Balloon for balloon catheters and method for manufacturing balloon for balloon catheters

Abstract

Provided is a balloon for balloon catheters that makes it easy to fold the balloon to reduce the outer diameter in the entire balloon including both end parts of the balloon, and that is capable of enhancing the inserting capability in a living body lumen.　A balloon (10) for balloon catheters has mountain fold parts (12) in a contraction state of the balloon (10). At least one of a proximal-side taper part (22) and a distal-side taper part (24) has an existence region (A1) in which the mountain fold parts (12) exist and a non-existence region (A2) in which the mountain fold parts do not exist. When folding lines (30) are disposed in the proximal-side taper part (22), the proximal ends of the folding lines (30) are positioned in the non-existence region (A2) and the distal ends of the folding lines (30) are positioned on the proximal side with respect to the distal end (22d) of the proximal-side taper part (22). When the folding lines (30) are disposed in the distal-side taper part (24), the proximal ends of the folding lines (30) are positioned on the distal side with respect to the proximal end (24p) of the distal-side taper part (24), and the distal ends of the folding lines (30) are positioned in the non-existence region (A2).

Description

Balloon for balloon catheter and method for manufacturing balloon for balloon catheter

[0001] The present invention relates to a balloon for a balloon catheter and a method for manufacturing a balloon for a balloon catheter.

[0002] The formation of narrowed areas due to calcification and other factors in the inner walls of blood vessels can lead to diseases such as angina pectoris and myocardial infarction. One treatment for these conditions is angioplasty, which uses a balloon catheter to dilate the narrowed area. Angioplasty is a minimally invasive treatment that does not require open chest surgery like bypass surgery, and is widely used.

[0003] A balloon catheter is inserted into a body cavity with its balloon deflated and delivered to the treatment site through the cavity. During delivery, the movement of the balloon is controlled by transmitting control from the proximal end to the distal end where the balloon is located. This requires that the catheter be easy to insert into the body cavity and easy to transmit control from the proximal end to the distal end (high pushability).

[0004] For example, Patent Document 1 discloses a medical catheter balloon that has three to six corners in a balloon cross section perpendicular to the catheter's long axis when the balloon is pressurized at 0.6 atm G, and at least the straight tubular portion has a substantially circular cross section when the balloon is inflated at 6 atm G. Patent Document 2 discloses a vascular occlusion balloon for a vascular occlusion balloon catheter, which is made of a stretchable and thermoplastic synthetic resin tube, and is provided with a bulging portion formed by plastic deformation, and a distal tubular portion and a proximal tubular portion that are smaller in diameter and thicker than the bulging portion, the bulging portion having a reduced diameter shape with wrinkles extending in the axial direction, and which is expandable by applying internal pressure. Patent Document 3 discloses a balloon catheter in which the outer diameter of the distal tip, the outer diameter of the balloon before inflation, and the outer diameter of the distal end of the shaft are approximately equal, and the balloon has a proximal end facing the shaft, a distal end facing the distal tip, and a bulging portion interposed between the proximal and distal ends and spaced apart from the tube, the distal end being thicker than the bulging portion. Patent Document 4 discloses a balloon shaping method including a placement step of placing the balloon in a mold having a cavity for shaping the balloon, and a shaping step of shaping the balloon using the mold, the shaping step including a heating and pressurizing process of heating the mold to a predetermined shaping temperature and pressurizing the balloon while maintaining the mold temperature at the shaping temperature for a predetermined shaping time, and a gradual cooling process of cooling the mold to a temperature higher than the glass transition temperature of the elastic resin material constituting the balloon but below the molding temperature during blow molding for a predetermined gradual cooling time.

[0005] JP 2005-323714 A International Publication No. 2013 / 122003 JP 2016-182183 A JP 2023-137344 A

[0006] However, in the conventional balloons described above, the tapered ends at both ends of the balloon tend to be thicker and more rigid than the straight section at the center of the balloon, which makes it difficult to fold the ends of the balloon to reduce its outer diameter when the balloon is deflated, leaving room for improvement in terms of the ease of insertion of the balloon into a biological lumen.

[0007] In view of the above circumstances, an object of the present invention is to provide a balloon for a balloon catheter, which can be easily folded so that the outer diameter of the entire balloon, including both ends of the balloon, is small, thereby improving insertability through a biological lumen, and a method for manufacturing such a balloon.

[0008] The balloon for a balloon catheter according to an embodiment of the present invention that has solved the above problems is as follows: [1] A balloon for a balloon catheter having a longitudinal axis direction extending from a proximal side to a distal side and radial and circumferential directions perpendicular to the longitudinal axis direction, the balloon having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, and a distal tapered portion located distal to the straight tube portion, the balloon having mountain fold portions in a deflated state where the balloon membrane forming the apex of a wing-shaped portion is bent in a mountain fold, at least one of the proximal tapered portion and the distal tapered portion has, in the longitudinal axis direction, a presence region where the mountain fold portion is present and an absence region where the mountain fold portion is not present, at least one of the proximal tapered portion and the distal tapered portion has at least one fold where the balloon membrane is bent and extending in the longitudinal axis direction,

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[420] [430 [4] The balloon for a balloon catheter according to any one of [1] to [3], wherein in a cross section perpendicular to the longitudinal axis direction, the cross-sectional shape of the balloon in at least one of the proximal tapered section and the distal tapered section is a polygon having vertices and sides, including a vertex, and the folds are located on the sides.[5] The balloon for a balloon catheter according to [4], wherein the number of folds is twice the number of vertices of the cross-sectional shape of the balloon in a cross section perpendicular to the longitudinal axis direction. [6] The balloon for a balloon catheter according to [4] or [5], wherein the number of folds is plural, and the folds are located on both sides of the vertices in the circumferential direction in the cross section perpendicular to the longitudinal axis direction. [7] The balloon for a balloon catheter according to any one of [1] to [6], wherein the folds include a first fold and a second fold that are adjacent to each other in the circumferential direction, and when the folds are arranged in the proximal tapered portion, the distance between the proximal end of the first fold and the proximal end of the second fold in the proximal tapered portion is smaller than the distance between the distal end of the first fold and the distal end of the second fold in the proximal tapered portion, and when the folds are arranged in the distal tapered portion, the distance between the distal end of the first fold and the distal end of the second fold in the distal tapered portion is smaller than the distance between the proximal end of the first fold and the proximal end of the second fold. [8] The balloon for a balloon catheter according to any one of [1] to [7], wherein, when the fold is located in the proximal tapered portion, the distal end of the fold is located more proximal than the proximal end of the mountain fold in the proximal tapered portion; and, when the fold is located in the distal tapered portion, the proximal end of the fold is located more distal than the distal end of the mountain fold in the distal tapered portion.

[0009] The manufacturing method of a balloon for a balloon catheter according to an embodiment of the present invention that solves the above-mentioned problems is as follows: [9] A method for manufacturing a balloon for a balloon catheter having a longitudinal axis direction extending from a proximal side to a distal side and radial and circumferential directions perpendicular to the longitudinal axis direction, the method comprising: a balloon-constituting member preparing step of preparing a balloon-constituting member having a straight tube section, a proximal tapered section located proximal to the straight tube section, a proximal sleeve section located proximal to the proximal tapered section, a distal tapered section located distal to the straight tube section, and a distal sleeve section located distal to the distal tapered section, a jig preparing step of preparing a jig having a first inner wall surface that defines a first lumen extending in the longitudinal axis direction, the first inner wall surface being contactable with the outer surface of the balloon-constituting member, and a first insertion step of inserting at least a portion of the proximal tapered section or the distal tapered section into the first lumen.

[10] The method for manufacturing a balloon for a balloon catheter according to [9], wherein in the first insertion step, at least a portion of one of the proximal tapered portion and the distal tapered portion is inserted into the first lumen while the balloon component is pulled in the longitudinal axis direction.

[11] The method for manufacturing a balloon for a balloon catheter according to [9] or

[10] , further comprising a second insertion step, after the first insertion step, of inserting at least a portion of the other of the proximal tapered portion and the distal tapered portion into the first lumen, wherein in the second insertion step, at least a portion of the other of the proximal tapered portion and the distal tapered portion is inserted into the first lumen while the balloon component is pulled in the longitudinal axis direction.

[12] The method for manufacturing a balloon for a balloon catheter according to any one of [9] to

[11] , wherein the inner diameter of the jig in the first lumen is equal to or greater than the outer diameter of the proximal sleeve portion and the outer diameter of the distal sleeve portion, and has a portion that is smaller than the outer diameter of the proximal tapered portion and the outer diameter of the distal tapered portion.

[13] The method for manufacturing a balloon for a balloon catheter according to any one of [9] to

[12] , wherein the jig further has a second lumen extending in the longitudinal axis direction, the maximum cross-sectional area of ​​the second lumen is larger than the maximum cross-sectional area of ​​the first lumen in a cross section perpendicular to the longitudinal axis direction, the cross-sectional shape of the first lumen in the cross section perpendicular to the longitudinal axis direction is circular, and the cross-sectional shape of the second lumen in the cross section perpendicular to the longitudinal axis direction is polygonal.

[14] The method for manufacturing a balloon for a balloon catheter according to

[13] , wherein the first lumen includes a proximal first lumen and a distal first lumen, the proximal first lumen being disposed proximal to the second lumen and the distal first lumen being disposed distal to the second lumen, and further comprising a proximal third lumen proximal to the second lumen and distal to the proximal first lumen, the cross-sectional area of ​​the lumen decreasing proximally, and the method for manufacturing a balloon for a balloon catheter according to

[13] , wherein the first lumen includes a proximal first lumen and a distal first lumen, the proximal first lumen being disposed proximal to the second lumen and distal to the proximal first lumen, the cross-sectional area of ​​the lumen decreasing distally.

[15] The method for manufacturing a balloon for a balloon catheter according to

[11] , wherein in the first insertion step, one of the proximal end of the proximal tapered section and the distal end of the distal tapered section is inserted into the first lumen, and in the second insertion step, the other of the proximal end of the proximal tapered section and the distal end of the distal tapered section is inserted into the first lumen.

[16] The method for manufacturing a balloon for a balloon catheter according to any of [9] to

[15] , further comprising: a parison preparation step of preparing a parison having a longitudinal axis direction extending from the proximal side to the distal side, and a radial direction and a circumferential direction perpendicular to the longitudinal axis direction, and having a lumen extending in the longitudinal axis direction; and a balloon-component molding step of stretching the parison in a state where it is placed in the lumen of the jig to form the balloon-component, wherein the parison preparation step and the balloon-component molding step are performed before the balloon-component preparation step.

[17] The method for manufacturing a balloon for a balloon catheter according to

[16] , further comprising a second insertion step of inserting at least a portion of the other of the proximal tapered portion and the distal tapered portion into the first lumen after the first insertion step, wherein the temperature of the jig in the first insertion step and the second insertion step is lower than the temperature of the jig in the balloon component molding step.

[0010] In the balloon for balloon catheter described above, when a fold is disposed in the proximal tapered portion, the proximal end of the fold is located in a non-fold region of the proximal tapered portion, and the distal end of the fold is located proximal to the distal end of the proximal tapered portion. Also, when a fold is disposed in the distal tapered portion, the proximal end of the fold is located distal to the proximal end of the distal tapered portion, and the distal end of the fold is located in a non-fold region. This results in a configuration in which the balloon has a fold in at least one of the proximal and distal tapered portions. As a result, when the balloon is deflated, the proximal and distal tapered portions of the balloon are easily folded, making it easier to fold the balloon so as to reduce the overall outer diameter. Furthermore, according to the method for manufacturing a balloon for a balloon catheter, by inserting at least a portion of the proximal tapered portion or the distal tapered portion of the balloon component into the first lumen of the jig, which allows contact between the first inner wall surface and the outer surface of the balloon component, it is possible to impart a crease to one of the proximal tapered portion or the distal tapered portion of the balloon. As a result, when the balloon is deflated, the proximal tapered portion or the distal tapered portion of the balloon is easily folded, making it easier to fold the balloon so that the overall outer diameter of the balloon is reduced.

[0011] 1 shows a side view of a balloon in an expanded state according to one embodiment of the present invention. A cross-sectional view II-II of the balloon shown in FIG. 1. A cross-sectional view III-III of the balloon shown in FIG. 1. A cross-sectional view IV-IV of the balloon shown in FIG. 1. A cross-sectional view VI-VI of the balloon shown in FIG. 5. A cross-sectional view VII-VII of the balloon shown in FIG. 5. A cross-sectional view VIII-VIII of the balloon shown in FIG. 5. A side view of a balloon catheter having the balloon shown in FIG. 1. A side view of a balloon component in a manufacturing method according to one embodiment of the present invention. A cross-sectional view XI-XI of the balloon component shown in FIG. 10. A cross-sectional view XII-XII of the balloon component shown in FIG. 10. A cross-sectional view in the longitudinal axis direction of a jig in a manufacturing method according to one embodiment of the present invention. A cross-sectional view XIV-XIV of the jig shown in FIG. 13. A cross-sectional view XV-XV of the jig shown in FIG. 13. A schematic diagram of a first insertion step in a manufacturing method according to one embodiment of the present invention.

[0012] The present invention will be described below based on the embodiments, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the above and below-described purposes, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience. In such cases, please refer to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to helping understand the features of the present invention.

[0013] 1. Balloon for balloon catheter A balloon for balloon catheter according to an embodiment of the present invention is a balloon for a balloon catheter having a longitudinal axis direction extending from the proximal side to the distal side, and a radial direction and a circumferential direction perpendicular to the longitudinal axis direction, the balloon having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, and a distal tapered portion located distal to the straight tube portion, and in a deflated state of the balloon, the balloon has a mountain fold portion where the balloon membrane forming the apex of the wing-shaped portion is bent in a mountain fold, and at least one of the proximal tapered portion and the distal tapered portion has a region where the mountain fold portion exists and a region where the mountain fold portion exists in the longitudinal axis direction. and a non-existence region where no fold is present, and in at least one of the proximal tapered portion and the distal tapered portion, the balloon membrane is bent and has at least one fold extending in the longitudinal direction, and when a fold is located in the proximal tapered portion, the proximal end of the fold in the proximal tapered portion is located in the non-existence region and the distal end of the fold is located proximal to the distal end of the proximal tapered portion, and when a fold is located in the distal tapered portion, the proximal end of the fold in the distal tapered portion is located distal to the proximal end of the distal tapered portion and the distal end of the fold is located in the non-existence region.

[0014] A balloon for a balloon catheter according to an embodiment of the present invention will be described below with reference to Figures 1 to 9. Figures 1 to 4 show a balloon according to an embodiment of the present invention in an expanded state, with Figure 1 being a side view of the balloon in the expanded state. Figure 2 is a cross-sectional view II-II of the balloon shown in Figure 1, showing a cross-sectional view perpendicular to the longitudinal axis direction at the straight portion of the balloon. Figure 3 is a cross-sectional view III-III of the balloon shown in Figure 1, showing a cross-sectional view perpendicular to the longitudinal axis direction at the proximal tapered portion of the balloon. Figure 4 is a cross-sectional view IV-IV of the balloon shown in Figure 1, showing a cross-sectional view perpendicular to the longitudinal axis direction at the distal tapered portion of the balloon. Figures 5 to 8 show a balloon according to an embodiment of the present invention in a deflated state, with Figure 5 being a side view of the balloon in the deflated state. Fig. 6 is a VI-VI cross-sectional view of the balloon shown in Fig. 5, showing a cross-sectional view perpendicular to the longitudinal axis direction at the straight tube portion of the balloon, Fig. 7 is a VII-VII cross-sectional view of the balloon shown in Fig. 5, showing a cross-sectional view perpendicular to the longitudinal axis direction at the proximal tapered portion of the balloon, Fig. 8 is a VIII-VIII cross-sectional view of the balloon shown in Fig. 5, showing a cross-sectional view perpendicular to the longitudinal axis direction at the distal tapered portion of the balloon, Fig. 9 is a side view of a balloon catheter having the balloon shown in Fig. 1.

[0015] 1 and 5, the balloon 10 of the present invention is a balloon 10 for a balloon catheter 1 having a longitudinal axis direction x extending from the proximal side to the distal side, and a radial direction y and a circumferential direction z perpendicular to the longitudinal axis direction x. In this specification, a balloon for a balloon catheter may be simply referred to as a "balloon."

[0016] In this specification, the direction toward the user's hand in the longitudinal axis direction x is referred to as the proximal side, and the opposite side from the proximal side, i.e., the direction toward the patient, is referred to as the distal side. Furthermore, when each component or part is divided into two equal parts along the longitudinal axis direction x of the balloon 10, the distal part of each component or part is referred to as the distal portion of each component or part, and the proximal part of each component or part is referred to as the proximal portion of each component or part. The distal end of each component or part is the most distal end of each component or part. The proximal end of each component or part is the most proximal end of each component or part. The term "end" includes the peripheral portion of the end. In other words, the distal end refers to the distal end and the peripheral portion of the distal end, and the proximal end refers to the proximal end and the peripheral portion of the proximal end.

[0017] Components and parts other than the balloon 10 also have longitudinal axis directions, radial directions, and circumferential directions, which may or may not be the same as the longitudinal axis directions x, radial directions y, and circumferential directions z of the balloon 10. However, for ease of understanding, this specification will be described as assuming that all components and parts have the same longitudinal axis directions x, radial directions y, and circumferential directions z as the longitudinal axis directions x, radial directions y, and circumferential directions z of the balloon 10.

[0018] The balloon 10 is located at the distal portion of the balloon catheter 1. The balloon 10 can be expanded by introducing fluid into the lumen of the balloon 10, and can be deflated by expelling fluid from the lumen of the balloon 10.

[0019] The balloon catheter 1 dilates the stenotic site by inserting the balloon 10 provided at the distal end of the balloon catheter 1 into the lumen of the blood vessel, delivering it to the stenotic site, and then inflating the balloon 10. When inserting the balloon 10 into the stenotic site or removing it from the body, fluid is discharged from the lumen of the balloon 10 to cause it to contract, and the wing-shaped portion of the balloon 10 can be wrapped around the shaft 40 of the balloon catheter 1 to reduce the outer diameter of the balloon 10.

[0020] As shown in Figures 1 to 8, the balloon 10 has a straight tube section 23, a proximal tapered section 22 located proximal to the straight tube section 23, and a distal tapered section 24 located distal to the straight tube section 23.

[0021] The straight tube portion 23 preferably has a substantially cylindrical shape with approximately the same diameter in the longitudinal axis direction x when the balloon 10 is inflated, but may have different diameters in the longitudinal axis direction x. The proximal tapered portion 22 and the distal tapered portion 24 preferably have a substantially conical or truncated conical shape with a diameter decreasing away from the straight tube portion 23 when the balloon 10 is inflated. Having the straight tube portion 23 have the largest diameter when the balloon 10 is inflated, the straight tube portion 23 can sufficiently contact the lesion when the balloon 10 is inflated at a lesion such as a stenosis, facilitating treatment such as dilation of the lesion. Furthermore, having the proximal tapered portion 22 and the distal tapered portion 24 reduced in diameter when the balloon 10 is inflated can facilitate reducing the outer diameters of the proximal and distal ends of the balloon 10 when the balloon 10 is deflated. Furthermore, the step between the shaft 40 of the balloon catheter 1 and the balloon 10 can be reduced, facilitating insertion of the balloon 10 into a body cavity.

[0022] 1 and 5, the balloon 10 preferably further includes a proximal sleeve portion 21 located proximal to the proximal tapered portion 22 and a distal sleeve portion 25 located distal to the distal tapered portion 24. The proximal tapered portion 22, the straight tube portion 23, and the distal tapered portion 24 are portions that expand when a fluid is introduced into the balloon 10, whereas the proximal sleeve portion 21 and the distal sleeve portion 25 are preferably portions that do not expand. Because the proximal sleeve portion 21 and the distal sleeve portion 25 are portions that do not expand, it is easier to firmly fix at least a portion of the proximal sleeve portion 21 and at least a portion of the distal sleeve portion 25 to a member such as the shaft 40.

[0023] Examples of materials that can be used to form the balloon 10 include polyamide resins such as nylon 11 and nylon 12, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyurethane resins, and thermoplastic elastomers such as polyether block amide copolymers.

[0024] The balloon 10 can be obtained by biaxially stretching or blow molding a parison. The parison is a cylindrical member made of resin and has an internal cavity. Like the balloon 10, the parison has a longitudinal axis direction x, a radial direction y, and a circumferential direction z. The parison can be obtained, for example, by extrusion molding a resin using a cylindrical mold.

[0025] As shown in Figures 5 and 6, when the balloon 10 is in a deflated state, the balloon 10 has mountain folds 12 in which the balloon membrane forming the apex P1 of the wing-shaped portions 11 is bent in a mountain-like manner. The wing-shaped portions 11 refer to the portions of the balloon 10 that are folded over and overlapped with the inner surface of the balloon 10 facing inward when the balloon 10 is in a deflated state, forming a wing shape. The apex P1 of the wing-shaped portions 11 refers to the end of the wing-shaped portions 11 that is farthest from the centroid P2 of the balloon 10 in a cross section perpendicular to the longitudinal axis direction x when the balloon 10 is in a deflated state. The presence of the wing-shaped portions 11 in the balloon 10 makes it easier to fold the balloon 10 so that its outer diameter is reduced when the balloon 10 is in a deflated state, thereby making it easier to reduce the invasiveness of the balloon catheter 1.

[0026] 5 , at least one of the proximal tapered portion 22 and the distal tapered portion 24 has, in the longitudinal axis direction x, a presence region A1 where the mountain fold 12 is present and a non-presence region A2 where the mountain fold 12 is not present. Note that it is sufficient if either the proximal tapered portion 22 or the distal tapered portion 24 has the presence region A1 and the non-presence region A2 in the longitudinal axis direction x, but it is preferable that both the proximal tapered portion 22 and the distal tapered portion 24 have the presence region A1 and the non-presence region A2 in the longitudinal axis direction x.

[0027] The wing-shaped portions 11 are preferably located in the longitudinal axis direction x over the entire straight tube portion 23 of the balloon 10 and over a portion of at least one of the proximal tapered portion 22 and the distal tapered portion 24. That is, the mountain folds 12 are preferably located in the straight tube portion 23 and over a portion of at least one of the proximal tapered portion 22 and the distal tapered portion 24. Furthermore, the wing-shaped portions 11 are more preferably located in the longitudinal axis direction x over the entire straight tube portion 23 of the balloon 10, over a portion of the proximal tapered portion 22, and over a portion of the distal tapered portion 24. In this case, the mountain folds 12 are located in the straight tube portion 23, a portion of the proximal tapered portion 22, and a portion of the distal tapered portion 24.

[0028] 5, 7, and 8, the balloon membrane is bent to have at least one fold 30 extending in the longitudinal axis direction x in at least one of the proximal tapered portion 22 and the distal tapered portion 24. That is, the fold 30 may be disposed in the proximal tapered portion 22 or the distal tapered portion 24. Alternatively, there may be a plurality of folds 30, and the folds 30 may be disposed in both the proximal tapered portion 22 and the distal tapered portion 24. The balloon membrane refers to the membrane that forms the balloon 10.

[0029] The fold 30 extending in the longitudinal axis direction x includes the case where the extension direction of the fold 30 is parallel to the longitudinal axis direction x and the case where the extension direction of the fold 30 includes a component in the longitudinal axis direction x. Specifically, the extension direction of the fold 30 is parallel to the longitudinal axis direction x, or the angle between the extension direction of the fold 30 and the longitudinal axis direction x is greater than 0 degrees and less than 90 degrees. The angle between the extension direction of the fold 30 and the longitudinal axis direction x is preferably 0 degrees or greater, more preferably 5 degrees or greater, and even more preferably 10 degrees or greater, and is preferably 80 degrees or less, more preferably 70 degrees or less, and even more preferably 60 degrees or less.

[0030] The folds 30 can function as guides when introducing a fluid into the lumen of the balloon 10 to expand the balloon 10, and then removing the fluid to deflate the balloon 10 and fold the balloon 10. The folds 30 may be mountain folds or valley folds of the balloon membrane.

[0031] Methods for forming folds 30 in balloon 10 include, for example, using a folding device on a deflated balloon 10, or pressing down the area of ​​balloon 10 where folds 30 are to be formed and then deflating (pleating).

[0032] 5 and 7 , when the fold 30 is disposed in the proximal tapered portion 22, the proximal end of the fold 30 is located in the non-existence region A2, and the distal end of the fold 30 is located proximal to the distal end 22d of the proximal tapered portion 22. Because the proximal end of the fold 30 is located in the non-existence region A2 and the distal end of the fold 30 is located proximal to the distal end 22d of the proximal tapered portion 22, the balloon membrane is more likely to be folded by the fold 30 in the proximal tapered portion 22, where the balloon membrane tends to be thicker than in the straight tube portion 23 and therefore more rigid and less likely to fold when the balloon 10 is deflated. Therefore, when the balloon 10 is deflated, the proximal tapered portion 22 of the balloon 10 is more likely to fold, making it easier to fold the balloon 10 so that its outer diameter is reduced.

[0033] As shown in Figures 5 and 8, when a fold 30 is disposed in the distal tapered portion 24, the proximal end of the fold 30 is located distal to the proximal end 24p of the distal tapered portion 24, and the distal end of the fold 30 is located in the non-folding region A2. The proximal end of the fold 30 is located distal to the proximal end 24p of the distal tapered portion 24, and the distal end of the fold 30 is located in the non-folding region A2. Since the proximal end of the fold 30 is located distal to the proximal end 24p of the distal tapered portion 24 and the distal end of the fold 30 is located in the non-folding region A2, the fold 30 facilitates folding of the balloon membrane in the distal tapered portion 24, where the balloon membrane tends to be difficult to fold during deflation of the balloon 10 due to its greater thickness and greater rigidity than the balloon membrane in the straight tube portion 23. As a result, the distal tapered portion 24 of the balloon 10 is easily folded when the balloon 10 is deflated, allowing the balloon 10 to be easily folded to a smaller outer diameter.

[0034] As shown in Figures 5, 7, and 8, the folds 30 are preferably located in the proximal tapered portion 22 and the distal tapered portion 24. That is, it is preferable that the folds 30 exist in both the proximal tapered portion 22 and the distal tapered portion 24. By locating the folds 30 in the proximal tapered portion 22 and the distal tapered portion 24, when the balloon 10 is in a deflated state, the balloon membrane is more likely to fold in both the proximal tapered portion 22 and the distal tapered portion 24, making it easier to fold the balloon 10 so that the outer diameter becomes smaller overall.

[0035] It is preferable that there are multiple folds 30 in the proximal tapered portion 22 and multiple folds 30 in the distal tapered portion 24. In other words, it is preferable that there are multiple folds 30 in both the proximal tapered portion 22 and the distal tapered portion 24. By having multiple folds 30 in both the proximal tapered portion 22 and the distal tapered portion 24, it becomes easier to fold the balloon 10 so that the outer diameter of the balloon 10 becomes smaller in both the proximal tapered portion 22 and the distal tapered portion 24, and it becomes easier to fold the balloon 10 so that the outer diameter of the entire balloon 10 becomes smaller.

[0036] The number of folds 30 arranged in the proximal tapered portion 22 may be the same as or different from the number of folds 30 arranged in the distal tapered portion 24. When the number of folds 30 arranged in the proximal tapered portion 22 is different from the number of folds 30 arranged in the distal tapered portion 24, the number of folds 30 arranged in the proximal tapered portion 22 may be greater than or less than the number of folds 30 arranged in the distal tapered portion 24. In particular, it is preferable that the number of folds 30 arranged in the proximal tapered portion 22 is the same as the number of folds 30 arranged in the distal tapered portion 24. By having the same number of folds 30 in the proximal tapered portion 22 as the number of folds 30 in the distal tapered portion 24, the outer diameter at the proximal tapered portion 22 and the outer diameter at the distal tapered portion 24 when the balloon 10 is deflated can be made approximately the same, making the balloon 10 easier to handle.

[0037] When there are a plurality of folds 30, the lengths of the folds 30 in the longitudinal axis direction x may be the same or different. The length of the fold 30 in the longitudinal axis direction x refers to the length from the proximal end of the fold 30 to the distal end of the fold 30 in the longitudinal axis direction x.

[0038] As shown in Figure 5, it is preferable that the fold 30 does not lie on an extension line L1 of the mountain fold 12 in the longitudinal direction x. By not having the fold 30 lie on the extension line L1 of the mountain fold 12, the fold 30 will be different from the mountain fold 12 that forms the apex P1 of the wing-shaped portion 11 when the balloon 10 is in a deflated state. This makes it easier to form the wing-shaped portion 11 neatly throughout the balloon 10 when the balloon 10 is in a deflated state, and makes it easier to fold the balloon 10 so that the outer diameter thereof becomes smaller.

[0039] 3-4 and 7-8, the cross-sectional shape of balloon 10 in the longitudinal axis direction x at least one of proximal tapered portion 22 and distal tapered portion 24 is preferably a polygon having vertices 13 and sides 14. By having a polygonal cross-sectional shape at least one of proximal tapered portion 22 and distal tapered portion 24, at least one of proximal tapered portion 22 and distal tapered portion 24, which have a polygonal cross-sectional shape, can be easily folded when balloon 10 is deflated.

[0040] The cross-sectional shape of the balloon 10 in the longitudinal axis direction x at the proximal tapered portion 22 and the distal tapered portion 24 is preferably a polygon having vertices 13 and sides 14. That is, the cross-sectional shape of the balloon 10 in the longitudinal axis direction x is preferably a polygon at both the proximal tapered portion 22 and the distal tapered portion 24. By having the cross-sectional shape of the balloon 10 in the proximal tapered portion 22 and the distal tapered portion 24 be a polygon, both the proximal tapered portion 22 and the distal tapered portion 24 can be easily folded when the balloon 10 is in a deflated state, and the balloon 10 can be easily folded so that the outer diameter of the entire balloon 10 is small.

[0041] The cross-sectional shape of the balloon 10 in the straight tube section 23 in the longitudinal axis direction x is preferably a polygon having vertices 13 including vertices and sides 14. It is particularly preferable that the cross-sectional shapes of the balloon 10 in the proximal tapered section 22, the straight tube section 23, and the distal tapered section 24 in the longitudinal axis direction x be polygons having vertices 13 including vertices and sides 14. The polygonal cross-sectional shape of the balloon 10 in the straight tube section 23 facilitates the formation of the wing-shaped portions 11 with the vertices 13 of the polygonal cross-sectional shape of the balloon 10 as the vertices P1 of the wing-shaped portions 11. As a result, mountain folds 12 are more likely to be formed in the balloon 10 along the longitudinal axis direction x, and the balloon 10 is more likely to be folded so that its outer diameter becomes smaller when it is deflated.

[0042] The polygonal cross-sectional shape of the balloon 10 includes polygons with clearly defined corners and straight sides, as well as rounded polygons with rounded corners and polygons with at least some curved sides. Examples of polygonal cross-sectional shapes of the balloon 10 include triangles, rectangles, and pentagons. Of these, a triangular cross-sectional shape of the balloon 10 is preferred. Having a triangular cross-sectional shape of the balloon 10 makes it easier to appropriately determine the number and size of the mountain folds 12 and folds 30 formed on the balloon 10.

[0043] 3-4 and 7-8 , when the cross-sectional shape of balloon 10 in at least one of proximal tapered portion 22 and distal tapered portion 24 in the longitudinal axis direction x is a polygon having vertices 13 including apexes and sides 14, folds 30 are preferably located at sides 14. By locating folds 30 at sides 14, depressions are more likely to be formed at sides 14 when balloon 10 is deflated. This makes it easier to control the folded shape of balloon 10 in the deflated state in at least one of proximal tapered portion 22 and distal tapered portion 24.

[0044] 7 and 8 , the number of folds 30 is preferably twice the number of vertices 13 in the cross-sectional shape of the balloon 10 taken in a cross section perpendicular to the longitudinal axis direction x. Specifically, in at least one of the proximal taper portion 22 and the distal taper portion 24, the number of folds 30 in at least one of the proximal taper portion 22 and the distal taper portion 24 is preferably twice the number of vertices 13 in the cross-sectional shape of the balloon 10 taken in a cross section perpendicular to the longitudinal axis direction x. In other words, when the cross-sectional shape of the balloon 10 in at least one of the proximal taper portion 22 and the distal taper portion 24 is an n-sided polygon, the number of folds 30 is preferably (n×2).

[0045] Specifically, it is preferable that two folds 30 are arranged on each side 14 of the cross-sectional shape of the balloon 10 in at least one of the proximal tapered portion 22 and the distal tapered portion 24. For example, if the cross-sectional shape of the proximal tapered portion 22 is a triangle having three vertices 13, it is preferable that the number of folds 30 in the proximal tapered portion 22 be six, which is twice the number of vertices 13, that is, three, in the cross-sectional shape of the balloon 10 in the proximal tapered portion 22.

[0046] By having the number of folds 30 be twice the number of vertices 13 of the cross-sectional shape of the balloon 10 in a cross section perpendicular to the longitudinal axis direction x, the folds 30 are more likely to be positioned in appropriate positions in at least one of the proximal tapered section 22 and the distal tapered section 24, making it easier to fold the balloon 10 so that its outer diameter becomes smaller when the balloon 10 is deflated.

[0047] As shown in Figures 7 and 8, there are preferably multiple folds 30, and in a cross section perpendicular to the longitudinal axis direction x, one fold 30 is preferably located on either side of the apex 13 in the circumferential direction z. Specifically, in at least one of the proximal tapered section 22 and the distal tapered section 24, one fold 30 is preferably located on either side of the apex 13 in the circumferential direction z in a cross section perpendicular to the longitudinal axis direction x. That is, in a cross section perpendicular to the longitudinal axis direction x in at least one of the proximal tapered section 22 and the distal tapered section 24, one fold 30 is preferably located in the following order in the circumferential direction z: apex 13, then another fold 30. Having one fold 30 located on either side of the apex 13 in the circumferential direction z facilitates appropriate positioning of the folds 30 in at least one of the proximal tapered section 22 and the distal tapered section 24, making it easier to fold the balloon 10 so that its outer diameter becomes smaller when the balloon 10 is deflated.

[0048] As shown in Figures 5, 7, and 8, the fold 30 includes a first fold 31 and a second fold 32 that are adjacent to each other in the circumferential direction z. When the fold 30 is arranged in the proximal tapered portion 22, it is preferable that the distance D1 between the proximal end of the first fold 31 and the proximal end of the second fold 32 in the proximal tapered portion 22 is smaller than the distance D2 between the distal end of the first fold 31 and the distal end of the second fold 32. When the fold 30 is arranged in the distal tapered portion 24, it is preferable that the distance D3 between the distal end of the first fold 31 and the distal end of the second fold 32 in the distal tapered portion 24 is smaller than the distance D4 between the proximal end of the first fold 31 and the proximal end of the second fold 32.

[0049] In the longitudinal axis direction x, when the cross-sectional shape of the balloon 10 of the proximal tapered portion 22 and the distal tapered portion 24 is a polygon having a vertex portion 13 including a vertex and a side portion 14, it is preferable that the first fold 31 and the second fold 32 that are adjacent to each other in the circumferential direction z are arranged on the same side portion 14.

[0050] When the fold 30 is disposed in the proximal tapered portion 22, the distance D1 between the proximal end of the first fold 31 and the proximal end of the second fold 32 is smaller than the distance D2 between the distal end of the first fold 31 and the distal end of the second fold 32 in the proximal tapered portion 22, so that the distance between the first fold 31 and the second fold 32 decreases toward the proximal side. This allows the balloon 10 to be easily folded in a deflated state, reducing the outer diameter of the proximal end of the balloon 10, where the balloon membrane tends to be difficult to fold and bulky.

[0051] Furthermore, when the fold 30 is disposed in the distal tapered portion 24, the distance D3 between the distal end of the first fold 31 and the distal end of the second fold 32 in the distal tapered portion 24 is smaller than the distance D4 between the proximal end of the first fold 31 and the proximal end of the second fold 32, so that the distance between the first fold 31 and the second fold 32 decreases toward the distal side. As a result, the balloon 10 can be made easily foldable so that the outer diameter becomes smaller at the distal end of the balloon 10, which tends to be bulky due to the difficulty in folding the balloon membrane when the balloon 10 is deflated.

[0052] In particular, it is preferable that both the proximal tapered portion 22 and the distal tapered portion 24 have a first fold 31 and a second fold 32, respectively, and that in the proximal tapered portion 22, the distance D1 between the proximal end of the first fold 31 and the proximal end of the second fold 32 is smaller than the distance D2 between the distal end of the first fold 31 and the distal end of the second fold 32, and that in the distal tapered portion 24, the distance D3 between the distal end of the first fold 31 and the distal end of the second fold 32 is smaller than the distance D4 between the proximal end of the first fold 31 and the proximal end of the second fold 32. Since the distance D1 between the proximal ends of the first fold 31 and the second fold 32 in the proximal tapered portion 22 is smaller than the distance D2 between the distal ends, and the distance D3 between the distal ends of the first fold 31 and the second fold 32 in the distal tapered portion 24 is smaller than the distance D4 between the proximal ends, the balloon 10 is easier to fold at both the proximal and distal ends of the balloon 10, making it easier to reduce the outer diameter of the balloon 10.

[0053] 5 , when the fold 30 is located in the proximal tapered portion 22, the distal end of the fold 30 is preferably located proximal to the proximal end 12p of the mountain fold 12 in the proximal tapered portion 22. By locating the distal end of the fold 30 proximal to the proximal end 12p of the mountain fold 12 in the proximal tapered portion 22, the portion of the balloon 10 where the fold 30 is located does not overlap the portion of the mountain fold 12 in the longitudinal axis direction x. Therefore, when the balloon 10 is deflated, the fold 30 and the mountain fold 12 are less likely to interfere with each other, making it easier to fold the balloon 10 so that the outer diameter thereof becomes smaller.

[0054] Furthermore, when the fold 30 is disposed in the distal tapered portion 24, the proximal end of the fold 30 is preferably located distal to the distal end 12d of the mountain fold 12 in the distal tapered portion 24. By locating the proximal end of the fold 30 distal to the distal end 12d of the mountain fold 12 in the distal tapered portion 24, the portion of the balloon 10 where the fold 30 is located and the portion of the mountain fold 12 are located do not overlap in the longitudinal axis direction x. This reduces the likelihood of interference between the fold 30 and the mountain fold 12 when the balloon 10 is in a deflated state, making the balloon 10 easier to fold to a small outer diameter.

[0055] In particular, it is more preferable that the folds 30 are arranged in both the proximal tapered portion 22 and the distal tapered portion 24, and that in the proximal tapered portion 22, the distal end of the fold 30 arranged in the proximal tapered portion 22 is located proximal to the proximal end 12p of the mountain fold 12, and that in the distal tapered portion 24, the proximal end of the fold 30 arranged in the distal tapered portion 24 is located distal to the distal end 12d of the mountain fold 12. The distal ends of the folds 30 in the proximal tapered portion 22 are located proximal to the proximal end 12p of the mountain fold 12, and the proximal ends of the folds 30 in the distal tapered portion 24 are located distal to the distal end 12d of the mountain fold 12, which reduces interference between the folds 30 and the mountain folds 12 in both the proximal tapered portion 22 and the distal tapered portion 24. As a result, the entire balloon 10 in the longitudinal axis direction x can be easily folded so that the outer diameter of the balloon 10 is small when the balloon 10 is in a deflated state.

[0056] The balloon 10 according to the embodiment of the present invention can be used in the balloon catheter 1. That is, the balloon catheter 1 can be provided with the balloon 10 for the balloon catheter 1 described above.

[0057] As shown in FIG. 9 , a balloon catheter 1 having a balloon 10 according to an embodiment of the present invention preferably includes a shaft 40. The balloon 10 is connected to the distal end of the shaft 40. The balloon 10 can be expanded by introducing a fluid through the lumen of the shaft 40, and can be deflated by discharging the fluid. To control the expansion and contraction of the balloon 10, an indeflator (a balloon pressurizer) can be used to introduce or discharge the fluid. The fluid may be, for example, saline or a mixture of a contrast agent and saline. The fluid may also be a pressurized fluid pressurized by a pump or the like.

[0058] 9 shows a so-called rapid exchange type balloon catheter 1 having a guidewire port 50 midway from the distal side to the proximal side of the shaft 40 and an inner shaft 60 that functions as a guidewire passage from the guidewire port 50 to the distal side of the shaft 40. The balloon catheter 1 preferably has a proximal shaft 41 and a distal shaft 42. The proximal shaft 41 and the distal shaft 42 may be separate members, and the proximal end of the distal shaft 42 may be connected to the distal end of the proximal shaft 41 to form the shaft 40 that extends from the balloon 10 to the proximal end of the balloon catheter 1. Alternatively, a single shaft 40 may extend from the balloon 10 to the proximal end of the balloon catheter 1, and the proximal shaft 41 and the distal shaft 42 may each be composed of multiple tubular members.

[0059] The shaft 40 preferably has a fluid flow path and a guidewire insertion path therein. To configure the shaft 40 to have a fluid flow path and a guidewire insertion path therein, for example, an inner shaft 60 disposed inside the shaft 40 may function as a guidewire insertion path, and the space between the shaft 40 and the inner shaft 60 may function as a fluid flow path. In such a configuration, it is preferable that the inner shaft 60 extends from the distal end of the shaft 40 and passes through the balloon 10, with the distal portion of the balloon 10 connected to the inner shaft 60 and the proximal portion of the balloon 10 connected to the shaft 40.

[0060] The shaft 40 is preferably made of resin, metal, or a combination of resin and metal. Using resin as the constituent material of the shaft 40 facilitates imparting flexibility and elasticity to the shaft 40. Furthermore, using metal as the constituent material of the shaft 40 can improve the deliverability of the balloon catheter 1. Examples of resins that can be used to form the shaft 40 include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluorine-containing resins, vinyl chloride resins, silicone resins, natural rubber, synthetic rubber, and the like. These may be used alone or in combination. Examples of metals that can be used to form the shaft 40 include stainless steels such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloys, Co-Cr alloys, and combinations thereof. When the shaft 40 is composed of a proximal shaft 41 and a distal shaft 42 that are separate members, the proximal shaft 41 may be made of resin, and the distal shaft 42 may be made of metal, for example. The shaft 40 may also have a laminated construction of different materials or the same materials.

[0061] The balloon 10 and the shaft 40 can be joined by bonding with an adhesive, welding, or by attaching a ring-shaped member to the overlapping portion of the end of the balloon 10 and the shaft 40 and crimping the end. Of these, it is preferable that the balloon 10 and the shaft 40 are joined by welding. By welding the balloon 10 and the shaft 40 together, the bond between the balloon 10 and the shaft 40 is less likely to come apart even when the balloon 10 is repeatedly expanded or contracted, thereby improving the bond strength.

[0062] A tip member 70 is preferably provided at the distal end of the balloon catheter 1. The tip member 70 may be provided at the distal end of the balloon catheter 1 as a separate member from the inner shaft 60 and connected to the distal end of the balloon 10, or the inner shaft 60 may extend distally beyond the distal end of the balloon 10 and function as the tip member 70.

[0063] Radiopaque markers 80 may be placed on the inner shaft 60 inside the balloon 10 at the location where the balloon 10 is located in the longitudinal axis direction x so that the position of the balloon 10 can be confirmed under X-ray fluoroscopy. The radiopaque markers 80 are preferably placed at positions corresponding to both ends of the straight tube portion of the balloon 10, or may be placed at a position corresponding to the center of the straight tube portion of the balloon 10 in the longitudinal axis direction x.

[0064] The number of radiopaque markers 80 is not particularly limited, and may be one or more. The shape of the radiopaque marker 80 is not particularly limited, and examples thereof include a cylindrical shape, a polygonal cylindrical shape, or another cylindrical shape, a C-shaped cross section with a notch in the cylinder, and a coil shape with a wound wire. Among these, the shape of the radiopaque marker 80 is preferably cylindrical.

[0065] Examples of materials that can be used to form the radiopaque marker 80 include radiopaque materials such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, and cobalt-chromium alloys.

[0066] A hub 5 may be provided on the proximal side of the shaft 40, and the hub 5 preferably has a fluid injection section 6 that communicates with a flow path for fluid supplied inside the balloon 10.

[0067] The shaft 40 and the hub 5 can be joined by, for example, bonding with an adhesive or welding. Among these, it is preferable that the shaft 40 and the hub 5 are joined by adhesive. By bonding the shaft 40 and the hub 5, the bond strength between the shaft 40 and the hub 5 can be increased, thereby improving the durability of the balloon catheter 1, even when the shaft 40 and the hub 5 are made of different materials, for example, when the shaft 40 is made of a highly flexible material and the hub 5 is made of a highly rigid material.

[0068] Although not shown, the present invention can also be applied to so-called over-the-wire balloon catheters, which have a guidewire passage extending from the distal to the proximal side of the shaft. In the case of an over-the-wire balloon catheter, it is preferable that the inflation lumen and the guidewire lumen extend to a hub located on the proximal side, and that the proximal openings of each lumen are provided in a bifurcated hub.

[0069] In the case of a rapid exchange type catheter, it is preferable that an appropriate coating is applied to the outer wall of at least one of the proximal shaft 41 and the distal shaft 42, and it is more preferable that a coating is applied to both the proximal shaft 41 and the distal shaft 42. In the case of an over-the-wire type catheter, it is preferable that an appropriate coating is applied to the outer wall of the outer shaft.

[0070] The coating can be a hydrophilic coating or a hydrophobic coating depending on the purpose, and can be applied by immersing the shaft 40 in a hydrophilic or hydrophobic coating agent, by applying a hydrophilic or hydrophobic coating agent to the outer wall of the shaft 40, or by covering the outer wall of the shaft 40 with a hydrophilic or hydrophobic coating agent. The coating agent may contain drugs or additives.

[0071] Examples of hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, methyl vinyl ether maleic anhydride copolymer, and the like, or hydrophilic coating agents made from any combination thereof.

[0072] Examples of hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic urethane resin, carbon coat, diamond coat, diamond-like carbon (DLC) coat, ceramic coat, and substances terminated with alkyl groups or perfluoroalkyl groups and having low surface free energy.

[0073] 2. Manufacturing method of balloon for balloon catheter

[0074] A method for manufacturing a balloon for a balloon catheter according to an embodiment of the present invention is a method for manufacturing a balloon for a balloon catheter having a longitudinal axis direction extending from the proximal side to the distal side and radial and circumferential directions perpendicular to the longitudinal axis direction, the method comprising the following steps: a balloon-component preparation step of preparing a balloon-component having a straight tube section, a proximal tapered section located proximal to the straight tube section, a proximal sleeve section located proximal to the proximal tapered section, a distal tapered section located distal to the straight tube section, and a distal sleeve section located distal to the distal tapered section; a jig preparation step of preparing a jig having a first inner wall surface that defines a first lumen extending in the longitudinal axis direction, the first inner wall surface being contactable with the outer surface of the balloon-component; and a first insertion step of inserting at least a portion of one of the proximal tapered section and the distal tapered section into the first lumen.

[0075] A balloon catheter according to an embodiment of the present invention will now be described with reference to Figures 10 to 16. Figure 10 is a side view of a balloon component in a manufacturing method according to an embodiment of the present invention. Figure 11 is a cross-sectional view of the balloon component shown in Figure 10 taken along line XI-XI, representing a cross-section perpendicular to the longitudinal axis of the proximal sleeve portion of the balloon component. Figure 12 is a cross-sectional view of the balloon component shown in Figure 10 taken along line XII-XII, representing a cross-section perpendicular to the longitudinal axis of the proximal tapered portion of the balloon component. Figure 13 is a cross-sectional view of a jig taken along line XIV-XIV, representing a cross-section perpendicular to the longitudinal axis of the first lumen, and Figure 15 is a cross-sectional view of the jig shown in Figure 13 taken along line XV-XV, representing a cross-section perpendicular to the longitudinal axis of the second lumen. Figure 16 is a schematic diagram of a first insertion step in a manufacturing method according to an embodiment of the present invention.

[0076] A method according to an embodiment of the present invention is a method for manufacturing a balloon 10 for a balloon catheter 1 as shown in FIG. 9 , which has a longitudinal axis direction x extending from the proximal side to the distal side, and a radial direction y and a circumferential direction z perpendicular to the longitudinal axis direction x.

[0077] In the description of the manufacturing method of a balloon for a balloon catheter, portions that are the same as those described above in "1. Balloon for a Balloon Catheter" will be omitted. The proximal sleeve portion, proximal tapered portion, straight tube portion, distal tapered portion, and distal sleeve portion of the balloon component 20 will be described using the same reference numerals as the proximal sleeve portion 21, proximal tapered portion 22, straight tube portion 23, distal tapered portion 24, and distal sleeve portion 25 of the balloon 10 in "1. Balloon for a Balloon Catheter" above. However, in this section "2. Manufacturing Method of a Balloon for a Balloon Catheter," the reference numerals 21, 22, 23, 24, and 25 refer to the proximal sleeve portion, proximal tapered portion, straight tube portion, distal tapered portion, and distal sleeve portion of the balloon component 20.

[0078] A manufacturing method according to an embodiment of the present invention includes a balloon-constituting-member preparation step of preparing a balloon-constituting member 20. The balloon-constituting member 20 is a member that constitutes the balloon 10. As shown in Figures 10 to 12, the balloon-constituting member 20 includes a straight tube section 23, a proximal tapered section 22 located proximal to the straight tube section 23, a proximal sleeve section 21 located proximal to the proximal tapered section 22, a distal tapered section 24 located distal to the straight tube section 23, and a distal sleeve section 25 located distal to the distal tapered section 24.

[0079] The straight tube portion 23 is preferably substantially cylindrical, having approximately the same diameter in the longitudinal axis direction x, but may have different diameters in the longitudinal axis direction x. The proximal tapered portion 22 and the distal tapered portion 24 are preferably formed into a substantially conical or truncated conical shape, with diameters decreasing with increasing distance from the straight tube portion 23. Having the largest diameter in the straight tube portion 23 allows the straight tube portion 23 to sufficiently contact the lesion when the balloon 2 is inflated at a lesion such as a stenosis, facilitating treatment such as dilation of the lesion. Furthermore, having the proximal tapered portion 22 and the distal tapered portion 24 reduced in diameter allows the outer diameters of the proximal and distal ends of the balloon 10 to be easily reduced when the balloon 10 is deflated. Furthermore, the step between the shaft 40 and the balloon 10 of the balloon catheter 1 can be reduced, facilitating insertion of the balloon 10 into a body cavity.

[0080] It is preferable that the proximal sleeve section 21 and the distal sleeve section 25 are non-expandable sections, whereas the proximal tapered section 22, the straight tube section 23, and the distal tapered section 24 are sections that expand when a fluid is introduced into the balloon 10. By having the proximal sleeve section 21 and the distal sleeve section 25 be non-expandable sections, it becomes easier to firmly fix at least a portion of the proximal sleeve section 21 and at least a portion of the distal sleeve section 25 to a member such as the shaft 40.

[0081] Examples of materials that can be used to form the balloon component 20 include polyamide resins such as nylon 11 and nylon 12, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyurethane resins, and thermoplastic elastomers such as polyether block amide copolymers.

[0082] The balloon-constituting member 20 can be obtained by biaxially stretching or blow molding a parison. The parison is made of resin and is a cylindrical member with an internal cavity. Like the balloon-constituting member 20, the parison has a longitudinal axis direction x, a radial direction y, and a circumferential direction z. The parison can be obtained, for example, by extrusion molding a resin using a cylindrical mold.

[0083] A manufacturing method according to an embodiment of the present invention includes a jig preparation step of preparing a jig 100. As shown in Figures 13 to 15, the jig 100 has a first inner wall surface 121 that defines a first lumen 111 extending in the longitudinal axis direction x, and the first inner wall surface 121 can come into contact with the outer surface of the balloon-constituting member 20. In other words, the jig 100 has the first lumen 111 that extends in the longitudinal axis direction x, and when the balloon-constituting member 20 is placed in the first lumen 111 of the jig 100, the first inner wall surface 121 that defines the first lumen 111 can come into contact with the outer surface of the balloon-constituting member 20.

[0084] The jig 100 may be composed of one member or multiple members. For example, the jig 100 may be composed of multiple members connected to each other in the longitudinal axis direction x. The jig 100 may also be separable in the radial direction y. The separability of the jig 100 makes it easier to insert the balloon-constituting member 20 into the lumen of the jig 100. The members constituting the jig 100 may be joined by engaging adjacent members together, or adjacent members may be attached with magnets and joined by the attractive force of the magnets.

[0085] The material constituting the jig 100 is preferably metal or resin. Examples of metals constituting the jig 100 include iron, copper, aluminum, and alloys thereof. Specifically, iron alloys include stainless steel, copper alloys include brass, and aluminum alloys include duralumin. These materials may be used alone or in combination of two or more. Examples of resins constituting the jig 100 include polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, polyester resins such as PET, aromatic polyether ketone resins such as PEEK, polyether polyamide resins, polyurethane resins, polyimide resins, fluorine-based resins such as PTFE, PFA, and ETFE, and synthetic resins such as polyvinyl chloride resins. These materials may be used alone or in combination of two or more.

[0086] Among these, the material constituting the jig 100 is preferably a metal, and more preferably stainless steel. By making the jig 100 out of a metal, the jig 100 can have sufficient conductivity and strength. Furthermore, by making the jig 100 out of stainless steel, the jig 100 can be easily formed because stainless steel is easy to process.

[0087] 16 , the manufacturing method according to the embodiment of the present invention includes a first insertion step of inserting at least a portion of either the proximal tapered portion 22 or the distal tapered portion 24 into the first lumen 111. That is, in the first insertion step, at least a portion of the proximal tapered portion 22 or at least a portion of the distal tapered portion 24 of the balloon component 20 is inserted into the first lumen 111 of the jig 100. Note that the hatching on the balloon component 20 in FIG. 16 does not represent a cross section, but rather serves to make it easier to understand the balloon component 20 disposed in the lumen of the jig 100.

[0088] By including the first insertion step of inserting at least a portion of either the proximal tapered portion 22 or the distal tapered portion 24 into the first lumen 111, the outer surface of either the proximal tapered portion 22 or the distal tapered portion 24 of the balloon component 20 comes into contact with the first inner wall surface 121 of the jig 100. By bringing the outer surface of either the proximal tapered portion 22 or the distal tapered portion 24 into contact with the first inner wall surface 121, the balloon membrane of the balloon component 20 in either the proximal tapered portion 22 or the distal tapered portion 24 inserted into the first lumen 111 is bent to form a crease, and a crease can be formed in either the proximal tapered portion 22 or the distal tapered portion 24. As a result, when the balloon 10 is deflated, one of the proximal tapered portion 22 and the distal tapered portion 24 is more likely to fold, making it easier to fold the balloon 10 so that the overall outer diameter of the balloon 10 is smaller.

[0089] In the first insertion step, when at least a portion of the proximal tapered portion 22 is inserted into the first lumen 111, it is preferable to insert the proximal sleeve portion 21 into a distal opening of the jig 100 that communicates with the first lumen 111, and position the proximal end of the proximal tapered portion 22 inside the first lumen 111. Furthermore, in the first insertion step, when at least a portion of the distal tapered portion 24 is inserted into the first lumen 111, it is preferable to insert the distal sleeve portion 25 into a proximal opening of the jig 100 that communicates with the first lumen 111, and position the distal end of the distal tapered portion 24 inside the first lumen 111.

[0090] In the first insertion step, it is preferable to insert at least a portion of the proximal tapered portion 22 or the distal tapered portion 24 into the first lumen 111 while the balloon component 20 is pulled in the longitudinal direction x. That is, in the first insertion step, it is preferable to insert at least a portion of the proximal tapered portion 22 or the distal tapered portion 24 into the first lumen 111 while pulling the balloon component 20 in the longitudinal direction x to apply tension. By inserting at least a portion of the proximal tapered portion 22 or the distal tapered portion 24 into the first lumen 111 while the balloon component 20 is pulled in the longitudinal direction x, tension is applied to the balloon component 20, causing the balloon membrane to dent in the proximal tapered portion 22 and the distal tapered portion 24, and making it easier to reduce the outer diameters of both ends of the proximal tapered portion 22 and the distal tapered portion 24. This makes it easier to insert at least a portion of either the proximal tapered portion 22 or the distal tapered portion 24 into the first lumen 111, making it easier to perform the first insertion step and to easily create a crease in the balloon component 20.

[0091] To pull the balloon component 20 in the longitudinal axis direction x, for example, the proximal sleeve portion 21 and the distal sleeve portion 25 of the balloon component 20 may be grasped, and the proximal sleeve portion 21 may be pulled proximally and the distal sleeve portion 25 may be pulled distally.

[0092] Preferably, the manufacturing method according to the embodiment of the present invention further includes, after the first insertion step, a second insertion step of inserting at least a portion of the other of the proximal tapered portion 22 and the distal tapered portion 24 into the first lumen 111. That is, it is preferable that in the first insertion step, at least a portion of either the proximal tapered portion 22 or the distal tapered portion 24 is inserted into the first lumen 111, and further, in the second insertion step, the other of the proximal tapered portion 22 and the distal tapered portion 24 that was not inserted into the first lumen 111 in the first insertion step is inserted into the first lumen 111. Specifically, for example, if at least a portion of the proximal tapered portion 22 is inserted into the first lumen 111 in the first insertion step, it is preferable that at least a portion of the distal tapered portion 24 is inserted into the first lumen 111 in the second insertion step.

[0093] By further including the second insertion step after the first insertion step, it is possible to impart creases to the balloon membrane in both the proximal tapered portion 22 and the distal tapered portion 24, making it easier to fold the balloon 10 so that the outer diameter thereof becomes smaller in both the proximal tapered portion 22 and the distal tapered portion 24.

[0094] In the second insertion step, it is preferable that the balloon component 20 be pulled in the longitudinal axis direction x while at least a portion of the other of the proximal tapered portion 22 and the distal tapered portion 24 is inserted into the first lumen 111. By inserting at least a portion of the other of the proximal tapered portion 22 and the distal tapered portion 24 into the first lumen 111 while the balloon component 20 is pulled in the longitudinal axis direction x in the second insertion step, tension is applied to the balloon component 20, which tends to reduce the outer diameters of both ends of the proximal tapered portion 22 and the distal tapered portion 24, making it easier to insert the other of the proximal tapered portion 22 and the distal tapered portion 24 into the first lumen 111.

[0095] 11 to 15 , it is preferable that the inner diameter d100 of the jig 100 in the first lumen 111 is larger than or equal to the outer diameter D25 of the proximal sleeve portion 21 and the distal sleeve portion 25, and has a portion that is smaller than the outer diameter D24 of the proximal tapered portion 22 and the distal tapered portion 24. In other words, it is preferable that the inner diameter d100 of the jig 100 in the first lumen 111 is larger than the outer diameter D25 of the proximal sleeve portion 21 and the distal sleeve portion 25, and has a portion that is smaller than the outer diameter D24 of the proximal tapered portion 22 and the distal tapered portion 24, or is equal to the outer diameter D25 of the proximal sleeve portion 21 and the distal sleeve portion 25, and has a portion that is smaller than the outer diameter D24 of the proximal tapered portion 22 and the distal tapered portion 24. The outer diameter of the proximal sleeve portion 21, the outer diameter D25 of the distal sleeve portion 25, the outer diameter of the proximal tapered portion 22, and the outer diameter D24 of the distal tapered portion 24 all refer to the maximum outer diameters of the balloon component 20 when expanded.

[0096] Since the inner diameter d100 of the jig 100 in the first lumen 111 is larger than or equal to the outer diameter D25 of the proximal sleeve portion 21 and the distal sleeve portion 25, and has a portion that is smaller than the outer diameter D24 of the proximal tapered portion 22 and the distal tapered portion 24, it is possible to easily insert the proximal tapered portion 22 into the first lumen 111 through the proximal sleeve portion 21, and to easily insert the distal tapered portion 24 through the distal sleeve portion 25, and it is also possible to easily bring the outer surfaces of the proximal tapered portion 22 and the distal tapered portion 24 into contact with the first inner wall surface 121, making it easier to impart a crease to the balloon membrane.

[0097] The inner diameter d100 of the jig 100 in the first lumen 111 is preferably at least 1.03 times, more preferably at least 1.05 times, and even more preferably at least 1.07 times the outer diameter D25 of the proximal sleeve portion 21 and the distal sleeve portion 25. By setting the lower limit of the ratio of the inner diameter d100 of the jig 100 in the first lumen 111 to the outer diameter D25 of the proximal sleeve portion 21 and the distal sleeve portion 25 within the above range, it becomes easier to insert the proximal sleeve portion 21 and the distal sleeve portion 25 into the first lumen 111, and it becomes less likely that the balloon membrane will be damaged when the proximal tapered portion 22 and the distal tapered portion 24 are inserted into the first lumen 111. Furthermore, the inner diameter d100 of the jig 100 in the first lumen 111 is preferably 1.5 times or less, more preferably 1.4 times or less, and even more preferably 1.3 times or less the outer diameter D25 of the proximal sleeve portion 21 and the distal sleeve portion 25. By setting the upper limit of the ratio of the inner diameter d100 of the jig 100 in the first lumen 111 to the outer diameter D25 of the proximal sleeve portion 21 and the distal sleeve portion 25 within the above range, it becomes easier to form creases in the proximal tapered portion 22 and the distal tapered portion 24 when they are inserted into the first lumen 111.

[0098] The inner diameter d100 of the jig 100 in the first lumen 111 is preferably 80% or less, more preferably 70% or less, and even more preferably 60% or less, of the outer diameter D24 of the proximal tapered portion 22 and the distal tapered portion 24. By setting the upper limit of the ratio of the inner diameter d100 of the jig 100 in the first lumen 111 to the outer diameter D24 of the proximal tapered portion 22 and the distal tapered portion 24 within the above range, it becomes easier to crease the balloon membrane by inserting the proximal tapered portion 22 or the distal tapered portion 24 into the first lumen 111. Furthermore, the inner diameter d100 of the jig 100 in the first lumen 111 is preferably 20% or more, more preferably 30% or more, and even more preferably 40% or more of the outer diameter D24 of the proximal tapered portion 22 and the distal tapered portion 24. By setting the lower limit of the ratio between the inner diameter d100 of the jig 100 in the first lumen 111 and the outer diameter D24 of the proximal taper portion 22 and the distal taper portion 24 within the above range, when the proximal taper portion 22 or the distal taper portion 24 is inserted into the first lumen 111 and the outer surface of the proximal taper portion 22 or the distal taper portion 24 comes into contact with the first inner wall surface 121, the balloon membrane is less likely to be scratched and the balloon component 20 is less likely to be damaged.

[0099] 13 to 15, the jig 100 further has a second lumen 112 extending in the longitudinal axis direction x, and in a cross section perpendicular to the longitudinal axis direction x, the maximum cross-sectional area of ​​the second lumen 112 is larger than the maximum cross-sectional area of ​​the first lumen 111, and the cross-sectional shape of the first lumen 111 in the cross section perpendicular to the longitudinal axis direction x is preferably circular, and the cross-sectional shape of the second lumen 112 in the cross section perpendicular to the longitudinal axis direction x is preferably polygonal. In other words, the jig 100 preferably further has a second inner wall surface 122 that defines the second lumen 112 extending in the longitudinal axis direction x.

[0100] The jig 100 has a second lumen 112 whose maximum cross-sectional area is larger than that of the first lumen 111, and the cross-sectional shape of the first lumen 111 is circular and the cross-sectional shape of the second lumen 112 is polygonal. Therefore, when a balloon component 20 is placed in the lumen of the jig 100, depressions are likely to be formed in the portions of the balloon component 20 placed in the first lumen 111 that are located on extensions of the sides of the polygonal cross-sectional shape of the second lumen 112. This makes it possible to easily control the positions of folds formed in the balloon membrane at the proximal tapered portion 22 and the distal tapered portion 24 while preventing damage to the outer surface of the balloon component 20 placed in the first lumen 111.

[0101] The polygonal cross-sectional shape of the second lumen 112 has vertices including the vertices of the polygon and polygonal sides. The polygonal cross-sectional shape of the second lumen 112 includes polygons with clearly defined vertices and straight sides, as well as rounded polygons with rounded corners and polygons with at least some curved sides. Examples of polygonal cross-sectional shapes of the second lumen 112 include triangles, rectangles, and pentagons. Among these, a triangular cross-sectional shape of the second lumen 112 is preferred. The triangular cross-sectional shape of the second lumen 112 facilitates appropriate determination of the number and size of folds formed in the proximal tapered portion 22 and the distal tapered portion 24 of the balloon component 20.

[0102] In a cross section perpendicular to the longitudinal axis direction x, the maximum inner diameter of the second lumen 112 is preferably 1.00 times or more, more preferably 1.05 times or more, and even more preferably 1.10 times or more, the maximum outer diameter of the straight tube portion 23 of the balloon component 20. Setting the lower limit of the ratio of the maximum inner diameter of the second lumen 112 to the maximum outer diameter of the straight tube portion 23 within the above range makes it easier to place the balloon component 20 in the second lumen 112 of the jig 100. Furthermore, in a cross section perpendicular to the longitudinal axis direction x, the maximum inner diameter of the second lumen 112 is preferably 1.50 times or less, more preferably 1.45 times or less, and even more preferably 1.40 times or less, the maximum outer diameter of the straight tube portion 23 of the balloon component 20. By setting the upper limit of the ratio between the maximum inner diameter of the second lumen 112 and the maximum outer diameter of the straight tube portion 23 within the above range, when the balloon component 20 is placed in the lumen of the jig 100, the straight tube portion 23 of the balloon component 20 is more likely to be supported by the second inner wall surface 122 that defines the second lumen 112. As a result, the balloon component 20 can be more easily and stably placed in the lumen of the jig 100.

[0103] In a cross section perpendicular to the longitudinal axis direction x, the maximum cross-sectional area of ​​the second lumen 112 is preferably 1.5 times or more, more preferably 2.0 times or more, and even more preferably 2.5 times or more, the maximum cross-sectional area of ​​the first lumen 111. By setting the lower limit of the ratio of the maximum cross-sectional area of ​​the second lumen 112 to the maximum cross-sectional area of ​​the first lumen 111 within the above range, it is possible to facilitate insertion of the proximal sleeve portion 21 and the distal sleeve portion 25 of the balloon component 20 into the first lumen 111 of the jig 100. Furthermore, in a cross section perpendicular to the longitudinal axis direction x, the maximum cross-sectional area of ​​the second lumen 112 is preferably 10 times or less, more preferably 8 times or less, and even more preferably 6 times or less, the maximum cross-sectional area of ​​the first lumen 111. By setting the upper limit value of the ratio between the maximum cross-sectional area of ​​the second lumen 112 and the maximum cross-sectional area of ​​the first lumen 111 within the above range, the difference between the cross-sectional area of ​​the first lumen 111 and the cross-sectional area of ​​the second lumen 112 does not become too large, making it easier to control the position of the folds formed in the proximal taper portion 22 and the distal taper portion 24.

[0104] 13 , the first lumen 111 includes a proximal first lumen 111P and a distal first lumen 111D, and it is preferable that the proximal first lumen 111P is disposed proximally relative to the second lumen 112, and the distal first lumen 111D is disposed distally relative to the second lumen 112. That is, it is preferable that the second lumen 112 is located between the proximal first lumen 111P and the distal first lumen 111D in the longitudinal axis direction x, and that the proximal first lumen 111P, the second lumen 112, and the distal first lumen 111D are disposed in this order from the proximal side to the distal side.

[0105] 13 , the jig 100 preferably further includes a proximal third lumen 113P, the cross-sectional area of ​​which decreases proximally, located proximal to the second lumen 112 and distal to the proximal first lumen 111P, and a distal third lumen 113D, the cross-sectional area of ​​which decreases distally, located distal to the second lumen 112 and proximal to the distal first lumen 111D. That is, the jig 100 preferably further includes a third inner wall surface 123 that defines the proximal third lumen 113P and the distal third lumen 113D. Furthermore, the proximal first lumen 111P, the proximal third lumen 113P, the second lumen 112, the distal third lumen 113D, and the distal first lumen 111D are preferably arranged in this order from the proximal to the distal side in the longitudinal axis direction x.

[0106] Preferably, the cross-sectional area of ​​the proximal third lumen 113P decreases proximally, and the cross-sectional area of ​​the distal third lumen 113D decreases distally. That is, the proximal third lumen 113P and the distal third lumen 113D preferably have tapered lumens. The jig 100 having the proximal third lumen 113P and the distal third lumen 113D facilitates insertion of the balloon component 20 into the proximal first lumen 111P and the distal first lumen 111D, respectively, and facilitates processing to form creases in both the proximal tapered portion 22 and the distal tapered portion 24 of the balloon component 20.

[0107] Preferably, the proximal end of the proximal third lumen 113P is connected to the distal end of the proximal first lumen 111P, and the distal end of the proximal third lumen 113P is connected to the proximal end of the second lumen 112. Preferably, the proximal end of the distal third lumen 113D is connected to the distal end of the second lumen 112, and the distal end of the distal third lumen 113D is connected to the proximal end of the distal first lumen 111D. The configuration in which the proximal third lumen 113P and the distal third lumen 113D are connected to the proximal first lumen 111P, the second lumen 112, and the distal first lumen 111D, respectively, as described above, makes it easier to insert the balloon component 20 into the proximal first lumen 111P and the distal first lumen 111D, respectively.

[0108] In the first insertion step, it is preferable that one of the proximal end of the proximal taper portion 22 and the distal end of the distal taper portion 24 is inserted into the first inner cavity 111, and in the second insertion step, the other of the proximal end of the proximal taper portion 22 and the distal end of the distal taper portion 24 is inserted into the first inner cavity 111. When the first lumen 111 includes a proximal first lumen 111P and a distal first lumen 111D, it is preferable that in the first insertion step, the proximal end of the proximal taper portion 22 is inserted into the proximal first lumen 111P or the distal end of the distal taper portion 24 is inserted into the distal first lumen 111D, and in the second insertion step, either the proximal end of the proximal taper portion 22 or the distal end of the distal taper portion 24, whichever was not inserted into the first lumen 111 in the first insertion step, is inserted into the first lumen 111.

[0109] The proximal end of the proximal tapered portion 22 is a portion that includes the proximal end of the proximal tapered portion 22, and is preferably the portion that is located most proximal when the proximal tapered portion 22 is divided into three equal parts in the longitudinal axis direction x. The distal end of the distal tapered portion 24 is a portion that includes the distal end of the distal tapered portion 24, and is preferably the portion that is located most distal when the distal tapered portion 24 is divided into three equal parts in the longitudinal axis direction x.

[0110] In the first insertion step, one of the proximal end of the proximal tapered section 22 and the distal end of the distal tapered section 24 is inserted into the first lumen 111, and in the second insertion step, the other of the proximal end of the proximal tapered section 22 and the distal end of the distal tapered section 24 is inserted into the first lumen 111. This makes it easier to create creases in the proximal end of the proximal tapered section 22 and the distal end of the distal tapered section 24, which tend to have thicker membranes in the balloon component 20. This makes it easier to fold the balloon 10 so that the overall outer diameter is smaller when the balloon 10 is deflated.

[0111] The manufacturing method according to an embodiment of the present invention further includes a parison preparation step of preparing a parison having a lumen extending in the longitudinal axis direction x, a radial direction y and a circumferential direction z perpendicular to the longitudinal axis direction x, and a balloon-component molding step of stretching the parison while the parison is placed in the lumen of the jig 100 to form the balloon-component 20. The parison preparation step and the balloon-component molding step are preferably performed before the balloon-component preparation step. In other words, the jig 100 is preferably used in both the balloon-component molding step and the first insertion step.

[0112] In the balloon-constituting-member molding process, it is preferable that a portion of the parison in the longitudinal axis direction x is placed in the lumen of the jig 100. Placing a portion of the parison in the longitudinal axis direction x in the lumen of the jig 100 facilitates blow molding to form the balloon-constituting member 20 from the parison. The parison becomes the balloon-constituting member 20 through blow molding, and the jig 100 is preferably a blow-molding mold.

[0113] Because the manufacturing method of the present invention further includes a parison preparation step for preparing a parison and a balloon component molding step for stretching the parison placed in the lumen of the jig 100 to form the balloon component 20, the jig 100 serves as both a mold for stretching the parison to form the balloon component 20 and a jig for imparting creases to the proximal tapered portion 22 and the distal tapered portion 24 of the balloon component 20, making it possible to efficiently manufacture the balloon 10 from the parison via the balloon component 20.

[0114] The temperature of the jig 100 in the first and second insertion steps is preferably lower than the temperature of the jig 100 in the balloon-component molding step. By making the temperature of the jig 100 in the first and second insertion steps lower than the temperature of the jig 100 in the balloon-component molding step, unintended deformation of the balloon-component 20 is less likely to occur in the first and second insertion steps, and the efficiency of manufacturing the balloon 10 can be improved.

[0115] The balloon 10 manufactured by the manufacturing method according to the embodiment of the present invention can be used in the balloon catheter 1. In other words, the balloon catheter 1 includes the balloon 10 manufactured by the manufacturing method according to the embodiment of the present invention.

[0116] The balloon catheter 1 preferably includes a balloon 10 and a shaft 40. The balloon 10 is connected to the distal end of the shaft 40, and can be expanded by introducing a fluid through the lumen of the shaft 40, and can be deflated by discharging the fluid. To control the expansion and contraction of the balloon 10, an indeflator (a balloon pressurizer) can be used to introduce or discharge the fluid. The fluid can be, for example, saline or a mixture of a contrast agent and saline. The fluid can also be a pressurized fluid pressurized by a pump or the like.

[0117] This application claims the benefit of priority based on Japanese Patent Application No. 2024-060859 filed on April 4, 2024, and Japanese Patent Application No. 2024-073945 filed on April 30, 2024. The entire contents of the specifications of Japanese Patent Application No. 2024-060859 filed on April 4, 2024, and Japanese Patent Application No. 2024-073945 filed on April 30, 2024 are incorporated herein by reference.

[0118] 1: Balloon catheter 5: Hub 6: Fluid injection section 10: Balloon 11: Wing-shaped section 12: Mountain-folded section 12p: Proximal end of mountain-folded section 12d: Distal end of mountain-folded section 13: Apex section 14: Side section 20: Balloon component 21: Proximal sleeve section 22: Proximal tapered section 22d: Distal end of proximal tapered section 23: Straight tube section 24: Distal tapered section 24p: Proximal end of distal tapered section 25: Distal sleeve section 30: Fold 31: First fold 32: Second fold 40: Shaft 41: Proximal shaft 42: Distal shaft 50: Guidewire port 60: Inner shaft 70: Distal tip member 80: Radiopaque marker 100: Jig 111: First lumen 111P: Proximal first lumen 111D: Distal first lumen 112: Second lumen 113P: Proximal third lumen 113D: Distal third lumen 121: First inner wall surface 122: Second inner wall surface 123: Third inner wall surface P1: Apex of the wing-shaped portion P2: Centroid of the balloon A1: Presence region A2: Absence region L1: Extension line of the mountain fold in the longitudinal direction D1: Distance between the proximal end of the first fold and the proximal end of the second fold in the proximal tapered portion D2: Distance between the distal end of the first fold and the distal end of the second fold in the proximal tapered portion D3: Distance between the distal end of the first fold and the distal end of the second fold in the distal tapered portion D4: Distance between the proximal end of the first fold and the proximal end of the second fold in the distal tapered portion d100: inner diameter of the jig in the first lumen D24: outer diameter of the distal tapered portion D25: outer diameter of the distal sleeve portion

Claims

1. A balloon for a balloon catheter having a longitudinal axis direction extending from a proximal side to a distal side, and radial and circumferential directions perpendicular to the longitudinal axis direction, the balloon having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, and a distal tapered portion located distal to the straight tube portion, the balloon having, in a deflated state, a mountain fold portion where the balloon membrane forming the apex of a wing-shaped portion is bent in a mountain fold, at least one of the proximal tapered portion and the distal tapered portion has, in the longitudinal axis direction, a presence region where the mountain fold portion is present and an absence region where the mountain fold portion is not present, at least one of the proximal tapered portion and the distal tapered portion has at least one fold where the balloon membrane is bent and extending in the longitudinal axis direction, When the fold is located in the proximal tapered portion, the proximal end of the fold is located in the non-existence region, and the distal end of the fold is located proximal to the distal end of the proximal tapered portion; when the fold is located in the distal tapered portion, the proximal end of the fold is located distal to the proximal end of the distal tapered portion, and the distal end of the fold is located in the non-existence region.

2. The balloon for a balloon catheter according to claim 1, wherein the folds are arranged in the proximal tapered portion and the distal tapered portion.

3. A balloon for a balloon catheter according to claim 1, wherein the fold does not lie on an extension line of the mountain fold in the longitudinal direction.

4. A balloon for a balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal axis direction, the cross-sectional shape of the balloon at at least one of the proximal tapered section and the distal tapered section is a polygon having vertices and sides including a vertex, and the folds are located on the sides.

5. A balloon for a balloon catheter according to claim 4, wherein the number of folds is twice the number of vertices of the cross-sectional shape of the balloon in a cross section perpendicular to the longitudinal axis direction.

6. The balloon for a balloon catheter according to claim 4, wherein the number of folds is plural, and in a cross section perpendicular to the longitudinal axis direction, the folds are located on both sides of the apex in the circumferential direction.

7. A balloon for a balloon catheter as described in claim 1, wherein the folds include a first fold and a second fold that are adjacent to each other in the circumferential direction, and when the folds are arranged in the proximal tapered portion, the distance between the proximal end of the first fold and the proximal end of the second fold at the proximal tapered portion is smaller than the distance between the distal end of the first fold and the distal end of the second fold at the distal tapered portion, and when the folds are arranged in the distal tapered portion, the distance between the distal end of the first fold and the distal end of the second fold at the distal tapered portion is smaller than the distance between the proximal end of the first fold and the proximal end of the second fold.

8. A balloon for a balloon catheter as described in claim 1, wherein, when the fold is located in the proximal tapered portion, the distal end of the fold in the proximal tapered portion is located proximal to the proximal end of the mountain fold, and when the fold is located in the distal tapered portion, the proximal end of the fold in the distal tapered portion is located distal to the distal end of the mountain fold.

9. A method for manufacturing a balloon for a balloon catheter having a longitudinal axis direction extending from the proximal side to the distal side and radial and circumferential directions perpendicular to the longitudinal axis direction, the method comprising: a balloon component preparation step of preparing a balloon component having a straight tube section, a proximal tapered section located proximal to the straight tube section, a proximal sleeve section located proximal to the proximal tapered section, a distal tapered section located distal to the straight tube section, and a distal sleeve section located distal to the distal tapered section; a jig preparation step of preparing a jig having a first inner wall surface that defines a first lumen extending in the longitudinal axis direction, the first inner wall surface being contactable with the outer surface of the balloon component; and a first insertion step of inserting at least a portion of one of the proximal tapered section and the distal tapered section into the first lumen.

10. A method for manufacturing a balloon for a balloon catheter as described in claim 9, wherein in the first insertion step, at least a portion of one of the proximal tapered portion and the distal tapered portion is inserted into the first inner cavity while the balloon component is pulled in the longitudinal axis direction.

11. A method for manufacturing a balloon for a balloon catheter as described in claim 9, further comprising a second insertion step of inserting at least a portion of the other of the proximal tapered portion and the distal tapered portion into the first lumen after the first insertion step, wherein in the second insertion step, at least a portion of the other of the proximal tapered portion and the distal tapered portion is inserted into the first lumen while the balloon component is pulled in the longitudinal axis direction.

12. A method for manufacturing a balloon for a balloon catheter as described in claim 9, wherein the inner diameter of the jig in the first lumen is larger than or equal to the outer diameter of the proximal sleeve portion and the outer diameter of the distal sleeve portion, and has a portion smaller than the outer diameter of the proximal tapered portion and the outer diameter of the distal tapered portion.

13. A method for manufacturing a balloon for a balloon catheter as described in claim 9, wherein the jig further has a second lumen extending in the longitudinal axis direction, the maximum cross-sectional area of ​​the second lumen in a cross section perpendicular to the longitudinal axis direction is larger than the maximum cross-sectional area of ​​the first lumen, the cross-sectional shape of the first lumen in the cross section perpendicular to the longitudinal axis direction is circular, and the cross-sectional shape of the second lumen in the cross section perpendicular to the longitudinal axis direction is polygonal.

14. A method for manufacturing a balloon for a balloon catheter as described in claim 13, wherein the first lumen includes a proximal first lumen and a distal first lumen, the proximal first lumen being disposed proximal to the second lumen and the distal first lumen being disposed distal to the second lumen, and further comprising a proximal third lumen proximal to the second lumen and distal to the proximal first lumen, the cross-sectional area of ​​the lumen decreasing proximally, and further comprising a distal third lumen distal to the second lumen and proximal to the distal first lumen, the cross-sectional area of ​​the lumen decreasing distally.

15. A method for manufacturing a balloon for a balloon catheter as described in claim 11, wherein in the first insertion step, one of the proximal end of the proximal tapered portion and the distal end of the distal tapered portion is inserted into the first inner cavity, and in the second insertion step, the other of the proximal end of the proximal tapered portion and the distal end of the distal tapered portion is inserted into the first inner cavity.

16. A method for manufacturing a balloon for a balloon catheter as described in claim 9, further comprising: a parison preparation step of preparing a parison having a longitudinal axis direction extending from the proximal side to the distal side, and radial and circumferential directions perpendicular to the longitudinal axis direction, and having an inner cavity extending in the longitudinal axis direction; and a balloon component molding step of stretching the parison while it is placed in the inner cavity of the jig to form the balloon component, wherein the parison preparation step and the balloon component molding step are performed before the balloon component preparation step.

17. A method for manufacturing a balloon for a balloon catheter as described in claim 16, further comprising a second insertion step of inserting at least a portion of the other of the proximal tapered portion and the distal tapered portion into the first lumen after the first insertion step, wherein the temperature of the jig in the first insertion step and the second insertion step is lower than the temperature of the jig in the balloon component molding step.

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