JP2023137346A - Balloon shaping method - Google Patents

Abstract

To provide a balloon shaping method for evenly shaping a blade part so as to shrink the balloon to a profile before an expanding and shrinking operation even if the balloon is subjected to the expanding and shrinking operation over a plurality of times.SOLUTION: A method for executing shaping for a balloon 140 after blow molding used for a balloon catheter 100 includes: an arrangement process for arranging the balloon 140 in a metal mold 210 having a cavity S for shaping the balloon 140; and a shaping process for shaping the balloon 140 by the metal mold 210. The arrangement process includes first pressurization treatment for pressurizing the balloon with first pressure. The shaping process includes heating treatment for holding the metal mold temperature for a predetermined shaping time after raising the metal mold temperature of the metal mold 210 up to a predetermined shaping temperature, and second pressurization treatment for pressurizing the balloon 140 with second pressure higher than the first pressure by the time the metal mold temperature reaches the shaping temperature.SELECTED DRAWING: Figure 9

Description

The present invention relates to a balloon shaping method for shaping a balloon used in a balloon catheter.

2. Description of the Related Art In the medical field, balloon catheters are widely known for use in procedures to dilate lesions (such as stenotic areas) formed within a living body lumen. A balloon catheter includes a long shaft and a radially expandable balloon provided at the distal end of the shaft, and allows the deflated balloon to reach the diseased area via a narrow biological lumen. It can later be expanded to spread the lesion apart.

Patent Document 1 listed below discloses a general method for manufacturing a balloon catheter. The balloon is manufactured by a process in which a tubular parison is preformed in advance by stretch blow molding, and the preformed balloon is inflated, and a plurality of pressing members placed around the inflating and deflating part of the balloon are used to push the inflating and deflating part in the radial direction. The step includes a step of forming a wing part in a part of the expansion/contraction part by moving it to a predetermined position inside and crushing it.

JP2013-56070A

In procedures using a balloon catheter, the balloon may be expanded and contracted multiple times, such as once being expanded within a living body lumen, then deflated, moved to a different location of the lesion, and then expanded again.

However, if a balloon is repeatedly deformed from a folded state to an expanded state or from an expanded state to a folded state, it becomes difficult for the balloon to reduce its diameter to its pre-expanded profile when deflated and folded. It may happen. Therefore, the balloon catheter may have poor balloon passageability (recrossability).

To improve recrossability, it is required that the blades formed on the balloon be shaped uniformly so that they can be folded to reduce the diameter during wrapping. However, in the technology disclosed in Patent Document 1, when the balloon is sandwiched between molds, the distal part of the wing part may not reach the distal part of the cavity, and it is difficult to shape the wing part uniformly. Can not.

At least one embodiment of the present invention has been made in view of the above-mentioned circumstances, and specifically, the blades are configured such that even if the balloon is expanded or contracted multiple times, it can be deflated to the profile before the expansion or contraction operation. It is an object of the present invention to provide a method for shaping a balloon, which allows the balloon to be shaped uniformly.

The balloon shaping method according to the present embodiment is a balloon shaping method for shaping a balloon after blow molding used in a balloon catheter, and the balloon shaping method is a balloon shaping method for shaping a balloon after blow molding used in a balloon catheter. a arranging step of arranging the balloon; and a shaping step of shaping the balloon with the mold; the arranging step includes a first pressure treatment of applying pressure at a first pressure; The process includes heating the mold temperature of the mold to a predetermined shaping temperature and then holding it for a predetermined shaping time, and heating the balloon until the mold temperature reaches the shaping temperature. and a second pressurization process of pressurizing at a second pressure higher than the first pressure.

According to at least one embodiment of the present invention, the balloon can be uniformly shaped in an expanded state such that the distal portion of the vane extends to the distal portion of the cavity, thereby allowing the balloon to be shaped multiple times. Even if the profile is scaled up or down, it can be shrunk to the profile before the scaling operation during wrapping. Therefore, a balloon catheter equipped with a balloon shaped using this shaping method can maintain the initial balloon passageability because the diameter of the balloon is reduced to its pre-expansion/deflation state even if the balloon is expanded/contracted multiple times. .

FIG. 1 is a schematic configuration diagram of a balloon catheter according to the present embodiment. FIG. 2 is a cross-sectional view of the vicinity of the distal end of the balloon catheter according to the present embodiment. FIG. 1 is a functional block diagram of a shaping system that implements a balloon shaping method according to the present embodiment. FIG. 1 is a schematic configuration diagram of a shaping device used in a shaping method according to the present embodiment. It is a partially enlarged view of the shaping device when the mold is opened. It is a partially enlarged view of the shaping device when the mold is closed. It is a figure which shows the state before implementation of the 2nd pressurization process implemented in the shaping process of the shaping method based on this embodiment. It is a figure which shows the state after implementation of the 2nd pressurization process implemented in the shaping process of the shaping method based on this embodiment. It is a flowchart which shows the process sequence of the shaping method based on this embodiment. It is a flowchart which shows the processing procedure carried out in the shaping process of the shaping method based on this embodiment. It is a flowchart which shows the processing procedure carried out in the shaping process of the shaping method based on this embodiment. 3 is a timing chart showing an example of a balloon shaping method according to the present embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The embodiments shown here are exemplified to embody the technical idea of the present invention, and are not intended to limit the present invention. In addition, all other possible embodiments, examples, operational techniques, etc. that can be considered by those skilled in the art without departing from the gist of the present invention are included within the scope and gist of the present invention, and are described in the claims. inventions and their equivalents.

Furthermore, for the convenience of illustration and ease of understanding, the drawings attached to this specification may be represented schematically by changing the scale, vertical/width dimensional ratio, shape, etc. from the actual thing as appropriate, but these are merely examples. However, this does not limit the interpretation of the present invention.

Furthermore, in the following description, when ordinal numbers such as "first" and "second" are used, unless otherwise specified, these are used for convenience and do not define any order.

[Balloon catheter configuration]
First, the configuration of a balloon catheter 100 including a balloon 140 shaped by the balloon shaping method according to the present embodiment will be described.

As shown in FIG. 1 or 2, the balloon catheter 100 pushes the lesion by expanding a balloon 140 disposed at the distal end of the shaft 110 at the lesion, such as a stenosis formed in a biological lumen. It is a medical device that can be expanded to treat patients.

The balloon catheter 100 can be configured, for example, as a PTCA dilation balloon catheter used to dilate a narrowed portion of a coronary artery. However, the balloon catheter 100 is used for the purpose of treating and improving strictures formed in living organs such as other blood vessels, bile ducts, tracheas, esophagus, other digestive tracts, urethra, otorhinolaryngal cavities, and other organs. It is also possible to configure it for use.

In the following description, the side where the balloon 140 is placed is referred to as the "distal side" of the balloon catheter 100, the side where the hub 160 is placed is referred to as the "proximal end side" of the balloon catheter 100, and the direction in which the shaft 110 extends is referred to as the "axial direction". ”. Furthermore, unless otherwise specified, "distal end" means a certain range including the distal end (the most distal end) and its surroundings, and "proximal end" means the proximal end (most proximal end) and its surroundings. It means a certain range that includes.

The balloon catheter 100 is configured as a so-called "rapid exchange catheter device" in which a guide wire port 111 from which a guide wire G is led out is provided near the distal end of a shaft 110. Note that the balloon catheter 100 can also be configured as a so-called "over-the-wire catheter device" in which the guide wire lumen 121 is formed to extend from the distal end to the proximal end of the shaft 110.

The shaft 110 includes an inner tube 120 having a guide wire lumen 121 through which the guide wire G is inserted, and an outer tube 130 forming a pressurized medium lumen 131 through which a pressurized medium can flow between the inner tube 120 and the inner tube 120. , has. The shaft 110 has a double tube structure in which the inner tube 120 and the outer tube 130 are arranged concentrically by being inserted into the outer tube 130 .

A balloon 140 is liquid-tightly and airtightly joined to the distal end of the inner tube 120 by a known method such as welding. The balloon 140 has a distal end joined to the inner tube 120 and a proximal end joined to the outer tube 130.

The balloon 140 has a space 141 between it and the inner tube 120 into which a pressurized medium can flow. Balloon 140 expands when pressurized medium is introduced into space 141 . When the balloon 140 is inflated, the balloon catheter 100 pushes a portion of the balloon catheter 100 against a stenosis formed in a living body lumen, thereby expanding the stenosis.

For example, a tip can be attached to the distal end of the inner tube 120 to prevent damage to the living organ when the tip of the balloon catheter 100 comes into contact with the living organ (such as the inner wall of a blood vessel). The distal tip can be made of a more flexible resin material than the inner tube 120, for example.

The inner tube 120 can be provided with a contrast marker section. The contrast marker portion can be arranged, for example, at a position in the inner tube 120 that indicates the boundary with the distal end of the balloon 140, and in a position in the inner tube 120 that indicates the boundary with the proximal end of the balloon 140.

Examples of materials constituting the inner tube 120 and the outer tube 130 include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymers, and ethylene-vinyl acetate copolymers, thermoplastic resins such as soft polyvinyl chloride, and silicone rubber. , various rubbers such as latex rubber, various elastomers such as polyurethane elastomer, polyamide elastomer, and polyester elastomer, and crystalline plastics such as polyamide, crystalline polyethylene, and crystalline polypropylene. It is also possible to mix antithrombotic substances such as heparin, prostaglandin, urokinase, and arginine derivatives into these materials to make them antithrombotic materials.

As the material constituting the balloon 140, for example, an organic polymer material can be used. Specifically, polyolefins (for example, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these), polyvinyl chloride, polyamide, polyamide elastomer Elastic resin materials such as polyurethane, polyurethane elastomer, polyimide, fluororesin, a mixture thereof, or two or more of the above-mentioned polymer materials can be used, and among them, polyamide resin is preferred as the main material. It can be used for.

The balloon 140 is obtained by preforming a parison (tubular member) made of the above-mentioned elastic resin material by known stretch blow molding (for example, biaxial stretch blow molding), and subjecting it to a shaping process according to the present embodiment described later. For example, it becomes a product with high passability that can be used for multiple expansion/contraction operations.

As shown in FIG. 1, a hub 160 can be provided at the proximal end of the shaft 110. The hub 160 can be liquid-tightly and airtightly connected to a supply device (not shown) such as an indeflator for supplying pressurized medium.

A pressurized medium (e.g., saline, contrast agent, etc.) used to expand the balloon 140 may flow into the pressurized medium lumen 131 of the shaft 110 through the interior space (lumen) of the hub 160. can. The pressurized medium is supplied to the space 141 of the balloon 140 via the pressurized medium lumen 131 .

Balloon 140 may also have a coating formed over its outer surface. The coating can be composed of, for example, a hydrophilic coating layer that improves the sliding properties of the balloon 140 or a drug coating layer containing a predetermined drug. The specific materials for forming the hydrophilic coat layer and the drug coat layer are not particularly limited.

[Shaping method]
Next, a method for shaping a balloon according to this embodiment will be described with reference to FIGS. 3A to 9 as appropriate. The balloon shaping method can be performed by a shaping system 300 shown in FIG. 3A.

In the following description, a method of shaping the balloon 140 alone without joining the balloon 140 to the shaft 110 will be disclosed. However, the method for shaping the balloon can also be performed while the balloon 140 is joined to the shaft 110.

<System configuration>
First, the configuration of a shaping system 300 that can implement the balloon shaping method according to this embodiment will be described.

The shaping device 200 included in the shaping system 300 is a device that moves a mold 210 in a predetermined direction to sandwich a portion of the balloon 140 to form a predetermined shape. As shown in FIG. 3B, the shaping device 200 includes a plurality of molds 210 for shaping the balloon 140 in a predetermined direction, a moving section 220 for moving the molds 210 in a predetermined direction, and a moving section 220 for driving the moving section 220. The drive unit 230 is configured to include a drive unit 230. As shown in FIGS. 4A and 4B, the shaping device 200 is a device that includes an openable mold 210 that can be moved by a moving section 220 to open or close a cavity S, which will be described later.

As shown in FIG. 3A, the shaping system 300 also includes a heating unit 240 that heats the mold temperature of the mold 210, and a pressure adjustment unit that performs pressurization or depressurization to adjust the internal pressure of the balloon 140 to a predetermined pressure. 250, a medium supply section 260 that applies a cooling medium to the mold 210, and a control section 270 that collectively controls the driving of each section constituting the system. The shaping system 300 forms a predetermined shape on the balloon 140 while driving and controlling each part according to a drive instruction based on an operator's operation or a predetermined control program, for example, along a timing chart shown in FIG. Note that the shaping system 300 is not limited to the configuration shown in FIG. 3A, and other configuration requirements may be added or partially omitted as necessary.

Next, the configuration of the shaping device 200 will be described in detail. The molds 210 have substantially the same shape as each other, and are provided so as to be movable in the radial direction of the balloon 140 so as to surround the outer periphery of the balloon 140, which will be placed in a placement process described later. As shown in FIG. 4B, the molds 210 rotate and approach each other by moving with the outer peripheral surface of the mold 210 in contact with the inner peripheral surface of the moving part 220, so that adjacent molds 210 are aligned. Partial contact. As a result, a cavity S is formed, which is a molding space for shaping the balloon 140 into a desired shape. The cavity S has a blade forming space S1 in which the blade 150 is formed. When the balloon 140 is partially sandwiched between the molds 210 and subjected to a shaping process described below, a wing portion 150 that follows the shape of the cavity S is formed.

The moving part 220 has an annular shape with an inner circumferential shape that can fit into a part of the mold 210, and is arranged on the outer periphery of the mold 210. When shaping the balloon 140, the moving part 220 rotates in a predetermined direction (for example, clockwise in FIG. 3B) with the inner circumferential surface of the moving part 220 in contact with the outer circumferential surface of the mold 210, and while rotating it and moving it radially inward. A part of the inner peripheral surface of the moving part 220 continues to be in contact with a part of the outer peripheral surface of the mold 210 until the balloon 140 is shaped, so that the mold 210 can be moved smoothly. , and the balloon 140 can be shaped with uniform force.

The drive unit 230 moves (rotates) the moving unit 220 in a predetermined direction. The drive unit 230 is driven when the cavity S of the mold 210 is opened or closed. The drive unit 230 can adopt any configuration as long as it can drive the moving unit 220.

Note that the shaping device 200 is not limited to the above-mentioned configuration as long as it has a configuration that allows the balloon 140 to be shaped into a predetermined shape. Therefore, although the shaping device 200 is an open/close type that is composed of a plurality of molds 210 that are moved close to each other and separated from each other by a moving part 220, for example, the mold can be constructed of a plurality of divided parts, and the balloon 140 after being shaped can be shaped. When taking out, each divided portion may be separated and taken out (for example, a mold disclosed in Japanese Patent Application Laid-open No. 2003-62080). That is, the mold 210 may be of an open/close type or a split type, or may be of a type other than these.

As shown in FIG. 6, the balloon shaping method includes a "placing step" in which the balloon 140 is placed in a mold 210 having a cavity S for shaping the balloon 140, and a balloon 140 placed in the mold 210. The method includes at least a "shaping step" in which the balloon 140 is heated and pressurized to give the balloon 140 a predetermined shape. In the balloon shaping method, each step can be performed at the timing shown in FIG.

<Placement process>
The placement process is a process of placing the balloon 140 in the mold 210 of the shaping device 200.

The balloon 140 to be placed is preformed in advance and has a substantially cylindrical shape. The placement process includes, as shown in FIG. 7, a balloon placement process in which the balloon 140 is placed at a predetermined position inside the mold 210 (a spatial position where the cavity S is defined when the mold 210 is closed); The process includes a first pressurization process in which a first pressure is applied to the balloon 140, and a cavity closing process in which the mold 210 is closed and the cavity S is closed.

In the first pressurization process, the balloon 140 placed in the balloon placement process is pressurized at a predetermined first pressure. A part of the pressurized balloon 140 is sandwiched between the mold 210 and enters the blade forming space S1 when the mold 210 is closed to close the cavity S in the next cavity closing process. The first pressure applied in the first pressurization process is a pressure that can expand the balloon 140 to a certain extent, and is lower than at least the second pressure applied during the second pressurization process described later, specifically, 0. It is preferable to set it to 0.005 MPa or more and 0.5 MPa or less.

<Shaping process>
The shaping process is a process of giving a predetermined shape to the balloon 140 placed in the mold 210 in the placement process.

As shown in FIG. 7, the shaping process includes heating the mold 210 to a predetermined shaping temperature and maintaining the mold temperature at the shaping temperature for a predetermined shaping time; a second pressurization process in which the balloon 140 is pressurized at a second pressure higher than the first pressure until the mold temperature reaches the shaping temperature or the shaping temperature; a cooling process in which the mold temperature is cooled to a predetermined temperature or lower; The method includes an opening process of opening the mold 210 after the mold 210 has been cooled to a predetermined glass transition temperature.

The heat treatment is a process in which the mold temperature of the mold 210 is heated to a shaping temperature that is a temperature suitable for shaping the balloon 140, and then maintained for a predetermined shaping time.

In the heat treatment, the "shaping temperature" and "shaping time" can be set as appropriate depending on the constituent material and size of the balloon 140. For example, when polyamide resin is used as the main material for the elastic resin material constituting the balloon 140, the shaping temperature can be set within a range of 90° C. or higher and 140° C. or lower. The time for maintaining the state in which the shaping temperature is reached (shaping time) can be 30 seconds or more and 120 seconds or less.

In the second pressure treatment, a second pressure is applied to the balloon 140 until the mold temperature reaches the shaping temperature or the shaping temperature. The second pressurization process further expands the balloon 140 pressurized with the first pressure, and moves the distal part (tip part) of the blade part 150 to the distal part (tip part) of the blade part forming space S1. This is the process to reach it. The second pressure applied in the second pressure treatment is higher than at least the first pressure applied in the first pressure treatment, and specifically, it is preferably 1 MPa or more and 3 MPa or less. Note that the term "distal part of the blade part 150" means the end of the blade part 150 on the side far from the axial center of the balloon 140, and its surroundings. Moreover, the "distal part of the blade forming space S1" means the end part on the side far from the axial center of the cavity S with reference to the axial center and the surrounding area thereof.

As shown in FIG. 5A, when the balloon 140 pressurized in the first pressurization process moves from the placement process to the shaping process, the distal part of the blade part 150 is in the distal part of the blade part forming space S1. It may not arrive. As mentioned in the "Problems to be Solved by the Invention", this corresponds to a state in which when the balloon 140 is sandwiched between the molds 210, the entire blade part 150 does not extend to the distal part of the blade part forming space S1. do. Even if shaped in this state, the blade portion 150 will not be shaped uniformly and will be folded unevenly during wrapping, making it difficult to reduce the diameter. Therefore, in the balloon shaping method according to the present embodiment, in order to prevent the wing portion 150 from being shaped unevenly as described above, after the mold 210 is closed and the cavity S is closed, the mold 210 is closed and the cavity S is closed. The second pressure treatment is performed until the mold temperature reaches the shaping temperature or the shaping temperature. By performing the second pressurization process, as shown in FIG. 5B, the distal part of the vane part 150 reaches the distal part of the vane part forming space S1, so that the entire vane part 150 is It is possible to shape the entire part forming space S1. Note that, from the viewpoint of shaping, it is preferable that the second pressurizing treatment is performed before the mold temperature reaches the shaping temperature.

In this way, the balloon 140 that has been shaped by performing the second pressure treatment in the shaping process has the entire wing portion 150 shaped uniformly, so it will not expand or contract even if it is expanded or contracted multiple times. It becomes possible to shrink to the pre-operation profile. Therefore, even if the balloon catheter 100 equipped with the balloon 140 is expanded and contracted multiple times, the diameter of the balloon 140 can be reduced to a state where the profile before expansion and contraction is narrow, and the initial passability is maintained. .

The second pressurization process comes into play when the distal portion of the blade portion 150 reaches the distal portion of the blade forming space S1. Therefore, in the second pressure treatment, after applying the second pressure to the balloon 140 until the mold temperature reaches the shaping temperature or the shaping temperature, the second pressure can be released at a predetermined timing. . The timing of canceling the second pressurization process is not particularly limited, but from the viewpoint of shaping, it is set between after the heating process, which is when the shaping of the blade part 150 is finished in the shaping process, and until the cooling process is finished. is preferable.

Further, the second pressure treatment may be continued after the second pressure is applied to the balloon 140 in the shaping step until the cooling treatment ends.

Further, the shaping step may include a depressurization process in which the balloon 140 is depressurized to a pressure lower than the second pressure after the second pressurization process is performed.

The pressure reduction process is a process in which negative pressure is generated to reduce the pressure of the balloon 140 to a pressure lower than the second pressure and deflate it. The depressurization process mainly involves firmly shaping only the inner surface of the blade portion 150 (the surface facing the outer circumferential surface of the balloon 140 when the blade portion 150 is wrapped), and By creating a difference in film thickness and hardness due to the difference in the amount of heat applied to the inner surface of the blade part 150 and the surface that does not face the outer peripheral surface of the balloon 140 when wrapping The blade portion 150 can be easily wound around the inner surface side of the hard blade portion 150. Since the radius of the inner surface of the wing portion 150 is smaller than that of the outer surface, the wing portion 150 is easily wound inward, and the diameter of the balloon 140 can be reduced. That is, the depressurization process can give the balloon 140 a curl so that it has a small diameter when wrapping the wing portion 150. Therefore, the diameter of the balloon 140 can be reduced from the initial state, and the profile of the initial state can be maintained even if the balloon 140 is repeatedly expanded and contracted multiple times.

It is preferable that the depressurization process is performed after a predetermined period of time has elapsed from the start of the shaping time after the second pressurization process in the shaping process. The decompression treatment is performed after the balloon 140 is subjected to a second pressurization treatment, the inner and outer surfaces of the blade portion 150 are pressed against the inner wall surface 211 of the mold 210, and the entire blade portion 150 is shaped at the shaping temperature. By doing so, it is possible to form a stronger shape on the inner surface side of the blade portion 150.

Although the pressure during the decompression treatment depends on the constituent material and size of the balloon 140, it is specifically less than atmospheric pressure, preferably 0.01 MPa or more and 0.1 MPa or less.

The cooling process is a process of cooling the mold temperature to a predetermined temperature. The cooling process can firmly memorize the shape of the blade portion 150 of the balloon 140. The cooling process only needs to cool the mold 210 to a predetermined temperature. The cooling process is, for example, a process of stopping the heating of the mold 210 and waiting until it cools naturally to a predetermined temperature, or a process of supplying a cooling medium such as air or water to the mold 210 inside or outside the mold 210. (flowing into the cavity S of the mold 210 or spraying onto the outer peripheral surface of the mold 210) to cool the mold 210, a process of opening a part of the mold 210 to cool the mold 210, etc. It will be done. However, the cooling process is not limited to the illustrated process content as long as the mold temperature of the mold 210 can be cooled to a predetermined temperature.

In the opening process that is the next process after the cooling process, the mold 210 is opened after being cooled to below the glass transition temperature of the elastic resin material forming the balloon 140. When the balloon 140 is cooled to a temperature below the glass transition temperature, in addition to the advantages during the opening process, the shape of the wing portion 150 can be firmly memorized. Therefore, the cooling process is preferably a process of cooling the mold temperature to the glass transition temperature. The glass transition temperature serving as the target cooling temperature of the cooling process may be the glass transition temperature of any of the elastic resin materials forming the balloon 140.

The opening process is a process for opening the mold 210 (opening the cavity S) and taking out the balloon 140. The opening process can be performed after the mold 210 has been cooled to a glass transition temperature that is lower than the mold release temperature. As a result, the balloon 140 becomes lower than the mold release temperature, so that the balloon 140 is in a stable state with little volumetric expansion, and can be taken out from the mold 210 without sticking to the inner peripheral surface of the mold 210. Therefore, the surface of the balloon 140 is not damaged or wrinkled, and its pressure resistance can be stabilized.

Note that the "mold release temperature" is a temperature at which the sticking of the balloon 140 to the mold 210 is reduced and the balloon 140 can be easily removed from the mold 210. The mold release temperature is appropriately determined depending on the materials of the mold 210 and the balloon 140, and is, for example, 60° C. or higher and 70° C. or lower.

The opening process is preferably performed after reducing the pressure of the balloon 140 to 1 MPa or less. As a result, the balloon 140 contracts more than during the second pressurization process, so that sticking to the inner wall of the mold 210 can be more reliably eliminated.

The opening process may not be included in the shaping process if the balloon 140 is made of a material that can prevent sticking to the mold 210.

The balloon shaping method described above may include steps other than the "arranging step" and the "shaping step." The placement process may include processes other than the "balloon placement process," the "first pressurization process," and the "cavity closing process." The shaping process may include treatments other than "heat treatment," "second pressure treatment," "cooling treatment," and "opening treatment." Further, regarding each step and each process shown in FIGS. 6 to 8, the elements of the steps are presented in an exemplary order, and the elements are not limited to the specific order presented. Therefore, the order of each of the flowcharts shown in FIGS. 6 to 8 can be changed as long as it does not conflict with the processing of the present invention.

[motion]
Next, the operating procedure of the balloon shaping method according to this embodiment will be described. As a method for shaping the balloon, the steps and treatments shown in FIGS. 6 to 8 can be carried out in accordance with the timing chart shown in FIG.

The operator performs a placement step (S10). The operator first performs a balloon placement process (S11) and places the preformed balloon 140 in the mold 210 in an open state. Next, the operator performs a first pressurization process (S12) to pressurize the balloon 140 by applying a first pressure (for example, 0.005 MPa or more and 0.5 MPa or less). Next, the operator performs a cavity closing process (S13) to close the mold 210 and close the cavity S. As shown in FIG. 5A, when the mold 210 is closed while the first pressure is applied, a portion of the balloon 140 enters the wing forming space S1.

Subsequently, the operator performs a shaping step (S20). The operator first performs a heat treatment (S21) to heat the mold temperature of the mold 210 to the shaping temperature. The mold 210 is heated for a predetermined shaping time (for example, from 30 seconds to 120 seconds) after the mold temperature is heated to the shaping temperature (for example, from 90° C. to 140° C.) by driving the heating unit 240. Retained.

Next, the operator performs the second pressure treatment (S22) after starting the heat treatment until the mold temperature reaches the shaping temperature or the shaping temperature. In the second pressurization process, the pressure adjustment section 250 is driven to apply a second pressure (for example, 1 MPa or more and 3 MPa or less) to the balloon 140. By performing the second pressurization process, the distal portion of the blade portion 150 of the balloon 140 reaches the distal portion of the blade portion forming space S1 of the cavity S, as shown in FIG. 5B. Thereby, the blade portion 150 is uniformly shaped as a whole.

After shaping the balloon 140 that has been subjected to the second pressure treatment for a predetermined shaping time, the operator performs a cooling treatment (S23) to cool the mold 210. In the cooling treatment, for example, the mold temperature is cooled to a predetermined glass transition temperature. In the cooling process, the medium supply unit 260 can be driven to supply a cooling medium (for example, water or cooling air) to the mold 210.

Then, when the mold temperature of the mold 210 becomes equal to or lower than the glass transition temperature, the operator performs an opening process (S24). In the opening process, after the pressure of the balloon 140 is reduced (for example, to 1 MPa or less), the mold 210 is opened and the balloon 140 is taken out. The opening process cools the mold 210 to a temperature below the glass transition temperature of the elastic resin material forming the balloon 140, so that the balloon 140 can be easily removed without sticking to the inner wall surface 211. This completes the process of shaping the balloon 140.

The balloon 140 shaped through the shaping process can be joined to the distal end of the shaft 110 so as to be expandable and contractible by a known method. The balloon catheter 100 is manufactured by joining the balloon 140 to the distal end of the shaft 110 and then going through predetermined steps (such as a wing folding step and a hub attaching step).

[Effect]
As explained above, the balloon shaping method according to the present embodiment is a method for shaping the balloon 140 after blow molding used in the balloon catheter 100, and is a method for shaping the balloon 140 after blow molding. The method includes a placement step of arranging the balloon 140 in a mold 210 having a cavity S, and a shaping step of shaping the balloon 140 with the mold 210. Further, the placement step includes a first pressurization process of applying pressure at a first pressure, and the shaping step includes heating the mold temperature of the mold 210 to a predetermined shaping temperature and then holding it for a predetermined shaping time. and a second pressure treatment in which the balloon 140 is pressurized at a second pressure higher than the first pressure until the mold temperature reaches the shaping temperature or the shaping temperature.

By the second pressurization process, the distal part of the blade part 150 is expanded to reach the distal part of the blade part forming space S1 of the cavity S, and the entire blade part 150 is spread evenly within the blade part forming space S1. is shaped into. Therefore, the balloon 140 is shaped so that it can be deflated to the profile before the expansion/contraction operation even if the balloon 140 is expanded/contracted multiple times. Therefore, even if the balloon catheter 100 equipped with the balloon 140 is expanded and contracted multiple times, the diameter of the balloon 140 can be reduced to a state where the profile before expansion and contraction is narrow, and the initial passability is maintained. . Furthermore, from the viewpoint of shaping, the second pressurizing treatment can be performed until the mold temperature reaches the shaping temperature, thereby making it possible to uniformly shape the entire balloon 140.

Further, in the balloon shaping method according to the present embodiment, the shaping step may include a cooling process in which the temperature of the mold 210 at the shaping temperature is cooled to a predetermined temperature or lower.

By performing a cooling treatment to cool the balloon 140 after the heat treatment and the second pressure treatment, the shape of the blade portion 150 can be firmly memorized in the balloon 140. Therefore, the balloon 140 is uniformly shaped so that it can be deflated to the profile before the expansion/contraction operation even if the balloon 140 is expanded/contracted multiple times.

In addition, in the balloon shaping method according to the present embodiment, the second pressure treatment is performed by continuously pressurizing the balloon 140 after applying the second pressure to the balloon 140 in the shaping step until the cooling treatment ends. It's okay.

Thereby, after the balloon 140 is uniformly shaped as a whole at the shaping temperature, the shape of the entire blade portion 150 is firmly memorized by the cooling process.

Furthermore, in the balloon shaping method according to the present embodiment, the shaping step may include, after the second pressure treatment, a depressurization treatment of reducing the pressure of the balloon 140 to a pressure lower than the second pressure.

As a result, the balloon 140 has a smaller diameter than the conventional product in the initial state, and is shaped so that it can be deflated to the profile before the expansion/contraction operation even if the balloon 140 is expanded/contracted multiple times. Therefore, when wrapped, the balloon catheter 100 equipped with the balloon 140 has a smaller diameter than conventional products and has improved crossability in the initial state, and even after multiple expansion and contraction operations, the diameter remains small when deflated. Improves recrossability.

Furthermore, in the balloon shaping method according to the present embodiment, the shaping step includes an opening process in which the pressure of the balloon 140 is reduced to 1 MPa or less after the mold 210 has been cooled to the glass transition temperature, and then the mold 210 is opened. You may also include more.

Since the balloon 140 is lower than the mold release temperature, the balloon 140 is in a stable state with little volumetric expansion, and can be taken out from the mold 210 without sticking to the inner peripheral surface of the mold 210. Therefore, the surface of the balloon 140 is not damaged or wrinkled, and its pressure resistance can be stabilized.

100 balloon catheter,
110 shaft,
120 inner tube,
130 outer tube,
140 balloon,
150 blade part,
160 hub,
200 Shaping device,
210 Mold,
220 moving part,
230 drive unit,
240 heating section,
250 pressure adjustment section,
260 medium supply unit,
270 control unit,
300 shaping system,
G guide wire,
S cavity,
S1 Blade formation space.

Claims (9)

A balloon shaping method for shaping a balloon after blow molding used in a balloon catheter, the method comprising:
arranging the balloon in a mold having a cavity for shaping the balloon;
a shaping step of shaping the balloon with the mold,
The placement step includes a first pressurization process of pressurizing at a first pressure,
The shaping step includes:
A heating treatment in which the mold temperature of the mold is heated to a predetermined shaping temperature and then held for a predetermined shaping time;
a second pressurization process of pressurizing the balloon at a second pressure higher than the first pressure until the mold temperature reaches the shaping temperature or the shaping temperature;
How to shape balloons, including: 2. The balloon shaping method according to claim 1, wherein the second pressurizing treatment is performed before the mold temperature reaches the shaping temperature. 3. The balloon shaping method according to claim 1, wherein the shaping step includes a cooling process of cooling the mold to a predetermined temperature or lower. 4. The shape of the balloon according to claim 3, wherein the second pressure treatment continues to apply pressure after applying the second pressure to the balloon in the shaping step until the cooling treatment ends. How to attach. The shape of the balloon according to any one of claims 1 to 4, wherein the shaping step includes, after the second pressurization treatment, a depressurization treatment of reducing the pressure of the balloon to a pressure lower than the second pressure. How to attach. Any one of claims 1 to 5, wherein the shaping step further includes an opening process of opening the mold after the mold temperature has been cooled to below the glass transition temperature of an elastic resin material constituting the balloon. Balloon shaping method described in section. 7. The balloon shaping method according to claim 6, wherein the opening process involves opening the mold after reducing the pressure of the balloon to 1 MPa or less. The balloon is mainly made of polyamide resin,
The balloon according to any one of claims 1 to 7, wherein in the heat treatment, the shaping temperature is 90° C. or higher and 140° C. or lower, and the shaping time is between 30 seconds and 120 seconds. How to shape. The pressurizing force of the first pressurizing treatment is 0.005 MPa or more and 0.5 MPa or less,
The balloon shaping method according to any one of claims 1 to 8, wherein the pressurizing force of the second pressurizing treatment is 1 MPa or more and 3 MPa or less.