JP4887810B2 - Catheter insert and catheter insert set - Google Patents

Description

  The present invention relates to a catheter insertion tool, and more particularly to a catheter insertion tool in which relative rotation between a sheath hub and a strain relief is prevented, and a fitting operation between the sheath hub and the strain relief during manufacture is easy.

  Intra-aortic balloon pumping (IABP) used for the treatment of heart failure such as heart failure, percutaneous coronary angioplasty (PTCA) used for the treatment of expanding blood vessels around the heart, heart blood In treatment methods such as thermodilution catheterization (TDC) used to measure flow, a catheter is inserted into a patient's blood vessel. In order to insert such a catheter into a patient's blood vessel, a catheter insertion tool is generally used.

  The catheter insertion tool is usually composed of a sheath made of a thin-walled tube and a sheath hub connected to the proximal end of the sheath and having a lumen communicating with the lumen of the sheath. By using such a catheter insertion tool, the sheath is inserted into the patient's blood vessel, and the catheter is inserted from the outside of the patient's body through the lumen of the sheath hub and the lumen of the sheath. A catheter can be inserted.

  In such a catheter insertion tool, since the sheath is usually lower in rigidity than the sheath hub, the sheath is likely to kink in the vicinity of the connection portion between the sheath and the sheath hub (bent and easily deformed). Therefore, it is known that a strain relief (annular protector) is externally fitted to the connection portion between the sheath and the sheath hub of the catheter insertion tool in order to prevent kinking of the sheath (see Patent Document 1). . The strain relief is usually a member having intermediate rigidity between the sheath and the sheath hub, and by preventing a sudden change in rigidity at the connection portion between the sheath and the sheath hub, the stress concentration phenomenon at the connection portion is prevented, It functions to prevent kinking of the sheath.

  However, since the sheath hub is usually a member having a circular cross-sectional shape in the circumferential direction, the sheath hub and the strain relief may rotate relative to each other simply by fitting the strain relief to the connecting portion between the sheath and the sheath hub. Become. Handling of the catheter insertion tool is often performed by pinching the position of the strain relief by hand, and if the strain relief rotates with respect to the sheath hub, inconvenience may arise in handling of the catheter insertion tool. In particular, in a catheter insertion tool set using a combination of a catheter insertion tool (indicated as a sheath in Patent Document 2) and a dilator as described in Patent Document 2 by rotational fitting, a strain relief is used. If it rotates with respect to the sheath hub, even if you try to rotate and fit the dilator with the strain relief picked, the strain relief will run idle, making it impossible to rotate and fit the dilator. Has occurred.

  As a means to prevent relative rotation between the sheath hub and the strain relief, it may be possible to attach and fix them with an adhesive. However, it takes a lot of time and labor to apply and dry the adhesive. There arises a problem that the productivity of the tool becomes worse.

JP2000-170661 JP 2000-167062 A

  In view of the above circumstances, an object of the present invention is to provide a catheter insertion tool in which relative rotation between a sheath hub and a strain relief is prevented, and the fitting operation between the sheath hub and the strain relief during manufacture is easy. And

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has made the male section of the sheath hub into a rotationally symmetric polygonal shape and allows the sheath hub and the strain relief to be fitted into the male and female. Thus, it has been found that the fitting can be easily performed without requiring adhesion or the like, and the sheath hub and the strain relief do not rotate relative to each other, and the present invention has been completed.

  Thus, according to the present invention, a sheath having a distal end and a proximal end, a sheath hub connected to the proximal end of the sheath, and a strain relief externally fitted to a connection portion between the sheath and the sheath hub are provided. The sheath hub has a male part, the strain relief has a female part, and these are fitted by male-female fitting, and the circumferential cross-sectional shape of the male part of the sheath hub is rotationally symmetric A catheter insert that is polygonal is provided.

  In the above catheter insertion tool, it is preferable that the female part of the strain relief has a shape corresponding to the male part of the sheath hub.

  In said catheter insertion tool, it is preferable that the circumferential cross-sectional shape of the male part of a sheath hub is a concave polygon.

  According to the present invention, a dilator comprising the above catheter insertion tool, a dilator body having a distal end and a proximal end, and a dilator hub connected to the proximal end of the dilator body; A catheter insertion tool set is provided in which the sheath hub and the dilator hub can be rotationally fitted in a state where the dilator main body of the dilator is inserted through the sheath of the catheter insertion tool.

  ADVANTAGE OF THE INVENTION According to this invention, the relative rotation of a sheath hub and a strain relief is prevented, and the catheter insertion tool with which the fitting operation | work of a sheath hub and a strain relief at the time of manufacture is easy is provided.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

  FIG. 1 is a schematic view showing an embodiment of the catheter inserter set of the present invention, which is composed of the catheter inserter of the present invention and a dilator, and FIG. 1 (A) shows that the catheter inserter and the dilator are separated. FIG. 1B shows a state in which the dilator main body of the dilator is inserted through the sheath of the catheter insertion tool, and the sheath hub and the dilator hub are fitted. FIG. 2 is a perspective view showing a sheath hub and a strain relief of the catheter insertion tool shown in FIG. FIG. 3 is a perspective view showing another embodiment of the sheath hub and strain relief used in the catheter insertion tool of the present invention.

  The catheter insertion tool set of this embodiment shown in FIG. 1 includes a catheter insertion tool 10 and a dilator 11. The catheter insertion tool 10 is externally fitted to a sheath 1 having a distal end and a proximal end, a sheath hub 2 connected to the proximal end of the sheath 1, and a connection portion between the sheath 1 and the sheath hub 2. It consists of a strain relief 9 and a side injection tube 8 connected to the side of the sheath hub 2.

  The sheath 1 is, for example, a cylindrical shape formed of a polymer material such as a polyolefin such as polyethylene or polypropylene, a polyamide such as nylon, a polyamide elastomer, a polyurethane, a polyester such as polyethylene terephthalate or polybutylene terephthalate, a polyester elastomer, or a fluororesin. Consists of tubes. The material of the sheath 1 may be blended with an X-ray impermeable material such as bismuth oxide or barium sulfate so that the position of the sheath 1 inserted into the body can be confirmed by X-ray fluoroscopy. 1 may be coated with a hydrophilic polymer material such as polyethylene oxide in order to facilitate insertion / removal of the sheath 1 into / from the body.

  The inner diameter of the tube constituting the sheath 1 is preferably slightly larger than the outer diameter of the catheter inserted into the sheath 1, and is usually set in the range of 1.0 to 5.0 mm. Moreover, it is preferable that the thickness of the tube which comprises the sheath 1 is 0.03-0.30 mm. If the wall thickness is too small, the strength of the sheath 1 may be insufficient. If the wall thickness is too large, the outer diameter of the sheath 1 is increased, which increases the burden on the patient into which the sheath 1 is inserted. The length of the sheath 1 is usually 30 to 500 mm, and preferably 100 to 300 mm. If the length of the sheath 1 is too short, it becomes difficult to insert the sheath 1 into the blood vessel of the patient, and the catheter insertion tool 10 cannot be held in the state of being inserted into the patient. If the length is too long, the catheter insertion tool 10 may be difficult to handle.

  In the catheter insertion tool 10 of the embodiment shown in FIG. 1, the sheath hub 2 is connected to the proximal end of the sheath 1. The connection between the sheath 1 and the sheath hub 2 is, for example, such that the proximal end portion of the flared sheath 1 is externally fitted to a sheath connection portion 21 (see FIG. 2) located on the distal end side of the sheath hub 2. Further, a caulking pin (not shown) is externally fitted and caulked. The sheath hub 2 connected to the proximal end of the sheath 1 is a substantially cylindrical member having a cavity communicating with the lumen of the sheath 1 inside, and is usually a polyolefin such as polyethylene and polypropylene, polyamide, polycarbonate, polystyrene, and the like. It is formed of a polymer material. A tubular medical device such as a catheter or a dilator 11 described later can be normally inserted into the cavity of the sheath hub 2, and a hemostasis valve for preventing the passage of blood regardless of whether or not the catheter is inserted (see FIG. Not shown). As the hemostatic valve, a valve body constituted by providing a slit penetrating both surfaces in a plate-like body formed of an elastomer material is usually used. Thereby, the blood leakage outside the body through the catheter insertion tool 10 is prevented. Further, on the distal end side of the sheath hub 2 in which the hemostasis valve is accommodated, a ring-shaped cap 13 is provided to hold the hemostasis valve in the cavity of the sheath hub 2 while allowing a catheter or the like to be inserted into the slit of the hemostasis valve. Is fitted.

  As shown in FIG. 2, a male portion 22 for fitting the strain relief 9 by male-female fitting is provided at a portion adjacent to the proximal end side of the sheath connecting portion 21 located on the distal end side of the sheath hub 2. Is provided. In the catheter insertion tool 10 of this embodiment, the male section 22 has a circumferential cross-sectional shape (a cross-sectional shape in the circumferential direction of the sheath 1) in which an inner angle of less than 180 ° and an inner angle of more than 180 ° are alternately arranged. It is a dodecagon that is a concave polygon. In the catheter insertion tool 10 of the present embodiment, since the male portion 22 of the sheath hub 2 has such a shape, the strain relief 9 is caught at the corner portion of the male portion 22, and the sheath hub 2, the strain relief 9, Is prevented from rotating relative to each other.

  In the catheter insertion tool 10 of the present invention, the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 is not particularly limited as long as it is a rotationally symmetric polygon. For example, it is a concave polygon having an internal angle exceeding 180 °. Alternatively, it may be a convex polygon having only an inner angle of less than 180 °. However, from the viewpoint of more reliably preventing relative rotation between the sheath hub 2 and the strain relief 9, the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 is preferably a concave polygon. If the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 is a concave polygon, a portion of the strain relief 9 is fitted into the concave portion, so that relative rotation between the sheath hub 2 and the strain relief 9 is more reliably prevented. The In the case where the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 is a concave polygon, it is preferably a concave polygon in which an inner angle of more than 180 ° and an inner angle of less than 180 ° are alternately arranged, More preferably, it is a concave polygon in which inner angles of 210 ° to 330 ° and inner angles of 30 ° to 80 ° are alternately arranged. In this case, it is preferable that the interior angle exceeding 180 ° and the interior angle less than 180 ° are equal to each other. Further, when the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 is a concave polygon, the concave polygon is a hexagon, octagon, decagon, dodecagon, dodecagon, or dodecagon. Any one is preferable, and a dodecagon is particularly preferable.

  In the catheter insertion tool 10 of the present invention, the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 may be a rotationally symmetric convex polygon. When the cross-sectional shape is a convex polygon, the convex polygon is preferably a triangle to a dodecagon, and is preferably a quadrangle to a hexagon. If the number of corners of the convex polygon is too large, the relative rotation between the sheath hub 2 and the strain relief 9 may not be sufficiently prevented. In addition, in FIG. 3, the form whose circumferential direction cross-sectional shape of the male part 22 of the sheath hub 2 is square was shown as another embodiment of the sheath hub 2 used with the catheter insertion tool of this invention.

  The size of the polygon forming the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 is not particularly limited, but the diameter of the minimum circumscribed circle for this polygon is usually in the range of 5 to 15 mm. The length of each side of the polygon that forms the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 is determined according to the size of the sheath hub 2 and is not particularly limited, but is usually in the range of 1 to 10 mm. It is particularly preferable that the lengths of the sides of the polygon are all equal.

  The polygon forming the circumferential cross-sectional shape of the male portion 22 of the sheath hub 2 has a rotationally symmetric shape, so that there is no inconvenience that the sheath hub 2 and the strain relief 9 cannot be fitted unless they are aligned in a specific direction. This saves the effort required for facing. That is, in the catheter insertion tool 10 of the present invention, the fitting operation between the sheath hub 2 and the strain relief 9 is easy. In addition, it is preferable that the polygon which makes the circumferential cross-sectional shape of this male part 22 is rotationally symmetrical every 45 degrees or more. If the rotational symmetry is less than 45 °, relative rotation between the sheath hub 2 and the strain relief 9 may not be sufficiently prevented.

  In the present invention, “the circumferential cross-sectional shape of the male portion of the sheath hub is a rotationally symmetric polygon” means that the circumferential cross-sectional shape of the male portion of the sheath hub is rotationally symmetric in a mathematically strict sense. It is not intended to be a polygon or a polygon, and is a concept having a width without departing from the present invention. For example, even if the corners are rounded polygons or some of the sides that form the polygons include curves, if the overall cross-sectional shape is generally polygonal, The circumferential cross section of the male part is a rotationally symmetric polygon.

  The size of the male portion 22 of the sheath hub 2 is preferably larger toward the proximal end side along the axial direction of the sheath hub 2 (the axial direction of the sheath 1) as shown in FIGS. If the male part 22 of the sheath hub 2 has such a shape, the fitting with the strain relief becomes easier. In addition, it is preferable that the taper provided in the male part 22 of the sheath hub 2 has a taper angle of 5 ° to 20 °. The sheath hub 2 is preferably provided with a circumferentially extending groove 24 adjacent to the proximal end of the male portion 22. By providing such a groove 24 in the sheath hub 2, the sheath hub 2 and the strain relief 9 can be more reliably fitted.

  The axial length of the male portion 22 of the sheath hub 2 is not particularly limited, but is usually in the range of 3 to 10 mm.

  In the catheter insertion tool 10 of the present embodiment shown in FIG. 1, a cavity for housing a hemostasis valve is provided inside a sheath hub main body 23 that is a portion located on the most proximal end side of the sheath hub 2. 2 is provided with a thread groove 25 for rotationally fitting the dilator 11 as described later (see FIG. 2). In addition, a branch pipe 6 having a lumen communicating with the inside of the sheath hub 2 is also provided on the outer peripheral surface of the sheath hub 2, and a side injection pipe 8 is connected to the branch pipe 6 (see FIG. 2).

  A strain relief 9 is externally fitted to the outer peripheral surface of the connecting portion between the sheath 1 and the sheath hub 2 of the catheter insertion tool 10 of the present embodiment by male-female fitting with the male portion 22 of the sheath hub 2. The strain relief 9 is a member that functions to prevent kinking of the sheath 1 in the vicinity of the connection portion with the sheath hub 2. In this embodiment, a female portion 31 for fitting with the male portion 22 of the sheath hub 2 is provided inside. It is a tubular body having a substantially conical outer shape.

  The material for forming the strain relief 9 is not particularly limited, but the strain relief 9 is preferably selected so that the rigidity of the strain relief 9 is intermediate between the sheath 1 and the sheath hub 2 and is rich in elasticity. Preferably there is. Specifically, rubber or an elastomer is preferable, and more specifically, a thermoplastic elastomer such as a styrene-based elastomer, an olefin-based elastomer, or a polyester elastomer is preferable. Further, the Shore hardness of the material forming the strain relief 9 is Shore D hardness, preferably 30 to 50, and particularly preferably 35 to 45. If the material forming the strain relief 9 is not appropriate, there is a possibility that the kink of the sheath 1 may not be sufficiently prevented. In particular, if the material is too flexible, the relative rotation between the sheath hub 2 and the strain relief 9 may not be sufficiently prevented. is there.

  In the catheter insertion tool 10 of the present invention, the shape of the female portion 31 provided inside the strain relief 9 is not particularly limited as long as the male-female fitting with the male portion 22 of the sheath hub 2 is possible. Although it may be a substantially cylindrical cavity, a shape corresponding to the male portion 22 of the sheath hub 2 is preferable. That is, the female portion 31 of the strain relief 9 is preferably a hollow cavity whose circumferential cross-sectional shape (cross-sectional shape in the circumferential direction of the sheath 1 of the catheter insertion tool 10) is a polygon that is rotationally symmetric. In the case where the male portion 22 of the sheath hub 2 is a dodecagon that is a concave polygon in which inner angles exceeding 180 ° and inner angles less than 180 ° are alternately arranged as in the embodiment shown, the strain relief 9 The female portion 31 is also preferably a cavity having a similar circumferential cross-sectional shape. If the shape of the female portion 31 of the strain relief 9 is a shape corresponding to the male portion 22 of the sheath hub 2, relative rotation between the sheath hub 2 and the strain relief 9 is more reliably prevented, and the sheath hub 2 at the time of manufacture The fitting operation with the strain relief 9 becomes easier.

  The size of the female portion 31 (air cavity) of the strain relief 9 is not particularly limited as long as the male-female fitting with the male portion 22 of the sheath hub 2 is possible, but may be slightly smaller than the male portion 22 of the sheath hub 2. More specifically, the diameter of the minimum circumscribed circle with respect to the circumferential cross-sectional shape of the female portion 31 of the strain relief 9 is preferably 85 to 99% of that of the male portion 22 of the sheath hub 2. . If the size of the female portion 31 of the strain relief 9 is slightly smaller than the male portion 22 of the sheath hub 2, the force that the strain relief 9 presses the male portion 22 of the sheath hub 2 works, so that the strain relief 9 and the sheath hub 2 The frictional force with the male part 22 is strengthened, and the relative rotation between the sheath hub 2 and the strain relief 9 is more reliably prevented.

  When the size of the male portion 22 of the sheath hub 2 is increased toward the proximal end side along the axial direction of the sheath hub 2 as in the embodiment shown in FIG. 2, the female portion 31 of the strain relief 9 is provided. Correspondingly, it is preferable that the proximal end side becomes larger (wider). When the sheath hub 2 is provided with a circumferentially extending groove 24 adjacent to the proximal end of the male part 22, the sheath hub 2 extends in the circumferential direction in which the groove 24 can be fitted to the inner peripheral surface of the strain relief 9. Protrusions 32 are preferably provided.

  Although the external shape of the strain relief 9 is not particularly limited, it is preferable that the outer shape of the strain relief 9 is a substantially conical shape that becomes smaller toward the distal end side as in the embodiment shown in FIG. If the strain relief 9 has such a shape, the effect of alleviating a sudden change in rigidity at the connection portion between the sheath 1 and the sheath hub 2 is increased, and kink of the sheath 1 is more reliably prevented.

  The axial length of the strain relief 9 is not particularly limited, but is preferably set to be slightly longer than the length of the sheath connecting portion 21 and the male portion 22 of the sheath hub 2. It is preferable that the length is 5 to 20 mm longer than the length of the sheath connecting portion 21 and the male portion 22.

  In the catheter insertion tool 10 of the present invention, the sheath hub 2 and the strain relief 9 are fitted by male-female fitting, and their relative rotation is sufficiently prevented. Therefore, from the viewpoint of improving the productivity of the catheter insertion tool 10, it is preferable not to perform bonding using an adhesive. However, these may be bonded for the purpose of further reliably preventing the relative rotation between the sheath hub 2 and the strain relief 9.

  One end of a side injection tube 8 that is a tube formed of a transparent elastomer material is connected to the branch tube 6 of the sheath hub 2 of the catheter insertion tool 1 of the present embodiment, and a three-way stopcock is connected to the other end of the side injection tube 8. 7 is attached. The side injection tube 8 can be used for the purpose of injecting a drug solution such as heparin into a patient's blood vessel or connecting a blood pressure measuring device.

  When inserting the catheter insertion tool 10 into a patient's body, a dilator 11 as shown in FIG. 1 is usually used. Therefore, the catheter insertion tool 10 is generally provided as a catheter insertion tool set in combination with the dilator 11.

  A dilator 11 that is combined with a catheter inserter 10 to form a catheter inserter set is usually connected to a dilator body 14 having a distal end and a proximal end, and a proximal end of the dilator body 14. It is constituted by a dilator hub 12. The dilator body 14 is made of a polymer material such as a polyolefin such as polyethylene or polypropylene, a polyamide such as nylon, a polyamide elastomer, a polyurethane, a polyester such as polyethylene terephthalate or polybutylene terephthalate, a polyester elastomer, or a fluororesin. A tubular body having a tapered distal end side. The material of the dilator main body 14 may be blended with an X-ray opaque material such as bismuth oxide or barium sulfate so that the position of the dilator main body 14 inserted into the body can be confirmed by X-ray fluoroscopy. In addition, the outer peripheral surface of the dilator body 14 may be coated with a hydrophilic polymer material such as polyethylene oxide in order to facilitate the insertion and removal of the dilator body 14.

  The inner diameter of the dilator body 14 is preferably such a diameter that a guide wire can be inserted, and is usually set in a range of 0.1 to 2.0 mm. Moreover, the outer diameter of the dilator main body 14 is usually set in accordance with the inner diameter of the sheath 1 of the catheter insertion tool 10 used in combination, and the length of the dilator main body 14 is set in combination with the catheter insertion tool 10 used in combination. It is set to be slightly longer than the length of the sheath 1 and is usually 10 to 100 mm longer than the length of the sheath 1.

  The dilator hub 12 of the dilator 11 is fitted so that the sheath hub 2 and the dilator hub 12 can be fitted with the dilator body 14 of the dilator 11 inserted through the sheath 1 of the catheter insertion tool 10. It is a member provided with a combination means, and is usually formed of a polymer material such as polyolefin such as polyethylene or polypropylene, polyamide, polycarbonate or polystyrene. In the dilator 11 of the embodiment shown in FIG. 1, a screw fitting protrusion (not shown) for rotationally fitting with the sheath hub 2 of the catheter insertion tool 10 is provided on the inner peripheral surface side of the dilator hub 12. Yes.

  In order to insert a catheter into a patient's blood vessel using the catheter insertion tool set, the following may be performed. That is, first, as shown in FIG. 1 (B), the dilator main body 14 of the dilator 11 is inserted into the sheath 1 of the catheter insertion tool 10, the sheath hub 2 and the dilator hub 12 are fitted, and the catheter is inserted. The tool 10 and the dilator 11 are combined. Next, if the patient is punctured with the taper portion on the distal end side of the dilator main body 14 along the guide wire previously inserted into the blood vessel of the patient, the puncture hole gradually expands. The tool 10 (sheath 1) can be inserted into the patient's body. After the sheath 1 of the catheter insertion tool 10 reaches the blood vessel of the patient, the sheath hub 2 and the dilator hub 12 are disengaged, and the dilator 11 is removed from the catheter insertion tool 10 to remove the catheter insertion tool 10. Thus, a catheter or the like can be inserted into a patient's blood vessel.

  As in the embodiment shown in FIG. 1, the catheter insertion tool set having a configuration in which the sheath hub 2 and the dilator hub 12 are fitted by rotational fitting such as screw fitting is provided between the sheath hub 2 and the dilator hub 12. It is excellent in that the fitting is surely performed and the unintentional disconnection is less likely. In such a catheter insertion tool set of rotational fitting, in many cases, the dilator hub 12 is rotationally fitted after the sheath hub 2 is fixed by grasping the position of the strain relief 9 of the catheter insertion tool 10. Is done. In this case, if the strain relief 9 and the sheath hub 2 rotate relative to each other, even if the strain relief 9 is picked and the dilator hub 12 is rotationally fitted, the strain relief 9 is idled and the sheath hub 2 Since it is not fixed, the dilator hub 12 cannot be rotationally fitted. That is, the catheter insertion tool 10 of the present invention, which is characterized in that the relative rotation between the sheath hub 2 and the strain relief 9 is prevented, is a catheter insertion tool set in which the sheath hub 2 and the dilator hub 12 are rotationally fitted. In the case where it is provided, it can be said that it exhibits a particularly excellent effect as compared with a conventional catheter insertion tool.

It is the schematic which shows embodiment which concerns on the catheter insertion tool set of this invention which consists of the catheter insertion tool of this invention, and a dilator, FIG. 1 (A) shows a state with a separate catheter insertion tool and a dilator. FIG. 1B shows a state where the dilator body of the dilator is inserted through the sheath of the catheter insertion tool, and the sheath hub and the dilator hub are fitted. It is a perspective view which shows the sheath hub and strain relief of the catheter insertion tool shown in FIG. It is a perspective view which shows another embodiment of the sheath hub and strain relief used with the catheter insertion tool of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheath 2 Sheath hub 6 Branch pipe 7 Three-way cock 8 Side injection pipe 9 Strain relief 10 Catheter insertion tool 11 Dilator 12 Dilator hub 13 Cap 14 Dilator main body 21 Sheath connection part 22 Male part 23 Sheath hub main body 24 Groove 25 Screw groove 31 Female part 32 protrusion

Claims (2)

A sheath having a distal end and a proximal end, a sheath hub connected to the proximal end of the sheath, and a strain relief externally fitted to a connection portion between the sheath and the sheath hub. The sheath hub has a male portion. The strain relief has a female part, and these are catheter insertion tools fitted by male-female fitting,
The circumferential cross-sectional shape of the male part of the sheath hub is a rotationally symmetric concave polygon ,
The female part of the strain relief has a shape corresponding to the male part of the sheath hub,
The concave polygon is a concave polygon in which inner angles of 210 ° to 330 ° and inner angles of 30 ° to 80 ° are alternately arranged,
The size of the male portion of the sheath hub is larger toward the proximal end side along the axial direction of the sheath hub, and the female portion of the strain relief is correspondingly larger toward the proximal end side, The sheath hub is provided with a circumferentially extending groove adjacent to the proximal end of the male part, and a circumferentially extending protrusion that can be fitted into the groove is provided on the inner peripheral surface of the strain relief. Yes,
Catheter insertion in which the diameter of the minimum circumscribed circle with respect to the circumferential sectional shape of the female portion of the strain relief is 85 to 99% of the diameter of the minimum circumscribed circle with respect to the circumferential sectional shape of the male portion of the sheath hub Ingredients. A catheter insertion tool according to claim 1 ;
A dilator comprising a dilator body having a distal end and a proximal end, and a dilator hub connected to the proximal end of the dilator body;
A catheter insertion tool set in which a sheath hub and a dilator hub can be rotationally fitted in a state in which a dilator main body of a dilator is inserted through a sheath of a catheter insertion tool.

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