JP2013090717A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter that can control the inconvenience that the visibility of imaging decreases.SOLUTION: The catheter 10 is provided with a catheter body 11 and a hub 12. The catheter body 11 is provided with a tube body 15, and an imaging coil 16 embedded in the tube body 15. The imaging coil 16 is formed such that one wire 27 is wound around the axial direction of the tube body 15 like a spiral shape. The imaging coil 16 includes a dense winding section 21 that functions as an imaging marker, and a sparse winding section 22 that is disposed continuously to the dense winding section 21 and whose winding pitch of the wire 27 is larger than that of the dense winding section 21. A pitch change region 26 in which the winding pitch of the wire 27 is gradually enlarged from the winding pitch of the dense winding section 21 is disposed while parting from the dense winding section 21 in a predetermined consecutive range from the dense winding section 21 in the sparse winding section 22.

Description

  The present invention relates to a catheter.

  A catheter is a hollow medical device that is inserted into a body cavity, tube, blood vessel, or the like, and is used for, for example, suctioning a thrombus, securing a passage of a blood vessel in an obstructed or stenotic state, and injecting an angiographic contrast agent. Such a catheter is provided with a contrast marker at the tip or the like, and the position of the catheter inserted into the body can be grasped from outside the body by this contrast marker.

  As this type of contrast marker, for example, Patent Document 1 discloses a contrast coil in which a single wire having radiopacity is spirally wound between an inner layer and an outer layer of a catheter tube made of a synthetic resin. It is disclosed. Such a contrast coil includes a densely wound portion that functions as a contrast marker and a loosely wound portion having a spiral pitch larger than that of the densely wound portion, and the densely wound portion and the loosely wound portion are alternately arranged in the axial direction. It is comprised by. When manufacturing a catheter tube having such a contrast coil, first, the contrast coil is formed by winding a wire around the outer periphery of the inner tube constituting the inner layer, and then the outer periphery of the inner tube so as to cover the contrast coil. An outer layer is formed on the substrate.

JP 2007-236472 A

  By the way, in the above-mentioned contrast coil, since the winding pitch of the wire material is greatly changed at the boundary between the densely wound portion and the loosely wound portion, stress concentration is likely to occur at the boundary. Therefore, for example, during the manufacture of a catheter tube, when the contrast coil is formed on the outer peripheral side of the inner tube and the contrast coil is covered with the outer layer, that is, while the contrast coil is exposed, If the tube is bent, stress concentration occurs at the boundary portion of the contrast coil, and there is a possibility that the wire rod frays at the boundary portion. In that case, there is a concern that the length of the densely wound portion (length in the axial direction) is shortened and the visibility of contrast is reduced. Further, it is conceivable that the winding diameter of the contrast coil increases due to fraying of the wire. In this case, the outer layer may become thin or the wire may be exposed from the outer layer at the portion where the winding diameter is increased.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a catheter capable of suppressing the disadvantage that the contrast visibility is lowered in a configuration including a contrast coil.

  In order to solve the above-mentioned problems, a catheter according to a first aspect of the present invention is a contrast medium formed by spirally winding a single wire rod provided in the resin tube and in the axial direction of the resin tube. A coil, and the contrast coil includes a densely wound portion that functions as a contrast marker, and a coarsely wound portion that is provided continuously with the densely wound portion and has a larger winding pitch of the wire than the densely wound portion. And a fraying suppression portion that suppresses fraying of the wire rod at a boundary portion between the densely wound portion and the coarsely wound portion is provided in the contrast coil.

  According to the present invention, it is possible to suppress the length of the densely wound portion functioning as a contrast marker from being shortened by suppressing fraying of the wire at the boundary between the densely wound portion and the coarsely wound portion in the contrast coil. Thereby, the fall of the visibility of contrast can be controlled. Moreover, it can suppress that the winding diameter of the contrast coil becomes large in the frayed part by suppressing fraying of a wire. Therefore, in the configuration in which the imaging coil is embedded in the resin tube, it is possible to suppress the disadvantage that the resin layer outside the frayed wire becomes thin or the frayed wire is exposed from the resin layer.

  The catheter according to a second aspect of the present invention is the catheter according to the first aspect, wherein the wire is wound around the rough winding portion in a predetermined range continuous from the dense winding portion as the fray suppressing portion as the flanking portion is separated. A pitch change region in which the pitch is gradually increased from the winding pitch of the densely wound portion is provided.

  According to the present invention, the winding pitch of the wire gradually increases from the winding pitch of the densely wound portion as it moves away from the densely wound portion in a predetermined range (pitch change region) continuous from the densely wound portion in the coarsely wound portion. Therefore, it is possible to alleviate stress concentration at the boundary between the densely wound portion and the coarsely wound portion. Thereby, fraying of the wire at the boundary can be suppressed. In addition, since the pitch change region is provided in the adjacent portion between the densely wound portion and the coarsely wound portion, it is possible to suppress local changes in rigidity at the boundary portion between the densely wound portion and the roughly wound portion. Therefore, the effect of the first invention can be obtained while suppressing a decrease in the kink resistance of the catheter.

  A catheter of a third invention is the catheter according to the first or second invention, wherein the resin tube has a coil inner layer formed inside the contrast coil as a resin layer, and the contrast enhancement unit as the fray suppression unit An adhering portion for adhering the boundary portion of the coil to the inner layer of the coil is provided.

  According to the present invention, the boundary between the densely wound portion and the coarsely wound portion in the contrast coil is fixed to the outer peripheral surface of the coil inner layer disposed inside the contrast coil in the resin layer of the resin tube. The fraying of the wire at the boundary can be suppressed.

  A catheter of a fourth invention is the catheter according to any one of the first to third inventions, wherein the resin tube has a coil inner layer formed inside the contrast coil as a resin layer, The boundary portion is provided with a biting portion in which the amount of biting of the wire into the coil inner layer is larger than the portion other than the boundary portion of the contrast coil as the fray suppression portion. .

  According to the present invention, the wire rod of the contrast coil bites into the outer peripheral surface of the coil inner layer at the boundary portion between the densely wound portion and the coarsely wound portion more greatly than the portion other than the boundary portion. The degree of fixation between the wire and the coil inner layer can be increased. Thereby, fraying of the wire at the boundary portion can be suppressed.

  The catheter according to a fifth aspect of the present invention is the catheter according to any one of the first to fourth aspects, wherein the contrast coil includes a plurality of the closely wound portions disposed in the axial direction of the resin tube, and each of the closely wound portions. And the coarsely wound portion provided so as to connect the loosely wound portions, and the fray suppressing portion is provided for each boundary portion between the coarsely wound portion and each of the closely wound portions.

  When contrast markers (closely wound portions) are arranged at a plurality of locations in a resin tube, it is conceivable to form a contrast coil having a plurality of closely wound portions using a single wire. In that case, between the plurality of densely wound portions, a coarsely wound portion is provided to connect both of them, and at each boundary portion between the coarsely wound portion and the densely wound portions on both sides thereof, the fraying of the wire respectively Problems can arise. Therefore, in the present invention, a fray suppression unit is provided for each boundary portion of the contrast coil. Thereby, since it can suppress that length becomes short about each closely wound part, the fall of visibility can be suppressed suitably in this contrast coil. Moreover, since it can suppress that the space | interval of each closely wound part becomes large by suppressing that the length of each closely wound part becomes short, it uses the space | interval of each closely wound part as a reference (reference length). It is possible to prevent the measurement accuracy from being lowered when measuring the length of the lesioned part.

  The catheter according to a sixth aspect of the present invention is the catheter according to any one of the first to fifth aspects, wherein the rough winding portion is disposed at least one of both end portions of the contrast coil in the axial direction of the resin tube. It is characterized by.

  By the way, it is considered that the rigidity is high at the site where the contrast coil is provided in the catheter, whereas the rigidity is low at the site where the contrast coil is not provided. In this case, the rigidity of the catheter greatly changes at the end of the contrast coil, and there is a concern in terms of kink resistance. In this respect, in the present invention, since the rough winding portion is arranged at the end of the contrast coil, the change in the rigidity of the catheter can be suppressed, and as a result, the decrease in kink resistance can be suppressed.

  According to a seventh aspect of the catheter of the sixth aspect, in the coarse winding portion disposed at the end in the axial direction in the contrast coil, the wire rod is separated from the dense winding portion adjacent to the coarse winding portion. The winding pitch of is increased.

  According to the present invention, since the change in the rigidity of the catheter at the end of the contrast coil can be further suppressed, the decrease in kink resistance can be further suppressed.

Sectional drawing which expands and shows the front end side of a catheter main body. The side view which shows schematic structure of a catheter. The figure which shows a mode that a contrast coil is formed. The time chart which shows the time-dependent change of the moving speed of an inner pipe. Sectional drawing which shows the front end side of the catheter main body in other embodiment. Sectional drawing which shows the front end side of the catheter main body in other embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. First, a schematic configuration of the catheter 10 will be described with reference to FIG. FIG. 2 is a side view showing a schematic configuration of the catheter 10.

  As shown in FIG. 2, the catheter 10 includes a tube-shaped catheter main body 11 and a hub 12 attached to the proximal end portion of the catheter main body 11.

  A guide wire G is inserted into the lumen 13 (see FIG. 1) of the catheter body 11 when the catheter 10 is inserted into a blood vessel or the like. The lumen 13 is used as a passage for a contrast medium, a chemical liquid, a cleaning liquid, and the like. The hub 12 functions as an insertion port for the guide wire G into the lumen 13, an injection port for a contrast medium, a chemical solution, a cleaning solution, and the like into the lumen 13, and also functions as a grip portion when operating the catheter 10. To do. The length of the catheter 10 is 1 m to 2 m.

  Next, the configuration of the distal end side (distal end side) of the catheter body 11 will be described with reference to FIG. FIG. 1 is an enlarged cross-sectional view of the distal end side of the catheter body 11.

  As shown in FIG. 1, the catheter body 11 includes a tube body 15 formed in a tubular shape from a synthetic resin, and a contrast coil 16 embedded in the tube body 15. The tube body 15 has a multilayer structure in which a plurality of types of resins are laminated. Specifically, an inner layer 17 that forms the inner peripheral surface of the tube body 15 (catheter body 11), and the tube body 15 And an outer layer 18 forming an outer peripheral surface. Here, the tube body 15 corresponds to a resin tube, and the inner layer 17 corresponds to a coil inner layer.

  The inner layer 17 is formed of a synthetic resin, for example, using polytetrafluoroethylene (PTFE) as a low friction material. As a result, when a guide wire or other catheter is inserted into the lumen 13 of the catheter body 11, the sliding resistance generated between the inserted guide wire or other catheter and the inner peripheral surface of the catheter body 11 is reduced. It can be reduced. However, a low friction material other than PTFE may be used as a material for forming the inner layer 17, and other fluorine-based resins such as polyvinylidene fluoride and perfluoroalkoxy resin may be used. Moreover, materials other than fluororesin may be used, for example, polyamide, polyimide, high-density polyethylene, or the like may be used.

  The outer layer 18 is formed of a synthetic resin, for example, a polyamide resin. However, the material forming the outer layer 18 is not necessarily limited to the polyamide resin, and for example, polyimide, polyimide elastomer, polypropylene, polyethylene, polyethylene terephthalate, polyurethane, silicon rubber, or the like may be used. In addition, you may give the hydrophilic coating or hydrophobic coating for improving the slippery on the outer peripheral surface of the catheter main body 11 (outer layer 18).

  The contrast coil 16 is configured to be visible from outside the body under X-ray projection. The contrast coil 16 is formed by winding a single wire 27 spirally around the axis of the tube body 15. The contrast coil 16 is embedded in the distal end side (distal end side) of the tube body 15, and specifically, embedded in the outer layer 18 with its inner peripheral side being in contact with the outer peripheral surface of the inner layer 17. . In addition, the winding diameter of the contrast coil 16 is constant throughout the axial direction of the contrast coil 16.

  The wire rod 27 is made of a metal material having radiopacity. As the material of the wire rod 27, for example, a metal material containing gold, silver, platinum, iridium or the like can be used. Moreover, the wire diameter of the wire 27 is constant over the entire length direction, and the wire diameter is set to 0.02 mm to 0.03 mm, for example.

  The contrast coil 16 includes a densely wound portion 21 and a coarsely wound portion 22 that are different in the winding pitch of the wire 27 (specifically, the length by which the wire 27 is displaced in the axial direction of the tube body 15 per turn of the wire 27). . Specifically, the contrast coil 16 includes a plurality (two in FIG. 2) of densely wound portions 21 and a plurality of (three in FIG. 2) coarsely wound portions 22 having a winding pitch larger than that of the closely wound portions 21. These densely wound portions 21 and coarsely wound portions 22 are alternately arranged in the axial direction.

  The densely wound portion 21 is a portion that functions as a contrast marker in the contrast coil 16. That is, the present contrast coil 16 grasps the position of the distal end side of the catheter body 11 by confirming the position of the tightly wound portion 21 under X-ray fluoroscopy. In the densely wound portion 21, the winding pitch of the wire rod 27 is constant throughout the axial direction, and specifically, the winding pitch of the wire rod 27 is the same as the wire diameter of the wire rod 27. In this case, in the densely wound portion 21, the wire rods 27 (in detail, the winding portions) adjacent in the axial direction are in contact with each other. Each closely wound portion 21 has the same length in the axial direction.

  Instead of bringing the wire rods 27 adjacent to each other in the axial direction in the densely wound portion 21, they may be close to each other with a predetermined minute gap therebetween. For example, by setting the winding pitch of the wire rod 27 to be larger than the wire diameter of the wire rod 27 and not more than twice the wire diameter of the wire rod 27, the adjacent wire rods 27 can be brought close to each other.

  The coarsely wound portion 22 includes an intermediate coarsely wound portion 22a provided between the densely wound portions 21 in the contrast coil 16, and two end roughly wound portions 22b provided at both end portions in the axial direction of the contrast coil 16. Is provided. The intermediate coarsely wound portion 22a includes a constant pitch region 25 formed in the intermediate portion in the axial direction and two pitch change regions 26 formed on both sides of the constant pitch region 25. In the constant pitch region 25, the winding pitch of the wire rod 27 is constant over the entire axial direction, and the winding pitch is larger than the winding pitch in the densely wound portion 21.

  On the other hand, in each pitch change region 26, the winding pitch of the wire 27 changes in the axial direction. In each pitch change region 26, the winding pitch of the wire rod 27 changes in a range larger than the winding pitch in the densely wound portion 21 and smaller than the winding pitch in the constant pitch region 25. Specifically, in each pitch change region 26, the winding pitch of the wire rod 27 gradually decreases as the distance from the constant pitch region 25 increases. In other words, in each pitch change region 26, the winding pitch of the wire 27 gradually increases from the winding pitch of the densely wound portion 21 as the distance from the adjacent closely wound portion 21 increases. Each is getting bigger. Here, the pitch change region 26 corresponds to a fray suppression unit.

  In each end rough winding part 22b, the winding pitch of the wire rod 27 increases as the distance from the adjacent dense winding part 21 increases. Specifically, the winding pitch gradually increases as the distance from the adjacent dense winding part 21 increases (more in detail). The winding pitch is larger (for each winding of the wire 27). In this case, the entire region of the end rough winding portion 22b corresponds to a “pitch change region”. Further, in each end rough winding portion 22 b, the end opposite to the dense winding portion 21 is a free end 29, and this free end 29 corresponds to the axial end of the contrast coil 16. The free end 29 of each end rough winding portion 22b, that is, both end portions of the contrast coil 16 (both end portions of the wire rod 27) are joined to the outer peripheral surface of the inner layer 17 of the tube body 15 by thermal welding. Thereby, it is suppressed that the contrast coil 16 is displaced with respect to the tube body 15. Further, since the contrast coil 16 is embedded in the tube body 15, the position shift of the contrast coil 16 is also suppressed from that point.

  Next, the manufacturing procedure of the catheter body 11 will be described with reference to FIG. FIG. 3 is a diagram showing how the contrast coil 16 is formed.

  First, as shown in FIG. 3, a coil forming step is performed in which the contrast coil 16 is formed by spirally winding the wire 27 around the outer peripheral surface of the inner tube 35 constituting the inner layer 17. In this step, the wire 27 is wound around the axis while moving the inner tube 35 in the axial direction while feeding the wire 27 from the wire supply device 30 (specifically, the nozzle 30a). This is done by wrapping around the inner tube 35. In this case, the moving speed of the inner tube 35 is adjusted so that the wire rod 27 is wound at a predetermined winding pitch. The movement of the inner tube 35 and the speed adjustment thereof are performed using a dedicated moving device (not shown). Here, it is assumed that the wire rod 27 is wound from the distal end side to the proximal end side of the inner tube 35 by moving the inner tube 35 with the distal end side in the axial direction as the head.

  Next, the adjustment contents when adjusting the moving speed of the inner tube 35 to wind the wire rod 27 at a predetermined winding pitch will be described. Hereinafter, the movement speed adjustment of the inner tube 35 will be described with reference to FIG. FIG. 4 is a time chart showing the change with time of the moving speed of the inner tube 35. This speed adjustment is realized by control by a controller of the moving device. Further, the rotation speed of the inner tube 35 is kept constant.

  As shown in FIG. 4, first, movement and rotation (in the axial direction) of the inner tube 35 is started at time t0. Thereby, winding of the wire 27 around the inner tube 35 is started. At this time, the moving speed of the inner tube 35 is set to V1. Before the time t0, the wire rod 27 is temporarily fixed in contact with the outer peripheral surface of the inner tube 35 in advance.

  From time t1 to time t2, the moving speed of the inner tube 35 is gradually decreased from V1 to V2 (V1> V2). Specifically, the moving speed of the inner tube 35 is decreased in proportion to the elapsed time from the time t1. In this case, the wire rod 27 is wound around the inner tube 35 such that the winding pitch becomes smaller from the distal end side toward the proximal end side. Thereby, the edge part rough winding part 22b of the front end side in the contrast coil 16 is formed.

  From time t2 to t3, the moving speed of the inner tube 35 is kept constant, specifically, V2. In this case, the wire rod 27 is wound around the inner tube 35 at a constant winding pitch. Thereby, the densely wound portion 21 on the distal end side in the contrast coil 16 is formed.

  From time t3 to t4, the moving speed of the inner tube 35 is gradually increased from V2 to V1. Specifically, the moving speed of the inner tube 35 is increased in proportion to the elapsed time from time t3. In this case, the wire rod 27 is wound around the inner tube 35 such that the winding pitch increases from the distal end side toward the proximal end side. As a result, a pitch change region 26 on the distal end side in the intermediate coarse winding portion 22a of the contrast coil 16 is formed.

  From time t4 to t5, the moving speed of the inner tube 35 is kept constant, specifically V1. In this case, the wire rod 27 is wound around the inner tube 35 at a constant winding pitch. Thereby, the constant pitch region 25 in the intermediate rough winding portion 22a is formed.

  From time t5 to t6, the moving speed of the inner tube 35 is decreased from V1 to V2. Specifically, the moving speed of the inner tube 35 is decreased in proportion to the elapsed time from time t5. In this case, the wire rod 27 is wound around the inner tube 35 such that the winding pitch becomes smaller from the distal end side toward the proximal end side. As a result, the base end side pitch change region 26 in the intermediate rough winding portion 22a is formed. Thus, the intermediate coarse winding portion 22a is formed.

  From time t6 to t7, the moving speed of the inner tube 35 is kept constant (V2), and thereafter the moving speed of the inner tube 35 increases from V2 to V1 from time t7 to t8. As a result, a base end side densely wound portion 21 and a base end side rough winding portion 22b in the contrast coil 16 are formed. Thereafter, the movement and rotation of the inner tube 35 stops at time t9. Thereby, winding of the wire 27 around the inner tube 35 is completed.

  Thereafter, the winding portion of the wire rod 27 wound between the time t0 and t1 and the time t8 to t9 in the winding of the wire rod 27, that is, the surplus portion is cut. Thereby, the contrast coil 16 is formed. Thereafter, both ends of the contrast coil 16 in the axial direction are joined to the outer peripheral surface of the inner tube 35 by thermal welding. Thereby, it is possible to prevent the contrast coil 16 from being displaced with respect to the inner tube 35 in subsequent steps (for example, a covering step described later).

  Next, a covering step of covering the contrast coil 16 from the outer peripheral side with an outer tube (not shown) constituting the outer layer 18 is performed. In this case, the outer peripheral surface of the inner tube 35 and the inner peripheral surface of the outer tube are joined by heat welding. Thereby, the tube main body 15 composed of the inner layer 17 and the outer layer 18 is formed, and the contrast coil 16 is embedded in the tube main body 15. That is, the catheter body 11 is formed. Thereafter, the manufacturing of the catheter 10 is completed by performing a process of connecting the hub 12 to the catheter body 11 as a post process.

  In the above description, the wire rod 27 is wound at a predetermined winding pitch by adjusting the moving speed of the inner tube 35 while keeping the rotation speed of the inner tube 35 constant. The wire rod 27 may be wound at a predetermined winding pitch by adjusting the rotational speed of the inner tube 35 while keeping the moving speed of the inner tube 35 constant. Further, the wire rod 27 may be wound at a predetermined winding pitch by adjusting both the moving speed and the rotating speed of the inner tube 35.

  Next, a method for using the catheter 10 will be described.

  First, a guiding catheter is inserted through a sheath introducer inserted into a blood vessel. Next, the guide wire G is inserted into the lumen 13 of the catheter 10 and the guiding catheter, and inserted to a position beyond the treatment target site or the inspection target site. Subsequently, the catheter 10 is inserted along the guide wire G to a treatment target site or a test target site while performing a push-pull or twist operation. At this time, the distal end portion of the catheter body 11 is introduced to the treatment target site or the test target site while confirming the position of the densely wound portion 21 of the contrast coil 16 under X-ray projection. When the distal end of the catheter body 11 reaches a treatment target site or a test target site, a medical solution or a contrast medium is injected to perform treatment or inspection.

  As described above, the contrast coil 16 has the rough winding portions 22 (end portion rough winding portions 22b) disposed at both ends in the axial direction thereof. It is suppressed that the rigidity changes extremely. Specifically, since the winding pitch of the wire 27 is increased as the distance from the densely wound portion 21 is increased at each end portion coarsely wound portion 22b, the change in rigidity is smoothed at both ends of the contrast coil 16. . Further, since the intermediate coarsely wound portion 22a is provided with two pitch change regions 26 adjacent to the densely wound portions 21, respectively, the catheter main body is located at the boundary between the intermediate coarsely wound portion 22a and each closely wound portion 21. 11 is suppressed from changing greatly. As a result, in this catheter body 11, a decrease in kink resistance due to the installation of the contrast coil 16 is suppressed. Therefore, when the catheter body 11 is inserted into the body, inconveniences such as bending of the catheter body 11 at the installation site of the contrast coil 16 can be suppressed.

  The catheter 10 is mainly passed through a blood vessel as described above, and is used for treating or examining the inside of the blood vessel. However, in the living body such as a ureter other than the blood vessel or a digestive tract, It can also be applied to “body cavity”.

  As mentioned above, according to the structure of this embodiment explained in full detail, the following outstanding effects are acquired.

  For a predetermined range that is continuous from the densely wound portion 21 in the coarsely wound portion 22 (specifically, the pitch changing region 26 in the intermediate coarsely wound portion 22a and the entire area in the end coarsely wound portion 22b). The winding pitch of the wire rod 27 was gradually increased from the winding pitch of the densely wound portion 21 as the distance from the portion 21 increased. In this case, since stress concentration occurring at the boundary between the densely wound portion 21 and the coarsely wound portion 22 can be alleviated, fraying of the wire 27 at the boundary can be suppressed. Thereby, it can suppress that the length of the closely wound part 21 which functions as a contrast marker becomes short, and can suppress the fall of the visibility of contrast. Further, by suppressing fraying of the wire rod 27, it is possible to suppress the winding diameter of the contrast coil 16 from increasing due to such fraying. Therefore, inconveniences such as thinning of the outer layer 18 at a portion where the wire 27 is frayed or exposure of the frayed wire 27 from the outer layer 18 can be suppressed.

  In the contrast coil 16 having a plurality of densely wound portions 21 arranged apart from each other in the axial direction of the tube main body 15 and a coarsely wound portion 22 (intermediate coarsely wound portion 22a) connecting the densely wound portions 21 to each other, In the coarsely wound portion 22a, a pitch change region 26 is provided for each boundary portion with each densely wound portion 21. In this case, since the fraying of the wire rod 27 can be suppressed at the boundary between the intermediate coarsely wound portion 22a and each densely wound portion 21, it is possible to suppress the length of each closely wound portion 21 from being shortened. Thereby, since it can suppress that the space | interval of each closely wound part 21 becomes large, when measuring the length etc. of the lesioned part in a body on the basis of the space | interval of closely wound parts 21 (reference | standard length), It can suppress that measurement accuracy falls.

  The boundary between the densely wound portion 21 and the coarsely wound portion 22 refers to the end of the densely wound portion 21 on the coarsely wound portion 22 side and the roughly wound portion at the portion where the closely wound portion 21 and the roughly wound portion 22 are continuous. 22 and an end portion on the close winding portion 21 side.

  The present invention is not limited to the above embodiment, and may be implemented as follows, for example.

  (1) In the above-described embodiment, the pitch change region is provided as a fray suppressing portion that suppresses fraying of the wire rod 27 at the boundary between the densely wound portion 21 and the coarsely wound portion 22 in the contrast coil 16. Is not necessarily limited to this. For example, by fixing the boundary portion between the densely wound portion 21 and the coarsely wound portion 22 in the contrast coil 16 to the outer peripheral surface of the inner layer 17 (corresponding to the inner layer of the coil) by thermal welding, the fraying of the wire 27 at the boundary portion is prevented. It may be suppressed. In this case, it is possible to form the entire area of the rough winding portion 22 at a constant winding pitch (equal pitch). As a method for fixing the boundary portion of the contrast coil 16 to the inner layer 17, other methods such as adhesion using an adhesive can be adopted in addition to thermal welding.

  (2) In the contrast coil 16, a biting portion in which the amount of biting into the inner layer 17 of the wire rod 27 is larger than the portion other than the boundary portion is provided at the boundary portion between the densely wound portion 21 and the coarsely wound portion 22. You may suppress the fray of the wire 27 in the said boundary part. For example, in the contrast coil 33 shown in FIG. 5, the amount of the wire 27 that bites into the inner layer 17 is larger at the end of the densely wound portion 21 on the coarsely wound portion 22 side than at the portion other than the end portion. That is, the end portion of the closely wound portion 21 corresponds to the biting portion 38. In this case, the winding force of the wire rod 27 is larger at the end portion of the densely wound portion 21 than the portion other than the end portion, and the fixing degree between the wire rod 27 and the inner tube 35 (inner layer 17) is increased. . Thereby, fraying of the wire rod 27 at the end portion of the densely wound portion 21 is suppressed.

  As a method for increasing the amount of biting into the inner tube 35 (inner layer 17) of the wire rod 27 at the boundary portion between the densely wound portion 21 and the coarsely wound portion 22 in the contrast coil 16, for example, the wire rod 27 is connected to the inner tube 35. When winding, the timing (for example, time t2, t3, t6 in FIG. 4) which switches from winding of the densely wound portion 21 (or coarsely wound portion 22) to winding of the coarsely wound portion 22 (or densely wound portion 21) by the wire rod 27 , T7), it is conceivable to temporarily stop the feeding of the wire 27 by the wire feeding device 30 or to limit the feeding amount of the wire 27. In this case, it is possible to temporarily generate a large tension (tension) to the wire 27 by temporarily stopping or restricting the feeding of the wire 27 even though the inner tube 35 is rotating, Thereby, the winding force of the wire 27 can be increased locally, that is, at the boundary portion of the contrast coil 16. Therefore, the amount of biting into the inner layer 17 of the wire rod 27 can be made larger at the boundary portion of the contrast coil 16 than at portions other than the boundary portion.

  (3) In the contrast coil 16 formed by one wire rod 27, the wire rod 27 is wound twice inside and outside at the boundary between the densely wound portion 21 and the coarsely wound portion 22 in the contrast coil 16. You may provide the overlapping part which 27 mutually overlaps in radial direction. In this case, in the overlapping portion, fraying on the inner wire rod 27 portion, that is, the wire rod 27 portion wound around the outer peripheral surface of the inner layer 17, can be suppressed by the outer wire rod 27 portion. Therefore, fraying of the wire 27 at the boundary portion of the contrast coil 16 can be suppressed.

  (4) Any one of a plurality of fray suppression units in total including four types of fray suppression units including the fray suppression unit (that is, the pitch change region) of the above embodiment and each of the fray suppression units of (1) to (3) above. May be used in combination. By doing so, fraying of the wire rod 27 at the boundary portion between the densely wound portion 21 and the coarsely wound portion 22 can be further suppressed.

  (5) The fray suppression part does not necessarily need to be provided corresponding to each boundary part between the densely wound part 21 and the coarsely wound part 22 in the contrast coil 16, and corresponds to a part of each boundary part. May be provided. For example, in the configuration of the above-described embodiment, it is conceivable that any one of the pitch change regions 26 of the intermediate coarse winding portion 22a is a constant pitch region.

  (6) For example, in the pitch change region 26 of the intermediate rough winding portion 22a, the winding pitch of the wire 27 is increased every two or three turns as the wire 27 is separated from the dense winding portion 21 adjacent to the change region 26. May be. Even in this case, stress concentration generated at the boundary between the densely wound portion 21 and the intermediate coarsely wound portion 22a in the contrast coil 16 can be alleviated, so that fraying of the wire 27 at the boundary can be suppressed.

  (7) In the above embodiment, the winding pitch of the wire rod 27 may be constant (that is, equal pitch) in at least one of the end rough winding portions 22b of the contrast coil 16. Even in this case, a change in rigidity at the end of the contrast coil 16 can be suppressed, and a decrease in kink resistance can be suppressed. However, considering the suppression of fraying of the wire 27 at the boundary between the end coarsely wound portion 22b and the densely wound portion 21, the winding pitch of the wire 27 at the end coarsely wound portion 22b as in the above embodiment. It is desirable to increase the distance from the densely wound portion 21. Further, in the contrast coil 16, either one or both of the end rough winding portions 22b may be omitted. However, in view of the decrease in kink resistance at the end of the contrast coil 16, it is desirable to provide the end rough winding portion 22b.

  (8) In the above-described embodiment, the present invention is applied to the contrast coil 16 including two closely wound portions 21 (three coarsely wound portions 22). However, as illustrated in FIG. The present invention may be applied to the contrast coil 40 including three or more 21. Further, as shown in FIG. 6B, the present invention may be applied to a contrast coil 50 having only one closely wound portion 21.

  (9) By the way, in order to reinforce the tube main body 15 made of a resin layer, a braided body formed by braiding reinforcing wires may be embedded in the tube main body 15. Therefore, the present invention may be applied to the tube main body 15 in which such a braided body is embedded. For example, the braided body is provided on the outer peripheral side of the inner layer 17 in the tube main body 15 and is arranged in a state of being embedded in the outer layer 18. The braided body is formed by knitting a wire made of a material having X-ray permeability into a mesh shape. In this case, the contrast coil 16 has radiopacity, whereas the braided body has no radiopacity. The contrast coil 16 is formed by winding the wire 27 around the outer periphery of the braided body. The imaging coil 16 is arranged in a state of being embedded in the outer layer 18. In such a configuration, the inner layer 17, the braided body, the contrast coil 16, and the outer layer 18 are arranged in this order from the inner side to the outer side in the radial direction (wall thickness direction) on the peripheral wall portion of the catheter body 11. Even in such a configuration, the same effects as in the above embodiment can be obtained. In addition, in the peripheral wall part of the catheter main body 11, you may arrange | position in order of the inner layer 17, the contrast coil 16, a braided body, and an outer layer toward the outer side from radial inside.

  (10) Some catheters are wound with the contrast coil exposed on the outer peripheral surface of the resin tube. In such a catheter, when it is inserted into a blood vessel and used and bent following a bent blood vessel, stress concentration occurs at the boundary portion between the densely wound portion and the coarsely wound portion in the contrast coil, and the wire rod 27 is formed at the boundary portion. There may be cases where fraying occurs. Therefore, the present invention may be applied to such a catheter.

  DESCRIPTION OF SYMBOLS 10 ... Catheter, 11 ... Catheter main body, 15 ... Tube main body, 16 ... Contrast coil, 21 ... Close winding part, 22 ... Coarse winding part, 26 ... Pitch change area | region, 27 ... Wire.

Claims (7)

A resin tube;
An imaging coil provided on the resin tube and formed by spirally winding one wire in the axial direction of the resin tube;
With
The contrast coil includes a densely wound portion that functions as a contrast marker, and a coarsely wound portion that is provided continuously with the densely wound portion and has a larger winding pitch of the wire than the densely wound portion,
The catheter, wherein the contrast coil is provided with a fray suppressing portion that suppresses fraying of the wire at a boundary portion between the densely wound portion and the coarsely wound portion.   In the rough winding portion, the winding pitch of the wire gradually increases from the winding pitch of the densely wound portion as the fray suppressing portion within a predetermined range continuing from the densely wound portion as the fray suppressing portion. The catheter according to claim 1, wherein a pitch change region is provided. The resin tube has a coil inner layer formed inside the contrast coil as a resin layer,
The catheter according to claim 1, wherein an anchoring portion that anchors the boundary portion of the contrast coil to the coil inner layer is provided as the fray suppression portion. The resin tube has a coil inner layer formed inside the contrast coil as a resin layer,
The boundary portion in the contrast coil is provided with a biting portion in which the amount of biting of the wire into the coil inner layer is larger than the portion other than the boundary portion in the contrast coil as the fray suppression portion. The catheter according to any one of claims 1 to 3, wherein: The contrast coil includes a plurality of the densely wound portions disposed in the axial direction of the resin tube, and the coarsely wound portion provided so as to connect the densely wound portions.
The catheter according to any one of claims 1 to 4, wherein the fraying suppression portion is provided for each boundary portion between the rough winding portion and each of the closely wound portions.   The catheter according to any one of claims 1 to 5, wherein the coarsely wound portion is disposed at at least one of both end portions of the contrast coil in the axial direction of the resin tube.   In the rough winding portion disposed at the end in the axial direction in the contrast coil, the winding pitch of the wire increases as the distance from the dense winding portion adjacent to the rough winding portion increases. The catheter according to claim 6.

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