Patent Description:
Treatment of a lesion of a blood vessel by use of a catheter has been widely practiced because of little surgical invasiveness. For example, in percutaneous coronary angioplasty (Percutaneous Transluminal Coronary Angioplasty), a balloon catheter is used for improving blood flow by pushing open a lesion part of a coronary artery. In general, a balloon catheter includes an elongated hollow shaft, a balloon provided on the distal side of the shaft, and a hub provided on the proximal side of the shaft. The balloon catheter may be provided with a drug eluting balloon having a surface coated with a drug.

The balloon of a balloon catheter is required to be as small as possible in diameter when deflated, for good passing properties in a blood vessel. The balloon is formed in a small diameter form by being wrapped at the time of manufacturing the catheter. The wrapping of the balloon is conducted by a pleating step of bending the balloon to form a plurality of wing shapes, for example, three or four wing shapes in the circumferential direction, and a folding step of folding the thus formed wing shapes toward one side in the circumferential direction.

As a conventional balloon wrapping apparatus, there may be mentioned, for example, the one described in Patent Document <NUM>. The balloon wrapping apparatus has a pleating section for performing pleating, and a folding section for performing folding. In addition, the balloon wrapping apparatus has a support base which supports the shaft of the balloon catheter and which is slidable such that the balloon can be inserted into each head.

The pleating section has a plurality of blades in the circumferential direction for shaping the balloon to have the wings. Between the plurality of blades, a space part extending along an insertion direction of the balloon is formed. In addition, the blades can be moved rotationally in such a manner as to change the shape of the space part. The balloon is inserted into the space part between the blades, and the balloon is narrowed by the blades moved rotationally, whereby wing shapes are formed.

The folding section has a plurality of blades movable rotationally such that the wing shapes formed in the balloon can be folded in the manner of being laid flat along the circumferential direction. The balloon is inserted into a region surrounded by the plurality of blades, and the blades are moved rotationally such as to close the region between the blades, whereby the wing shapes formed in the balloon are folded along the circumferential direction.

When wrapping the balloon, the balloon catheter is placed on the support base, and the support base is slid toward the pleating section, whereby the balloon is advanced into the pleating section, and pleating is conducted. When the balloon is drawn out of the pleating section, the balloon is subsequently advanced into the folding section, and folding is conducted.

Patent Document <NUM>: <CIT>
Patent Document <CIT> describes an apparatus and a method of folding a balloon and a holding of the distal end of the balloon catheter.

For improving passing properties of the balloon, the wing shapes should be formed into an accurate shape on the basis of a predetermined interval along the circumferential direction in wrapping of the balloon. For this purpose, the balloon should be positioned accurately at a center position of the pleating section. If the position of the balloon is deviated from the center position of the pleating section, the wing shapes formed in pleating may not become uniform. In addition, if the position of the balloon is deviated from the center position of the folding section, the wing shapes may be crushed at irregular parts, or back folding in which the wing shape is folded in the reverse direction in the circumferential direction may occur.

When the catheter is placed on the support base and the balloon is inserted into the pleating section, a portion near the distal end of the catheter having the balloon is not supported by the support base, and, therefore, the catheter is bent downward due to balloon's own weight. Accordingly, it is difficult to accurately position the balloon at the center position of the pleating section or the folding section.

The present invention has been made for solving the above-mentioned problems. It is therefore an object of the present invention to provide a balloon wrapping apparatus and a balloon wrapping method by which a balloon can be accurately positioned in relation to a pleating section and to a folding section. The invention is therefore defined in independent device claim <NUM> and independent method claim <NUM>. Further aspects of the invention are defined in dependent claims <NUM>-<NUM> and <NUM>, <NUM>.

A balloon wrapping apparatus according to the present invention for achieving the aforesaid object is a balloon wrapping apparatus for wrapping a balloon of a balloon catheter provided with the balloon at a distal portion of an elongated shaft according to claim <NUM>.

A balloon wrapping method according to the present invention for achieving the aforesaid object is a balloon wrapping method for wrapping a balloon of a balloon catheter provided with the balloon at a distal portion of an elongated shaft according to claim <NUM>.

Since the balloon wrapping apparatus configured as above-mentioned has the grasping section that grasps a part of the balloon catheter which part is on the distal side of the balloon, it is possible to restrain bending of the balloon catheter due to its own weight from being generated, and to accurately position the balloon in relation to the pleating section and the folding section. Therefore, the wing shapes of the balloon can be formed uniformly in the circumferential direction at the pleating section, and back folding can be restrained from occurring when the wing shapes are folded at the folding section.

When the grasping section has a grasping surface formed of a recessed curved surface, the balloon catheter can be restrained from being damaged when grasped by the grasping section, and, since a larger contact surface is realized, a high grasping force can be produced.

When the support base has a holding portion for holding the shaft, it is possible to hold the shaft and to maintain the position of the shaft in an appropriate manner. Therefore, the balloon can be accurately positioned in relation to the pleating section and the folding section.

When the balloon wrapping apparatus has a pulling section that applies a pulling force to the balloon catheter by moving the grasping section and the holding portion away from each other, bending of the balloon catheter due to its own weight can be restrained from occurring, by the pulling force. Therefore, the balloon can be accurately positioned in relation to the pleating section and the folding section.

When the balloon wrapping apparatus has a core metal member that is inserted in the shaft, a distal portion of the shaft inclusive of the balloon is supported by the core metal member in such a manner as not to bend. Therefore, the balloon can be accurately positioned in relation to, and inserted into, the pleating section and the folding section.

In the balloon wrapping method configured as above-mentioned, a pulling force is applied to the balloon catheter at the time of forming the balloon with the wing shapes and at the time of folding the wing shapes. Therefore, the balloon catheter can be restrained from bending due to its own weight. For this reason, the balloon can be accurately positioned in a position suitable for forming the balloon with the wing shapes or a position suitable for folding the wing shapes, and the wing shapes of the balloon can be formed uniformly in the circumferential direction or the wing shapes can be folded in a suitable direction.

The pulling force applied to the balloon catheter may be applied by pulling the balloon catheter with a force of not less than <NUM> N. As a result of this, bending of the balloon catheter due to its own weight can be suitably restrained from occurring.

The pulling force applied to the balloon catheter may be applied by grasping a distal portion of the balloon catheter and moving it by not less than <NUM>. As a result of this, bending of the balloon catheter due to its own weight can be suitably restrained from occurring.

An embodiment of the present invention will be described below, referring to the drawings. Note that the dimensional ratios in the drawings may be exaggerated and be different from the actual ratios, for convenience of explanation. Herein, the side of insertion of a balloon catheter <NUM> into a body lumen will be referred to as "distal end" or "distal side," and the side of an operator's hand operation will be referred to as "proximal end" or "proximal side.

A balloon wrapping apparatus according to the present embodiment is an apparatus capable of wrapping a balloon so as to wrap the balloon around a shaft, at the time of manufacturing a balloon catheter having a balloon at a distal portion of an elongated shaft.

The balloon catheter to be wrapped may be subjected to hydrophilic coating for the purpose of improving properties for delivery to a lesion part, or may have a balloon surface subjected to a surface treatment such as a plasma treatment or irradiation with UV rays, but this is not particularly restrictive. There can also be used a balloon catheter in which the surface of a balloon has been subjected to a drug coating for delivery of a drug to a lesion part.

In the first place, a balloon catheter <NUM> will be described. As depicted in <FIG>, the balloon catheter <NUM> includes an elongated hollow shaft <NUM>, a balloon <NUM> provided at a distal-side end portion of the shaft <NUM>, and a hub <NUM> secured to a proximal-side end portion of the shaft <NUM>. The length of the balloon <NUM> in a major axis direction is not particularly limited, and is greater than approximately <NUM>. Preferably, the length of the balloon in the major axis direction is approximately <NUM> to <NUM>, more preferably <NUM> to <NUM>, and further preferably approximately <NUM> to <NUM>.

The diameter of the balloon <NUM> in a minor axis direction (the direction orthogonal to the major axis direction) is not particularly restricted, and is preferably not less than <NUM>, more preferably <NUM> to <NUM>, still more preferably <NUM> to <NUM>, and further preferably <NUM> to <NUM>. The material of the balloon <NUM> is not specifically restricted so long as it is flexible, and is composed, for example, of one or more of polyamides and polyamide elastomers. The surface of the balloon <NUM> preferably has a smooth surface, but it may not necessarily be smooth. The surface of the balloon <NUM> may have minute pores that do not penetrate the film, but may not necessarily have minute pores.

The shaft <NUM> includes a hollow outer tube <NUM> and a hollow inner tube <NUM>. The inner tube <NUM> is accommodated in the hollow inside of the outer tube <NUM>, and the shaft <NUM> has a double-tube structure at its distal portion. The hollow inside of the inner tube <NUM> is a guide wire lumen <NUM> in and through which a guide wire <NUM> is to be inserted and passed. In addition, an inflation lumen <NUM> through which an inflation fluid for the balloon <NUM> is permitted to flow is formed in the hollow inside of the outer tube <NUM> and on the outside of the inner tube <NUM>. The inner tube <NUM> is opening to the exterior at an opening portion <NUM>.

The inner tube <NUM> protrudes to the distal side beyond a distal end of the outer tube <NUM>. The balloon <NUM> has a proximal-side end portion fixed to a distal portion of the outer tube <NUM>, and has a distal-side end portion fixed to a distal portion of the inner tube <NUM>. As a result of this, the inside of the balloon <NUM> communicates with the inflation lumen <NUM>. The balloon <NUM> can be inflated by injecting an inflation fluid into the balloon <NUM> through the inflation lumen <NUM>. The inflation fluid may be either a gas or a liquid; for example, a gas such as helium gas, CO<NUM> gas and O<NUM> gas or a liquid such as a physiological saline solution and a contrast medium can be used as the inflation fluid.

The outer tube <NUM> and the inner tube <NUM> are preferably formed from a material that has a certain degree of flexibility. Examples of such a material include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomers, or mixtures of two or more of them, flexible polyvinyl chloride resin, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethane, fluoro-resin such as polytetrafluoroethylene, silicone rubbers, and latex rubbers.

Where the balloon catheter <NUM> is used in such a manner that the elongated shaft <NUM> thereof is inserted into a body organ and the balloon <NUM> provided on the distal side thereof is inflated at a lesion part, it is possible to push open the lesion part and thereby to perform a treatment. The shaft <NUM> is provided, at a position near the distal side, with the opening portion <NUM> through which to introduce the guide wire <NUM>. In other words, this balloon catheter <NUM> is a so-called rapid exchange type catheter.

In the next place, the balloon wrapping apparatus will be described. As depicted in <FIG>, the balloon wrapping apparatus has a pleating section <NUM>, a folding section <NUM> and a support base <NUM> disposed on a base <NUM> formed in a base shape. The pleating section <NUM> is capable of forming a balloon <NUM> with wing shapes projecting in radial directions. The folding section <NUM> is capable of folding the wing shapes formed in the balloon <NUM> in the manner of laying the wing shapes flat in a circumferential direction. The support base <NUM> is capable of disposing and holding the balloon catheter <NUM> thereon. The wing shapes formed in the balloon <NUM> are formed of pleats of balloon thin film material having a length extending substantially in a major axis direction of the balloon <NUM>, and are so formed that the pleats project in the circumferential direction from the major axis of the balloon <NUM>, as viewed in a section perpendicular to the major axis of the balloon <NUM>. The length of the wing shapes in the major axis direction does not exceed the length of the balloon <NUM>, and is approximately <NUM> to <NUM>, preferably approximately <NUM> to <NUM>, more preferably approximately <NUM> to <NUM>, and further preferably approximately <NUM> to <NUM>. The length by which the wing shape projects in the circumferential direction from the shaft <NUM> is <NUM> to <NUM>. The number of the wing shapes is not particularly limited, and can be selected from among two, three, four, five, six and seven. In this embodiment, three wing shapes are adopted.

A film supplying section <NUM> for supplying a first film <NUM> and a second film <NUM> to the pleating section <NUM> is disposed on the base <NUM>, adjacently to the pleating section <NUM>. In addition, a film supplying section <NUM> for supplying a first film <NUM> and a second film <NUM> to the folding section <NUM> is disposed on the base <NUM>, adjacently to the folding section <NUM>.

The pleating section <NUM> has a front surface plate <NUM> perpendicular to the base <NUM>, and the front surface plate <NUM> has an insertion hole 10a through which a distal portion of the balloon catheter <NUM> can be inserted. In addition, the folding section <NUM> has a front surface plate <NUM> perpendicular to the base <NUM>, and the front surface plate <NUM> has an insertion hole 20a through which the distal portion of the balloon catheter <NUM> can be inserted. The front surface plate <NUM> of the folding section <NUM> is oriented in a direction different by a predetermined angle from a direction in which the front surface plate <NUM> of the pleating section <NUM> is oriented.

The support base <NUM> is formed, on the side remote from the pleating section <NUM> and the folding section <NUM>, with a hole 4a in which a support rod 1b projecting upward from the base <NUM> is pivotally fitted. By being slid on an upper surface of the base <NUM> with the support rod 1b as a center, the support base <NUM> can be positioned in a position for facing the front surface plate <NUM> of the pleating section <NUM> and in a position for facing the front surface plate <NUM> of the folding section <NUM>.

Two positioning sections 1a capable of positioning the support base <NUM> to be oriented in two different directions are provided on the base <NUM>. In <FIG>, the support base <NUM> is positioned in contact with the positioning section 1a projecting from the base <NUM>, in such a manner as to face the front surface plate <NUM> of the pleating section <NUM>. The support base <NUM> can also be positioned such as to face the front surface plate <NUM> of the folding section <NUM>, by putting the support base <NUM> in contact with the positioning section 1a on the other side.

The support base <NUM> includes a base section <NUM> placed on the base <NUM>, and a holding base section <NUM> which can be moved horizontally on the base section <NUM>. The base section <NUM> includes a bottom surface portion 30a placed on an upper surface of the base <NUM> and positioned by the positioning section 1a, and a side surface portion 30b extending vertically upward from a side portion of the bottom surface portion 30a. A slide guide portion 30c for guiding a sliding movement of the holding base section <NUM> toward the pleating section <NUM> or the folding section <NUM> is formed at an upper surface of the bottom surface portion 30a.

As depicted in <FIG>, the holding base section <NUM> is formed substantially in the shape of a rectangular parallelepiped which makes contact with the bottom surface portion 30a and the side surface portion 30b of the base section <NUM>. A lower surface of the holding base section <NUM> is slidably guided by the slide guide portion 30c of the bottom surface portion 30a. Besides, an upper surface of the holding base section <NUM> has a groove-shaped placing portion 31a on which the shaft <NUM> of the balloon catheter <NUM> can be placed. Besides, the holding base section <NUM> is provided with a holding portion <NUM> such as to cover from above a part of the placing portion 31a. The holding portion <NUM> is capable of holding, and thereby fixing, the shaft <NUM> of the balloon catheter <NUM> placed on the placing portion 31a. The holding portion <NUM> includes a holding rod 32a intersecting the placing portion 31a, a flexible contact portion 32b covering the holding rod 32a, a rotational support portion 32c for supporting the holding rod 32a rotatably in relation to the holding base section <NUM>, and a coil 32d (elastic member) for pressing the contact portion 32b against the placing portion 31a by rotating the rotational support portion 32c. With the contact portion 32b moved away from the placing portion 31a in such a manner as to stretch the coil 32d, the shaft <NUM> can be placed on the placing portion 31a. With the contact portion 32b put into contact with the shaft <NUM> in a state in which the shaft <NUM> is placed on the groove-shaped placing portion 31a, the shaft <NUM> can be held by a pressing force of the coil 32d. In this instance, since the contact portion 32b is flexible, the shaft <NUM> can be suitably held without damage. Note that a flexible material may be disposed in a region in which the shaft <NUM> is pressed by the contact portion 32b, of the placing portion 31a. In addition, in the present embodiment, as depicted in <FIG>, the shaft <NUM> is fixed from above by the holding portion <NUM> that intersects the shaft <NUM>, but the fixation may be conducted by other method so long as the shaft <NUM> can be fixed. For instance, the shaft <NUM> of the balloon <NUM> may be fixed by sandwiching the shaft <NUM> in the manner of putting flexible materials such as silicone resin into contact with the surface of the shaft <NUM>, from both sides in a direction substantially perpendicular to the axis of the shaft <NUM>. In fixing the shaft <NUM> by sandwiching it with flexible materials, the sandwiching may be conducted by applying attractive forces of magnets. In addition, the core metal member <NUM> in the shaft <NUM> may be formed of a magnetic material, and the core metal member <NUM> may be fixed by magnets.

The core metal member <NUM> is formed in a thin elongated wire-like shape or a hollow shape from a metallic material. As the metallic material for forming the core metal member <NUM>, there is selected a material having such a degree of harness that a distal portion of the shaft <NUM> inclusive of the balloon <NUM> will not bend due to its own weight where the core metal member <NUM> is inserted in the balloon <NUM> and the shaft <NUM>. The metallic material for forming the core metal member <NUM> is not specifically restricted, and examples thereof include stainless steel, Ni-Ti alloys, tungsten, and hard metals. In addition, the core metal member <NUM> may be formed by annealing any of these metallic materials, for realizing a shape memory property.

The core metal member <NUM> is formed in a substantially circular shape in section, and its outside diameter is equal to the inside diameter of the inner tube <NUM> or smaller than the inside diameter by <NUM> to <NUM>. If the outside diameter of the core metal member <NUM> is smaller than the aforesaid appropriate value in relation to the inside diameter of the inner tube <NUM>, the balloon <NUM> part cannot be held sufficiently by the core metal member <NUM>, and bending of the balloon <NUM> would occur. As a result, the shaft <NUM> may be distorted when the balloon <NUM> is formed with wing shapes by the pleating section <NUM>. On the other hand, if the outside shape of the core metal member <NUM> is greater than the aforesaid appropriate value in relation to the inside diameter of the inner tube <NUM>, the core metal member <NUM> may interfere with the inner surface of the inner tube <NUM>, possibly breaking the inner tube. With the outside diameter of the core metal member <NUM> set as above-mentioned, these problems can be prevented from occurring.

In a state in which the support base <NUM> faces the front surface plate <NUM> of the pleating section <NUM>, the center of the insertion hole 10a formed in the front surface plate <NUM> is located on an extension line of the placing portion 31a of the holding base section <NUM>. Therefore, the balloon catheter <NUM> having the shaft <NUM> placed on the placing portion 31a is inserted into the pleating section <NUM> through the center position of the insertion hole 10a. In a state in which the support base <NUM> faces the front surface plate <NUM> of the folding section <NUM>, the center of the insertion hole 20a formed in the front surface plate <NUM> is located on an extension line of the placing portion 31a of the holding base section <NUM>. For this reason, the balloon catheter <NUM> having the shaft <NUM> placed on the placing portion 31a is inserted into the folding section <NUM> through the center position of the insertion hole 20a by slidably moving the holding base section <NUM> on the base section <NUM>.

As depicted in <FIG>, a traction section <NUM> for grasping and pulling a part of the balloon catheter <NUM> which part is on the distal side of the balloon <NUM> is provided on a side of the pleating section <NUM> and the folding section <NUM> which side is opposite to the side of facing the support base <NUM>. The traction section <NUM> includes a grasping section <NUM> for grasping a part of the balloon catheter <NUM> which part is on the distal side of the balloon <NUM>, and a pulling section <NUM> for applying a pulling force to the balloon catheter by moving the grasping section <NUM>.

The pulling section <NUM> includes a sliding portion <NUM> fitted to a guide groove portion 1c formed in the base <NUM>, a pinion <NUM> meshing with a rack 1d having teeth arranged rectilinearly on the base <NUM>, and a dial <NUM> for rotating the pinion <NUM>. The sliding portion <NUM> is a portion to which the grasping section <NUM> is interlocked, and which is slidably fitted in the guide groove portion 1c of the base <NUM>. By sliding in the guide groove portion 1c, the sliding portion <NUM> moves the grasping section <NUM> rectilinearly. The pinion <NUM> is rotated by rotating the dial <NUM>, and, by meshing with the rack 1d, it moves the sliding portion <NUM> along the guide groove portion 1c. Therefore, with the dial <NUM> rotated, the pulling section <NUM> can move the grasping section <NUM> rectilinearly, thereby applying a pulling force to the balloon catheter <NUM> grasped by the grasping section <NUM>. With the pulling force applied to the balloon catheter <NUM>, the balloon catheter <NUM> can be restrained from bending due to its own weight.

As depicted in <FIG>, the grasping section <NUM> includes a collet chuck <NUM> and a chuck holder <NUM> for holding the collet chuck <NUM>.

The collet chuck <NUM> is formed with slits <NUM> in such a manner that a plurality (in the present embodiment, four) of clamping portions <NUM> having clamping surfaces <NUM> shaped in conformity with the shape of an object to the grasped are aligned in a circumferential direction. The collet chuck <NUM> is formed with a tapered surface <NUM> at an outer circumferential surface on the side of an end portion where the clamping portions <NUM> are formed, and is formed with an interlock portion <NUM> for interlock with the pulling section <NUM> on the side opposite to the side where the clamping portions <NUM> are formed. The interlock portion <NUM> is formed to be smaller than the clamping portions <NUM> in outside diameter. A stepped portion <NUM> where the outside diameter is reduced is formed between the clamping portions <NUM> and the interlock portion <NUM>. The clamping surfaces <NUM> are formed of groove-shaped curved surfaces extending along the axis of the balloon catheter <NUM>, and can grasp the balloon catheter <NUM> on a surface basis such as to prevent, as securely as possible, deformation of the balloon catheter <NUM>. Note that a scroll chuck, a drill chuck or an independent chuck may be used in place of the collet chuck <NUM>. In addition, the number of the clamping portions need only be two or more, and is not limited to four.

The chuck holder <NUM> includes a first holder <NUM> which the interlock <NUM> of the collet chuck <NUM> penetrates, and a second holder <NUM> with which the clamping portions <NUM> of the collet chuck <NUM> make contact. The first holder <NUM> is a tubular member which the interlock portion <NUM> of the collet chuck <NUM> penetrates, and is provided on one end side thereof with a contact portion <NUM> capable of making contact with the stepped portion <NUM> of the collet chuck <NUM> in such a manner that the stepped portion <NUM> is caught thereon, and an outer circumferential surface of the contact portion <NUM> is formed with a first screw portion <NUM>. The second holder <NUM> is a tubular member having a second screw portion <NUM> screw engaged with the first screw portion <NUM>, and is formed at an inner circumferential surface thereof with a tapered pressing-in surface <NUM> making contact with the tapered surface <NUM> of the chuck holder <NUM>. When the collet chuck <NUM> is disposed inside the first holder <NUM>, the stepped portion <NUM> is put in contact with the contact portion <NUM>, the second screw portion <NUM> of the second holder <NUM> is screw engaged with the first screw portion <NUM> of the first holder <NUM>, and the second holder <NUM> is rotated, as depicted in <FIG>, the second holder <NUM> is moved in the direction of coming closer to the first holder <NUM>. When the second holder <NUM> is moved in the direction of coming closer to the first holder <NUM>, the pressing-in surface <NUM> of the second holder <NUM> slides on the tapered surface <NUM> of the collet chuck <NUM>, and the clamping portions <NUM> are deformed in such a manner that the slits <NUM> are narrowed, so that the clamping surfaces <NUM> come closer to one another. As a result of this, a distal portion of the balloon catheter <NUM> can be clamped in the center of the clamping surfaces <NUM>. Note that the part clamped by the clamping portions <NUM> need only be a part on the distal side of the inflating portion of the balloon <NUM>, and is the inner tube <NUM> (and the core metal member <NUM>).

Examples of the material or materials which can be used for constituting the collet chuck <NUM> and the chuck holder <NUM> include metals such as stainless steel and aluminum, and resins such as fluoro-resins, acrylonitrile-butadiene-styrene resin, and polyethylene.

When the balloon catheter <NUM> is grasped by the collet chuck <NUM>, the core metal member <NUM> is disposed inside the guide wire lumen <NUM> such that the balloon catheter <NUM> will not be crushed. The core metal member <NUM> preferably has its distal portion protruding to the distal side beyond the guide wire lumen <NUM>, and preferably has its proximal portion protruding from the opening portion <NUM>.

Now, the structure of the pleating section <NUM> will be described below. As illustrated in <FIG>, the pleating section <NUM> is provided therein with three blades <NUM> (wing forming members). Each of the blades <NUM> is a plate-shaped member which is the same in sectional shape at each position along the axial direction of the balloon catheter <NUM> inserted. The blades <NUM> are disposed such that they are at an angle of <NUM>° from one another, with the center position in regard of insertion of the balloon <NUM> as a reference. In other words, the blades <NUM> are disposed at regular angular intervals along the circumferential direction. The blade <NUM> has a rotational center portion 12a near an outer circumferential end portion thereof, and can be moved rotationally about the rotational center portion 12a. In addition, the blade <NUM> has a moving pin 12d extending in the axial direction, on the inner circumferential side of the rotational center portion 12a. The moving pin 12d is fitted in a fitting groove 14a formed in a rotary member <NUM> which is rotatable in the pleating section <NUM>. The rotary member <NUM> is interlocked with a beam portion <NUM> extending substantially horizontally. The rotary member <NUM> is movable rotationally by receiving a rotating force from the beam portion <NUM> which is inclined by receiving a force from a drive source <NUM> such as a hydraulic cylinder or a motor. When the rotary member <NUM> is rotated, the moving pins 12d fitted in the fitting grooves 14a are moved in the circumferential direction, whereby each of the blades <NUM> is moved rotationally about the rotational center portion 12a. With the three blades <NUM> rotated, a space region in a central area surrounded by the blades <NUM> can be narrowed. Note that the number of the blades <NUM> need only be two or more, and is not particularly limited.

The blade <NUM> has a first shape forming portion 12b and a second shape forming portion 12c which are substantially arcuate in shape, at inner circumferential end portions on the side opposite to the rotational center portion 12a. Attendant on rotary movement of the blade <NUM>, the first shape forming portion 12b makes contact with the surface of the balloon <NUM> inserted in the pleating section <NUM>, whereby the balloon <NUM> can be formed with a wing shape projecting in a radial direction. Attendant on rotary movement of the blade <NUM>, the second shape forming portion 12c makes contact with the wing portion formed in the balloon <NUM>, whereby the wing shape can be curved in a predetermined direction. In addition, the pleating section <NUM> has a heater (not depicted) for heating the blades <NUM>. Note that the blades <NUM> may have a function of cooling. The length of the blade <NUM> along the axial direction of the balloon catheter <NUM> is greater than the length of the balloon <NUM>. Besides, the lengths of the first shape forming portion 12b and the second shape forming portion 12c of the blade <NUM> may or may not range over the whole length of the blade <NUM>.

The blades <NUM> are supplied with the first film <NUM> and the second film <NUM> which are formed of resin, from the film supplying section <NUM>. For guiding each of the films, a plurality of rotary shaft portions <NUM> are provided in the pleating section <NUM>. The first film <NUM> is supplied from a first film holding section <NUM> and through the rotary shaft portion <NUM> to be fed to a surface of the blade <NUM> disposed at an upper part. In addition, the first film <NUM> is fed through the blade <NUM> and the rotary shaft portion <NUM> to reach a film take-up section <NUM> which is rotationally driven by a drive source (not depicted) such as a motor. The second film <NUM> is supplied from a second film holding section <NUM> and through the rotary shaft portion <NUM> to be fed to the two blades <NUM> disposed at lower parts. In addition, the second film <NUM> is fed through the rotary shaft portion <NUM> to reach the film take-up section <NUM>. As a result of these, a center position of the pleating section <NUM> in which the balloon <NUM> is inserted is in the state of being surrounded by the first film <NUM> and the second film <NUM>.

The first film <NUM> and the second film <NUM> have a protecting function for preventing direct contact of the balloon <NUM> with the surfaces of the blades <NUM> when the balloon <NUM> is inserted into the pleating section <NUM> and the blades <NUM> are moved rotationally to form the balloon <NUM> with wing shapes. After the wing shapes of the balloon <NUM> are formed, predetermined lengths of the first film <NUM> and the second film <NUM> are taken up by the film take-up section <NUM>. In other words, the portions of the first film <NUM> and the second film <NUM> which portions have once made contact with the balloon <NUM> do not make contact with the balloon <NUM> again, and new portions of the films are supplied to the center position of the pleating section <NUM> every time the balloon <NUM> is inserted.

As depicted in <FIG>, in a state before insertion of the balloon <NUM>, the first shape forming portions 12b and the second shape forming portions 12c of the three blades <NUM> are in the state of being spaced from one another. A central region between the blades <NUM> is surrounded by the substantially arcuate first shape forming portions 12b, and the balloon <NUM> yet to be wrapped can be inserted therein.

In forming the balloon <NUM> with wing shapes, first, the shaft <NUM> of the balloon catheter <NUM> is placed on the placing portion 31a of the support base <NUM> and is held by the holding portion <NUM>. The inflation fluid is injected into the balloon <NUM> through a three-way cock attached to the hub <NUM>, the hub <NUM> and the inner tube <NUM>, whereby the balloon <NUM> is put into a state of being inflated to a certain extent. In addition, the blades <NUM> of the pleating section <NUM> are heated. The core metal member <NUM> is inserted into the guide wire lumen <NUM>. By the core metal member <NUM>, the shaft <NUM> is restrained from bending due to its own weight. As a result, the balloon <NUM> can be inserted, with accurate positioning, into the center position of the pleating section <NUM>.

The core metal member <NUM> is formed in a thin elongated wire-like shape from a metallic material. The metallic material for forming the core metal member <NUM> is not specifically restricted, and examples thereof include stainless steel, Ni-Ti alloys, Ni-Ti alloys, tungsten, and hard metals. In addition, the core metal member <NUM> may be formed by annealing any of these metallic materials, to realize a shape memory property. The core metal member <NUM> is formed in a substantially circular shape in section, and its outside diameter is smaller than the inside diameter of the inner tube <NUM> by <NUM> to <NUM>.

Next, as depicted in <FIG>, the holding base section <NUM> is moved by sliding on the base section <NUM>, whereby the balloon catheter <NUM> is inserted into the pleating section <NUM> through the insertion hole 10a. In this instance, since the core metal member <NUM> is inserted in the guide wire lumen <NUM>, the shaft <NUM> is restrained from bending due to its own weight, and the balloon <NUM> can be accurately positioned in the center position of the pleating section <NUM>.

Subsequently, a portion of the balloon catheter <NUM> which portion is on the distal side of the balloon <NUM> is grasped by the grasping section <NUM>. Thereafter, the dial <NUM> of the pulling section <NUM> is rotated, whereon the grasping section <NUM> is moved rectilinearly, a pulling force is applied to the balloon catheter <NUM> grasped by the grasping section <NUM>, and bending of the balloon catheter <NUM> due to its own weight is reduced.

Next, the rotary member <NUM> is rotated by operating the drive source <NUM>, whereon the blades <NUM> are rotated, the first shape forming portions 12b of the blades <NUM> come closer to one another, and the central region between the blades <NUM> is narrowed, as depicted in <FIG>. Attendant on this, the balloon <NUM> inserted in the central region between the blades <NUM> is pressed against the inner tube <NUM> by the first shape forming portions 12b. A portion of the balloon <NUM> which portion is not pressed by the first shape forming portion 12b is pushed out into a gap between a distal portion of one blade <NUM> and the second shape forming portion 12c of the blade <NUM> adjacent to the one blade <NUM>, whereby a wing shape curved to one side is formed. Since the balloon <NUM> is heated by the blades <NUM>, the wing shapes thus formed can be maintained in their shape. In this way, the balloon <NUM> is formed with three wing shapes in the circumferential direction. Note that the number of blades <NUM> is not particularly limited so long as it is two or more.

In this instance, surfaces of the blades <NUM> which surfaces make contact with the balloon <NUM> are covered with the first film <NUM> and the second film <NUM>, so that the balloon <NUM> does not make direct contact with the surfaces of the blades <NUM>. After the balloon <NUM> is formed with the wing shapes, the blades <NUM> are moved rotationally in the manner of being returned into their original positions, and the balloon <NUM> is withdrawn from the pleating section <NUM>. Note that in the process of pleating, a step of excessively inflating the balloon <NUM> and then deflating the balloon <NUM> a little or a step of inflating the balloon <NUM> while avoiding excessive inflation and then deflating the balloon <NUM> a little may be provided.

Now, the structure of the folding section <NUM> will be described below. As illustrated in <FIG>, the folding section <NUM> is provided therein with ten blades <NUM> (folding members). Each of the blades <NUM> is a plate-shaped member formed to be the same in sectional shape at each position along the axial direction of the balloon catheter <NUM> to be inserted. The blades <NUM> are disposed such that they are at an angle of <NUM>° from one another, with the center position in regard of insertion of the balloon as a reference. In other words, the blades <NUM> are disposed at regular angular intervals along the circumferential direction. The blade <NUM> has a rotational center portion 22a near a substantial center thereof, and can be moved rotationally about the rotational center portion 22a. In addition, the blade <NUM> has a moving pin 22c extending in the axial direction, near a substantially outer circumferential end portion thereof. The moving pin 22c is fitted in a fitting groove 23a formed in a rotary member <NUM> which is rotatable in the folding section <NUM>. The rotary member <NUM> is interlocked with a beam portion <NUM> extending substantially horizontally. The rotary member <NUM> is movable rotationally by receiving a rotating force from the beam portion <NUM> which is inclined by receiving a force from a drive source <NUM> such as a hydraulic cylinder or a motor. When the rotary member <NUM> is rotated, the moving pins 22c fitted in the fitting grooves 23a are moved in the circumferential direction, whereby each of the blades <NUM> is moved rotationally about the rotational center portion 22a. With the ten blades <NUM> moved rotationally, a space region in a central area surrounded by the blades <NUM> can be narrowed. Note that the number of the blades <NUM> is not particularly limited.

The blade <NUM> is bent on the distal side, and has a distal portion 22b in a pointing shape. Attendant on rotary movement of the blade <NUM>, the distal portion 22b makes contact with a surface of the balloon <NUM> inserted in the folding section <NUM>, whereby the wing shape formed in the balloon <NUM> can be folded in the manner of lying flat in the circumferential direction. In addition, the folding section <NUM> has a heater (not depicted) for heating the blades <NUM>. Note that the blades <NUM> may have a function of cooling.

The blades <NUM> are supplied with a first film <NUM> and a second film <NUM> from a film supplying section <NUM>. The film supplying structure is the same as in the case of the pleating section <NUM>. The first film <NUM> and the second film <NUM> are disposed opposite to each other in such a manner as to sandwich a central space region surrounded by the blades <NUM>. By the first film <NUM> and the second film <NUM>, the balloon <NUM> inserted in the folding section <NUM> can be prevented from making direct contact with the surfaces of the blades <NUM>. The first film <NUM> and the second film <NUM> are fed through the blades <NUM>, to reach a film take-up section <NUM> which is rotationally driven by a drive source (not depicted) such as a motor.

As depicted in <FIG>, in a state before insertion of the balloon <NUM>, the distal portions 22b of the blades <NUM> are in the state of being spaced from one another in a circumferential direction. The balloon <NUM> formed with the wing shapes can be inserted into a central region which is surrounded by the blades <NUM> and which is between the first film <NUM> and the second film <NUM>.

After the balloon catheter <NUM> is inserted into the pleating section <NUM> and the balloon <NUM> is formed with the wing shapes as aforementioned, the balloon catheter <NUM> is detached from the grasping section <NUM> provided in the pleating section <NUM>. Next, the holding base section <NUM> is moved on an upper surface of the base section <NUM> to be spaced from the pleating section <NUM>, and the balloon catheter <NUM> is withdrawn from the pleating section <NUM>. Subsequently, the support base <NUM> is moved by sliding on the upper surface of the base section <NUM>, to position the support base <NUM> in a position of facing the front surface plate <NUM> of the folding section <NUM>. Thereafter, the holding base section <NUM> is moved on the upper surface of the base section <NUM>, to insert the balloon catheter <NUM> into the folding section <NUM> through the insertion hole 20a. The blades <NUM> of the folding section <NUM> have already been heated. Besides, the blades <NUM> may not necessarily be heated, or may be cooled. In this instance, as depicted in <FIG>, the shaft <NUM> is maintained in the state of being held by the holding portion <NUM> of the support base <NUM>. The core metal member <NUM> is also inserted in the balloon catheter <NUM>, like in the case of insertion into the pleating section <NUM>. Next, a part of the balloon catheter <NUM> which part is on the distal side of the balloon <NUM> is grasped by the grasping section <NUM> provided in the folding section <NUM>. Thereafter, the dial <NUM> of the pulling section <NUM> is rotated, whereon the grasping section <NUM> is moved rectilinearly, and a pulling force is applied to the balloon catheter <NUM> grasped by the grasping section <NUM>, whereby bending of the balloon catheter <NUM> due to its own weight is reduced.

In this way, also in the case where the balloon catheter <NUM> is inserted into the folding section <NUM>, with the balloon catheter <NUM> grasped and pulled, the shaft <NUM> is restrained from bending due to its own weight, and the balloon <NUM> can be accurately positioned in the center position of the folding section <NUM>.

After the balloon <NUM> formed with the wing shapes is inserted in the folding section <NUM>, the rotary member <NUM> is rotated by operating the drive source <NUM>, whereon the blades <NUM> are moved rotationally, the distal portions 22b of the blades <NUM> come closer to one another, and the central region between the blades <NUM> is narrowed, as illustrated in <FIG>. Attendant on this, the balloon <NUM> inserted in the central region between the blades <NUM> is put into a state in which the wing shapes are laid flat in the circumferential direction by the distal portions 22b of the blades <NUM>. Since the blades <NUM> are preliminarily heated before insertion of the balloon <NUM> and the balloon <NUM> is heated by the blades <NUM>, the wing shapes laid flat in the circumferential direction by the blades <NUM> can be maintained in their shape. Note that the blades <NUM> may be preliminarily cooled.

In this instance, the surfaces of the blades <NUM> which surfaces make contact with the balloon <NUM> are covered with the first film <NUM> and the second film <NUM>, so that the balloon <NUM> does not make direct contact with the surfaces of the blades <NUM>. After the wing shapes of the balloon <NUM> are folded, the blades <NUM> are moved rotationally in the manner of being returned to their original positions. Next, the balloon catheter <NUM> is detached from the grasping section <NUM>, and the balloon <NUM> is withdrawn from the folding section <NUM>. Thereafter, the holding of the shaft <NUM> by the holding portion <NUM> is released, and wrapping of the balloon <NUM> of the balloon catheter <NUM> is completed.

While a case in which the balloon <NUM> of a rapid exchange type catheter is wrapped by the balloon wrapping apparatus has been described hereinabove, a balloon <NUM> of an over-the-wire type catheter can also be wrapped by the same balloon wrapping apparatus.

As has been described above, the balloon wrapping apparatus according to the present embodiment is a balloon wrapping apparatus for wrapping a balloon <NUM> of a balloon catheter <NUM> provided with the balloon at a distal portion of an elongated shaft <NUM>, and includes: the pleating section <NUM> that has a plurality of blades <NUM> (wing forming members) aligned with space parts therebetween in the circumferential direction, and that forms the balloon <NUM> with wing shapes projecting in radial directions by clamping by the blades <NUM> the balloon <NUM> caused to enter into the space parts by moving rotationally the blades <NUM>; the folding section <NUM> that has a plurality of blades <NUM> (folding members) aligned in the circumferential direction, and that folds the wing shapes formed in the balloon <NUM> in the circumferential direction by moving rotationally the blades <NUM>; the support base <NUM> that supports a part of the shaft <NUM> which part is on the proximal side of the balloon <NUM>, and that makes the distal portion of the shaft <NUM> positionable in relation to the pleating section <NUM> and the folding section <NUM>; and the grasping section <NUM> capable of grasping a part of the balloon catheter <NUM> which part is on the distal side of the balloon <NUM>.

The balloon wrapping apparatus configured as above-described has the grasping section <NUM> for grasping a part of the balloon catheter <NUM> which part is on the distal side of the balloon <NUM>, and, therefore, the balloon wrapping apparatus can restrain the balloon catheter <NUM> from bending due to its own weight and can accurately position the balloon <NUM> in relation to the pleating section <NUM> and the folding section <NUM>. Accordingly, the wing shapes of the balloon <NUM> can be formed uniformly in the circumferential direction in the pleating section <NUM>, and occurrence of wrapping in the reverse direction (back folding) in the folding section <NUM> can be restrained.

In addition, since the support base <NUM> has the holding portion <NUM> for maintaining the position of the shaft <NUM>, the support base <NUM> can clamp the shaft <NUM> to suitably maintain the position of the shaft <NUM>, and can accurately position the balloon <NUM> in relation to the pleating section <NUM> and the folding section <NUM>. In addition, since the shaft <NUM> can be held by the holding portion <NUM>, a pulling force can be applied to the balloon catheter <NUM> from the distal side.

Besides, since the balloon wrapping apparatus has the pulling section <NUM> for applying a pulling force to the balloon catheter <NUM> by moving the grasping section <NUM> and the holding portion <NUM> away from each other, it is possible to restrain the balloon catheter <NUM> from bending due to its own weight, by the pulling force, and to accurately position the balloon <NUM> in relation to the pleating section <NUM> and the folding section <NUM>. The pulling force to be applied is preferably not less than <NUM> N, more preferably <NUM> to <NUM> N. In addition, the distance by which the balloon catheter <NUM> is pulled for applying the pulling force to the balloon catheter <NUM> is preferably not less than <NUM>, more preferably <NUM> to <NUM>.

In addition, since the grasping surface of the grasping section <NUM> is formed of a recessed curved surface, the balloon catheter <NUM> can be restrained from being damaged when grasped by the grasping section <NUM>, and, owing to a larger contact surface, a high grasping force can be produced.

Besides, since the balloon wrapping apparatus has the core metal member <NUM> inserted in the shaft <NUM>, a distal portion of the shaft <NUM> inclusive of the balloon <NUM> is supported by the core metal member <NUM> in such a manner as not to bend, and can be accurately positioned, and inserted, in relation to the pleating section <NUM> and the folding section <NUM>. Besides, with the core metal member <NUM> inserted in the shaft <NUM>, the shaft <NUM> can be restrained from being crushed at the grasping section <NUM> or the holding portion <NUM>.

In addition, the present invention also includes the balloon wrapping method. The balloon wrapping method is a balloon wrapping method for wrapping a balloon <NUM> of a balloon catheter <NUM> provided with the balloon <NUM> at a distal portion of an elongated shaft <NUM>, the balloon wrapping method including: a step of forming the balloon <NUM> with wing shapes projecting in radial directions; and a step of folding the wing shapes formed in the balloon <NUM> along a circumferential direction, in which in at least one of the step of forming the wing shapes and the step of folding the wing shapes along the circumferential direction, a part of the balloon catheter <NUM> which part is on a distal side of the balloon <NUM> is grasped and a pulling force is applied to the balloon catheter <NUM> in a state in which the position of the shaft <NUM> is maintained.

In the balloon wrapping method configured as above-described, a pulling force is applied to the balloon catheter <NUM> at the time of forming the balloon <NUM> with the wing shapes and at the time of folding the wing shapes, and, therefore, bending of the balloon catheter <NUM> due to its own weight can be restrained from occurring. For this reason, the balloon <NUM> can be accurately positioned in a position suitable for forming the balloon <NUM> with the wing shapes or in a position suitable for folding the wing shapes, and the wing shapes of the balloon <NUM> can be formed uniformly in the circumferential direction or the wing shapes can be folded in an appropriate direction.

Besides, the pulling force applied to the balloon catheter <NUM> can be applied by pulling the balloon catheter with a force of not less than <NUM> mN. As a result of this, bending of the balloon catheter <NUM> due to its own weight can be suitably restrained from occurring.

In addition, the pulling force applied to the balloon catheter <NUM> can be applied by grasping a distal portion of the balloon catheter <NUM> and then moving it by not less than <NUM>. As a result of this, bending of the balloon catheter <NUM> due to its own weight can be suitably restrained from occurring.

Note that the present invention is not limited only to the aforementioned embodiment, and various modifications can be made by those skilled in the art within the technical thought of the present invention. For instance, while the two traction sections <NUM> provided in the pleating section <NUM> and the folding section <NUM> are configured in the same structure in the aforementioned embodiment, they may be different in structure. In addition, while the pulling section <NUM> is provided such as to apply the pulling force to the balloon catheter <NUM> from the distal side in the aforementioned embodiment, the pulling section may be provided such as to apply the pulling force to the balloon catheter <NUM> from the proximal side.

Now, a pleating section <NUM> according to another embodiment will be described below. As illustrated in <FIG>, the pleating section <NUM> according to another embodiment is provided with an insertion assisting section <NUM> for assisting the insertion of the balloon catheter <NUM> into the insertion hole 10a. The insertion assisting section <NUM> can be interlocked with the holding base section <NUM> that holds the shaft <NUM> of the balloon catheter <NUM>. The insertion assisting section <NUM> includes an elongated assisting shaft <NUM>, an interlock portion <NUM> for interlocking the assisting shaft <NUM> and the holding base section <NUM>, and a support portion <NUM> for supporting the interlock portion <NUM> in a slidable manner. The interlock portion <NUM> includes an elongated interlock shaft <NUM>, and a fixing portion <NUM> for fixing the assisting shaft <NUM> and the interlock shaft <NUM>.

One end of the interlock shaft <NUM> is fixed to the assisting shaft <NUM> by the fixing portion <NUM>. The other end of the interlock shaft <NUM> abuts on, and is interlockable with, a holding base side interlock portion <NUM> of the holding base section <NUM>. The holding base side interlock portion <NUM> has, for example, a fixing screw <NUM> for fixing the assisting shaft <NUM>.

The assisting shaft <NUM> is formed at a distal portion thereof with a cavity portion <NUM> into which the core metal member <NUM> to be inserted in the balloon catheter <NUM> can be inserted. With the core metal member <NUM> inserted in the cavity portion <NUM>, the balloon catheter <NUM> can be restrained from bending. Note that the assisting shaft <NUM> can also hold the shaft <NUM> of the balloon catheter <NUM>. The assisting shaft <NUM> can enter a back surface hole 11b provided in the pleating section <NUM> on the side opposite to the insertion hole 10a, and can protrude from the insertion hole 10a to the exterior.

In inserting the balloon catheter <NUM> into the pleating section <NUM>, the assisting shaft <NUM> is inserted into the back surface hole 11b of the pleating section <NUM> and is protruded from the insertion hole 10a, as depicted in <FIG>. Next, the core metal member <NUM> is inserted into the cavity portion <NUM> of the assisting shaft <NUM>, and the interlock shaft <NUM> is fixed to the holding base section <NUM>. Thereafter, as depicted in <FIG>, the holding base section <NUM> is moved toward the pleating section <NUM>, whereon the balloon catheter <NUM> is inserted through the insertion hole 10a into the inside of the pleating section <NUM>. In this instance, the assisting shaft <NUM> is also moved together with the holding base section <NUM>, and, therefore, the balloon <NUM> can be inserted into a central area of the blades <NUM> of the pleating section <NUM> while a state of the balloon <NUM> being held by the assisting shaft <NUM> is maintained. As a result of this, the balloon <NUM> can be accurately positioned, and inserted, in relation to the pleating section <NUM>. Note that the insertion assisting section <NUM> may be provided in the folding section <NUM>.

In addition, the support base for holding the balloon catheter <NUM> may have such a structure as to be able to rotate the balloon catheter <NUM> about its axis in a state of holding the balloon catheter <NUM>. In this case, with the balloon catheter <NUM> rotated in a direction reverse to the folding direction, during folding of the wing shapes of the balloon <NUM> by the folding section <NUM>, the effect of restraining back folding can be further enhanced.

Illustrative examples will be described below. Drug-coated balloons of Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM> were produced under the conditions set forth in Tables <NUM> to <NUM> below.

A coating liquid was prepared by dissolving L-serine ethyl ester hydrochloride (<NPL>) and paclitaxel (<NPL>) in a mixed liquid of anhydrous ethanol, tetrahydrofuran, acetone and distilled water. A three-way cock was attached to a hub portion of a balloon catheter (material of balloon: nylon, the surface being smooth and non-porous) <NUM> in diameter and <NUM> in length when inflated, the balloon was inflated at <NUM> atm, and coating with the coating liquid was slowly conducted such that the amount of paclitaxel on the balloon would be approximately <NUM>µg/mm<NUM>. After the coating, the balloon catheter was dried, to produce a drug-coated balloon.

A core metal member (material: SUS) in the form of wire (solid) <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on a support base of a balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to a holding base section by a holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to an air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into a distal support (assisting shaft) of a pleating section <NUM>. The balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having three blades. After the balloon was pushed in completely, the heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to a folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into a distal support (assisting shaft) of the folding section, and the balloon portion was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the folding section having ten blades. After the balloon was pushed in completely, the heated blades were slowly closed, then, from the point of time when the first film and the second film made contact with the wings, the balloon catheter was slowly rotated in the direction reverse to the rotary movement direction of the blades, and the rotation of the balloon was finished before the blades were closed completely. The ten blades were held in a closed state for a while, after which the blades were slowly opened, to spread the first film and the second film. Thereafter, the balloon was drawn back from the folding section.

A core metal member (material: SUS) in the form of wire <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on a support base of a balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into the distal support (assisting shaft) of the pleating section. The balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having three blades. After the balloon was pushed in completely, the heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to the folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into the distal support (assisting shaft) of the folding section, and the balloon portion was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the folding section having ten blades. After the balloon was pushed in completely, the heated blades were slowly closed. The ten blades were held in a closed state for a while, after which the blades were slowly opened, to spread the first film and the second film. Thereafter, the balloon was drawn back from the folding section.

A core metal member (material: SUS) in the form of wire <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on the support base of the balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into the distal support (assisting shaft) of the pleating section. The balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having three blades. After the balloon was pushed in completely, the heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

A core metal member (material: SUS) in the form of wire <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on the support base of the balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into the distal support (assisting shaft) of the pleating section. The balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having four blades. After the balloon was pushed in completely, the heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In the same procedure as in the production example of the drug-coated balloon in Comparative Example <NUM>, a drug-coated balloon of a balloon catheter (material of balloon: nylon, the surface being smooth and non-porous) <NUM> in diameter and <NUM> in length was produced.

A core metal member (material: SUS) in the form of wire <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on the support base of the balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into, and fixed to, a collet chuck affixed to the distal support (assisting shaft) of the pleating section. Next, the balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having four blades. After the balloon was pushed in completely, the position of the distal support was fixed. Subsequently, the support base section with the shaft of the balloon catheter fixed thereto was pulled backward by <NUM> and was fixed. The heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to a folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into, and fixed to, a collet chuck affixed to a distal support (assisting shaft) of the folding section. Subsequently, the balloon portion was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the folding section having eight blades. After the balloon was pushed in completely, the position of the distal support was fixed, and the support base section with the shaft of the balloon catheter fixed thereto was pulled backward by <NUM> and was fixed. The heated blades were slowly closed, then, from the point of time when the first film and the second film made contact with the wings, the balloon catheter was slowly rotated in the direction reverse to the rotary movement direction of the blades, and the rotation of the balloon was finished before the blades were closed completely. The eight blades were held in a closed state for a while, after which the blades were slowly opened, to spread the first film and the second film, and the balloon was drawn back from the folding section.

A hollow core metal member (material: SUS) <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on the support base of the balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into, and fixed to, a collet chuck affixed to the distal support (assisting shaft) of the pleating section. Next, the balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having four blades. After the balloon was pushed in completely, the position of the support base section with the shaft of the balloon catheter fixed thereto was fixed. Subsequently, the distal support was pulled forward by <NUM>, and was then fixed. The heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to a folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into, and fixed to, the collet chuck affixed to the distal support (assisting shaft) of the folding section. Subsequently, the balloon portion was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the folding section having twelve blades. After the balloon was pushed in completely, the position of the support base section with the shaft of the balloon catheter fixed thereto was fixed. Subsequently, the distal support was pulled forward by <NUM> and was then fixed. The heated blades were slowly closed, then, from the point of time when the first film and the second film made contact with the wings, the balloon catheter was slowly rotated in the direction reverse to the rotary movement direction of the blades, and the rotation of the balloon was finished before the blades were closed completely. The twelve blades were held in a closed state for a while, after which the blades were slowly opened, to spread the first films, and the balloon was drawn back from the folding section.

A hollow core metal member (material: SUS) <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on the support base of the balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into, and fixed to, a collet chuck affixed to the distal support (assisting shaft) of the pleating section. Next, the balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having four blades. After the balloon was pushed in completely, the position of the distal support was fixed. Subsequently, the support base section with the shaft of the balloon catheter fixed thereto was pulled backward with a force of <NUM> N, and was then fixed. The heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to a folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into, and fixed to, the collet chuck affixed to the distal support (assisting shaft) of the folding section. Subsequently, the balloon portion was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the folding section having twelve blades. After the balloon was pushed in completely, the position of the distal support was fixed, and the support base section with the shaft of the balloon catheter fixed thereto was pulled backward by a force of <NUM> N and was fixed. The heated blades were slowly closed, then, from the point of time when the first film and the second film made contact with the wings, the balloon catheter was slowly rotated in the direction reverse to the rotary movement direction of the blades, and the rotation of the balloon was finished before the blades were closed completely. The twelve blades were held in a closed state for a while, after which the blades were slowly opened, to spread the films, and the balloon was drawn back from the folding section.

A hollow core metal member (material: SUS) <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on the support base of the balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into, and fixed to, a collet chuck affixed to the distal support (assisting shaft) of the pleating section. Next, the balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having four blades. After the balloon was pushed in completely, the position of the support base section with the shaft of the balloon catheter fixed thereto was fixed. Subsequently, the distal support was pulled forward with a force of <NUM> N, and was then fixed. The heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to a folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into, and fixed to, the collet chuck affixed to the distal support (assisting shaft) of the folding section. Subsequently, the balloon portion was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the folding section having twelve blades. After the balloon was pushed in completely, the position of the support base section with the shaft of the balloon catheter fixed thereto was fixed. Subsequently, the distal support was pulled forward with a force of <NUM> N, and was then fixed. The heated blades were slowly closed, then, from the point of time when the first film and the second film made contact with the wings, the balloon catheter was slowly rotated in the direction reverse to the rotary movement direction of the blades, and the rotation of the balloon was finished before the blades were closed completely. The twelve blades were held in a closed state for a while, after which the blades were slowly opened, to spread the films, and the balloon was drawn back from the folding section.

A core metal member (material: SUS) in the form of wire <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on a support base of a balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into the distal support (assisting shaft) of the pleating section. Subsequently, the balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having three blades. After the balloon was pushed in completely, the heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to a folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into a distal support (assisting shaft) of the folding section. Subsequently, the balloon portion was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the folding section having twelve blades. After the balloon was pushed in completely, the heated blades were slowly closed, then, from the point of time when the first film and the second film made contact with the wings, the balloon catheter was slowly rotated in the direction reverse to the rotary movement direction of the blades, and the rotation of the balloon was finished before the blades were closed completely. The twelve blades were held in a closed state for a while, after which the blades were slowly opened, to spread the first film and the second film. Thereafter, the balloon was drawn back from the folding section.

In the same procedure as in the production example of the drug-coated balloon in Comparative Example <NUM>, a drug coated balloon of a balloon catheter (material of balloon: nylon, the surface being smooth and non-porous) <NUM> in diameter and <NUM> in length was produced. Coating was conducted such that the amount of paclitaxel on the balloon would be approximately <NUM>µg/mm<NUM>.

A core metal member (material: SUS) in the form of wire <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on a support base of a balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into the distal support (assisting shaft) of the pleating section. Subsequently, the balloon was pushed in between the blades of the pleating section having three blades. Note that the pleating section was not provided with films. After the balloon was pushed in completely, the heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to a folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into a distal support (assisting shaft) of the folding section, and the balloon portion was pushed in between the blades of the folding section having ten blades. Note that the pleating section was not provided with films. After the balloon was pushed in completely, the heated blades were slowly closed. The ten blades were held in a closed state for a while, after which the blades were slowly opened, and the balloon was drawn back from the folding section.

In the same procedure as in the production example of the drug-coated balloon in Comparative Example <NUM>, a drug-coated balloon of a balloon catheter (material of balloon: nylon, the surface being smooth and non-porous) <NUM> in diameter and <NUM> in length was produced. Coating was conducted such that the amount of paclitaxel on the balloon would be approximately <NUM>µg/mm<NUM>.

A core metal member (material: SUS) in the form of wire <NUM> in diameter and <NUM> in length was inserted into a guide wire lumen of the dried drug-coated balloon, the balloon catheter was placed on the support base of the balloon wrapping apparatus such that the drug coating portion did not make contact with the support base, and a shaft of the balloon catheter was fixed to the holding base section by the holding portion fitted with silicone rubber. In this instance, the three-way cock of the hub of the balloon catheter was attached to the air injection and suction mechanism for inflating and deflating the balloon of the wrapping apparatus. The core metal member protruding from a distal portion of the balloon catheter was inserted into, and fixed to, a collet chuck affixed to the distal support (assisting shaft) of the pleating section. Next, the balloon was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the pleating section having four blades. After the balloon was pushed in completely, the heated blades were slowly closed simultaneously with starting of pleating, to press the blades against the balloon, and air inside the balloon was slowly sucked to deflate the balloon. The blades were held in the closed state for a while, to form wings, and then the blades were slowly opened, to spread the films. Thereafter, the balloon was drawn back from the pleating section.

In a condition where the balloon catheter formed with the wings was held in a deflated state, the support base was slid to the folding section. Next, the core metal member protruding from the distal portion of the balloon catheter was inserted into, and fixed to, a collet chuck affixed to the distal support (assisting shaft) of the folding section. Subsequently, the balloon portion was pushed in between a first film and a second film (material: PTFE, thickness: <NUM>) which are difficult to electrostatically charge and smooth and which were passed between blades of the folding section having ten blades. After the balloon was pushed in completely, the heated blades were slowly closed. The ten blades were held in a closed state for a while, after which the blades were slowly opened, to spread the first film and the second film. Thereafter, the balloon was drawn back from the folding section.

For the drug-coated balloons produced in Comparative Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM>, the amount of paclitaxel remaining on the balloon was measured in the following procedure.

The drug-coated balloon after folding was immersed in a methanol solution, followed by shaking by use of a shaker for <NUM> minutes, to extract paclitaxel present in the coating on the balloon. The light absorbance, at <NUM>, of the methanol solution into which paclitaxel had been extracted was measured by highspeed liquid chromatography using an ultraviolet-and-visible absorptiometer, and the amount of paclitaxel per balloon ([ug/balloon]) was determined. Further, from the amount of paclitaxel thus obtained and the surface area of the balloon, the amount of paclitaxel per unit area of balloon ([µg/mm<NUM>]) was calculated.

In Table <NUM>, the amount of paclitaxel (theoretical value) on the balloon upon coating and the amount of paclitaxel (measured value) on the balloon after folding are depicted as amount per unit area. In addition, retention rate of paclitaxel after folding was calculated by dividing the amount of paclitaxel on the balloon after folding by the amount of paclitaxel on the balloon upon coating, and multiplying the quotient by <NUM>.

As depicted in Table <NUM>, in every one of Comparative Examples <NUM> to <NUM>, the retention rate of paclitaxel was high. On the other hand, in Comparative Examples <NUM> and <NUM>, the retention rate of paclitaxel was as low as less than <NUM>%. Note that the films were used in the pleating and folding in Comparative Examples <NUM> to <NUM>, but films were not used in the pleating and folding in Comparative Examples <NUM> and <NUM>. It could be confirmed that detachment of the drug coating layer can be reduced by using films in pleating and folding.

For the drug-coated balloons prepared under the conditions of Comparative Example <NUM> and Comparative Example <NUM>, the generation rate of back folding upon folding was evaluated.

The wrapping direction of wings of the drug-coated balloons upon folding was observed on a digital microscope. In the case where the wrapping directions of the wings were not in one direction and there was the wings whose wrapping direction was reverse to the normal direction, the case was counted as back folding.

Table <NUM> depicts the number of drug-coated balloons in which back folding was generated, the total number of drug-coated balloons subjected to folding, and generation rate of back folding. The generation rate of back folding was calculated by dividing the number of drug-coated balloons in which back folding was generated by the total number of drug-coated balloons subjected to folding, and multiplying the quotient by <NUM>.

As depicted in Table <NUM>, in the method of Comparative Example <NUM> in which the balloon was rotated during folding, back folding was scarcely generated. On the other hand, in the method of Comparative Example <NUM> in which the balloon was not rotated during folding, back folding was generated in approximately one half of the samples subjected to folding. Accordingly, it could be confirmed that the rotation of the balloon during folding has an effect to reduce the generation of back folding.

Claim 1:
A balloon wrapping apparatus for wrapping a balloon (<NUM>) of a balloon catheter (<NUM>) provided with the balloon (<NUM>) at a distal portion of an elongated shaft (<NUM>), the balloon wrapping apparatus comprising:
a pleating section (<NUM>) that has a plurality of wing forming members (<NUM>) aligned with space parts therebetween in a circumferential direction, and that forms the balloon (<NUM>) with wing shapes projecting in radial directions by clamping by the wing forming members (<NUM>) the balloon (<NUM>) caused to enter into the space parts by moving rotationally the wing forming members (<NUM>);
a folding section (<NUM>) that has a plurality of folding members aligned in a circumferential direction, and that folds the wing shapes formed in the balloon (<NUM>) by moving rotationally the folding members;
a support base (<NUM>) that supports a part of the shaft (<NUM>) which part is on a proximal side of the balloon (<NUM>), and that makes the distal portion of the shaft (<NUM>) positionable in relation to the pleating (<NUM>) section and the folding section (<NUM>); and
a grasping section (<NUM>) including a collet chuck (<NUM>) forming clamping portions (<NUM>) and a chuck holder (<NUM>) for holding the collet chuck (<NUM>), capable of grasping only a part of the balloon catheter (<NUM>) which part is on a distal side of the balloon (<NUM>), and wherein the part clamped by the clamping portions (<NUM>) is an inner tube (<NUM>).