraining member 6a have been described as examples, but the same may be true for the other splines 3 and restraining members 6. In this case, the splines 3 in each set are positioned away from the central axis side of the shaft 2, and the restraining member 6 is inserted into the closest set of lumens 7, so that the restraining members 6 are unlikely to interfere with each other.

[0033] As shown in FIG. 6, each spline 3 may have one or more electrodes 5. The electrode 5 is a ring-shaped electrode for measuring electric potential or for cauterization. The electrodes 5 of the same spline 3 are arranged apart from each other along the longitudinal direction of the spline 3. In this case, the intervals between adjacent electrodes 5 may be constant or may be different. Also, the number of electrodes 5 of each spline 3 may be the same or different.

[0034] The electrodes 5 are made of a material having electrical conductivity. For example, the electrodes 5 are made of a metal having good electrical conductivity, such as aluminum (Al), copper (Cu), stainless steel, gold (Au), platinum (Pt), etc. The length of the electrodes 5 is, for example, 0.5 mm to 2.0 mm. The outer diameter of the electrodes 5 may be equal to the outer diameter of the spline 3, and is, for example, 0.5 mm to 1.6 mm.

[0035] Conductive wires are individually and electrically connected to the electrodes 5. The conductive wires pass from inside the spline 3 through the shaft 2 and the handle 8 described below, and are connected to an external power supply device via the handle 8. As an example, the conductive wires connected to the electrodes 5 of the spline 3a pass through the lumen 7a1 or lumen 7b1 of the spline 3a while being electrically insulated from each other. The same applies to the splines 3 other than the spline 3a.

[0036] As shown in Figs. 2 and 4, the tip member 4 may cover a part including the tip of the spline 3a (hereinafter referred to as "tip portion"), the tip of the spline 3c, and the protrusion 15a of the restraining member 6a. In other words, the tip of the spline 3a, the tip of the spline 3c, and the protrusion 15 of the restraining member 6a may be covered with the tip member 4. The tip member 4 may have any shape, and is cap-shaped as an example. The tip member 4 may be made of any material, and is made of known resins such as nylon, nylon elastomer, polycarbonate, etc., or known metals such as stainless steel, etc. The tip member 4 may cover all of the tip of each spline 3 and the protrusion 15 of each restraining member 6.

[0037] 8 is a cross-sectional view taken along the line BB in FIG. 6. As shown in FIG. 8, in a plan view seen from the base end side of the tip member 4, the wall constituting the inner surface of the tip member 4 may have adjacent recesses 9a and 9b. At least a part of the tip of the spline 3a may be located in the recess 9a, and at least a part of the tip of the spline 3b may be located in the recess 9b. Here, "at least a part of the tip of the spline 3 is located in the recess 9" means that the spline 3 has a part overlapping the region of the recess 9 in a plan view seen from the base end side of the tip member 4. If such a configuration is satisfied, the recesses 9a and 9b can prevent the tip of the spline 3a from being displaced from the tip of the spline 3b when the spline 3a and the spline 3b are deformed.

[0038] The shapes of the recesses 9a and 9b are, for example, semicircular in plan view from the base end side of the tip member 4. The wall portion constituting the recess 9a may or may not be in contact with the spline 3a. Similarly, the wall portion constituting the recess 9b may or may not be in contact with the spline 3b. Note that FIG. 8 illustrates an example in which the wall portion constituting the inner surface of the tip member 4 has eight recesses 9. In this way, the wall portion constituting the inner surface of the tip member 4 may have recesses 9 corresponding to each spline 3.

[0039] The inside of the tip member 4 may be filled with an adhesive. If such a configuration is satisfied, the splines 3a, 3c, and the restraining member 6a are firmly joined by the adhesive, so that the splines 3a and 3c are held at a more appropriate distance. This also applies to the splines 3 other than the splines 3a and 3c, and the restraining member 6 other than the restraining member 6a.

[0040] As shown in Fig. 5, the tip member 4 may include a bundling member 10 therein for bundling the protrusions 15a of the restraining members 6a. Here, bundling the protrusions 15a means restraining the protrusions 15a so that they do not move in a plane perpendicular to the central axis of the shaft 2. If such a configuration is satisfied, the bundling member 10 suppresses twisting of the restraining members 6a, and it becomes easier to effectively link the deformation of the splines 3a and 3c via the restraining members 6a. The bundling member 10 may bundle each of the protrusions 15 of all the restraining members 6.

[0041] The binding member 10 may have any shape, structure, or material as long as it is a member capable of bundling the protruding portion 15a. As an example, the binding member 10 has a plate-like shape having an upper surface on the tip side (hereinafter referred to as the "first surface") and a lower surface on the base side (hereinafter referred to as the "second surface") which is the reverse side of the first surface. The second surface faces the tip surface of the spline 3a and the tip surface of the spline 3c. Furthermore, the binding member 10 is provided with a through hole 16a penetrating from the first surface to the second surface, into which the protruding portion 15a of the restraining member 6a is inserted. In addition, the side surface connecting the first surface and the second surface of the binding member 10 (hereinafter referred to as the "third surface") may have a shape corresponding to the wall portion constituting the inner surface of the tip member 4. Specifically, it may have a shape having a protruding portion corresponding to each recess 9 of the tip member 4. In addition, the material constituting the binding member 10 may have a high rigidity. For example, the binding member 10 is made of a known metal such as stainless steel. The binding member 10 may be provided with through holes 16 corresponding to the protrusions 15 of the respective binding members 6.

[0042] The through hole 16a may have any shape as long as the protrusion 15a of the restraining member 6a can be inserted therein. As an example, the shape of the through hole 16a is an ellipse in a plan view seen from the first surface side of the binding member 10. The other through holes 16 may have the same shape.

[0043] As shown in FIG. 5, the restraining member 6a corresponding to the splines 3a and 3c and the restraining member 6b corresponding to the splines 3b and 3d may have their respective protrusions 15a and 15b bent in different directions when viewed from the distal end. Here, "viewed from the distal end" means viewing the catheter 1 from the distal end side of the catheter 1. The restraining members 6a and 6b are in a relationship in which they partially overlap in the circumferential direction of the catheter 1. In this embodiment, the restraining member 6a is bent toward the radially outer side of the catheter 1 more than the restraining member 6b. The same may be true for the restraining members 6 other than the restraining members 6a and 6b that partially overlap in the circumferential direction of the catheter 1.

[0044] In this way, the protrusions 15 of the first restraining member 6 corresponding to the first set of splines 3 and the second restraining member 6 corresponding to the second set of splines 3 including the spline 3 sandwiched between the two splines 3 constituting the first set of splines 3 may be bent in different directions as viewed from the tip side. This makes it difficult for the restraining members 6 to interfere with each other, making processing easier. Such restraining members 6 can be made of, for example, shape memory alloy wires bent into different shapes.

[0045] Fig. 9 is a schematic diagram showing an example of the overall structure of the catheter 1 of the present disclosure. As shown in Fig. 10, the catheter 1 may include a handle 8 connected to the base end side of the shaft 2. The handle 8 is a part that an operator such as a doctor grasps or holds when using the catheter 1. The handle 8 may include a handle main body 11 attached to the base end side of the shaft 2, a rotation operation unit 12, and a slide member 13.

[0046] The handle body 11 corresponds to the portion that the operator actually grips. The handle body 11 may have any shape. As an example, the handle body 11 has a shape that extends along the central axis of the shaft 2. The handle body 11 is made of a known resin, such as polycarbonate, polyacetal, ABS, etc.

[0047] The rotation operation unit 12 is a part that is operated, such as by rotating, when bending or flexing the vicinity of the tip of the shaft 2 in both directions. The base ends of a pair of pull wires are fixed to the rotation operation unit 12 within the handle body 11. The tips of the pair of pull wires pass from within the handle body 11 through the shaft 2 and are fixed to the tip side of the shaft 2. Therefore, when the rotation operation unit 12 is operated, the pull wires are pulled toward the base end side, and the tip side of the shaft 2 to which the tips of the pull wires are fixed is bent or flexed.

[0048] The slide member 13 is a part that is subjected to a deformation operation such as a sliding operation by an operator when the shape of the spline 3 is changed between the undeployed shape or contracted shape and the deployed shape or expanded shape. The slide member 13 is slidable along the central axis of the shaft 2 in the handle body 11.

[0049] A base end of a deformation member 14 is fixed to the slide member 13. A tip end of the deformation member 14 passes through the inside of the shaft 2 from inside the handle body 11 and is fixed in the tip member 4. The slide member 13 is movable to any position along the central axis of the shaft 2 in the handle body 11. Therefore, depending on the position of the slide member 13, the shape of the spline 3 can be deformed to the above-mentioned non-deployed shape or contracted shape, the deployed shape or expanded shape, or any intermediate shape between the non-deployed shape and the deployed shape.

[0050] The deformation member 14 may have any shape, structure, or material as long as it is long. As an example, the deformation member 14 is a wire that is thicker than the restraint member 6.

[0051] Fig. 10 is a cross-sectional view taken along line CC shown in Fig. 6. As shown in Fig. 10, the shaft 2 has a large lumen 18 at a position including the center on the radially inner side. The large lumen 18 extends from the base end to the tip end of the shaft 2. The shaft 2 has eight small lumens 17a to 17h arranged in the circumferential direction around the large lumen 18, and two pullwire lumens 19a, 19b arranged symmetrically about the center of the shaft 2. The eight small lumens 17a to 17h are arranged adjacent to each other in this order in the clockwise direction along the circumferential direction when viewed from the tip end side.

[0052] The first and second ends of each of the multiple restraining members 6 may be disposed within the shaft 2. Specifically, the first end of restraining member 6a is disposed within small lumen 17a, and the second end of restraining member 6a is disposed within small lumen 17c. Similarly, the first end of restraining member 6b is disposed within small lumen 17b, and the second end of restraining member 6b is disposed within small lumen 17d. The same may be true for the other restraining members 6.

[0053] A pair of pull wires 22a, 22b extend from the base end to the tip end within shaft 2. Specifically, pull wire 22a is disposed within pull wire lumen 19a. Pull wire 22b is disposed within pull wire lumen 19b. As a result, the pair of pull wires 22a, 22b are disposed symmetrically with respect to approximately the center of shaft 2 in a cross-sectional view perpendicular to the axis of shaft 2 shown in FIG.

[0054] In the cross-sectional view shown in FIG. 10, the eight small lumens 17a to 17h are arranged symmetrically with respect to a line 24 passing through the center positions of the pair of pull wires 22a and 22b. Specifically, the small lumens 17a and 17f, the small lumens 17b and 17e, the small lumens 17c and 17d, and the small lumens 17g and 17h are each arranged symmetrically with respect to the line 24. Therefore, the multiple restraining members 6 arranged in the multiple small lumens 17 are also arranged symmetrically with respect to the line 24. As a result, when bending the vicinity of the tip of the shaft 2 in two directions on the same plane using the pair of pull wires 22a and 22b, bias in flexibility and weight balance on both sides of the plane is reduced, thereby improving planarity.

[0055] In this embodiment, the term "axis symmetric" is used for convenience, but in the actual shaft 2, it is not required that each small lumen 17 is provided in strict axis symmetry. For example, each small lumen 17 may be disposed within a predetermined distance from the axis symmetric position. Specifically, the distance of each small lumen 17 from the axis symmetric position may be within 30% of the diameter of each lumen 17, preferably within 20%, and more preferably within 10%.

[0056] In the cross-sectional view shown in Fig. 10, the eight small lumens 17a to 17h are arranged point-symmetrically with respect to the axis of the shaft 2. Specifically, the small lumens 17a and 17e, the small lumens 17b and 17f, the small lumens 17c and 17g, and the small lumens 17d and 17h are each arranged point-symmetrically with respect to the axis of the shaft 2. Therefore, the multiple restraining members 6 arranged in the multiple small lumens 17 are also arranged point-symmetrically with respect to the axis of the shaft 2. This reduces the bias in flexibility and weight balance at the position facing the axis of the shaft 2, thereby further improving planarity.

[0057] In this embodiment, the term "point symmetry" is used for convenience, but in the actual shaft 2, it is not required that each small lumen 17 is provided strictly point symmetrically. For example, each small lumen 17 may be disposed within a predetermined distance from the point symmetric position. Specifically, the distance of each small lumen 17 from the point symmetric position may be within 30% of the diameter of each lumen 17, preferably within 20%, and more preferably within 10%.

[0058] Furthermore, as described above, by arranging multiple restraining members 6 in the small lumen 17 that is arranged around the large lumen 18 of the shaft 2, it is possible to ensure a wide cross-sectional area perpendicular to the axial direction of the large lumen 18. This makes it easier to arrange the multiple conducting wires 26, the water supply tube 28, the deformation member 14 that is arranged at a position including the center of the water supply tube 28, and other components that are arranged in the large lumen 18, as shown in Fig. 10.

[0059] As described above, the catheter 1 according to the first embodiment has been described as including eight splines 3a to 3h. However, the number of splines 3 included in the catheter 1 is not limited to eight, and may be four or more. However, as described above, from the viewpoint of performing well-balanced operations using the pair of pull wires 22, it is preferable that the number of splines 3 is an even number.

[0060] [Second embodiment] A second embodiment of the present disclosure will be described with reference to Figures 11 to 13. In the following embodiments, among the components described in the first embodiment, the same content as in the first embodiment may be applied to the components not described below. Figure 11 is a perspective view showing a schematic example of a deformation state near the tip of a catheter 101 according to a second embodiment.

[0061] The catheter 101 includes a shaft 102 to be inserted into the body, a plurality of splines 103a to 103l connected to the distal end of the shaft 102, and a distal end member 104 connected to the distal end of each of the plurality of splines 103a to 103l. The splines 103a to 103l are arranged adjacent to each other in this order in a clockwise direction along the circumferential direction as viewed from the distal end. The catheter 101 of this embodiment differs from the catheter 1 of the first embodiment in that it includes 12 splines 103a to 103l. The configuration of each spline 103 is the same as the spline 3 of the first embodiment. The shaft 102 and the distal end member 104 are the same as the shaft 2 and the distal end member 4 of the first embodiment, respectively, except that they are shaped to correspond to the 12 splines 103a to 103l. In FIG. 11, the spline 103 is in a "basket shape" as an expanded shape, similar to FIG. 1 of the first embodiment.

[0062] FIG. 12 is an enlarged view of the distal end region T shown in FIG. 11, with the distal end member 104 removed from among the members constituting the catheter 101 shown in FIG. 11. FIG. 13 is a schematic view seen from the distal end side, with the distal end member 104 removed from among the members constituting the catheter 101 shown in FIG. 11. As shown in FIG. 12 and FIG. 13, the restraining member 106a restrains the spline 103a and the spline 103d. The restraining member 106b restrains the spline 103b and the spline 103e. The restraining member 106c restrains the spline 103c and the spline 103f. Thus, in this embodiment, one set of splines 103a and 103d are disposed with two splines 103b and 103c belonging to the other set sandwiched therebetween. This is the same for the other splines 103.

[0063] As shown in Fig. 13, the protruding portions of the restraining member 106a corresponding to the splines 103a and 103d, the restraining member 106b corresponding to the splines 103b and 103e, and the restraining member 106c corresponding to the splines 103c and 103f may be bent in different directions as viewed from the distal end side. The restraining members 106a, 106b, and 106c are in a relationship in which they partially overlap in the circumferential direction of the catheter 101. In this embodiment, the restraining member 106a is bent more toward the inside in the radial direction of the catheter 101 than the restraining members 106b and 106c. The restraining member 106b is bent less than the restraining members 106a and 106c. Restraint member 106c is bent more radially outwardly of catheter 101 than restraint members 106a and 106b. The same may be true for restraint members 106 that partially overlap in the circumferential direction of catheter 101 other than restraint members 106a, 106b, and 106c. As a result, catheter 101 of this embodiment can also achieve the same effects as the first embodiment.

[0064] [Third embodiment] A third embodiment of the present disclosure will be described with reference to Fig. 14 to Fig. 16. Fig. 14 is a perspective view showing a schematic example of a deformed state near the tip of a catheter 201 according to the third embodiment. The catheter 201 includes a shaft 2 and a plurality of splines 3a to 3j connected to the tip side of the shaft 2. Although not shown in Fig. 14, the catheter 201 may include a tip member, similar to the catheter 1 of the first embodiment.

[0065] The catheter 201 of this embodiment differs from the catheter 1 of the first embodiment in that the connecting portion of the restraining member 206 does not protrude to the tip side. FIG. 15 is an enlarged view of the connecting portion of the plurality of restraining members 206. As shown in FIG. 15, each restraining member 206 has a structure in which the restraining members 206 adjacent in the circumferential direction are intertwined with each other. Specifically, in the example shown in FIG. 15, when the clockwise direction in the circumferential direction as viewed from the tip side is taken as the positive direction, the connecting portion of each restraining member 206 is disposed so as to be located more distally than the connecting portion of the adjacent restraining member 206 in the negative direction and more proximal than the connecting portion of the adjacent restraining member 206 in the positive direction. In this way, by forming the connecting portions of each restraining member 206 into an intertwined structure, the relative positions of the plurality of restraining members 206 can be stabilized without using a member such as the bundling member 10 of the first embodiment.

[0066] 16 is a diagram showing an example in which the connecting portion of each of the restraining members 206 is not exposed from the tip side of the spline 3. Even with such a configuration, each of the restraining members 206 can obtain the same effects as those described above.

[0067] The above describes the embodiments of the present disclosure in detail. The above-mentioned embodiments merely show specific examples of implementing the present disclosure. The contents of the embodiments do not limit the technical scope of the present disclosure, and many design changes such as changes, additions, and deletions of components are possible within the scope of the idea of ​​the present disclosure defined in the claims. A new embodiment with a design change has the effects of each of the combined embodiments and modifications. In the above-mentioned embodiments, the contents for which such design changes are possible are emphasized by adding notations such as "in this embodiment" and "in this embodiment", but design changes are permitted even in contents without such notations. Any combination of components included in each embodiment is also valid as an aspect of the present disclosure. The hatching on the cross section of the drawing does not limit the material of the object to which the hatching is added.

[0068] The embodiment may be specified by the items described below. [1st item] A shaft (2) to be inserted into the body; A plurality of sets of splines (3) connected to the tip side of the shaft (2), Two splines (3) constituting a set of splines (3) are arranged with at least one spline (3) belonging to another set therebetween, The plurality of sets of splines (3) are each restricted in their mutual movement by a single restricting member (6). Catheter (1). [Second item] The restraining member (6) has a first end and a second end, At least a portion of the first end side of the restraining member (6) is located within one of the splines (3) that constitute the pair of splines (3), At least a portion of the second end side of the restraining member (6) is located within the other spline (3) that constitutes the pair of splines (3), The restraining member (6) has a connecting portion that connects the tip of one spline (3) to the tip of the other spline (3). A catheter (1) as described in item 1. [3rd item] The connecting portion of the restraining member (6) is a tip end of one spline (3) and a protruding portion (15) protruding further toward the tip side than the tip end of the other spline (3). A catheter (1) as described in item 2. [4th item] a first restraining member (6) corresponding to the first set of splines (3) and a second restraining member (6) corresponding to the second set of splines (3) including a spline (3) sandwiched between two splines (3) constituting the first set of splines (3), each have a protruding portion (15) bent in a different direction when viewed from the tip side; A catheter (1) as described in item 3. [Item 5] A first end and a second end of each of the plurality of restraining members (6) are disposed within the shaft (2); In a cross-sectional view perpendicular to the axis of the shaft (2), the plurality of restraining members (6) are arranged symmetrically with respect to a straight line (24) passing through the center positions of the pair of pull wires (22). A catheter (1) according to any one of items 2 to 4. [Item 6] A first end and a second end of each of the plurality of restraining members (6) are disposed within the shaft (2); In a cross-sectional view perpendicular to the axis of the shaft (2), a plurality of restraining members (6) are arranged point-symmetrically with respect to the axis of the shaft (2). A catheter (1) according to any one of items 2 to 4. [Item 7] The gear further includes a tip member (4) that covers the tip portions of the plurality of sets of splines (3) and the protrusions (15) of the plurality of restraining members (6). A catheter (1) according to item 3 or 4. [Item 8] The tip member (4) includes a bundling member (10) therein for bundling the protrusions (15) of the plurality of restraining members (6). A catheter (1) as described in item 7. [Item 9] The binding member (10) is shaped like a plate having a first surface and a second surface that is the reverse side of the first surface, The second surface faces the tip surface of each of the sets of splines (3), The binding member (10) is provided with through holes (16) penetrating from the first surface to the second surface, into which the protrusions (15) of the respective restraining members (6) are inserted. A catheter (1) as described in item 8. [Item 10] the plurality of restraining members are wires; A catheter (1) according to any one of items 1 to 9. [Item 11] A shaft (2) to be inserted into the body; A plurality of splines (3) connected to the tip side of the shaft (2), The plurality of splines (3) include a first spline (3) and a second spline (3), The first spline (3) and the second spline (3) are disposed with at least one other spline (3) therebetween, and their mutual movements are restricted by a first restricting member (6). Catheter (1). [Explanation of symbols]

[0069] 1 catheter, 2 shaft, 3 spline, 4 tip member, 6 restraining member, 10 binding member, 15 protrusion, 16 through hole, 22 pull wire.

Claims

1. A shaft that is inserted into the body; a plurality of sets of splines each consisting of two splines connected to a tip side of the shaft; Two splines constituting the set of splines are disposed with at least one spline belonging to another set therebetween, The plurality of sets of splines are each constrained from moving relative to one another by a single constraining member. catheter.

2. The restraining member has a first end and a second end. At least a portion of the first end side of the restraining member is located within one of the splines constituting the set of splines, At least a portion of the second end side of the restraining member is located within the other spline of the pair of splines, the restraining member has a connecting portion that connects a tip end of the one spline to a tip end of the other spline, The catheter of claim 1.

3. the connecting portion of the restraining member is a protruding portion protruding toward the tip side beyond the tip of the one spline and the tip of the other spline, The catheter of claim 2.

4. a first restraining member corresponding to the first set of splines and a second restraining member corresponding to the second set of splines including a spline sandwiched between two splines constituting the first set of splines, the protruding portions of each of the first restraining member and the second restraining member are bent in different directions as viewed from the tip end side; The catheter of claim 3.

5. the first end and the second end of each of the plurality of restraining members are disposed within the shaft; In a cross-sectional view perpendicular to an axis of the shaft, the plurality of restraining members are arranged symmetrically with respect to a line passing through a center position of each of the pair of pull wires. A catheter according to any one of claims 2 to 4.

6. the first end and the second end of each of the plurality of restraining members are disposed within the shaft; In a cross-sectional view perpendicular to the axis of the shaft, the plurality of restraining members are arranged point-symmetrically with respect to the axis of the shaft. A catheter according to any one of claims 2 to 4.

7. a tip member covering a tip portion of each of the plurality of sets of splines and a protrusion portion of each of the plurality of restraining members, The catheter according to claim 3 or 4.

8. The tip member includes a bundling member therein for bundling the protrusions of each of the plurality of restraining members. The catheter of claim 7.

9. The binding member has a plate shape having a first surface and a second surface that is a reverse surface of the first surface, the second surface faces a tip surface of each of the plurality of sets of splines, The binding member is provided with through holes penetrating from the first surface to the second surface, into which the protrusions of the respective binding members are inserted. The catheter of claim 8.

10. the plurality of restraining members are wires; The catheter of claim 1.

11. A shaft that is inserted into the body; a plurality of splines connected to a tip side of the shaft; the plurality of splines include a first spline and a second spline, The first spline and the second spline are disposed with at least one other spline therebetween, and their mutual movements are restricted by a first restricting member. catheter.

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