JP5736472B1 - Medical guidewire - Google Patents

Abstract

In a medical guide wire in which a coil having an outer layer and an inner layer is arranged at the distal end portion of a core wire, the rotation transmission performance to the distal end side and the lesion area are reduced as the core wire is reduced in diameter by the two layer structure. Improves drilling performance. A core wire distal end portion (2B) has a connecting truncated cone (26) in which first and second truncated cones (26A, 26B) are connected. The outer diameter ratio of the large-diameter portion and the small-diameter portion of the connecting truncated cone 26 joined to the inner coil 4 is the outer diameter ratio between the rear end side and the front end side of the inner coil 4 and the rear end side of the outer coil 3. Make it higher than the outer diameter ratio on the tip side. It is possible to improve the perforation performance of the occluded lesion by reducing the rotation angle on the proximal side and increasing the torsional moment toward the distal end during the rotation operation. [Selection] Figure 1

Description

  The present invention relates to a medical guide wire used for treating a vascular lesion.

  Conventional treatment of vascular lesions such as vascular stenosis and occlusions using a medical guide wire (hereinafter referred to as a guide wire) provided with a single coil spring or the like at the tip, or the inside through which a core wire is inserted Using a guide wire provided with a coil spring consisting of a two-layer structure of an outer coil concentric with the inner coil on the outside of the coil, the distal end reaches the lesioned part, a stenosis part of the blood vessel, a complete occlusion part, etc. Is undergoing diameter expansion treatment for vascular lesions.

  In such a case, in order to penetrate the guide wire into the vascular lesion, high rotation transmission performance, perforation performance, and repeated fatigue resistance from the proximal side (rear end side) to the distal end side are required.

  Patent Document 1 describes a guide wire having a two-layer structure of an inner coil and an outer coil in which a coil spring at a tip portion is concentric.

  Patent Document 2 describes a guide wire related to characteristics such as bending rigidity of a core wire on the rear end side of a coil spring at the front end portion.

JP-A-8-317989 Japanese Patent No. 4623906

  The guide wire described in Patent Document 1 has a two-layer structure of an inner coil made of a radiopaque wire and an outer coil made of stainless steel, a shape memory alloy or the like, and uses a core wire made mainly of an elastic material for a spring. The technical contents to improve the rotation transmission performance to the tip side.

  In the guide wire described in Patent Document 2, the core wire is made of stainless steel or a nickel-titanium superelastic metal, and the core wire on the rear end side of the coil spring at the front end portion has a bending rigidity that changes linearly in the longitudinal direction. It is a technical content that improves the operability of the surgeon by eliminating sudden resistance.

  And both Patent Documents 1 and 2 make the outer diameter ratio of the front end and the rear end of the inner coil larger than the outer diameter ratio of the front end and the rear end of the outer coil with respect to the thin core wire in the coil, By specifying the shape of the distal end of the thin core wire, the rotation angle on the rear end side is reduced and the torsional force on the distal end side is increased to provide high rotational transmission performance to the distal end side and perforation at the obstructed lesion. There is no description about the technical contents that have improved the performance. These performances are important technical issues for passing a guide wire through a vascular lesion.

  This invention is made | formed in view of the said subject, and it aims at providing the guide wire which improves the permeability | transmittance in a vascular lesion part drastically.

  In order to achieve the above-mentioned object, the guide wire of the present invention has a rear end side having a large diameter and a core wire tip portion that gradually changes in diameter toward the tip end is inserted into the inner coil and the outer coil. The inner coil is wound with a stainless steel wire, and the front end and the rear end are joined to the front end of the core wire. The outer coil has a longer length in the longitudinal direction than the inner coil, is concentric on the outer side of the inner coil, and is wound with a wire rod made of a radiopaque wire at the front end side and a radiation transmissive stainless steel wire at the rear end side. Is joined to the tip of the inner coil and the tip of the core wire tip, and the rear end is joined to the core wire tip. The inner coil and the outer coil are composed of a rear end diameter large-diameter portion, an intermediate taper portion, and a front end diameter small equal-diameter portion from the rear end side toward the front end side. A1 (mm) for the diameter, A2 (mm) for the outer diameter of the small diameter part of the tip, B1 (mm) for the outer diameter of the rear coil diameter of the outer coil, and the outer diameter of the small diameter part of the tip Is B2 (mm), the outer diameter ratio (A1 / A2) of the inner coil is larger than the outer diameter ratio (B1 / B2) of the outer coil {(A1 / A2)> (B1 / B2)} .

  The leading end of the core wire has an articulated truncated cone in which at least two truncated cones are connected in the longitudinal direction, and one truncated cone has a longitudinal length on the rear end side. Gradually decrease from the head cone toward the front cone, and the ratio of the outer diameter between the large diameter of the rear end and the small outer diameter of the rear end (large diameter of the rear end / front end) The outer diameter of the outer diameter gradually increases from the truncated cone on the rear end side toward the truncated cone on the distal end side.

From the central position of the cross section of the maximum diameter of the articulated head cone, D0 (mm), the minimum outer diameter is D1 (mm), the total length is L (mm), and the maximum outer diameter is D0 (mm). When the outer diameter of the connected head cone is Dm (mm) at an arbitrary position X satisfying L>X> 0, the outer diameter Dm (mm) of the connected head cone is Dm. > {D0− (D0−D1) X / L} is satisfied.

The connecting head cone at the front end of the core wire is composed of a first head cone and a second head cone from the rear end side to the tip end, and the outer diameter ratio of the second head cone (large diameter at the rear end). small-diameter outer diameter of the outer diameter / tip) is characterized when's go magnitude than the outer of the first frusto cone diameter ratio (small diameter outer diameter of the large-diameter outer diameter / the tip of the rear end).

  The second truncated cone is joined to the rear end of the inner coil at the large diameter portion on the rear end side, the outer diameter of the joint portion is d (mm), and the minimum outer diameter of the tip is D1 (mm). The outer diameter ratio d / D1 of the second truncated cone in the inner coil, the outer diameter ratio A1 / A2 of the inner coil, and the outer diameter ratio (B1 / B2) of the outer coil are (d / D1) > (A1 / A2)> (B1 / B2) is satisfied.

  The outer diameter ratio (d / D1) of the second truncated cone in the inner coil is 1.50 or more and 4.20 or less, and the outer diameter ratio (A1 / A2) of the inner coil is 1.15 or more and 2.80. Hereinafter, the outer diameter ratio (B1 / B2) of the outer coil is 1.10 or more and 1.80 or less.

  The guide wire of the present invention compensates for the decrease in torsional force accompanying the small diameter of the core wire in the inner coil by making the outer diameter ratio A1 / A2 of the inner coil larger than the outer diameter ratio B1 / B2 of the outer coil. And the rotation transmission performance to the front end side can be improved. In addition, the tip of the core wire that penetrates the inner coil and the outer coil is an articulated frustocone that connects the shape of the frustocone, and the longitudinal length of the frustocone gradually changes toward the tip. The outer diameter ratio between the tip and rear end of the truncated cone gradually decreases and increases toward the tip, thereby reducing the rotation angle on the rear end and increasing the torsional force on the tip. High rotation transmission performance to the side and perforation performance at the occluded lesion can be improved.

  Both the inner coil and the outer coil are composed of a rear end diameter large equal diameter portion, an intermediate taper portion, and a front end diameter small equal diameter portion from the rear end side toward the front end side, and the outer coil has an outer diameter ratio A1 / A2 of the outer coil. The outer diameter ratio is larger than B1 / B2. The reason is as follows. The core wire joined to the inner coil and the outer coil is reduced in diameter from the rear end side to the front end side, and the torsional moment is reduced as the diameter is reduced. By making the outer diameter ratio A1 / A2 of the inner coil joined to the thin core wire larger than the outer diameter ratio B1 / B2 of the outer coil, the decrease in the torsional moment is compensated even for the thin core wire. Because of that. And it is because the rotation transmission performance to the front end side can be improved by the combined use of both the inner coil and the outer coil being tapered and having the same shape.

  Moreover, the core wire tip portion inserted through the inner coil and the outer coil has a structure of an articulated truncated cone in which at least two truncated cones are connected in the longitudinal direction, and one truncated cone is in the longitudinal direction. Is gradually reduced from the truncated cone on the rear end side toward the truncated cone on the distal end side, and the outer diameter ratio between the larger outer diameter of the rear end and the smaller outer diameter of the distal end ( The outer diameter of the rear end (large outer diameter / small diameter of the front end) gradually increases from the truncated cone at the rear end toward the truncated cone at the distal end. The reason for this is to obtain a structure of the tip end portion of the core wire that reduces the rotation angle by the rotation operation on the proximal side from the rear end side toward the tip end side and increases the torsional moment toward the tip end side.

  In addition, the outer diameter of the connecting truncated cone satisfies a certain relational expression. The reason is that the outer diameter ratio of the most advanced truncated cone is the highest value while the tip of the core wire has a narrow tapered shape. Thereby, the rotation angle by the rotation operation on the proximal side can be reduced, the torsional moment toward the distal end side can be increased, and the perforation performance of the obstructed lesion can be dramatically improved.

The connecting head cone at the front end of the core wire is composed of a first head cone and a second head cone from the rear end side to the tip end, and the outer diameter ratio of the second head cone (large diameter at the rear end). small-diameter outer diameter of the outer diameter / tip) is characterized when's go magnitude than the outer of the first frusto cone diameter ratio (small diameter outer diameter of the large-diameter outer diameter / the tip of the rear end). The reason for this is to reduce the rotation angle on the proximal side, improve the bending rigidity and buckling resistance of the tip, increase the torsional moment toward the tip, and dramatically improve the perforation performance of the completely occluded lesion. It is.

  The outer diameter ratio of the second truncated cone in the inner coil at the tip of the core wire (larger outer diameter of the inner coil and the joint / outer diameter of the distal end) is the outer diameter ratio of the inner coil (the diameter of the rear end). The outer diameter ratio of the inner coil (larger outer diameter of the rear end / smaller outer diameter of the distal end) is larger than the outer diameter ratio of the outer coil (the diameter of the rear end). Larger outer diameter / smaller outer diameter at the tip). The reason for this is that the outer diameter ratio of the second truncated cone is the highest, in combination with the complementary action of the torsional moment reduction of the thin wire by making the outer diameter ratio of the inner coil larger than the outer diameter ratio of the outer coil. By doing so, the torsional moment toward the distal end side can be further increased while being a thin wire, and the perforation performance of the occluded lesion can be dramatically improved.

  The connecting truncated cone at the tip of the core wire is composed of two truncated cones, and the outer diameter ratio d / D1 of the second truncated cone in the inner coil joined to the inner coil is 1.50 or more. 20 or less, the outer coil outer diameter ratio A1 / A2 is 1.15 or more and 2.80 or less, and the outer coil outer diameter ratio B1 / B2 is 1.10 or more and 1.80 or less. The outer diameter ratio d / D1 of the double truncated cone is larger than the outer diameter ratio A1 / A2 of the inner coil, and the outer diameter ratio A1 / A2 of the inner coil is larger than the outer diameter ratio B1 / B2 of the outer coil. It is characterized by that. The reason is as follows. If it falls below the above range, the rotation angle by the rotation operation on the proximal side from the rear end side toward the distal end side increases, and the torsional moment toward the distal end side decreases to allow the narrowed part and the completely occluded lesion part to pass. Will be difficult. In addition, if it exceeds the above range, the rotation angle on the hand side will decrease, but due to the generation of a high torsional moment, the torsional strength of the thin core wire joined to the inner coil and the coil wire of the inner coil itself will be insufficient. This is because the coil begins to meander without being able to withstand this high torsional moment, leading to a reduction in the rotation transmission performance to the tip side. In addition, the practical dimensions of the site to be treated (for cardiovascular treatment or for lower limb blood vessel treatment, etc.), the inner diameter of the blood vessel, and each medical device (guiding catheter, balloon catheter, microcatheter, etc.) used for the diameter expansion treatment It is because it considered together.

It is the side view which notched a part which shows the whole guide wire of 1st Embodiment of this invention. It is a partially notched side view which shows the front-end | tip part of a guide wire. It is a side view which shows the articulated truncated cone with which two truncated cones continue. It is a side view which shows the connection truncated cone of 2nd Embodiment in which three truncated cones continue. It is a side view which compares and shows the difference of the outer diameter of the connection truncated cone of a core wire front-end | tip part, and the outer diameter of a virtual single truncated cone.

  Hereinafter, embodiments of the guide wire (medical guide wire) of the present invention will be described. 1 and 2 show a guide wire 1 according to a first embodiment of the present invention, FIG. 1 shows the whole, and FIG. 2 shows a main part of a tip portion. The guide wire 1 has a core wire 2, an outer coil 3, an inner coil 4, a fluorine resin film 6, and a hydrophilic resin film 7. The core wire 2 has a core wire rear end portion 2A and a core wire front end portion 2B, and is gradually changed in diameter from the rear end side to the front end side. The inner coil 4 is inserted through the core wire tip 2B, and is joined to the core wire tip 2B by a rear end joint 5C and a rounded tip joint 5A. The outer coil 3 is outside the inner coil 4 and is longer in the longitudinal direction than the inner coil 4 and is concentrically arranged. The rear end joint portion 5B and the front end joint portion 5A are connected to the core wire front end portion 2B. It is joined. The fluororesin coating 6 is formed on the outer periphery of the thick core wire 2 on the rear end side. The hydrophilic resin film 7 is formed on the outer periphery of the outer coil 3. Note that the guide wire 1 of the present invention has a very small diameter compared to the length. For this reason, the guide wire 1 of the present invention is difficult to show in a predetermined area when the vertical and horizontal scale ratios are the same.

  The core wire 2 has a first constant diameter portion 21, a first tapered portion 22, a second constant diameter portion 23, a second tapered portion 24, a third constant diameter portion 25, a first flange, from the rear end side toward the front end side. The outer diameter is 0.3556 mm (0.014 inch for cardiovascular treatment) in the order of the connecting truncated cone 26 in which the head cone 26A and the second truncated cone 26B are connected, and the fourth equal diameter portion 27 in this order. The diameter is gradually changed from 0.060 mm to 0.060 mm. The articulated truncated cone 26 gradually decreases and contracts from the outer diameter of the larger diameter side to 0.160 mm and from the outer diameter of the smaller diameter side to 0.060 mm. The rear end joint 5B of the outer coil 3 is joined to the outer diameter of 0.180 mm on the larger diameter side of the first truncated cone 26A by using a brazing material or the like, and the rear end joint 5C of the inner coil 4 is joined. Are joined to the outer diameter of 0.125 mm on the larger diameter side of the second truncated cone 26B by using a brazing material or the like.

  As the core wire 2, a stainless steel wire, a Ni-Ti alloy wire, or the like is used. For example, as shown in JP-A-2002-69586, a high-strength stainless steel wire manufactured by repeating wire drawing and annealing is used. Alternatively, as shown in JP-A-2002-69555, a Ni—Ti alloy wire manufactured by heat treatment under a predetermined condition is used. Preferably, an austenitic stainless steel wire having a tensile strength of 2200 MPa to 3500 MPa is used. This is because the tensile strength can be easily improved by the reduced diameter drawing process, and the centerless grinding process of the shape of the connecting truncated cone 26 described later is facilitated. Here, the connected truncated cone 26 refers to a structure in which a plurality of truncated cones are provided in the longitudinal direction by performing grinding or the like using one wire. Moreover, the core wire front end portion 2B and the core wire rear end portion 2A may be the core wire 2 in which different wire materials are welded and joined, for example, a combination of the materials of the core wire.

  The outer coil 3 has an outer diameter B1 of the rear end diameter equal diameter portion 311 of 0.330 mm, a length in the longitudinal direction of 125 mm, and an outer diameter of the intermediate taper portion 312 gradually changing from 0.330 mm to 0.260 mm. One with a length of 20 mm in the longitudinal direction, an outer diameter B2 of the small-diameter portion 313 having a small tip diameter of 0.260 mm, a length in the longitudinal direction of 15 mm, and a wire diameter t1 of the coil wire of 0.060 mm. Or it is a coil formed by winding a plurality of wires. The outer first coil 31 on the distal end side is made of platinum or a radiopaque wire of platinum and nickel and has a length in the longitudinal direction of 40 mm. The outer second coil 32 on the rear end side is made of a stainless steel wire that transmits radiation and has a longitudinal length of 120 mm.

  The outer first coil 31 and the outer second coil 32 are screwed with a coil wire and joined by means of a brazing material or the like at the intermediate joint 5D. Further, instead of screw-joining, coil wires may be joined together by means such as welding. The material of the coil wire of the outer first coil 31 is preferably an austenitic stainless steel wire having a tensile strength of 2200 MPa to 3500 MPa among stainless steel wires. This is because the fatigue resistance can be improved by high torsional stress and high initial tension by obtaining a coil wire having high tensile strength and winding it into a densely wound shape.

  In the inner coil 4, the outer diameter A1 of the rear end diameter large equal diameter portion 411 is 0.185 mm, the length in the longitudinal direction is 20 mm, and the outer diameter of the intermediate taper portion 412 is gradually changed from 0.185 mm to 0.130 mm. The length in the longitudinal direction is 20 mm, the outer diameter A2 of the small-diameter portion 413 with a small tip diameter is 0.130 mm, the length in the longitudinal direction is 15 mm, and the wire diameter t2 of the coil wire is 0.030 mm. Or it is a coil formed by winding a plurality of wires.

  The outer diameter ratio B1 / B2 between the outer diameter B1 of the rear end diameter large equal diameter portion 311 of the outer coil 3 and the outer diameter B2 of the distal end small equal diameter portion 313 is 0.3556 mm as an outer diameter for cardiovascular treatment. When considered, it is 1.10 or more and 1.50 or less (about 1.27 in the first embodiment), and the maximum outer diameter of a guide wire used for lower limb vascular treatment is 0.4572 mm (0.018 inch). ), The outer diameter ratio B1 / B2 is 1.10 or more and 1.80 or less. In consideration of both cardiovascular treatment and lower limb vascular treatment, the outer diameter ratio B1 / B2 is 1.10 or more and 1.80 or less, preferably 1.15 or more and 1.80 or less.

  The outer diameter ratio A1 / A2 of the outer diameter A1 of the rear end diameter large equal diameter portion 411 of the inner coil 4 and the outer diameter A2 of the small tip diameter equal diameter portion 413 is 0.3556 mm for the cardiovascular treatment. When considered, it is 1.15 or more and 1.70 or less (about 1.42 in the first embodiment), and the maximum outer diameter of the guide wire used for lower limb blood vessel treatment is 0.4572 mm (0.018 inch). Considering the case, the outer diameter ratio A1 / A2 is 1.15 or more and 2.80 or less. In consideration of both cardiovascular treatment and lower limb vascular treatment, the outer diameter ratio A1 / A2 is 1.15 or more and 2.80 or less, preferably 1.15 or more and 2.75 or less, more preferably. Is 1.25 or more and 2.75 or less.

  The outer diameter ratio B1 / B2 between the outer diameter B1 of the rear end diameter larger equal diameter portion 311 of the outer coil 3 and the outer diameter B2 of the smaller tip diameter equal diameter portion 313 is 1.10 or more and 1.80 or less. The outer diameter ratio A1 / A2 between the outer diameter A1 of the rear end diameter larger equal diameter portion 411 and the outer diameter A2 of the smaller tip diameter equal diameter portion 413 is 1.15 or more and 2.80 or less, which is the first embodiment. Then, the outer diameter ratio B1 / B2 of the outer coil 3 is about 1.27, the outer diameter ratio A1 / A2 of the inner coil 4 is about 1.42, and the outer diameter ratio A1 / A2 of the inner coil 4 is equal to the outer coil. 3 is larger than the outer diameter ratio B1 / B2.

  The reason why the outer diameter ratio B1 / B2 of the outer coil 3 and the outer diameter ratio A1 / A2 of the inner coil 4 are in the above ranges is that the torsional moments are the large diameter portions 311 and 411 at the rear end and the small diameter portion 313 at the front end. 413 is proportional to the outer diameter ratios B1 / B2 and A1 / A2, and if it falls below the lower limit value, the torsional moment from the rear end side to the front end side becomes lower, and the lesion tissue of the stenosis part and the completely occluded lesion part This is because it is difficult to allow the guide wire to pass through. If the upper limit is exceeded, the torsional strength of the thin coil wire itself of the inner coil 4 is insufficient due to the generation of a high torsional moment, and the coil begins to meander without being able to withstand the high torsional force. This is because the rotation transmission performance to the side is reduced. This is because the site to be treated, the inner diameter of the blood vessel, and the practical dimensions of each medical device used for the diameter expansion treatment are taken into consideration.

  The reason why the outer diameter ratio A1 / A2 of the inner coil 4 is larger than the outer diameter ratio B1 / B2 of the outer coil 3 will be described below.

  In the first embodiment, the rear end joint portion 5C of the inner coil 4 is joined on the larger diameter side of the second truncated cone body 26B on the distal end side in the connected truncated cone body 26 of the core wire 2, and the core wire 2 of the joint portion is connected. Has an outer diameter of 0.125 mm. In addition, the rear end joint portion 5B of the outer coil 3 is joined on the larger diameter side of the first truncated cone body 26A on the rear end side in the first embodiment of the connecting truncated cone bodies 26 of the core wire 2. The outer diameter of the core wire 2 is 0.180 mm, and the outer diameter of the core wire 2 to which the rear end joint portion 5C is joined is clearly smaller in the inner coil 4 than in the outer coil 3. This is because when the thick core wire 2 on the rear end side is rotated, the torsional moment of the inner coil 4 is proportional to the outer diameter of the outer coil 3 being smaller than the outer diameter of the core wire 2 joined by the rear end joint portion 5C. Lower than torsional moment. Then, by increasing the outer diameter ratio A1 / A2 of the inner coil 4 to be greater than the outer diameter ratio B1 / B2 of the outer coil 3, the decrease in the torsional moment of the inner coil 4 is complemented and the rotation transmission performance to the tip side is improved. Because it can.

  3 and 4 show the core tip portions 2B and 2C having different shapes, and FIG. 3 shows the core tip portion 2B of the first embodiment in which the truncated cone has two connected truncated cones 26. FIG. 4 shows the core wire tip 2C of the second embodiment when there are three truncated cones. Except for the core end portions 2B and 2C, the other specifications are the same as those of the first embodiment, and the same components are denoted by the same reference numerals. In FIG. 3, the core wire front end portion 2 </ b> B is composed of a connecting truncated cone 26 and a fourth equal diameter portion 27 from the rear end side to the front end side. The connecting truncated cone 26 has a longitudinal length L1 of 100 mm, a large outer diameter D0 of 0.180 mm, and a small outer diameter D2 of 0.125 mm. The length L2 of the second truncated cone 26B is 50 mm, the second truncated cone 26B having a large outer diameter D2 of 0.125 mm and a small outer diameter D1 of 0.060 mm as viewed from the second truncated cone 26B. Consists of a head cone. The fourth constant diameter portion 27 has a length L0 in the longitudinal direction of 10 mm and an outer diameter of 0.060 mm. The core wire tip 2B may or may not be provided with the fourth constant diameter portion 27. If the flexibility, bending deformability, etc. of the most advanced portion are important, the most advanced perforation capability is provided. If it is important, it is preferable not to provide it. The choice depends on the symptoms of the lesion.

  The longitudinal length L1 of the first truncated cone 26A is 100 mm, and the longitudinal length L2 of the second truncated cone 26B is 50 mm, which decreases from the rear end side to the distal end side (L1> L2). The outer diameter ratio D0 / D2 of the first truncated cone 26A is 1.44, and the outer diameter ratio D2 / D1 of the second truncated cone 26B is about 2.08, from the rear end side to the front end side. ({D0 / D2} <{D2 / D1}).

  In FIG. 4, the core wire tip 2C is composed of an articulated truncated cone 30 connecting the first to third truncated cones 26A, 26B, and 26C. The first truncated cone 26A has a longitudinal length of L1 (mm) from the rear end side to the front end side, a large outer diameter of D0 (mm), and a small outer diameter of D2 (mm). . The second truncated cone 26B has a length in the longitudinal direction of L2 (mm), a large outer diameter of D2 (mm), and a small outer diameter of D3 (mm). The third truncated cone 26C has a length in the longitudinal direction of L3 (mm), a large outer diameter of D3 (mm), and a small outer diameter of D1 (mm). In addition, the 4th equal diameter part 27 shown in FIG. 3 is not provided.

  The longitudinal lengths L1, L2, L3 of the respective truncated cones 26A, 26B, 26C of the articulated truncated cone 30 gradually decrease from the rear end side to the front end side (L1> L2> L3), and The outer diameter ratio (D0 / D2), (D2 / D3), (D3 / D1) of each truncated cone 26A, 26B, 26C gradually increases from the rear end side to the front end side {(D0 / D2) <(D2 / D3) <(D3 / D1)}.

  As described above, the core wire tips 2B and 2C of the present invention are connected truncated cones 26 and 30 in which at least two truncated cones are connected in the longitudinal direction, and the longitudinal length of one truncated cone is The length in the direction gradually decreases from the first truncated cone 26A on the rear end side to the truncated cone on the tip side of the second truncated cone 26B and the third truncated cone 26C, and 1 The outer diameter ratio between the large outer diameter of the rear end of each truncated cone and the smaller outer diameter of the tip end (the larger outer diameter of the rear end / the smaller outer diameter of the tip end) is the wharf on the rear end side. It is characterized by gradually increasing from the cone toward the tip cone. The reason for this is that the rotation angle on the rear end side is decreased to increase the torsional moment toward the front end, and the perforation performance at the stenosis and completely occluded lesion is improved by the high rotational transmission performance to the front end. It is for improving.

  More specifically, when the rotation angle of the front end is the same, the rotation angle on the rear end side can be reduced. The reason for this is that the rotation angle on the rear end side, that is, the torsion angle decreases as the torsional rigidity increases, and the torsional rigidity can be expressed by the product of the transverse elastic modulus and the sectional moment of inertia. This is because the structure of 30 has a higher moment of inertia in section than the structure of the virtual single truncated cone 260 shown by a two-dot chain line in FIGS.

  Further, when the rear end side is pushed and pulled, the bending rigidity and buckling resistance at the tip can be improved. The reason for this is that the bending stiffness can be expressed by the product of the longitudinal elastic modulus and the moment of inertia of the cross section, and the structure of the articulated truncated cones 26 and 30 has a secondary cross section of the structure of the single truncated cone 260 than the structure of the single truncated cone 260. This is because the moment is high. The compressive stress is inversely proportional to the area of the cross section, and the compressive stress decreases as the cross section area increases. The cross-sectional area of the articulated truncated cones 26, 30, particularly the node 28 (position where the outer diameter of the core wire greatly changes as compared with the others) is the same as that of the node 28 of the single truncated cone 260. And the compressive stress is low. Therefore, when the push-pull operation is performed in the longitudinal direction, the structure of the articulated truncated cones 26 and 30 is more resistant to seating than the structure of the single truncated cone 260 due to the presence of the node 28 having a particularly increased cross-sectional area. This is because the bending strength can be improved.

FIG. 5 is an explanatory diagram showing a relational expression between the outer diameter of the articulated head cone 26 of the core wire tip 2B and the outer diameter of the virtual single head cone 260 of the present invention. A solid line indicates the connected head cone 26 in the case of two head cones according to the first embodiment of the present invention, and a two-dot chain line indicates a virtual single head cone for explaining the relational expression. 260 is shown. The maximum outer diameter of the articulated head cone 26 is D0 (mm), the minimum outer diameter is D1 (mm), and the total length is L (mm).
In addition, from the center position of the cross section of the maximum outer diameter D0 (mm) of the connecting head cone 26 to the longitudinal direction, the outer diameter of the connecting head cone 26 at an arbitrary position X is set to Dm (mm). When the outer diameter of the single head cone 260 is Dx, the outer diameter Dx is:
Dx = D0− (D0−D1) X / L (1)
This can be expressed by the relational expression (1). Since the outer diameter Dm of the articulated head cone 26 at an arbitrary position X satisfying L>X> 0 is larger than the outer diameter D (Dm> Dx),
Dm> {D0- (D0-D1) X / L} (2)
It can be expressed by the relational expression

  The present invention is characterized in that the core wire tip portions 2B and 2C satisfy the relational expression (2). The reason for this is a core wire that reduces the rotation angle on the rear end side, improves the bending rigidity and buckling resistance of the tip, and increases the torsional moment of the tip to further improve the drilling performance and fatigue resistance at the lesion. This is because the structures of the tip portions 2B and 2C can be obtained.

  Next, the outer diameter ratio of the truncated cone when the number of the connected truncated cones 26 of the core wire tip 2B is two will be described with reference to FIGS. In the present invention, the outer diameter ratio of the truncated cone (large outer diameter at the rear end / small outer diameter at the tip) is such that the first truncated cone 26A on the rear end side is connected to the second truncated cone on the distal end side. In the first embodiment, the outer diameter ratio D0 / D2 of the first truncated cone 26A is 1.44, and the outer diameter ratio D2 / D1 of the second truncated cone 26B is At about 2.08, the outer diameter ratio D2 / D1 of the second truncated cone 26B is greater than the outer diameter ratio D0 / D2 of the first truncated cone {(D2 / D1)> (D0 / D2)} .

Next, in the first embodiment, the outer diameter ratio D2 / D1 of the second truncated cone 26B in the inner coil 4 is about 2.08, and the outer diameter ratio A1 / A2 of the inner coil 4 is about 1. .42, the outer coil 3 has an outer diameter ratio B1 / B2 of about 1.27. In the present invention, the outer diameter ratio D2 / D1 of the second truncated cone 26B in the inner coil 4, the outer diameter ratio A1 / A2 of the inner coil 4, and the outer diameter ratio B1 / B2 of the outer coil 3 are: ,
(D2 / D1)> (A1 / A2)> (B1 / B2) (7)
The above relational expression (7) is satisfied. The reason for this is that the second truncated cone is used in combination with the complementary action of the decrease in the torsional moment of the thin wire by making the outer diameter ratio A1 / A2 of the inner coil 4 larger than the outer diameter ratio B1 / B2 of the outer coil 3. This is because by increasing the outer diameter ratio D2 / D1 of the body 26B, the torsional moment toward the distal end side can be further increased while being a thin wire, and the perforation performance of the obstructed lesion can be dramatically improved. . The relational expression (7) is such that the outer diameter of the core tip portion 2B of the rear end joint portion 5C joined to the rear end of the inner coil 4 of the second truncated cone 26B is equal to that of the second truncated cone 26B. It is a relational expression in the case where the outer diameter D2 of the large diameter portion completely coincides, and in the manufacturing process, it may be joined in the vicinity of the large diameter outer diameter D2. In consideration of such a case, when the outer diameter of the second truncated cone 26B joined at the rear end joining portion 5C of the inner coil 4 is d, the general formula is corrected.
(D / D1)> (A1 / A2)> (B1 / B2) (8)
The following relational expression (8).

  Next, according to the present invention, the outer diameter ratio d / D1 of the second truncated cone 26B in the inner coil 4 is 1.50 or more and 4.20 or less, and the outer diameter ratio A1 / A2 of the inner coil 4 is 1. The outer diameter ratio B1 / B2 of the outer coil 3 is 15 or more and 2.80 or less, and the outer diameter ratio d / D1 of the second truncated cone 26B in the inner coil 4 is the largest. Next, the outer diameter ratio of the inner coil 4 is A1 / A2, and the outer diameter ratio of the outer coil 3 is then decreased in the order of B1 / B2. The reason for this is that if it falls below the above range, the torsional moment from the rear end side to the front end side becomes low. In particular, the torsional strength due to the diameter reduction of the second truncated cone 26B is insufficient, and the constricted part and the completely closed part It becomes difficult to pass through. If the value exceeds the above range, the torsional strength of the thin coil wire itself of the inner coil 4 is insufficient due to the generation of a high torsional moment, and the coil begins to meander without being able to withstand this high torsional moment. This is because the rotation transmission performance to the side is reduced. In addition, the site to be treated (for cardiovascular treatment or for lower limb blood vessel treatment, etc.), the inner diameter of the blood vessel, and the practical dimensions of each medical device (guiding catheter, balloon catheter, microcatheter, etc.) used for diameter expansion treatment were also considered. Because.

  In each of the above embodiments, the rear end diameter large equal diameter portions 311 and 411 and the intermediate taper portions 312 and 412 are wound in a closely wound shape, and the tip diameter small equal diameter portions 313 and 413 are loosely wound. However, it is possible to appropriately change the portion that is formed into a densely wound shape or the portion that is formed into a loosely wound shape.

DESCRIPTION OF SYMBOLS 1 Guide wire 2 Core wire 2A Core wire rear end part 2B, 2C Core wire front-end | tip part 3 Outer coil 4 Inner coil 5A Front end junction part 5B Rear end junction part (outer coil)
5C Rear end joint (inner coil)
6 Fluororesin film 7 Hydrophilic resin film 26, 30 Articulated truncated cone 26A First truncated cone 26B Second truncated cone 26C Third truncated cone

Claims (1)

The rear end side has a large diameter and gradually changes the diameter of the core wire through the inner coil and the outer coil. The inner coil is wound with a stainless steel wire, and the front end and the rear end are connected to the front end of the core. Is formed by joining
The outer coil has a distal end side wound with a radiopaque wire and a rear end side with a radiation transparent stainless steel wire. The outer coil is concentrically outside the inner coil and longer in the longitudinal direction than the inner coil. In the medical guide wire formed by joining the tip to the tip of the inner coil and the tip of the core wire tip, and joining the rear end to the tip of the core wire,
The inner coil and the outer coil are composed of a rear end diameter large equal diameter part, a middle taper part, and a front end diameter small equal diameter part from the rear end side toward the front end side,
The outer diameter of the large inner diameter portion of the rear end of the inner coil is A1, the outer diameter of the smaller outer diameter portion of the inner coil is A2, the outer diameter of the larger outer diameter portion of the outer coil is B1, and the outer diameter of the outer coil is small. When the outer diameter of the equal diameter portion is B2, the outer diameter ratio (A1 / A2) of the inner coil is larger than the outer diameter ratio (B1 / B2) of the outer coil {(A1 / A2)> ( B1 / B2)}, and
The core wire tip portion is an articulated head cone in which at least two or more head cones are joined in the longitudinal direction, and one head cone has the longitudinal head having a longitudinal length on the rear end side. Gradually decrease from the cone toward the head cone on the front end side, and the outer diameter ratio between the large outer diameter of the rear end and the small outer diameter of the rear end (large diameter of the rear end / front end) The outer diameter of the head) gradually increases from the head cone on the rear end side toward the head cone on the front end side,
From the center position to the tip of the cross-section with the maximum outer diameter D0, the minimum outer diameter D1, the total length L, the maximum outer diameter D0, and the maximum outer diameter D0 of the articulated head cone, at any position X satisfying L>X> 0 When the outer diameter of the articulated head cone is Dm, the outer diameter Dm of the articulated head cone satisfies the relational expression of Dm> {D0− (D0−D1) X / L}. Medical guidewire.

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