JP2007229245A - Tube for catheter and control method of manufacturing device of tube for catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tube for a catheter, whose rigidity is changed in the length direction, and a control method of a manufacturing device of the catheter tube capable of easily manufacturing it. <P>SOLUTION: In the catheter tube in which a reinforcement wire is braided, the density of braiding is changed in the length direction of the tube for the catheter. Also, the composition of a resin layer is also changed in the length direction of the tube for the catheter. By performing inline molding including reinforcement wire braiding especially, the change of the reinforcement wire density is maintained to the last. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a catheter tube and a method for controlling a catheter tube manufacturing apparatus, and more particularly to a catheter tube whose rigidity changes in the length direction and a method for controlling the catheter tube manufacturing apparatus.

  For guiding catheters used in contrast catheters, microcatheters, PCI (Percutaneous Coronary Intervention) or PTCA (Percutaneous Transluminal Coronary Angioplasty), moderate rigidity (bending rigidity) and twisting strength (torsional rigidity) for intravascular insertion operations Is needed.

  The catheter is inserted into the blood vessel, and there is almost no part that is completely straight. In particular, since the tip of the catheter must reach the target position along the guide wire without damaging the blood vessel in the tortuous blood vessel, it is desirable that the catheter tip is soft so as to follow the blood vessel bending. Such a property that is easy to proceed along the bending of the blood vessel is called trackability.

  On the other hand, it is desirable that the proximal portion of the catheter is as hard as possible from the viewpoint of performing operations such as percutaneously inserting the catheter into the blood vessel and advancing it to the target site, or rotating the catheter around the axis. Such a characteristic that the pushing force is easily transmitted to the tip without being attenuated is called pushability, and the response to torsion is called torque.

  Thus, catheters (ie, catheter tubes) are required to have characteristics such as trackability, pushability, and torque characteristics, and it is difficult to satisfy all of these characteristics with a tube having uniform rigidity in the length direction. is there. That is, if the overall rigidity is large, the pushability is good, but the tip is less likely to follow the bending of the blood vessel, and there is a high possibility that the blood vessel wall is damaged or a hole is made in the blood vessel wall. Further, if the overall rigidity is small, the trackability is good, but the pushed force is absorbed by the deformation of the catheter tube itself, specifically, the undulation, and is difficult to transmit to the tip. Further, when the undulation becomes severe, bending (kink) occurs, and there is a possibility that the blood vessel wall is also damaged.

  Therefore, conventionally, in the manufacture of a contrast catheter, a plurality of tubes having different rigidity are connected, and a catheter whose rigidity decreases from the proximal end toward the distal end is manufactured. The catheter / tube whose rigidity changes in this way is called a hardness (rigid) inclined catheter / tube.

  Specifically, the hardness gradient catheter is manufactured as follows. First, a tube containing a so-called blade (reinforcing wire) is prepared as a tube for a near end portion that is required to have the highest rigidity. The braided tube is a tube formed by weaving a reinforcing wire on a tubular first resin layer and further coating it with a second resin layer. Next, a second tube which is not reinforced and is more flexible than the bladed tube is connected to the tip of the bladed tube by thermal fusion or the like. When forming a tube with a blade, a method of providing a flexible part without a reinforcing line by removing the reinforcing line only at the far end and coating the second resin layer may be used. Then, a short resin tube having a rubber elasticity, called a soft tip, is further connected to the tip of the second tube or the portion of the tube with blades where there is no reinforcing wire. Such a hardness gradient catheter is described in Patent Document 1, for example.

  In addition, as another method for manufacturing a hardness gradient catheter, as described in Patent Document 2, a method of extruding a resin tube while switching a plurality of resins having different rigidity, or as described in Patent Document 3 A method for changing the braid density of the reinforcing wire in the length direction has also been proposed.

Japanese Patent Publication No. 3-26617 Japanese Patent No. 3386802 Japanese Patent No. 3310031

  As described in Patent Document 1, a method of connecting a flexible tube without a reinforcing wire to the tip of a tube with a reinforcing wire, or a method of providing a portion without a reinforcing wire in a blade tube is a flexible tube. In addition, there is an advantage that it is easy to form a portion having no reinforcing wire or a pigtail type or a Judkins type. However, on the other hand, since there is no reinforcement, it is weak against twisting force and bending, and tends to cause kinking (collapse of the lumen due to bending). As a result, there is a risk of breakage due to an unreasonable operation during the operation.

  Moreover, the method of using resin switching molding by co-extrusion described in Patent Document 2 and the method of changing the braid density of the reinforcing wire in a stepwise manner described in Patent Document 3 are for producing a conventional tube with a reinforcing wire. Method: (1) The first resin layer is coated on a core wire (mandrel) by an extrusion molding machine and wound up. (2) This is applied to a braiding machine (brader) and applied onto the first resin layer. It is based on a three-stage process that weaves a reinforcing wire and then (3) returns to the extruder and coats the second resin layer, and the hardness gradient is a single factor by the braiding machine or the extruder. This is realized by controlling. That is, the hardness gradient of the completed catheter tube depends only on the hardness change of the resin in the former case, and only on the braid density of the reinforcing wire in the latter case. Therefore, it has been difficult to form a tube that satisfies all of the flexibility, kink resistance, and shape maintenance ability of the tip.

  The present invention has been made in view of such problems of the prior art, and it is easy to provide a catheter tube having characteristics that cannot be realized only by controlling the reinforcing line density and the composition of the resin layer, and such a catheter tube. It aims at providing the control method of the manufacturing apparatus of a catheter tube for manufacturing.

  The above-mentioned object is to provide a hollow tube made of the first resin layer, a reinforcing wire knitted on the first resin layer, and a first wire provided on the first resin layer so as to cover the reinforcing wire. A catheter tube having two resin layers, wherein the braided density of the reinforcing wire and the composition of the second resin layer are changed in the length direction of the catheter tube. Achieved.

  Further, the above-described object is to provide a first resin layer forming means for providing a first resin layer on the traveling core wire, and a reinforcing wire disposed on the first resin layer, which is disposed downstream of the first resin layer forming means. Knitting means for weaving, a second resin layer forming means for disposing a second resin layer so as to cover the reinforcing wire with a resin selected from a plurality of resins and arranged downstream of the knitting means, A method for controlling a catheter tube manufacturing apparatus, comprising a take-up means disposed downstream of a resin layer forming means and taking up a core wire on which a first resin layer, a reinforcing wire, and a second resin layer are formed. At least one of the take-up speed of the take-up means and the braid density of the braid means, and the second resin layer molding means, so that the density of the line and the composition of the second resin layer change in the length direction of the catheter tube. Use resin Also achieved by a control method of the apparatus for manufacturing a catheter tube characterized by having a Gosuru control process.

  With such a configuration, according to the present invention, it is possible to form a catheter tube in which both the reinforcing line density and the resin layer composition change in the length direction. A good catheter can be realized.

Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings.
The catheter tube according to this embodiment is characterized in that the density of the reinforcing wire and the composition of the resin layer both change in the length direction.

  Such a catheter tube of the present embodiment can be manufactured by the procedure as shown in FIG. First, a core wire having an outer diameter matching the inner diameter of the tube to be manufactured is prepared (a). Then, a first resin layer is formed on the core wire by extrusion coating or the like (b). Next, a reinforcing wire such as a stainless steel wire is knitted on the first resin layer (c). Further, a second resin layer is formed thereon by extrusion molding or the like (d), and finally the core wire is removed (e).

  Fig.1 (a) is a perspective view which shows the structural example in the manufacture process of the tube for catheters concerning this embodiment. Specifically, it shows a state before the second resin layer is provided and is cut to a predetermined length. The core wire is not shown.

  As shown to Fig.1 (a), the tube 10 for catheters of this embodiment is provided with the reinforcement wire over the whole length direction. However, the density of the reinforcing wire is not constant and varies in the length direction. More specifically, the density of the reinforcing wire in steps from the first portion 11 to the third portion 13 (the number of picks per unit length). Is rising.

  Furthermore, in the catheter tube 10 of the present embodiment, the composition of the second resin layer provided after the reinforcement wire is knitted as shown in FIG. 1A is also changed stepwise in the length direction of the catheter tube. Yes. In the example shown in FIG. 1B, a configuration in which the second resin layer is formed with three kinds of compositions in accordance with the density change of the reinforcing wire is shown.

  That is, the 2nd resin layer is comprised from the 1st-3rd parts 21-23 formed with the material from which hardness differs, respectively. In the present embodiment, the composition of the first to third portions 21 to 23 of the second resin layer is switched corresponding to the switching of the first to third portions 11 to 13 of the reinforcing wire. It is configured. FIG. 1C is a vertical cross-sectional view of the catheter tube of the present embodiment, and has a cross-sectional structure of a first resin layer 14, a reinforcing wire 15, and a second resin layer 16 from the inside.

  As will be described later, the catheter tube of the present embodiment is manufactured in-line as it is long, and cut into a predetermined length to manufacture individual tubes. Therefore, in the long state, the density of the reinforcing wire and the composition of the second resin layer periodically change as shown in FIG.

  Further, when the density of the reinforcing wire is changed stepwise as in this embodiment, a transition portion is provided so that the density of the reinforcing wire gradually changes to the next stage so that the density does not change suddenly. It is preferable. The length of the transition part that is formed changes gradually or suddenly when the tube take-up speed is changed to a speed that achieves the density of each stage when the rotation speed of the braider that weaves the reinforcing wire is constant. When the rotation speed of the braider is changed, it can be adjusted by changing the rotation speed gradually or abruptly.

FIG. 2 is a diagram illustrating a configuration example of the catheter tube manufacturing apparatus according to the present embodiment.
The manufacturing apparatus 100 of this embodiment is an in-line manufacturing apparatus, and after a long core wire wound around a reel is drawn out, a first resin layer, a reinforcing wire, and a second resin layer are sequentially formed on the core wire. And having a configuration of cutting to a certain size by a cutter.

  Specifically, as shown in FIG. 2, the core wire feeder 110, the first extruder 120, the brader 130, the second extruder 140, the cooling water tank 151, the external shape measuring device 153, and the take-up machine 154 are sequentially arranged from the upstream side. And a cutter 156 are arranged. The overall operation control is performed based on a control program set in advance by the control device 150.

  The core wire feeder 110 sends out the core wire wound around the reel 111 according to the take-up speed of the take-up device 154 described later. The first extruder 120 is means for providing a first resin layer on the core wire, and extrudes a resin having an appropriate property such as a polyamide-based resin to cover the core wire.

  The thickness of the first resin layer is substantially determined by the dimensions of the core wire and the extrusion die (die), but can be controlled by the running speed of the core wire and the amount of extruded resin within a certain range. In other words, if the amount of extrusion is constant, a resin layer is formed that is thinner as the running speed is faster and thicker as the running speed is slower. Therefore, when controlling the density of the reinforcing wire at the take-up speed, the extrusion amount is controlled according to the running speed. There is a need.

  The brader 130 knits a reinforcing wire on the first resin layer formed by the first extruder 120. Here, a horizontal type braider is used according to the running direction of the core wire. The braider has a configuration in which a plurality of bobbins around which a reinforcing wire to be knitted is wound are arranged so as to be movable on the circumference around the running direction of the catheter tube. And while pulling out the reinforcing wire from the bobbin, the bobbin moves on the circumference (hereinafter referred to as rotation of the braider) and intersects with each other, so that the outer periphery of the core wire provided with the first resin layer runs in the center. A reinforcing wire is knitted on the surface (that is, on the first resin layer).

The braiding speed of the brader 130 is variable, and when the traveling speed of the core wire is constant, increasing the bobbin moving speed (rotational speed) increases the density of the reinforcing wire per unit length of the tube and decreases the rotational speed. If it does, the density of a reinforcement wire will fall conversely. Even if the braiding speed is constant, the reinforcing wire density decreases if the take-up speed (traveling speed) of the core wire is increased, and the reinforcing line density increases if the traveling speed is decreased.
And the torsional rigidity and bending rigidity of the tube can be adjusted by weaving the reinforcing wire.

  When the reinforcement line density is increased, the circumferential component is dominant in the vector extending in the length direction of the reinforcement line, which is composed of the tube length direction component and the tube circumferential direction component. As a result, although it greatly contributes to an increase in torsional rigidity, the contribution to bending rigidity is small, and the characteristics of the resin layer become dominant. In addition, when the density of the reinforcing wire increases, the elasticity of the reinforcing wire becomes a support in the radial direction, and the force to maintain the outer shape of the tube increases, so that the shape maintenance performance increases (the lumen is less likely to collapse and the kink resistance performance is reduced). Get better).

  Conversely, when the reinforcement line density is lowered, the vector extending in the length direction of the reinforcement line is greatly affected by the longitudinal component of the tube, and the bending rigidity can be increased. And the ratio which a reinforcement wire contributes about torsional rigidity becomes low, and the characteristic which a resin layer has becomes dominant.

  The rotation speed of the brader 130 and the stop and restart of the rotation can be controlled by the control device 150. Further, the traveling speed of the core wire (taken speed by a take-up machine 154 described later) can also be controlled by the control device 150. As described above, by changing at least one of these, the density of the reinforcing wire can be changed in the length direction of the tube.

  In the conventional manufacturing method, the core wire wound around the reel with the first resin layer provided by an extruder is set on a single brader, and the reinforcing wire is knitted by the brader and is wound around another reel again. Then, this reel is set on the feeder of the extruder for providing the second resin layer, and the second resin layer is formed on the semi-finished product with the reinforcing wire through a non-continuous process. It was.

  However, according to the inventor's study, when the reinforcing wire density is changed in the length direction of the tube, the reinforcing wire is displaced and the density is changed at the time of deformation when being wound around the reel or when it is pulled out. Or slack is likely to occur. For this reason, in the discontinuous manufacturing process once wound on the reel, it is easy to maintain the initially woven reinforcing wire density throughout the period from the time when the reinforcing wire is knitted by the brader until the second resin layer is provided. Not.

  Furthermore, in the present embodiment, not only the reinforcing linear density but also the material of the second resin layer can be changed in the length direction of the tube. And since the switching timing of the resin material is determined in relation to the change in the reinforcing linear density, when the second resin layer is formed after being wound up once, the change in the reinforcing linear density and the switching of the resin material are performed. Positioning is required so that the timing satisfies a predetermined relationship, and considering idling until the extrusion is stabilized, there is a problem that implementation takes unrealistic time, labor, and raw materials.

  Therefore, as shown in FIG. 2, the manufacturing apparatus of the present embodiment is configured such that the semi-finished product that has exited the brader 130 is supplied to the second extruder 140 without being wound on a reel.

  Similar to the first extruder 120, the second extruder 140 of the present embodiment forms a second resin layer on the traveling catheter tube (with a reinforcing wire). However, unlike the first extruder 120 that forms the first resin layer using a single resin material, a plurality of extruders are used so that the second resin layer can be formed using a plurality of types of resin materials. It has a configuration that can be used by switching (three in this embodiment).

FIG. 4 is a diagram illustrating a state in which the configuration from the first extruder 120 to the second extruder 140 in FIG. 2 is viewed from above.
As shown in FIG. 4, the second extruder 140 in the present embodiment includes three extruders 140 a to 140 c and a resin switching machine 145. Each of the extruders 140a to 140c is configured to extrude resins having different physical properties (particularly hardness).

  The resin switching machine 145 has opening / closing means (for example, an electric valve) provided in each of the resin flow paths leading from each of the extruders 140a to 140c to the common crosshead die, and is controlled by the control device 150 described later, Each flow path can be opened and closed independently. A coating die is attached to the tip (downstream side) of the crosshead die body, and a second resin layer is coated on a core line passing through the central axis of the die.

  Therefore, by controlling the resin switching machine 145 to form the second resin layer while switching the resin supplied to the crosshead die, the second resin is composed of a plurality of portions each having different physical properties. Layers can be formed continuously. If a plurality of resin flow paths are opened by the resin switching machine 145, it is possible to form a resin layer having physical properties intermediate between the physical properties of the individual resins by overlapping a plurality of types of resins.

  Similarly to the first resin layer, the second resin layer is formed of a material having appropriate characteristics such as a polyamide-based resin. For example, the plurality of types of resins forming the second resin layer may be polyether block amide (PEBA) having different hardness.

  The catheter tube on which the second resin layer is formed by the second extruder 140 is supplied to the cutter 156 via the cooling water tank 151, the outer diameter measuring device 153, and the take-up device 154 disposed downstream. The control device 150 controls the amount of resin extrusion, resin switching, take-off speed, rotation of the braider, and the like. The control device 150 is a control computer, and controls the operation of the entire manufacturing apparatus based on a control program stored in advance and an instruction from the control panel 155 as a user interface.

  By controlling these molding conditions by the control device 150, it is possible to form the catheter tube while independently changing both the reinforcing linear density by the braider 130 and the resin forming the second resin layer. Become. Therefore, it is possible to realize a catheter having a finer and more complicated hardness gradient than the conventional technique in which only the reinforcing line density or only the resin composition is controlled.

  For example, by changing the reinforcement line density stepwise and switching the hardness of the second resin layer in a section where the reinforcement line density is high, it is possible to give a finer inclination to the hardness of the tip, for example. . It is also possible to switch the hardness of the second resin layer in the section where the reinforcing line density is low, and to increase the hardness in the section on the proximal end side. In addition, as shown in FIG. 3, the hardness of the resin layer is changed in accordance with the stage of the reinforcing line density, so that the characteristics required in individual sections that are difficult to achieve with the reinforcing line density alone are realized. good.

  The cooling water tank 151 cools the catheter tube for which the formation of the second resin layer has been completed, so that it can be taken out. The outer diameter measuring device 153 measures the outer diameter of the catheter tube that has come out of the cooling water tank 151. The control device 150 compares the predetermined target value and allowable error with the actual measurement value measured by the outer diameter measuring device 153, and takes up the winding speed as necessary so that the actual measurement value is included in the reference value range. The feedback control is performed to change the operation conditions related to the thickness of the resin layer, such as the extrusion speed and the extrusion amount.

  The take-up machine 154 takes up the core wire (the catheter tube) on which the resin layer and the reinforcing wire are formed at a predetermined speed according to the control of the control device 150. In this state, since the reinforcing wire is already covered and fixed by the second resin layer, the state at the time when the reinforcing wire density is output from the braider 130 is maintained.

  After the catheter tube thus produced is cut to a predetermined length by the cutter 156, the core tube is pulled out and removed to form the catheter tube. FIG. 3 is a view for explaining the density change of the reinforcing wire of the catheter tube and the cutting position by the cutter 156 according to the embodiment of the present invention. As shown in FIG. 3, the cutting is performed so that one end of the tube becomes a portion 13 where the density of the reinforcing wire is high and the other end becomes a portion 11 where the density of the reinforcing wire is low. By cutting out in this way, the tube can be used without waste.

  Since the catheter tube according to the present embodiment is provided with the entire reinforcing wire, the trackability and the pusher can be obtained by processing the tip (soft tip processing so that the reinforcing wire is not exposed from the cut surface). It is possible to use it as a catheter with good performance.

  As described above, according to the present embodiment, in the catheter tube having the reinforcing wire, by changing both the density of the reinforcing wire and the composition of the resin in the length direction, the characteristics required for each part of the catheter are further improved. It can be realized well. Therefore, a catheter with good performance such as trackability, pushability, and torque can be realized. In addition, since the entire catheter including the distal end has a reinforcing wire, safety risks such as tube tearing can be reduced.

In the present embodiment, the configuration in which the resin is switched for the second resin layer has been described. Of course, the first resin layer can also be an extruder capable of switching the resin in the same manner. In that case, finer rigidity tilt control is possible.
In addition, the types of resin that can be switched are not limited to three types, and may be two types or four or more types, and the ratio of both resins may be stepped at the switching transition portion. It is also possible to realize a continuous hardness gradient by smoothing the change in rigidity (hardness gradient) by changing the speed.

It is a perspective view which shows the structural example of the tube for catheters concerning embodiment of this invention. It is a figure which shows the structural example of the manufacturing apparatus of the catheter tube which concerns on embodiment of this invention. It is a figure explaining the density change of the reinforcement wire | line of the catheter tube which concerns on embodiment of this invention, a composition change of a 2nd resin layer, and a cutting position. It is a figure which shows the state which looked at the structure from the 1st extruder 120 to the 2nd extruder 140 in FIG. 2 from the top. It is a figure explaining the manufacturing method of the conventional catheter tube.

Claims (6)

A hollow tube made of a first resin layer;
A reinforcing wire knitted on the first resin layer;
A catheter tube having a second resin layer provided on the first resin layer so as to cover the reinforcing wire,
The catheter tube, wherein the braided density of the reinforcing wires and the composition of the second resin layer are changed in the length direction of the catheter tube.   Furthermore, the composition of the said 1st resin layer is changing in the length direction of the said tube for catheters, The catheter tube of Claim 1 characterized by the above-mentioned. First resin layer forming means for providing a first resin layer on the traveling core wire;
A knitting means that is arranged downstream of the first resin layer forming means and that knits a reinforcing wire on the first resin layer;
A second resin layer forming unit disposed downstream of the braiding unit and providing a second resin layer so as to cover the reinforcing wire with a resin selected from a plurality of resins;
A take-off means that is arranged downstream of the second resin layer forming means and takes up a core wire on which the first resin layer, the reinforcing wire, and the second resin layer are formed;
A method for controlling a catheter tube manufacturing apparatus comprising:
At least one of the take-up speed of the take-up means and the braid density of the braid means, so that the density of the reinforcing wires and the composition of the second resin layer change in the length direction of the catheter tube; A control method for a catheter tube manufacturing apparatus, comprising a control step of controlling a resin used by the resin layer forming means.   The apparatus for producing a catheter tube according to claim 3, wherein the braiding means is a horizontal type braider, and the braiding density is controlled by controlling a rotation speed of the horizontal type brader in the control step. Control method. The second resin layer molding means is
Multiple extruders;
A head common to the plurality of extrusion molding machines;
Opening and closing means for opening and closing a resin flow path leading to the head from the plurality of extrusion molding machines,
The method for controlling a catheter tube manufacturing apparatus according to claim 3 or 4, wherein the resin used by the second resin layer forming means is controlled by controlling the opening and closing means in the control step. . The first resin layer molding means includes:
Multiple extruders;
A head common to the plurality of extrusion molding machines;
Opening and closing means for opening and closing a resin flow path leading to the head from the plurality of extrusion molding machines,
The composition of the first resin layer is also changed in the length direction of the catheter tube by controlling the opening / closing means of the first resin layer forming means in the control step. A method for controlling a catheter tube manufacturing apparatus according to any one of claims 3 to 5.