JP2019170829A - Catheter assembly - Google Patents

Abstract

The present invention provides a catheter assembly capable of satisfactorily preventing false punctures by making the leading edge of an inner needle unexposed.
A catheter assembly 10 includes a catheter 12 and a hollow inner needle 14 having a distal end 15b at a predetermined position in the circumferential direction when viewed from the front. Further, the catheter assembly 10 has a shutter portion 71 that is smoother than the most distal end 15 b of the inner needle 14, and has a blunt needle 70 that is disposed in the inner needle 14 so as to freely advance and retract. The shutter portion 71 moves to the most distal end 15b side of the inner needle 14 in a state where the shutter portion 71 moves further than the most distal end 15b of the inner needle 14 by the advancement of the blunt needle 70.
[Selection] Figure 1

Description

  The present invention relates to a catheter assembly having a function of preventing needle puncture.

  Patent Document 1 discloses a catheter assembly having a double-structure needle in which an inner needle is inserted into a catheter. The user of the catheter assembly places the catheter on the patient side by causing the cartel to enter the blood vessel and detaching the inner needle from the catheter while the double-structure needle is punctured.

  Also, in this type of catheter assembly, if the inner needle remains exposed after the inner needle is removed, there is a risk that the needle will be accidentally stuck in an unintended location (an erroneous puncture will occur). In order to prevent such a false puncture, the catheter assembly is provided with a safety mechanism. For example, as a safety mechanism, a structure in which a simple rod-shaped member (safety member) is accommodated in the inner needle and the rod-shaped member protrudes toward the distal end side of the needle tip as the catheter advances.

JP 2015-47493 A

  However, the structure in which the rod-shaped member (safety member) projects as described above does not cover the needle tip of the inner needle, so even if the rod-shaped member protrudes, the part that first forms a wound in the living body The leading edge of the inner needle is exposed. Therefore, for example, when a finger or the like is brought closer to the tip of the position facing the leading edge of the inner needle, the leading edge of the inner needle may come into contact with the living body and be damaged (causes a false puncture).

  The present invention has been made in view of the above circumstances, and even with a structure in which a safety member protrudes from the inside of the inner needle, the leading edge of the inner needle is unexposed in a front view, so that a false puncture can be satisfactorily performed. It is an object to provide a catheter assembly that can be prevented.

  In order to achieve the above object, a catheter assembly according to the present invention includes a catheter, a hollow inner needle that is removably inserted into the catheter and has a leading edge at a predetermined position in the circumferential direction in a front view. A safety member having a shutter portion that is smoother than the forefront of the inner needle, and is disposed so as to be able to advance and retreat in the inner needle, and the shutter portion of the inner needle is moved forward by the advancement of the safety member. In the state which moved ahead rather than the most cutting edge, it moves to the most front side of the inner needle.

  Further, the catheter assembly preferably has an operation mechanism for moving the shutter portion in the proximal direction after the shutter portion has moved to the most distal side of the inner needle.

  In this case, the operation mechanism may be configured to move the shutter portion in the proximal direction based on the proximal end portion of the safety member moving in the distal direction.

  Furthermore, the operation mechanism may include a side moving unit that moves a part of the safety member to the side of the inner needle based on a predetermined trigger during the movement of the safety member in the distal direction.

  In addition to the above configuration, the operation mechanism includes a hole formed at a midway position of the inner needle, and the side moving portion is provided on a proximal end side with respect to the shutter portion, It is preferable that it is a receding spring part that becomes substantially linear by being elastically deformed in contact with the peripheral surface, and that enters the hole part and elastically recovers laterally as it moves to a position overlapping the hole part.

  And it is preferable that the said shutter part has a hook part which can be hooked on the forefront of the said inner needle.

  In particular, the hook portion preferably has a proximal end apex portion that is located on the proximal end side and on the radially outer side from the most distal end of the inner needle in a state where the shutter portion is moved in the proximal direction by the operation mechanism.

  In addition, when the shutter portion is present in the catheter, the shutter portion has a protruding piece portion that regulates contact between the catheter and the most distal end of the inner needle by contacting the inner peripheral surface of the catheter. preferable.

  Furthermore, the safety member may include a blocking spring portion that biases the shutter portion toward the most distal side of the inner needle in a state where the shutter portion is accommodated in the inner needle.

  Furthermore, it is preferable that the shutter portion has a shape that can be accommodated in the hollow portion of the inner needle in a front view in a state of being accommodated in the inner needle.

  Furthermore, the safety member may include a rigid portion that is connected to the base end of the blocking spring portion and is formed to be harder than the blocking spring portion.

  According to the present invention, in the catheter assembly, when the safety member disposed so as to be movable back and forth in the inner needle moves further forward than the most distal end of the inner needle, the shutter portion of the safety member moves toward the most distal side of the inner needle. To do. As a result, the leading edge of the inner needle can be unexposed in front view. For example, even when a finger of a living body approaches the leading edge from the tip of the inner needle, contact can be blocked by the shutter portion. . Therefore, the safety member can satisfactorily prevent the inner needle from being pierced and can further enhance the safety after use of the catheter assembly.

It is a perspective view showing the whole catheter assembly composition concerning a 1st embodiment of the present invention. FIG. 2A is a first plan view showing the operation of the catheter assembly of FIG. FIG. 2B is a second plan view illustrating the operation of the catheter assembly following FIG. 2A. FIG. 2C is a third plan view illustrating the operation of the catheter assembly following FIG. 2B. FIG. 2 is an exploded perspective view of the catheter assembly of FIG. 1. 4A is a plan view showing the needle holding member of FIG. FIG. 4B is a perspective view of the needle holding member as seen from the proximal end side. It is the perspective view which looked at the catheter operation member of FIG. 1 from the base end side and the lower side. FIG. 6A is a side sectional view showing a state in which a blunt needle is protruded from the inner needle. FIG. 6B is a perspective view showing a state in which the blunt needle is protruded from the inner needle. FIG. 7A is an enlarged side cross-sectional view showing a state where the shutter portion of the blunt needle is housed in the inner needle. FIG. 7B is an enlarged side sectional view showing a state in which the shutter portion of the blunt needle protrudes from the needle tip of the inner needle. 8A is a perspective view showing the blunt needle hub of FIG. FIG. 8B is a perspective view of the blunt needle hub as seen from the proximal end side. FIG. 3 is a first explanatory view showing an operation at the time of initial advancement of the catheter assembly of FIG. 1. FIG. 10 is a second explanatory diagram illustrating an operation at the time of initial advance following FIG. 9. FIG. 11 is a third explanatory diagram illustrating an operation at the time of initial advance following FIG. 10. It is an expanded side sectional view showing a relation with a catheter when a blunt needle protrudes from an inner needle in a catheter assembly concerning a modification. FIG. 13A is a schematic side view of a catheter assembly according to a second embodiment. 13B is a cross-sectional view taken along line XIIIB-XIIIB in FIG. 13A. FIG. 14A is a first explanatory view showing the operation of the catheter assembly of FIG. 13A. 14B is a cross-sectional view taken along line XIVB-XIVB in FIG. 14A. FIG. 15A is a second explanatory view showing the operation of the catheter assembly of FIG. 13A. 15B is a cross-sectional view taken along line XVB-XVB in FIG. 15A.

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

[First Embodiment]
As shown in FIG. 1, the catheter assembly 10 according to the first embodiment includes a catheter 12 that is inserted into the body from outside the patient's body, and the catheter 12 constructs a transfusion or blood transfusion introduction section in the patient (living body). To do. The catheter 12 is longer than the peripheral venous catheter (for example, applied to a central venous catheter, PICC, midline catheter, etc.). The catheter 12 may be configured as a peripheral venous catheter, or may be configured not only for a venous catheter but also for an artery such as a peripheral artery catheter.

  In addition to the catheter 12, the catheter assembly 10 includes an inner needle 14 that is removably inserted into the catheter 12, a catheter hub 20 that fixes and holds the catheter 12, an inner needle hub 30 that fixes and holds the inner needle 14, and A catheter operating member 60 for operating the catheter 12 and the catheter hub 20 is provided. The catheter assembly 10 includes a blunt needle 70 in the inner needle 14 and a blunt needle hub 80 that supports the blunt needle 70 in order to prevent erroneous insertion of the inner needle 14. The structure is such that the blunt needle 70 protrudes from. The blunt needle 70 is a name in the description of the present specification, and refers to a safety member configured to block the puncture of the inner needle 14 with respect to the living body.

  The catheter assembly 10 forms a multi-structure needle 16 in which the catheter 12, the inner needle 14, and the blunt needle 70 overlap in order from the outside toward the inside in an initial state before use. In the initial state of the multi-structure needle 16, the needle tip 15 of the inner needle 14 protrudes from the distal end of the catheter 12, and the distal end of the blunt needle 70 is proximal to the needle tip 15 (hole 14 d of the inner needle 14 described later). Located on the side. Further, the inner needle hub 30 constitutes a grip portion to be gripped by the user, and in addition to the proximal end side portion of the multi-structure needle 16, the catheter hub 20, the catheter operating member 60, and the blunt needle hub 80. Is housed.

  In using the catheter assembly 10, a user such as a doctor or nurse grasps the inner needle hub 30 and punctures the distal end of the multi-structure needle 16 into the blood vessel of the patient. While maintaining this puncture state, the user advances the catheter operation member 60 to advance the catheter 12 and the catheter hub 20 relative to the inner needle hub 30. In addition, when the catheter operating member 60 is initially advanced, the blunt needle 70 and the blunt needle hub 80 are integrally advanced with the catheter operating member 60. Thereby, the blunt needle 70 moves to a position where the needle tip 15 of the inner needle 14 can be prevented from being mistaken.

  After the initial advancement, the catheter 12 and the catheter hub 20 are further advanced relative to the inner needle 14 and the inner needle hub 30 (or the inner needle 14 and the inner needle hub 30 are moved backward relative to the catheter 12 and the catheter hub 20. The inner needle 14 is detached from the catheter 12 and the catheter hub 20 and separated into an indwelling body 18 and a waste body 19. The indwelling body 18 includes the catheter 12 and the catheter hub 20 and is placed on the patient side. On the other hand, the waste body 19 includes the inner needle 14, the inner needle hub 30, the blunt needle 70, and the blunt needle hub 80, and the blunt needle 70 prevents the inner needle 14 from being erroneously pierced. The waste body 19 is discarded by the user. Hereinafter, the configuration of the catheter assembly 10 will be specifically described.

  The catheter 12 of the catheter assembly 10 has moderate flexibility and includes an axially extending lumen 12a therein. Although the full length of the catheter 12 is not specifically limited, For example, it is good that it is 14-500 mm, Preferably it is 30-400 mm, or it is more preferable that it is 76-200 mm.

  The constituent material of the catheter 12 is preferably a soft resin material, for example, a fluorine-based resin such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroalkoxy fluororesin (PFA), Examples thereof include olefin resins such as polyethylene and polypropylene, or a mixture thereof, polyurethane, polyester, polyamide, polyether nylon resin, a mixture of an olefin resin and an ethylene / vinyl acetate copolymer, and the like.

  The proximal end portion of the catheter 12 is fixed to the distal end portion in the catheter hub 20 by appropriate fixing means such as caulking, fusion, and adhesion. The catheter hub 20 is exposed on the patient's skin in a state where the catheter 12 is inserted into the blood vessel of the patient, and is affixed with a tape or the like and placed with the catheter 12. The catheter hub 20 is connected to other medical devices (fluid or blood transfusion tubes).

  The catheter hub 20 has a cylindrical shape that is tapered in the distal direction, is formed to be harder than the catheter 12, and includes a flange portion 21 that protrudes radially outward on the outer peripheral surface of the proximal end thereof. An internal space 20 a communicating with the lumen 12 a of the catheter 12 is formed inside the catheter hub 20. In this internal space 20a, a hemostatic valve (not shown) that prevents leakage of blood that has flowed back when the multi-structure needle 16 is punctured, a plug (not shown) that allows infusion through the hemostasis valve as the connector of the infusion tube is inserted, etc. May be accommodated.

  The constituent material of the catheter hub 20 is not particularly limited, and for example, a thermoplastic resin such as polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, methacrylate-butylene-styrene copolymer may be applied.

  On the other hand, the inner needle 14 is configured as a hollow tubular body having rigidity capable of puncturing living body skin, and includes a sharp needle tip 15 on the distal end side. The needle tip 15 has a blade surface 15a that is inclined with respect to the axial center of the inner needle 14, and is formed in a backcut shape that is notched so that the opposite side of the blade surface 15a is inclined (see also FIG. 6A). ).

  The most distal end 15 b that protrudes most at the tip of the needle tip 15 is located at a predetermined position in the circumferential direction (lower side in FIG. 6A) in front view, and is closer to the axial center than the outer peripheral surface of the inner needle 14. It is in. The shape of the needle tip 15 is not particularly limited, and a shape having a blade surface that is simply cut obliquely with respect to the axis of the inner needle 14 or a lancet in which the two left and right blade surfaces form a peak at the center in the width direction. It may be formed into a shape.

  A hollow portion 14 a extending in the axial direction is provided inside the inner needle 14, and the hollow portion 14 a includes a distal end opening 14 b provided in the needle tip 15 and a base provided at the proximal end of the inner needle 14. It communicates with the end opening 14c (see FIG. 4B). Further, the inner needle 14 has a hole portion 14 d that communicates the hollow portion 14 a and the outside of the inner needle 14 at a position spaced apart from the needle tip 15 in the proximal direction.

  Examples of the constituent material of the inner needle 14 include stainless steel, aluminum or aluminum alloy, metal material such as titanium or titanium alloy, hard resin, ceramics, and the like. The inner needle 14 is firmly fixed to the inner needle hub 30 by appropriate fixing means such as fusion, adhesion, and insert molding.

  As shown in FIG. 3, the inner needle hub 30 is a structural part that can be handled integrally with the inner needle 14, and is configured by assembling a housing 31, a support member 40, and a needle holding member 50. The housing 31 includes a rectangular lower wall 32 and a pair of side walls 33 protruding upward from both lateral sides of the lower wall 32, and is formed in a bowl shape having an accommodation space 34 inside thereof. ing. The housing 31 can be made of, for example, the material mentioned in the catheter hub 20.

  The base end side of the lower wall 32 with respect to the intermediate portion in the longitudinal direction is formed as a thinner arrangement portion 35 than the intermediate portion in the longitudinal direction, and the arrangement portion 35 is provided with a plurality of mounting holes 36. Yes. A needle holding member 50 is attached to the arrangement portion 35. The pair of side walls 33 extends along the longitudinal direction of the lower wall 32 and has a groove-shaped rail portion 37 on the inner surface on the distal end side formed higher than the proximal end side. The pair of rail portions 37 is continuous with an open portion 37 a formed at the top of the distal end side of each side wall 33, and is continuous with the upper surface of each side wall 33 on the base end side. A pair of rail part 37 accommodates the side edge 61a of the catheter operation member 60 so that sliding is possible. One of the pair of side walls 33 (the left side wall 33 in FIG. 1) has a bulging portion 38 that bulges outward in the width direction, and this bulging portion 38 is for attaching a support member 40. An arrangement recess 38a is formed.

  In order to support the lower side of the catheter 12 (multiple structure needle 16) held by the catheter operating member 60, the support member 40 is rotatably mounted in the placement recess 38a. A guide recess 41 a that is continuous with the rail portion 37 is provided on the inner side in the width direction of the head 41 of the support shaft in the support member 40. Since the side edge 61a of the catheter operating member 60 is present in the guide recess 41a, the support member 40 is restricted from rotating and waits below the catheter 12 to suppress bending of the catheter 12. The support member 40 can rotate when the side edge 61a is removed from the guide recess 41a when the catheter operation member 60 advances, and rotates toward the outside of the side wall 33 when the hub accommodating portion 62 of the catheter operation member 60 contacts. To do. Thereby, the catheter hub 20 and the catheter operation member 60 are smoothly removed from the housing 31.

  The needle holding member 50 is a member to which the inner needle 14 is directly fixed, and is fixed to the arrangement portion 35 of the housing 31. Further, the needle holding member 50 constitutes a part of the moving mechanism 81 of the blunt needle 70 and guides the movement of the blunt needle hub 80 and also regulates the advancement and retreat of the blunt needle hub 80 at a predetermined position. have.

  As shown in FIGS. 3, 4 </ b> A, and 4 </ b> B, the needle holding member 50 has a width that is inserted into the accommodation space 34 of the housing 31 and has a mounting plate portion 51 that is mounted on the lower wall 32. The mounting plate portion 51 is formed in a cross-sectional shape that matches the arrangement portion 35 of the lower wall 32, and a plurality of mounting protrusions 51 a that are inserted and fitted into the plurality of mounting holes 36 are provided on the lower surface thereof.

  Further, the needle holding member 50 includes a rectangular tube-shaped frame structure 52 from the intermediate portion of the mounting plate portion 51 to the proximal end side. The frame structure 52 includes a side frame 53 on one side in the width direction of the mounting plate 51, a guide frame 54 on the other side in the width direction of the mounting plate 51, and an upper portion of the side frame 53. A cover portion 55 that bridges the upper portion of the guide frame 54 is provided. An arrangement space 52a in which the blunt needle hub 80 is slidably arranged is formed inside the mounting plate portion 51 and the frame structure 52 (side frame 53, guide frame 54, cover portion 55).

  In addition, a holding main body portion 56 that holds the inner needle 14 is provided between the covering portion 55 and the mounting plate portion 51 in the vicinity of the tip of the covering portion 55. The holding main body portion 56 is formed in a block shape, and its base end surface defines a movement limit in the distal direction of the blunt needle hub 80. A holding hole 56 a for holding the inner needle 14 is provided at a predetermined height position of the holding main body portion 56. The holding hole 56 a penetrates the holding main body 56 in the front-rear direction (the axial direction of the housing 31), and connects and fixes the proximal end portion of the inner needle 14.

  The guide frame 54 of the frame structure 52 includes a lower guide portion 57 and an upper guide portion 58. The lower guide portion 57 protrudes low from the upper surface of the mounting plate portion 51 and extends in the distal direction beyond the cover portion 55 from the proximal end of the needle holding member 50 in a plan view. The distal end of the lower guide portion 57 is located somewhat on the proximal end side with respect to the distal end of the mounting plate portion 51. This tip is formed on a flat surface and constitutes a retraction restricting surface 57a for restricting retraction of the blunt needle hub 80 described later.

  The upper guide part 58 is provided between the upper part of the lower guide part 57 and the cover part 55, and is formed shorter than the extension length of the cover part 55 in planar view. On the proximal end side of the upper guide portion 58, an inclined surface 58a is formed which is inclined inward in the width direction (inside the frame structure 52) from the most proximal end toward the distal end direction. Further, a tip surface side of the upper guide portion 58 from the inclined surface 58 a is a flat surface 58 b parallel to the side frame 53.

  On the other hand, as shown in FIG. 3 and FIG. 5, the catheter operating member 60 directly holds the catheter 12 and accommodates the catheter hub 20, so that the catheter 12 and the catheter hub 20 are connected to the inner needle 14 and the inner needle hub 30. The relative advance and retreat. The catheter operation member 60 is connected to the operation plate portion 61 extending in the longitudinal direction of the housing 31, the hub accommodation portion 62 that accommodates the proximal end of the operation plate portion 61 and accommodates the catheter hub 20, and the proximal end of the hub accommodation portion 62. And an engaged portion 63 that can be engaged with the blunt needle hub 80.

  The operation plate portion 61 is a portion where the user performs an advance / retreat operation, and the pair of side edges 61 a are disposed on the pair of rail portions 37 of the housing 31 and the upper surfaces of the pair of side walls 33 in an initial state. The operation plate 61 is flexible and can be bent in a direction away from the inner needle 14 by being formed thin. One or more catheter holding portions 64 including a pair of projecting pieces 64a capable of holding the catheter 12 are provided on the lower surface of the operation plate portion 61 along the longitudinal direction. When the operation plate 61 is curved, the pair of projecting pieces 64a sequentially removes the grasping of the catheter 12.

  The hub accommodating portion 62 includes an upper plate 65 that is continuous with the operation plate portion 61 and a pair of side plates 66 that protrude downward from the upper plate 65, and the lower portion is opened inside the upper plate 65 and the pair of side plates 66. An accommodation chamber 62a of the catheter hub 20 is formed. Further, the distal end sides of the pair of side plates 66 are formed to be narrower than the catheter hub 20 by being curved inward, and form a gap 66a that opens downward. The catheter hub 20 is detachably held by an appropriate frictional force by the upper plate 65 and the pair of side plates 66 of the hub accommodating portion 62.

  The engaged portion 63 has a semicircular appearance and is formed in a frame shape with a part cut away when viewed from the proximal direction. An insertion hole 68 a through which the inner needle 14 is passed is formed in the intermediate frame 68 at the center in the width direction of the engaged portion 63. Further, an engaged convex portion 69 is provided on the side surface of the intermediate frame 68 so as to be inclined outward in the width direction and toward the base end side. The blunt needle hub 80 is caught on the engaged convex portion 69. Further, in the intermediate frame 68, the side surface 68 b on the distal end side with respect to the engaged convex portion 69 is located at the outer side in the width direction than the side surface 68 c on the proximal end side with respect to the engaged convex portion 69.

  Next, the blunt needle 70 and the blunt needle hub 80 of the catheter assembly 10 will be described. The blunt needle 70 extends longer than the inner needle 14 and is slidably inserted into the hollow portion 14 a of the inner needle 14.

  The blunt needle 70 includes a shutter portion 71, a distal end side rigid portion 72, a lateral movement portion 73, and a proximal end side rigid portion 74 in order from the distal end toward the proximal end direction. Each part of the blunt needle 70 is integrally formed so as to be continuous in series. The material constituting the blunt needle 70 is only required to obtain desired hardness and elasticity. For example, stainless steel, superelastic alloy such as Ni-Ti alloy, shape memory alloy, cobalt alloy, gold, platinum Such a precious metal, a metal material such as a tungsten alloy, or a resin material having a predetermined hardness or higher.

  The shutter portion 71 is a portion that extends thinner and shorter than the distal end side rigid portion 72 in the distal end region of the blunt needle 70. The shutter portion 71 moves toward the most distal end 15b side by moving further forward than the needle tip 15 of the inner needle 14 as the blunt needle 70 moves. Thereby, the front end 15b is not exposed in the front end direction in front view. The total length of the shutter portion 71 is not particularly limited, but is designed to be slightly longer than the total length of the blade surface 15a, for example.

  Specifically, the shutter portion 71 includes a blocking spring portion 75 that extends in a predetermined length from the base end, and a hook portion that is folded back from the blocking spring portion 75 so as to form an acute angle with the extending direction of the blocking spring portion 75. 76 and a projecting piece 77 that bends in a different direction from the hook 76.

  The blocking spring portion 75 is connected to the center of the distal end surface of the distal end side rigid portion 72 and is inclined in a predetermined direction with respect to the axial center of the distal end side rigid portion 72 in a natural state where no external force is received. With this inclination, the blocking spring portion 75 is arranged such that the distal end connected to the hook portion 76 is disposed radially outside the outer peripheral surface of the distal end side rigid portion 72 with respect to the proximal end continuous to the distal end side rigid portion 72.

  The shutter portion 71 is entirely disposed in the hollow portion 14a of the inner needle 14 in the initial state shown in FIG. 7A. The shutter portion 71 is elastically deformed so that the blocking spring portion 75 is opposite to the most distal end 15b by the force received from the inner needle 14 by the projecting piece portion 77 coming into contact with the inner peripheral surface constituting the hollow portion 14a. Let Accordingly, the blocking spring portion 75 biases the shutter portion 71 (hook portion 76, protruding piece portion 77) toward the most distal end 15b side of the inner needle 14. On the other hand, when the hook portion 76 moves further forward than the leading edge 15b with the movement of the blunt needle 70 in the distal direction, the blocking spring portion 75 is elastically restored by the absence of external force from the inner needle 14, and the hook portion 76 is moved to the most advanced 15b side.

  The blocking spring portion 75 has a first surface 75a that faces the most distal end 15b of the inner needle 14, and a second surface 75b that is the surface opposite to the first surface 75a. The first surface 75a is formed in a flat shape, while the second surface 75b is formed in an arc shape.

  The hook portion 76 is bent with a predetermined accuracy (for example, in the range of 45 ° to 90 °) from the tip of the blocking spring portion 75 to the first surface 75a side, and is outside (the most distal end 15b side of the inner needle 14) and the base. It is comprised by the site | part inclined to the end side. For example, the hook portion 76 extends with a length equal to or greater than the thickness of the inner needle 14. The hook portion 76 is disposed at a position facing the most distal end 15b of the inner needle 14 in a state where the shutter portion 71 has moved to the tip of the inner needle 14, and the hook portion 76 is at the highest position based on the backward movement of the shutter portion 71 by the operation mechanism 79 described later. It arrange | positions in the position which adjoins or contacts the front-end | tip 15b.

  That is, the hook portion 76 is a portion that directly prevents the inner needle 14 from being exposed to the distal end direction of the distal end 15b by being disposed near and opposite to the distal end 15b in a front view. The inside of the hook portion 76 (the first surface 75a of the blocking spring portion 75 and the facing surface 76a of the most distal end 15b) extends at an inclination with respect to the axis of the inner needle 14, so that the most advanced 15b It is possible to guide the leading edge 15b to the valley portion along the slope even if it contacts with the. The connecting portion of the second surface 75b of the blocking spring portion 75 and the exposed surface 76b of the hook portion 76 (the surface opposite to the facing surface 76a) extends in an arc shape in the width direction and is formed in a slender shape. Even if it contacts, it can prevent hurting.

  The projecting piece 77 is further folded back from the end of the hook portion 76, thereby projecting short toward the distal direction and radially outward. The protruding end 77 a of the protruding piece 77 is formed in an arc shape along the inner peripheral surface of the inner needle 14. In the initial state, the projecting piece 77 is in contact with the inner peripheral surface of the hollow portion 14a of the inner needle 14, thereby elastically deforming the blocking spring portion 75 and the hook portion 76 so as to be separated from the most distal end 15b. .

  Further, the projecting piece 77 contacts the inner peripheral surface of the catheter 12 by moving outward in the radial direction of the inner needle 14 along with the elastic restoration of the blocking spring portion 75. Due to the contact of the projecting piece 77, the inner peripheral surface of the catheter 12 is positively separated from the leading edge 15b. For this reason, if an operation of retracting the catheter 12 with respect to the inner needle 14 is performed, the catheter piercing of the needle tip 15 into the inner peripheral surface of the catheter 12 is prevented.

  Returning to FIGS. 6A and 6B, the distal end side rigid portion 72 of the blunt needle 70 is formed in a solid bar shape that is slightly narrower than the hollow portion 14 a of the inner needle 14. For this reason, the distal end side rigid portion 72 is configured to be sufficiently harder than the shutter portion 71 and holds the base end of the shutter portion 71 so as to be elastically deformable. The distal-side rigid portion 72 is designed so that most of the distal-side rigid portion 72 remains in the hollow portion 14a even when the blunt needle 70 moves in the distal direction and the shutter portion 71 is exposed from the distal end opening 14b of the inner needle 14.

  The side moving portion 73 of the blunt needle 70 has a function of retracting the shutter portion 71 and the distal end side rigid portion 72 by a small distance when the hook portion 76 of the shutter portion 71 moves further forward than the most distal end 15b of the inner needle 14. Have In detail, the side moving part 73 is formed in an elongated leaf spring shape (hereinafter referred to as a retreating spring part 78). The retreating spring portion 78 is bent a predetermined length between the distal end side rigid portion 72 and the proximal end side rigid portion 74 by bending a plurality of times (twice in FIG. 6A). Specifically, the retreating spring portion 78 includes a first extending portion 78a, a first bent portion 78b, a second extending portion 78c, a second bent portion 78d, and a third extending from the distal end toward the proximal end side. It has an existing portion 78e.

  The first extending portion 78 a has a distal end connected to the distal end side rigid portion 72 and is inclined in a direction away from the most distal end 15 b of the inner needle 14. The first bent portion 78b is in contact with the inner peripheral surface of the inner needle 14 in the initial state, but enters the hole portion 14d formed in the inner needle 14 while the blunt needle 70 moves in the distal direction. As a result, the first bent portion 78b moves outward in the radial direction of the inner needle 14, and draws the first extending portion 78a in the proximal direction. In other words, the operation mechanism 79 for retracting the shutter portion 71 is configured by the retracting spring portion 78 of the blunt needle 70 and the hole portion 14 d of the inner needle 14.

  The second extending portion 78c, the second bent portion 78d, and the third extending portion 78e of the retreating spring portion 78 extend and bend in the opposite direction with respect to the first bent portion 78b, and have a valley shape in a side view. Is forming. The second bent portion 78d is in constant contact with the inner peripheral surface of the inner needle 14 while being accommodated in the hollow portion 14a, and the first bent portion 78b overlaps the hole portion 14d when the blunt needle 70 moves. In such a case, the distance is increased so as to move greatly outward in the radial direction.

  In the catheter assembly 10, when the blunt needle 70 advances with the movement of the catheter 12 and the hook portion 76 of the shutter portion 71 moves further than the most distal end 15 b of the inner needle 14, It is designed so that one bent portion 78b enters the hole portion 14d of the inner needle 14. By the movement of the retreating spring portion 78, the hook portion 76 is retreated toward the most distal end 15b and is disposed at a position close to or in contact with the most distal end 15b.

  Specifically, the shutter portion 71 is disposed in the positional relationship shown in FIG. 7B as the backward spring portion 78 moves backward. That is, the base end top portion 76c of the hook portion 76 where the hook portion 76 of the shutter portion 71 and the projecting piece portion 77 are connected is located on the outer side in the radial direction of the inner needle 14 with respect to the most distal end 15b, and is more proximal than the most distal end 15b. It comes to be located on the end side. As a result, the hook portion 76 can be reliably hooked to the needle tip 15 of the inner needle 14, and the state in which the needle tip 15 is blocked by the shutter portion 71 is favorably continued.

  Returning to FIG. 6A, the proximal end side rigid portion 74 of the blunt needle 70 is formed in a circular cross section and is rigid like the distal end side rigid portion 72, and extends along the hollow portion 14 a of the inner needle 14 along the axial direction. is doing. The base end side rigid portion 74 constitutes most of the entire length of the blunt needle 70, and the base end side is connected and fixed to the blunt needle hub 80.

  The blunt needle hub 80 is housed in the housing 31 such that the blunt needle 70 is fixedly held and is movable relative to the inner needle 14 and the inner needle hub 30. In the present embodiment, the blunt needle hub 80 is engaged with the catheter operation member 60, and an operation force (advance output or retraction force) is transmitted from the catheter operation member 60, so that the inside of the housing 31 is in the distal direction or the base. Move in the end direction. During the movement of the blunt needle hub 80, the needle holding member 50 of the inner needle hub 30 guides the blunt needle hub 80, restricts advancement, retreats, and the like with the above-described configuration. That is, the needle holding member 50, the catheter operation member 60, and the blunt needle hub 80 constitute a moving mechanism 81 that moves the blunt needle 70 as the catheter 12 moves.

  As shown in FIGS. 8A and 8B, the blunt needle hub 80 is a member in which a holding portion 82, a hinge portion 83, and an arm portion 84 are integrally formed, and is arranged at an appropriate position of the needle holding member 50 in an initial state. The The holding portion 82 is formed in a block shape (rectangular shape) that is long in the axial direction of the inner needle hub 30 and holds the proximal end side of the blunt needle 70. An arrangement groove 82a is provided at an upper corner of the intermediate portion in the width direction of the front end surface of the holding portion 82, and the blunt needle 70 is fixed to the arrangement groove 82a. In the assembled state of the catheter assembly 10, the distal end surface of the holding portion 82 is disposed to face the proximal end surface of the holding main body portion 56 (see also FIG. 9). Therefore, when the blunt needle hub 80 advances relative to the needle holding member 50 and the distal end surface of the holding portion 82 comes into contact with the proximal end surface of the holding main body portion 56, the subsequent advancement of the blunt needle hub 80 is restricted.

  The hinge portion 83 protrudes short from the side surface of the holding portion 82 in one width direction (direction orthogonal to the extending direction of the holding portion 82: left direction in the present embodiment), and is armed with respect to the holding portion 82 in plan view. It functions as a base point for rotating the portion 84. The hinge portion 83 is continuous from the distal end surface of the holding portion 82 and supports a position somewhat on the proximal side from the middle portion in the longitudinal direction of the arm portion 84. Further, the hinge portion 83 is formed thin at the front and rear, and is formed at the same height as the vertical height of the holding portion 82.

  The arm portion 84 has an inner surface continuous with the hinge portion 83 and extends in parallel with the holding portion 82 in the initial state. The arm portion 84 includes a distal end arm 85 that extends sufficiently long in the distal direction with the hinge portion 83 as a base point, and a proximal end arm 86 that extends short in the proximal direction. The distal arm 85 extends in the distal direction from the cover portion 55 of the needle holding member 50 in the initial state. The proximal arm 86 extends to the same position as the proximal end of the holding portion 82.

  A cutout 87 is provided on the outer surface of the arm portion 84. The notch 87 has a structure in which the lower corner portion of the arm portion 84 is thinned, and extends from the proximal end of the arm portion 84 toward the distal end. The front end of the notch 87 reaches the vicinity of the engaging portion of the arm portion 84, and the surface facing the notch 87 is regulated to be caught on the retraction regulating surface 57a (see FIG. 4A) of the lower guide portion 57 of the needle holding member 50. A surface 87a is formed. Note that the side surface on the tip side of the notch 87 of the arm portion 84 (tip arm 85) is contacted and guided by the lower guide portion 57 when the blunt needle hub 80 is moved.

  Further, a protrusion 88 protruding outward in the width direction is provided on the outer surface of the arm portion 84 (base end arm 86). The protrusion 88 is located above the notch 87 and faces the upper guide portion 58 of the needle holding member 50 in the initial state. Accordingly, the protrusion 88 is brought into contact with and guided by the upper guide portion 58 when the blunt needle hub 80 is moved. The protrusion 88 protrudes toward the outer side by a predetermined amount (in a range where it does not contact the side wall 33 of the housing 31). The distal end side of the protrusion 88 is a tapered surface 88a that is inclined in the proximal direction and outward.

  On the other hand, the inner surface of the arm portion 84 is formed in a stepped shape such that the lower side slightly protrudes inward with respect to the upper side according to the notch 87. That is, the lower side of the arm portion 84 is formed so as to be thin as much as the cutout 87 is provided, and is configured to be closer to the inner side than the upper side. An engaging portion 89 that engages with the engaged portion 63 of the catheter operation member 60 in the initial state is provided near the tip of the inner surface of the tip arm 85. The engaging portion 89 includes a first engaging convex portion 89a located at the distal end and a second engaging convex portion 89b located closer to the base end side than the first engaging convex portion 89a.

  The first engagement convex portion 89 a protrudes inward from the tip of the arm portion 84. The distal end surface of the first engagement convex portion 89 a is formed in a flat shape perpendicular to the extending direction of the arm portion 84, while the proximal end surface of the first engagement convex portion 89 a is the extension of the arm portion 84. It is formed on a curved surface that is oblique and curved with respect to the direction.

  The second engaging convex portion 89b protrudes inside the arm portion 84 at a position separated from the first engaging convex portion 89a by a predetermined interval (generally the thickness of the engaged convex portion 69). The second engaging convex portion 89b has a larger protruding amount than the first engaging convex portion 89a. Further, the distal end surface of the second engagement convex portion 89 b is inclined with respect to the extending direction of the arm portion 84, while the proximal end surface of the second engagement convex portion 89 b is the extending direction of the arm portion 84. It is formed in the flat shape orthogonal to.

  The catheter assembly 10 forms the initial state as shown in FIG. 9 by appropriately assembling the above members. In the initial state, the catheter operating member 60 is disposed in front of the needle holding member 50 (frame structure 52) mounted on the housing 31 with the catheter hub 20 accommodated in the hub accommodating portion 62. Most of the blunt needle hub 80 is accommodated in the arrangement space 52a of the needle holding member 50, and the arm portion 84 protrudes from the arrangement space 52a. The engaging portion 89 of the distal arm 85 is engaged with the engaged portion 63 of the catheter operation member 60. Specifically, the first engaging convex portion 89 a of the engaging portion 89 is positioned on the tip side of the engaged convex portion 69 of the engaged portion 63, and the second engaging convex portion 89 b of the engaging portion 89. Is located closer to the base end side than the engaged protrusion 69.

  In the initial state, the arm portion 84 of the blunt needle hub 80 extends in parallel to the blunt needle 70 and the holding portion 82. The projecting portion 88 of the blunt needle hub 80 is closer to the proximal end side than the upper guide portion 58 of the needle holding member 50 and is not in contact with the upper guide portion 58. The holding portion 82 that holds the blunt needle 70 faces the holding main body portion 56 of the needle holding member 50.

  The blunt needle 70 extending linearly from the holding portion 82 is inserted into the hollow portion 14 a of the inner needle 14 and extends through the inner needle 14, and the shutter portion 71 on the distal end side is the hole portion 14 d of the inner needle 14. It is located on the base end side. The inner needle 14 fixed to the inner needle hub 30 and the blunt needle 70 fixed to the blunt needle hub 80 are in phase with each other depending on the arrangement state of the hubs. Further, the inner needle 14 is inserted into the lumen 12 a of the catheter 12 to constitute a multi-structure needle 16.

  The catheter assembly 10 according to the present embodiment is basically configured as described above, and the effects thereof will be described below.

  The catheter assembly 10 is used when constructing a transfusion or infusion introduction section as described above. In use, when the user punctures the patient with the multi-structure needle 16, blood flows into the hollow portion 14 a of the inner needle 14. In the initial state, the blunt needle 70 is positioned on the proximal end side with respect to the hole portion 14d, so that the blood that has flowed flows into the lumen 12a of the catheter 12 through the hole portion 14d. As a result, the user can visually confirm the blood flashback and confirm the securing of the blood vessel.

  In the puncture state of the multi-structure needle 16, as shown in FIGS. 2A and 10, the user pushes out the catheter hub 20 by inserting the catheter operating member 60, and inserts the catheter 12 into the blood vessel. As the catheter operation member 60 advances, the blunt needle hub 80 that engages the catheter operation member 60 also advances. Specifically, the engaged convex portion 69 is hooked on the engaging portion 89 (first engaging convex portion 89 a) of the blunt needle hub 80 to pull the arm portion 84. Accordingly, the blunt needle 70 advances relative to the inner needle 14 together with the catheter 12.

  Here, the projecting portion 88 of the blunt needle hub 80 is spaced apart from the proximal end side of the upper guide portion 58 of the needle holding member 50 in the initial state. Therefore, although the initial stage of advancement of the catheter operating member 60 is most difficult to operate (heavy), the present catheter assembly 10 allows the blunt needle hub 80 to move smoothly without causing the needle holding member 50 to almost obstruct the movement. Can do.

  Further, when the user wants to pull back the catheter 12 inserted into the blood vessel, the user retreats the catheter operation member 60. By the retraction of the catheter operating member 60, the engaged convex portion 69 of the catheter operating member 60 is hooked on the second engaging convex portion 89b of the blunt needle hub 80 and pushed in the proximal direction, whereby the blunt needle hub 80 is also integrated. Retreat. As a result, the catheter 12 and the blunt needle 70 are retracted with respect to the inner needle 14.

  When the catheter operation member 60 moves to some extent in the distal direction, the protrusion 88 (tapered surface 88a) of the blunt needle hub 80 is guided inward by the inclined surface 58a of the upper guide portion 58. Even in this state, the distal end arm 85 of the blunt needle hub 80 is guided to advance by the outer surface on the distal end side contacting the lower guide portion 57, and the engaged state of the engaged portion 63 by the engaging portion 89 is continued. . Therefore, the base end arm 86 on the base end side with respect to the hinge portion 83 of the blunt needle hub 80 is elastically deformed as a whole and accumulates the spring force. In particular, at the stage where the protrusion 88 reaches the flat surface 58b of the upper guide portion 58, the proximal arm 86 is greatly curved.

  As shown in FIG. 11, when the catheter operation member 60 continues to advance, the notch 87 of the arm portion 84 reaches the distal end of the lower guide portion 57 of the needle holding member 50, and the outer surface on the distal end side is the lower guide portion. Exit the 57 guide. For this reason, the arm portion 84 that has been elastically deformed is opened outward while the tip arm 85 is moved outward in the width direction with the hinge portion 83 as a base point, and the lower guide portion 57 is inserted into the notch 87. .

  In this way, the distal arm 85 opens in the direction (outward direction) opposite to the direction orthogonal to the axial direction of the blunt needle 70, whereby the engagement between the first engaging convex portion 89a and the engaged convex portion 69 is achieved. Canceled. Therefore, the catheter operation member 60 leaves the blunt needle hub 80 when the user performs an advance operation, and advances the catheter 12 and the catheter hub 20. On the other hand, the blunt needle hub 80 remains on the proximal end side of the holding main body portion 56 of the needle holding member 50.

  Further, at the time of advancement before the engagement is released, the shutter portion 71 at the tip of the blunt needle 70 performs a first movement that protrudes further forward than the most distal end 15b of the inner needle 14. Based on this first movement, the blocking spring part 75 performs a second movement that moves the hook part 76 and the projecting piece part 77 toward the most distal end 15b.

  Then, at the disengagement position between the catheter operation member 60 and the blunt needle hub 80, the blunt needle 70 causes the retreating spring portion 78 to just enter the hole portion 14d of the inner needle 14 (see also FIG. 6A). That is, the shutter portion 71 and the distal end side rigid portion 72 are retracted by the first bent portion 78b of the retreating spring portion 78 being moved radially outward of the inner needle 14 by a predetermined trigger. Accordingly, a third movement is performed in which the hook portion 76 of the blunt needle 70 that has moved further forward than the leading edge 15b is moved backward in the proximal direction by the first and second movements.

  As shown in FIG. 7B, the hook portion 76 is disposed in the vicinity of the tip of the innermost needle 15b in the vicinity of the tip 15b, and the tip of the tip 15b is made unexposed by the hook 76. . In addition, the catheter 12 is supported by the projecting portion 77 of the blunt needle 70 so that the catheter 12 itself and the needle tip 15 are separated from each other.

  Further, when the front end 15 b is not exposed by the shutter portion 71, the blunt needle hub 80 is restricted from being retracted by the needle holding member 50. Specifically, the distal end of the arm portion 84 remains displaced outward in the width direction by the protrusion 88 and the upper guide portion 58, and in this state, the regulated surface 87 a constituting the notch 87 is at the distal end of the lower guide portion 57. It catches on the reverse regulating surface 57a. The blunt needle hub 80 is also restricted from moving in the distal direction because the holding main body portion 56 of the needle holding member 50 exists in front of the holding portion 82. Therefore, the blunt needle 70 maintains the unexposed state of the most advanced 15b well.

  Thereafter, as described above, the user sends the catheter operation member 60 from the distal end of the housing 31 (see FIG. 2B), and further separates the catheter hub 20 from the distal ends of the inner needle 14 and the blunt needle 70 (waste body 19). In addition, the user places the indwelling body 18 in the patient by separating the catheter operating member 60 from the catheter hub 20 (see FIG. 2C). On the other hand, the waste body 19 is discarded by the user. At this time, since the blunt needle 70 blocks the needle tip 15 of the inner needle 14, the inner needle 14 is prevented from being erroneously stuck.

  As described above, in the catheter assembly 10 according to the first embodiment, the blunt needle 70 is disposed in the inner needle 14 so as to be able to advance and retreat, and the shutter portion 71 of the blunt needle 70 is ahead of the most distal end 15b of the inner needle 14. In the moved state, the inner needle 14 moves to the most distal end 15b side. Thereby, the front-end | tip 15b of the inner needle 14 can be made unexposed in front view. Therefore, for example, even when a living finger approaches from the tip of the inner needle 14 toward the most distal end 15b, the contact can be blocked by the shutter portion 71. That is, the blunt needle 70 can more reliably prevent the inner needle 14 from being pierced more reliably, and can further increase the safety of the catheter assembly 10 after use.

  Further, the catheter assembly 10 moves the shutter portion 71 moved to the most distal end 15b side of the inner needle 14 by the operation mechanism 79 in the proximal direction, thereby sufficiently moving the shutter portion 71 to the most distal end 15b of the inner needle 14. Approach or touch. Therefore, the shutter part 71 can make the most advanced state 15b of the inner needle 14 a non-exposed state more favorably.

  In particular, the operating mechanism 79 moves the shutter portion 71 in the proximal direction as the blunt needle 70 advances in the distal direction. Therefore, the user can easily bring the shutter portion 71 close to the most distal end 15b of the inner needle 14 without performing any operation other than the advance operation of the blunt needle 70.

  Further, the catheter assembly 10 has a side moving portion 73 that moves a part of the blunt needle 70 to the side of the inner needle 14, thereby shortening the length of the blunt needle 70 with respect to the axial direction of the inner needle 14. be able to. Therefore, if the base end of the blunt needle 70 is fixed, the shutter portion 71 can be easily moved in the base end direction.

  In addition to the above configuration, the blunt needle 70 is substantially linear when the retreating spring portion 78 is in contact with the inner peripheral surface of the inner needle 14, so that the blunt needle 70 can be viewed from the proximal end side of the blunt needle 70. The moving force can be transmitted to the distal end side so that the shutter portion 71 can be smoothly advanced and retracted. On the other hand, the retreating spring part 78 can easily retreat the shutter part 71 on the front end side with respect to the retreating spring part 78 in accordance with the elastic recovery to the side by entering the hole 14d.

  The catheter assembly 10 has the hook portion 76, so that the hook portion 76 can be retracted to a position where it can be hooked on the most distal end 15 b of the inner needle 14 as the shutter portion 71 is retracted. Thereby, for example, even if a force is applied to the shutter portion 71 in a direction away from the inner needle 14, the hook portion 76 is hooked on the most distal end 15 b of the inner needle 14 and the unexposed state of the inner needle 14 is continued. Accordingly, it is possible to more firmly prevent the inner needle 14 from being pierced.

  In particular, when the shutter portion 71 is moved in the proximal direction, the proximal end apex portion 76c of the hook portion 76 is positioned on the proximal end side and the radially outer side with respect to the most distal end 15b of the inner needle 14, thereby the hook portion 76. Can be reliably hooked by the inner needle 14.

  Further, in the catheter assembly 10, since the shutter portion 71 has the protruding piece portion 77, the protruding piece portion 77 holds the catheter 12 in a state where the protruding piece portion 77 is exposed ahead of the most distal end of the inner needle 14. Push outward in the radial direction to move away from the leading edge 15b. Therefore, it is possible to suppress the catheter sticking that the inner needle 14 sticks into the inner peripheral surface of the catheter 12.

  The catheter assembly 10 urges the shutter portion 71 by the blocking spring portion 75 in a state where the shutter portion 71 is housed in the inner needle 14, so that the shutter portion 71 is moved to the tip of the most advanced 15 b. Then, the shutter portion 71 is simply moved to the most advanced 15b side.

  Since the shutter portion 71 has a shape that fits in the hollow portion 14a of the inner needle 14 in a front view, the shutter portion 71 can smoothly move through the hollow portion 14a and move toward the tip of the inner needle 14. In addition, the shutter portion 71 can be designed to have a width that is slightly narrower than the diameter of the hollow portion 14a, so that the leading edge 15b of the inner needle 14 can be blocked with a sufficient width.

  Further, the blunt needle 70 has the distal end side rigid portion 72, so that the proximal end of the blocking spring portion 75 can be firmly supported and the biasing by the blocking spring portion 75 can be realized. Further, it is possible to reliably transmit the moving force for moving the shutter unit 71 back and forth.

  The catheter assembly 10 can employ various applications and modifications. For example, the catheter assembly 10 does not include the operation mechanism 79 for retracting the blunt needle 70, that is, the shutter portion 71 does not have to be retracted. Even in this case, if the shutter portion 71 moves to the most distal end 15b side of the inner needle 14, the most distal end 15b is not exposed in a front view, and contact from the distal end side can be blocked.

  Further, for example, the blunt needle 70 may be configured not to include one or both of the hook portion 76 and the protruding piece portion 77. For example, the cutting edge 15b can be unexposed in a front view even if the blocking spring portion 75 is inclined and extends.

  Further, as shown in FIG. 12, the catheter assembly 10 has a proximal end top portion 76c of the hook portion 76 until the movement of the blunt needle 70 is restricted (the blunt needle hub 80 is engaged with the needle holding member 50). However, the structure located inside radial direction rather than the most distal end 15b of the inner needle 14 may be sufficient. Thereby, when the user wants to retract the catheter 12 in the middle of advancement, the blunt needle 70 can be retracted together with the retracting of the catheter 12.

  Furthermore, the operation mechanism 79 for retracting the shutter portion 71 of the blunt needle 70 is not limited to the above configuration, and various configurations can be adopted. For example, a configuration may be adopted in which the blunt needle 70 is urged in the proximal direction by an urging member (not shown) as the blunt needle 70 advances, and is retracted by a trigger such as a button pressing operation.

  Alternatively, the operation mechanism 79 may be configured to have the operation mechanism 79 closer to the proximal end side than the inner needle 14 (holding portion 82). In this case, the operation mechanism 79 can constitute a side moving unit 73 that moves a part of the blunt needle 70 to the side without being limited to the inner peripheral surface of the inner needle 14, and the retraction amount of the shutter unit 71. Can be increased. In addition, the degree of freedom in design such as the shape of the spring can be increased.

  Furthermore, the operating mechanism 79 not only forms a hole 14d for inserting the first bent portion 78b in the inner needle 14, but also a hole for inserting the second bent portion 78d as shown by a dotted line in FIG. 6A. 14e may be provided at a position opposite to the hole 14d. Thereby, the retraction amount of the shutter part 71 can be increased.

[Second Embodiment]
Next, a catheter assembly 10A according to a second embodiment will be described with reference to FIGS. In the following description, the same components as those of the catheter assembly 10 according to the first embodiment or components having the same functions are denoted by the same reference numerals, and detailed description thereof is omitted.

  This catheter assembly 10A is different from the first embodiment in the operation mechanism 90 for moving the blunt needle 120. Specifically, the catheter assembly 10A has an inner needle hub 100 formed in a cylindrical shape. The accommodation space 101 in the inner needle hub 100 is provided with a needle holding portion 102 for holding the inner needle 14, and a catheter hub 20 in which the catheter 12 is fixed to the distal end side of the needle holding portion 102 is accommodated. . Further, the catheter operation member 110 is inserted into the accommodation space 101, and the catheter operation member 110 is inserted to the inner portion of the inner needle hub 100 (the proximal end side with respect to the needle holding portion 102).

  A gear structure 103 that constitutes an operating mechanism 90 of the blunt needle 120 is provided on the inner wall that constitutes the accommodating space 101 of the inner needle hub 100. The gear structure 103 includes a first pinion 104 disposed on the upper side in a side view of the inner needle hub 100 and a second pinion 105 that meshes with the first pinion 104 on the lower side of the first pinion 104. Further, the thickness in the width direction of the first pinion 104 is formed to be thinner (for example, ½ the thickness) than the thickness in the width direction of the second pinion 105. The first pinion 104 meshes with the outer side in the width direction of the second pinion 105. In the gear structure 103 configured as described above, the first pinion 104 and the second pinion 105 rotate in opposite directions in a side view.

  On the other hand, the catheter operating member 110 is configured as a blunt needle operating portion that moves the blunt needle 120 and the blunt needle hub 130 in addition to advancing and retracting the catheter hub 20. For this reason, two racks (first rack 111 and second rack 112) are provided on the proximal end side of the catheter operation member 110 in correspondence with the gear structure portion 103.

  The first rack 111 is disposed at a height position where it can mesh with the first pinion 104, and extends a predetermined length along the axial direction of the inner needle hub 100. Further, as shown in FIG. 13B, the first rack 111 protrudes from the side surface of the catheter operation member 110 and is disposed at a position overlapping the first pinion 104.

  As shown in FIG. 13A, the second rack 112 is arranged at a height position at which the second rack 112 can mesh with the second pinion 105 on the base end side with respect to the first rack 111. The second rack 112 is formed shorter than the first rack 111. Further, as shown in FIG. 15B, the second rack 112 protrudes from the side surface of the catheter operation member 110 and is disposed at a position that is shifted in the width direction with respect to the first pinion 104 and overlaps the second pinion 105.

  And as shown to FIG. 13A and 13B, the blunt needle 120 which interrupts | blocks the inner needle 14 equips the front-end | tip with the shutter part 71 similar to the blunt needle 120 of 1st Embodiment. On the other hand, a proximal end side of the blunt needle 120 with respect to the shutter portion 71 is a rigid portion 121 in which a solid bar having a circular cross section extends in a series (linear shape). The base end of the rigid portion 121 is connected to the blunt needle hub 130, and the blunt needle 120 and the blunt needle hub 130 are configured to move integrally.

  The blunt needle hub 130 is slidably disposed relative to the inner needle hub 100 in the accommodation space 101. The blunt needle hub 130 is constituted by a blunt needle side rack 131 having meshing teeth on the upper surface. The blunt needle side rack 131 is formed to have the same width as the thickness of the second pinion 105 in the width direction, and meshes from the lower side of the second pinion 105. That is, the blunt needle hub 130 moves relative to the inner needle hub 100 as the second pinion 105 rotates. The longitudinal length of the blunt needle side rack 131 is designed to be slightly longer than the first rack 111 of the catheter operating member 110, and its proximal end position is closer to the proximal end side than the proximal end of the first rack 111 in the initial state. positioned.

  In the catheter assembly 10A configured as described above, in the initial state, the first pinion 104 meshes with the distal end side of the first rack 111 of the catheter operating member 110, and the distal end of the blunt needle side rack 131 of the blunt needle hub 130. The second pinion 105 is engaged with the side. On the other hand, the second rack 112 of the catheter operation member 110 exists at a position separated from the second pinion 105.

  Accordingly, when the user advances the catheter operation member 110, the first pinion 104 rotates counterclockwise in a side view, and the second pinion 105 that meshes with the first pinion 104 rotates clockwise. Therefore, the blunt needle side rack 131 that meshes with the second pinion 105 receives the clockwise rotational force of the second pinion 105 and moves in the distal direction relative to the inner needle 14 and the inner needle hub 100. become. That is, the blunt needle 120 in the inner needle 14 moves in the distal direction as the blunt needle hub 130 advances.

  Then, at the stage where the hook portion 76 of the shutter portion 71 of the blunt needle 120 has moved further forward than the most distal end 15 b of the inner needle 14, the first pinion 104 is just removed from the proximal end of the first rack 111. Similarly to the first embodiment, when the hook portion 76 moves further forward than the most distal end 15b, the hook portion 76 moves toward the most distal end 15b under the urging force of the blocking spring portion 75.

  In this state, the engagement between the blunt needle side rack 131 and the second pinion 105 is continued. When the user further advances the catheter operation member 110, the second rack 112 is engaged with the second pinion 105. When the second rack 112 is engaged, the second pinion 105 rotates counterclockwise as the second rack 112 advances. That is, the blunt needle side rack 131 receives counterclockwise rotational force from the second pinion 105 and moves in the proximal direction relative to the inner needle 14 and the inner needle hub 100. That is, the shutter portion 71 (hook portion 76) is also retracted, and the hook portion 76 is hooked on the most distal end 15b of the inner needle 14. Thereby, the interruption | blocking state of the inner needle 14 by the shutter part 71 is constructed | assembled.

  The catheter assembly 10 </ b> A may include a mechanism that regulates the retraction limit of the blunt needle 120 as well as restricting the retraction of the blunt needle 120 by the hook portion 76 being caught by the needle tip 15. For example, as shown by a dotted line in FIG. 15A, the mechanism portion is provided with an engagement protrusion 106 on the inner needle hub 100 and an engagement recess 132 on the blunt needle hub 130, respectively. By engaging the engaged recess 132, the retraction of the blunt needle 120 and the blunt needle hub 130 may be regulated.

  As described above, the catheter assembly 10A according to the second embodiment includes the operation mechanism 90 that performs both advancement and retraction of the blunt needle 120 with the advancement movement of the blunt needle operation unit (catheter operation member 110). Thus, the cutting-edge 15b of the inner needle 14 can be blocked by the shutter portion 71 of the blunt needle 120 with a simple operation. Moreover, the operation mechanism 90 can easily adjust the amount of advancement and retreat of the blunt needle 120 by appropriately designing the gear ratio. For example, the blunt needle 120 may be maintained in the advanced state until the catheter 12 is inserted into the blood vessel to some extent, and the blunt needle 120 may be retracted immediately before the insertion is completed.

DESCRIPTION OF SYMBOLS 10, 10A ... Catheter assembly 12 ... Catheter 14 ... Inner needle 14a ... Hollow part 14d ... Hole 15 ... Needle tip 15b ... Most advanced 20 ... Catheter hub 30, 100 ... Inner needle hub 50 ... Needle holding member 60, 110 ... Catheter operation member 70, 120 ... blunt needle 71 ... shutter part 72 ... distal end side rigid part 73 ... lateral movement part 74 ... proximal end side rigid part 75 ... blocking spring part 76 ... hook part 76c ... proximal end top part 77 ... protrusion Single part 78 ... Spring part 79, 90 ... Operating mechanism 80, 130 ... Blunt needle hub 103 ... Gear structure part 121 ... Rigid part

Claims (11)

A catheter;
A hollow inner needle that is removably inserted into the catheter and has a leading edge at a predetermined position in the circumferential direction in a front view;
A safety member having a shutter part that is more gradual than the leading edge of the inner needle, and arranged to be able to advance and retreat in the inner needle; and
The catheter assembly is characterized in that the shutter portion moves toward the most distal side of the inner needle in a state where the shutter member has moved further forward than the most distal end of the inner needle due to advancement of the safety member. The catheter assembly of claim 1.
A catheter assembly comprising an operation mechanism for moving the shutter portion in the proximal direction after the shutter portion has moved to the most distal side of the inner needle. The catheter assembly of claim 2,
The operation mechanism is configured to move the shutter portion in the proximal direction based on the proximal end portion of the safety member moving in the distal direction. The catheter assembly of claim 3,
The operating mechanism includes a side moving unit that moves a part of the safety member to the side of the inner needle based on a predetermined trigger during movement of the safety member in the distal direction. Solid. The catheter assembly according to claim 4.
The operating mechanism includes a hole formed at an intermediate position of the inner needle,
The lateral movement portion is provided on a proximal end side with respect to the shutter portion, is brought into contact with the inner peripheral surface of the inner needle and is elastically deformed to be substantially linear, and moves to a position overlapping the hole portion. A catheter assembly, wherein the catheter assembly is a retracting spring part that elastically recovers laterally by entering the hole part. The catheter assembly according to any one of claims 2 to 5,
The said shutter part has a hook part which can be hooked on the forefront of the said inner needle. The catheter assembly characterized by the above-mentioned. The catheter assembly according to claim 6.
The hook portion has a proximal end apex portion that is located on the proximal end side and radially outward from the most distal end of the inner needle in a state where the shutter portion is moved in the proximal direction by the operation mechanism. Catheter assembly. The catheter assembly according to any one of claims 1 to 7,
When the shutter portion is present in the catheter, the shutter portion has a protruding piece portion that regulates contact between the catheter and the most distal end of the inner needle by contacting the inner peripheral surface of the catheter. A catheter assembly. The catheter assembly according to any one of claims 1 to 8,
The catheter assembly, wherein the safety member includes a blocking spring portion that biases the shutter portion toward the most distal side of the inner needle in a state where the shutter portion is accommodated in the inner needle. The catheter assembly of claim 9,
The catheter assembly, wherein the shutter portion is housed in the inner needle and has a shape that fits into a hollow portion of the inner needle in a front view. The catheter assembly according to claim 9 or 10,
The catheter assembly, wherein the safety member includes a rigid portion that is continuous with a base end of the blocking spring portion and is formed to be harder than the blocking spring portion.

Images