JP2023137345A - Balloon shaping method - Google Patents

Abstract

To provide a balloon shaping method capable of shaping a balloon 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 while achieving reduction in diameter in an initial state.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 shaping process includes heating and pressurizing treatment for increasing the metal mold temperature of the metal mold 210 up to a predetermined shaping temperature, and pressurizing the balloon 140 while keeping the metal mold temperature at the shaping temperature by a predetermined shaping time, cooling treatment for cooling the temperature of the metal mold 210 to a predetermined temperature or lower; and decompression treatment for decompressing the balloon 140 to the pressure lower than the pressure for pressurizing the balloon during the heating and pressurizing treatment to the cooling treatment.SELECTED DRAWING: Figure 8

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).

Furthermore, by reducing the diameter of the balloon profile from its initial state, it is possible to improve not only the recrossability but also the initial passageability (crossability) of the balloon catheter. The shaping method has not been established.

At least one embodiment of the present invention has been made in view of the above-mentioned circumstances, and specifically, it is possible to reduce the diameter of the balloon in the initial state, and the balloon can be expanded and contracted even if the balloon is expanded and contracted multiple times. It is an object of the present invention to provide a balloon shaping method capable of shaping the balloon so that it can be deflated to its pre-operation profile.

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. The method includes a placement step of arranging the balloon, and a shaping step of shaping the balloon with the mold, and the shaping step includes heating the mold temperature of the mold to a predetermined shaping temperature. , a heating and pressurizing process that pressurizes the balloon while maintaining the shaping temperature for a predetermined shaping time, a cooling process that cools the temperature of the mold to a predetermined temperature or less, and a heating and pressurizing process that includes the cooling. During the treatment, a depressurization treatment is included in which the pressure is reduced to a pressure lower than the pressure at which the balloon is pressurized.

According to at least one embodiment of the present invention, it is possible to reduce the diameter of the balloon in the initial state, and to shape the balloon so that it can be deflated to the profile before the expansion/contraction operation even if the balloon is expanded/contracted multiple times. can. Therefore, a balloon catheter equipped with a balloon shaped by this shaping method has improved crossability even in the initial state, and even if the balloon is expanded and contracted multiple times, the diameter of the balloon will be reduced to the state before expansion and contraction. Therefore, the catheter has excellent recrossability.

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. FIG. 3 is a partially enlarged sectional view showing the state of the blade portion of the balloon during heating and pressurizing treatment. FIG. 3 is a partially enlarged cross-sectional view showing the state of the blade portion of the balloon during depressurization treatment. 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. 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 can be 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 performing a shaping process according to the present embodiment described later. This product has high passability and can be used for multiple expansion and 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 8 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 with each other. Partial contact. As a result, a cavity S is formed, which is a molding space for shaping the balloon 140 into a desired shape. When the balloon 140 is partially sandwiched between the molds 210 and subjected to the 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 mold 210 of the shaping device 200 is an open/close type, for example, the mold is configured with a plurality of divided parts, and when taking out the shaped balloon 140, each divided part is divided and taken out. (For example, the mold disclosed in JP-A No. 2003-62080) may be used. 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 step is a step in which the balloon 140 is placed with the mold 210 of the shaping device 200 open.

The balloon 140 to be placed is preformed in advance and has a substantially cylindrical shape. In the placement process, the balloon 140 may be placed inside the mold 210 in a state where it is pressurized with a predetermined pressure in advance, or may be placed in a state where it is not pressurized. FIG. 4A shows a state in which the balloon 140 is placed inside the mold 210 in a pressurized state.

<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.

In the shaping process, as shown in FIG. 8, the temperature of the mold 210 is heated to a predetermined shaping temperature, and the balloon 140 is heated while maintaining the mold temperature at the shaping temperature for a predetermined shaping time. The process includes a heating and pressurizing process to press the mold, a cooling process to cool the mold temperature to a predetermined temperature or lower, and an opening process to open the mold 210 after the mold 210 has been cooled to a predetermined temperature or lower.

In the heating and pressurizing treatment, 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 a predetermined pressure is applied to the balloon 140 for a predetermined shaping time. .

In the heating and pressurizing treatment, "shaping temperature", "pressure applied to balloon 140", and "shaping time" can be set as appropriate depending on the constituent material and size of 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. Further, the pressure (pressure force) applied to the balloon 140 can be 1 MPa or more and 4 MPa or less. The time for pressurizing the balloon 140 after reaching the shaping temperature (shaping time) can be 30 seconds or more and 120 seconds or less. The balloon 140 is heated and pressurized to form a plurality of blades 150 on a portion of its outer peripheral surface.

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 can be opened after the balloon 140 is cooled to a temperature below the glass transition temperature of the elastic resin material forming the balloon 140, which is lower than the mold release temperature. 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, it is preferable that the cooling treatment is a treatment in which the mold temperature is cooled to below 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 depressurization process is a process in which negative pressure is generated to reduce the pressure to a pressure lower than the pressure when pressurizing the balloon 140 and deflate it. As shown in FIG. 8, the depressurization treatment is performed during a decompression treatment period will be carried out within The decompression treatment mainly shapes only the inner surface 151 of the blade portion 150 to create a difference in film thickness and hardness due to the difference in the amount of heat applied to the outer surface 152 of the blade portion 150 and the inner surface 151 of the blade portion 150. By doing so, the blade portion 150 can be easily wound around the inner surface 151 side of the blade portion 150 having a thick film thickness or hardness. Since the radius of the inner surface 151 of the wing portion 150 is smaller than that of the outer surface 152, 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.

Note that the "inner surface" of the wing section 150 formed on the balloon 140 refers to the surface on the side facing the outer peripheral surface of the balloon 140 when the wing section 150 is wrapped, as shown in FIGS. 5A and 5B. The "outer surface" refers to the surface that does not face the outer peripheral surface of the balloon 140 when the wing portion 150 is wrapped.

As described above, in the heating and pressurizing treatment, the balloon 140 is pressurized at a predetermined pressure, and the expanded balloon 140 is shaped into the wing portion 150. At this time, as shown in FIG. 5A, the balloon 140 is pressurized during the heating and pressurizing treatment, so that the inner surface 151 and the outer surface 152 of the blade portion 150 are aligned with the inner wall surface 211 of the mold 210 (the contour surface of the cavity S). The entire blade portion 150 is shaped by being pressed against it. On the other hand, in the depressurization process, the balloon 140 pressurized in the heating and pressurizing process is depressurized to a predetermined pressure. As shown in FIG. 5B, the balloon 140 is depressurized within the decompression treatment period X, so that only the inner surface 151 of the blade portion 150 is pressed against the inner wall surface 211 of the mold 210, and the inner surface 151 side of the blade portion 150 is shaped. be attached.

In this way, the depressurization process can cause the inner surface 151 of the blade portion 150 to firmly memorize the shape. Therefore, by performing the depressurization treatment in addition to the heating and pressurization treatment during the decompression treatment period further shaped. Therefore, when the balloon 140 is wrapped, it has a smaller diameter than conventional products, improving the crossability in the initial state, and even after multiple expansion and contraction operations, the diameter can be reduced when deflated, improving the recrossability. .

It is preferable that the depressurization process is carried out at the timing when a predetermined time has elapsed since the balloon 140 was pressurized in the heating and pressurizing process, that is, after the elapse of a predetermined time from the start of the shaping time. Moreover, it is more preferable that the reduced pressure treatment is performed during the heating and pressurizing treatment. The balloon 140 is pressurized by heating and pressurizing, and the inner surface 151 and outer surface 152 of the wing section 150 are pressed against the inner wall surface 211 of the mold 210, so that the entire wing section 150 is shaped. Therefore, by performing the depressurization process after shaping the blade portion 150 as a whole, it is possible to form a stronger shape on the inner surface 151 side.

Further, when the pressure reduction treatment is performed during the shaping time during the heating and pressurization treatment, it is preferable to reduce the pressure for a shorter pressure reduction time than the pressurization time of the balloon 140. In other words, as shown in FIG. 8, in the shaping period Y in which shaping is performed during the heating and pressurizing process, the depressurizing period Y1 in which the depressurizing process is performed is shorter than the pressurizing period Y2 in which the pressurizing process is performed. is preferable (pressurization period Y2>depressurization period Y1). As described above, in the shaping process, the balloon 140 is most shaped during the shaping period Y during which the mold 210 is pressed at the shaping temperature. Therefore, in the shaping time, it is preferable to satisfy the relationship of heating time>depressurization time so that the inner surface 151 of the blade part 150 can be more firmly shaped while ensuring sufficient pressurization time for the balloon 140. .

The pressure reduction process may be performed after the shaping time has elapsed. In other words, the mold temperature during the depressurization process may be lower than the mold temperature (shaping temperature) during the heating and pressurizing process. For example, if the pressure is reduced at the timing of transition from the heating and pressurizing process to the cooling process after the shaping time shown in FIG. can be further shaped. At this time, the mold temperature is lower than the shaping temperature, but the inner surface 151 is pressed against the inner wall surface 211 of the mold 210 while the balloon 140 is cooled to the glass transition temperature of the elastic resin material. This allows the shape to be strongly memorized.

In the pressure reduction treatment, the inner surface 151 of the blade portion 150 is pressed against the inner wall surface 211 of the mold 210, so that the pressure is reduced to a lower pressure than the pressure during the heating and pressure treatment. 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. Moreover, the pressure reduction process only needs to be carried out at least within the pressure reduction process period X, and for example, the pressure may be reduced multiple times in a rectangular waveform, or the pressure may be reduced in stages.

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 heating and pressurizing treatment, 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 shaping process may include treatments other than "heating and pressure treatment," "cooling treatment," "decompression treatment," and "opening treatment." Further, regarding each step and each process shown in FIGS. 6 and 7, 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 and 7 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 processes shown in FIGS. 6 and 7 can be carried out in accordance with the timing chart shown in FIG. 8.

The operator performs a placement step (S10). The operator prepares the preformed balloon 140 and places it in the mold 210 in an open state. Next, as shown in FIG. 4B, the operator drives the drive unit 230 to move the moving unit 220, closes the mold 210, closes the cavity S, and starts the shaping process (S20).

When carrying out the shaping process, the operator first performs heating and pressure treatment (S21). The heating and pressure treatment is performed by closing the mold 210, driving the heating unit 240 to heat the mold temperature of the mold 210 to a shaping temperature (for example, 90° C. or higher and 140° C. or lower), and then adjusting the pressure. The balloon 140 is pressurized (eg, 1 MPa or more and 4 MPa or less) for a shaping time (eg, 30 seconds or more and 120 seconds or less) by driving the section 250.

The operator performs a pressure reduction process (S22) between the heating and pressurizing process and the cooling process. In the balloon 140, only the inner surface 151 of the wing portion 150 is pressed against the inner wall surface 211 of the mold 210 by the depressurization process. Therefore, while the blade portion 150 is shaped as a whole in the heating and pressurizing process, the inner surface 151 is further shaped in the depressurizing process.

The operator performs the cooling process (S23) at the timing when the shaping time has elapsed. Thereby, the mold temperature of the mold 210 is cooled from the shaping temperature to a predetermined 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 for cooling.

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. After joining the balloon 140 to the distal end of the shaft 110, the balloon catheter 100 is manufactured through predetermined processes (such as a blade folding process and a hub attaching process).

[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 shaping process includes heating and pressurizing the mold 210 to a predetermined shaping temperature and pressurizing the balloon 140 while maintaining the shaping temperature for a predetermined shaping time; 210 to a predetermined temperature or lower, and a depressurization process to reduce the pressure to a pressure lower than the pressure at which the balloon 140 is pressurized between the heating and pressurizing treatments.

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.

Further, in the balloon shaping method according to the present embodiment, the depressurization treatment is performed after a predetermined time has elapsed after the balloon 140 is pressurized in the heating and pressurizing treatment, and the depressurization time of the depressurization treatment during the shaping time is It is better to make the pressurization time shorter than the pressurization time.

In the shaping process, the period during which the balloon 140 is most shaped is the period during which the mold 210 is pressed at the shaping temperature, so if the depressurization process is performed at the above timing, the pressurization time of the balloon 140 can be reduced. The entire blade portion 150 can be firmly secured and shaped, and the inner surface 151 of the blade portion 150 can provide a stronger shape.

Further, in the balloon shaping method according to the present embodiment, the pressure reduction treatment is preferably performed to reduce the pressure to below atmospheric pressure.

By performing the pressure reduction treatment below atmospheric pressure, the inner surface 151 of the blade portion 150 is pressed against the inner wall surface 211 of the mold 210. Therefore, the shape of the inner surface 151 side of the blade portion 150 of the balloon 140 is firmly memorized, and when wrapped, the balloon 140 can be made smaller in diameter than conventional products.

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,
151 Inner surface of the blade part,
152 Outer surface of the blade part,
160 hub,
200 Shaping device,
210 Mold,
211 Inner wall surface of mold (contour surface of cavity)
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.

Claims (8)

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 shaping step includes:
heating and pressurizing the balloon by heating the mold temperature of the mold to a predetermined shaping temperature and pressurizing the balloon while maintaining the shaping temperature for a predetermined shaping time;
a cooling process that cools the temperature of the mold to a predetermined temperature or lower;
Between the heating and pressurizing treatment and the cooling treatment, a depressurization treatment that reduces the pressure to a pressure lower than the pressure when pressurizing the balloon;
How to shape balloons, including: 2. The balloon shaping method according to claim 1, wherein the depressurization treatment is performed after a predetermined period of time has elapsed after pressurizing the balloon in the heating and pressurization treatment. 3. The balloon shaping method according to claim 2, wherein the depressurization treatment is performed during the heating and pressurization treatment. 4. The balloon shaping method according to claim 2, wherein the pressure reduction time of the pressure reduction treatment during the shaping time is shorter than the pressurization time of the balloon. The balloon shaping method according to any one of claims 1 to 4, wherein the pressure reduction treatment involves reducing the pressure to below atmospheric pressure. 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,
In the heating and pressure treatment, the shaping temperature is 90° C. or more and 140° C. or less, the pressure of the balloon is 1 MPa or more and 4 MPa or less, and the shaping time is 30 seconds or more and 120 seconds or less. , A method for shaping a balloon according to any one of claims 1 to 7.