JP2016007429A - Indwelling needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indwelling needle facilitating pull-out of an inner needle and scarcely causing accidental detachment of a protector.SOLUTION: The indwelling needle includes: an inner needle 111; an outer needle 131; an outer needle hub 132 provided at a rear end of the outer needle 131; and a needle tip protector 151 detachably engaged with the outer needle hub 132. The outer needle hub 132 includes a storage part 133 having a recessed part 133a provided at the rear end and capable of storing the needle tip protector 151. When the length of a side wall of the recessed part 133a is L1, the length of the needle tip protector 151 is L2, and an interval between the recessed part 133a and the needle tip protector 151 at the rear end of the recessed part 133a is L3, the indwelling needle satisfies a relational expression of L2-L1<L3.

Description

  The present disclosure relates to an indwelling needle, and more particularly, to an indwelling needle provided with a safety mechanism that protects a used needle tip.

  Conventionally, an indwelling needle that is assembled so that an inner needle passes through an outer needle is known. Generally, the inner needle is a metal needle having a sharp tip, and the outer needle is made of a resin having elasticity. The indwelling needle is punctured into the patient's blood vessel with the inner needle and the outer needle assembled. Thereafter, the inner needle is removed and the outer needle is placed in the patient's blood vessel. By using an indwelling outer needle, infusion, hemodialysis, blood collection, and the like can be performed.

  The pulled out inner needle is discarded, but since the inner needle has a sharp tip, it is necessary to discard it with a protective cap or the like. On the other hand, a needle stick accident is likely to occur when wearing a protective cap or the like. For this reason, a mechanism for automatically protecting the needle tip after use is required.

  For example, a protector is incorporated into an outer needle hub provided at the rear end portion of the outer needle, and when the inner needle is pulled out from the outer needle, the distal end portion of the protector is closed by the force of the spring and covers the distal end portion of the inner needle. At the same time, a mechanism in which the protector is detached from the outer needle hub has been proposed (see, for example, Patent Document 1). However, the conventional spring-type protector has a problem that a large force is required to pull out the inner needle because the biasing force of the spring is applied to the inner needle. Inadvertently applying a large force when pulling the inner needle may cause pain to the patient and damage the patient's blood vessels.

  In view of this, a protection mechanism has been proposed in which the force of the magnet is used to engage the outer needle hub and the protector and close the protector tip (see, for example, Patent Document 2). By using the force of the magnet, there is an advantage that it is not necessary to apply a large force when the inner needle is pulled out.

JP 2010-88520 A International Publication No. 2013/027355 Pamphlet

  However, the conventional magnet type protector has a problem that the protector is easily detached from the outer needle hub before the inner needle is completely pulled out from the outer needle. The same problem occurs when the force required to pull out the inner needle is reduced, not limited to the magnet type. If the protector is detached from the outer needle hub before the inner needle is completely pulled out from the outer needle, the distal end portion of the inner needle is not accommodated in the protector, and the distal end of the inner needle is exposed. If the engaging force between the protector and the outer needle hub is increased, it is possible to make it difficult to remove the protector, but it is difficult to smoothly remove the protector from the outer needle hub.

  An object of the present disclosure is to make it possible to realize an indwelling needle in which the inner needle can be easily pulled out and the protector is not easily detached.

  One aspect of the indwelling needle of the present disclosure includes an inner needle, an outer needle through which the inner needle can be inserted, an outer needle hub provided at a rear end portion of the outer needle, and an inner needle inserted into the outer needle. An inner needle is inserted and includes a needle tip protector that is detachably engaged with the outer needle hub. The needle tip protector has a front end side opening portion and a rear end side opening portion, and a cylinder through which the inner needle is inserted. And a closing portion that closes the distal end side opening when the distal end portion of the inner needle is accommodated inside the cylindrical portion, the inner needle can pass through the front end side opening, and the rear end The outer needle hub includes a housing portion having a recess that can receive the needle tip protector, the length of the side wall of the recess is L1, and the length of the needle tip protector is L2. When the distance between the concave portion at the rear end portion of the concave portion and the needle tip protector is L3, the relationship of L2-L1 <L3 is satisfied.

  In one aspect of the indwelling needle, L2-L1 may be 0 or less.

  In one mode of the indwelling needle, the blocking portion includes a first magnetic member provided at the distal end portion of the cylindrical portion, and a first magnetic member side when the distal end of the inner needle is accommodated in the cylindrical portion. And a second magnetic member that closes the front end side opening, and the outer needle hub has a third magnetic member provided on the rear end side, and the first magnetic member and the second magnetic member At least one of the two magnetic members is a magnet, and in a state where the inner needle is inserted through the outer needle, the needle tip protector includes at least one of the first magnetic member and the second magnetic member, and the third magnetic member. May be detachably engaged with the outer needle hub.

  One aspect of the indwelling needle further includes an inner needle hub provided at a rear end portion of the inner needle, and the inner needle hub has a cover portion that is provided at the distal end portion and is fitted on the side wall of the housing portion, The length of the portion may be equal to or longer than the length of the portion protruding from the outer needle of the inner needle.

  In one aspect of the indwelling needle, the housing portion may be separable from other portions of the outer needle hub.

  According to the indwelling needle of the present disclosure, the inner needle can be easily pulled out and the protector can be prevented from being unintentionally detached.

It is sectional drawing which shows the assembled state of the indwelling needle which concerns on one Embodiment. (A) And (b) is sectional drawing which shows the outer needle and inner needle of the indwelling needle which concern on one Embodiment, respectively. It is sectional drawing which shows the needle point protector of the indwelling needle which concerns on one Embodiment. (A)-(d) is sectional drawing which shows operation which pulls out the inner needle of the indwelling needle which concerns on one Embodiment in order. (A)-(d) is sectional drawing which expands and shows operation which pulls out the inner needle of the indwelling needle which concerns on one Embodiment in order. It is sectional drawing which shows the relationship between a needlepoint protector and an accommodating part. It is sectional drawing which shows the modification of the indwelling needle which concerns on one Embodiment. It is sectional drawing which shows the modification of the indwelling needle which concerns on one Embodiment.

  In this embodiment, unless otherwise specified, when using the indwelling needle 100, the side that becomes the patient side is referred to as the front end, and the side to which the other medical device on the opposite side is connected is referred to as the rear end.

  As shown in FIGS. 1, 2 (a), and 2 (b), the indwelling needle 100 of this embodiment is assembled with an inner needle 111 inserted through an outer needle 131. An inner needle hub 112 is provided at the rear end portion of the inner needle 111. An outer needle hub 132 is provided at the rear end portion of the outer needle 131. The outer needle hub 132 has a receiving portion 133 provided at the rear end. In a state where the inner needle 111 is inserted into the outer needle 131 and assembled, the needle tip protector 151 is accommodated in the accommodating portion 133.

  As shown in FIG. 3, the needle tip protector 151 has a front end side opening 152a and a rear end side opening 152b, a cylindrical portion 152 through which the inner needle 111 is inserted, and a front end of the inner needle 111 is cylindrical. And a closing portion 153 that closes the distal end side opening 152 a when housed in the portion 152. The closing portion 153 includes a fixed first magnetic member 161 and a second magnetic member 162 that can slide in the closing portion passage 156 provided at the distal end portion of the cylindrical portion 152. At least one of the first magnetic member 161 and the second magnetic member 162 is a magnet. At least one of the first magnetic member 161 and the second magnetic member 162 also functions as a member that engages the needle tip protector 151 with the accommodating portion 133.

  In the present embodiment, the cylindrical portion 152 is a stepped cylindrical shape having a front end side larger than a rear end side and having a step portion in an intermediate portion in the axial direction. The large-diameter portion on the distal end side has a substantially D-shaped cross section in which a part of a circle is cut off. The large-diameter portion is provided with a closing portion passage 156 in which the second magnetic member 162 is accommodated so as to be movable in the radial direction. The first magnetic member 161 is fixed so as to be exposed in the closing portion passage 156. When the inner needle 111 is inserted through the distal end side opening 152a, the closing portion passage 156 is closed by the inner needle 111, and the second magnetic member 162 disposed in the closing portion passage 156 is the first magnetic member 162. Cannot move to the magnetic member 161 side. Although the second magnetic member 162 may come into contact with the inner needle 111, the force applied to the inner needle 111 is thereby very small and hardly affects the withdrawal of the inner needle 111. When the needle tip 111a of the inner needle 111 is accommodated in the cylindrical portion 152, the closing portion passage 156 is opened, and the second magnetic member 162 slides and moves in the closing portion passage 156, so that the second magnetic member The member 162 is attracted to the first magnetic member 161 by a magnetic force. Thereby, the front end side opening 152a is closed.

  The housing part 133 has a third magnetic member 163. The third magnetic member 163 is arranged so that an attractive force is generated between at least one of the first magnetic member 161 and the second magnetic member 162. As a result, the needle tip protector 151 can be engaged with the accommodating portion 133. Hereinafter, a configuration in which an attractive force is generated between the third magnetic member 163 and the first magnetic member 161 will be described as an example. In this case, when the first magnetic member 161 is a magnet, the third magnetic member 163 may be a magnet or a magnetic body that is not a magnet. When the first magnetic member 161 is a magnetic body that is not a magnet, the third magnetic member 163 is a magnet.

  For example, as shown in FIGS. 4A and 5A, in a state where the inner needle 111 is inserted through the outer needle 131 and assembled, the first magnetic member 161 and the third magnetic member 163 Are arranged opposite to each other, and the needle tip protector 151 is detachably engaged with the accommodating portion 133 by an attractive force generated between the first magnetic member 161 and the third magnetic member 163.

  When the inner needle 111 is moved to the rear end side as shown in FIGS. 4B and 5B, the cover portion 114 of the inner needle hub 112 is separated from the accommodating portion 133, but the needle tip protector 151 is And held in the state of being engaged with the accommodating portion 133. When the inner needle 111 is further moved to the rear end side, the drop-off preventing portion 118 provided on the inner needle 111 reaches the distal end side opening portion 152 a of the cylindrical portion 152. Since the diameter of the front end side opening 152a is larger than the maximum width of the fall prevention part 118, the fall prevention part 118 can pass through the front end side opening 152a.

  When the inner needle 111 is further moved to the rear end side, as shown in FIGS. 4C and 5C, the needle tip 111a of the inner needle 111 is accommodated in the needle tip protector 151, and the distal end side opening 152 a is closed by the second magnetic member 162. Since the first magnetic member 161 and the second magnetic member 162 are attracted by magnetic force, the distal end side opening 152a is not opened by changing the direction of the needle tip protector 151 or the like.

  When the inner needle 111 is further moved to the rear end side, the drop-off prevention unit 118 reaches the rear end side opening 152b. Since the maximum width of the dropout prevention portion 118 is larger than the diameter of the rear end side opening portion 152b, the dropout prevention portion 118 cannot pass through the rear end side opening portion 152b. For this reason, as shown in FIGS. 4D and 5D, the needle tip protector 151 moves to the rear end side together with the inner needle 111, and the needle tip protector 151 is detached from the outer needle hub 132. Since the needle tip 111a of the inner needle 111 is housed in the needle tip protector 151 and the distal end side opening 152a is closed, the inner needle 111 can be safely discarded.

  In the present embodiment, the needle tip protector 151 is engaged with the housing portion 133 by the attractive force of the first magnetic member 161 and the third magnetic member 163, and can be disengaged by a small force. For this reason, the inner needle 111 can be smoothly pulled out from the outer needle 131. However, when a finger or the like touches the needle tip protector 151 when pulling out the inner needle 111, the needle tip protector 151 is unintentionally detached from the outer needle hub 132 before the needle tip 111a of the inner needle 111 is received. There is a fear.

  If the needle tip protector 151 is detached from the outer needle hub 132 before the needle tip 111a of the inner needle 111 is accommodated, the needle tip 111a of the inner needle 111 remains exposed, and safety cannot be ensured. However, in the indwelling needle 100 of the present embodiment, the needle tip protector 151 is accommodated in the recess 133a of the accommodating portion 133. Further, as shown in FIG. 6, when the length of the side wall of the concave portion 133a is L1, the length of the needle tip protector 151 is L2, and the distance between the concave portion 133a and the needle tip protector 151 at the rear end portion of the concave portion 133a is L3. , L2-L1 <L3 is satisfied. For this reason, until the inner needle 111 is completely pulled out from the outer needle 131, the fingertip protector 151 is hardly touched by a finger or the like. Therefore, the needle tip protector 151 can be hardly detached from the outer needle hub 132 before the needle tip 111a of the inner needle 111 is accommodated. By not touching the needle tip protector 151 with a finger or the like, an effect of reducing the risk of infection can be obtained. L2-L1 may be 0 or less, and the side wall length L1 of the recess 133a may be greater than or equal to the length L2 of the needle tip protector 151. By setting L2−L1 ≦ 0, it is possible to further reduce the possibility that a finger or the like touches the needle tip protector 151.

  Further, when the inner needle 111 is tilted greatly when the inner needle 111 is pulled out, the friction between the inner needle 111 and the needle tip protector 151 increases, and the needle tip protector 151 is removed before the distal end side opening 152a is closed. There is a risk of detachment from the needle hub 132. However, since the indwelling needle 100 of this embodiment has a long outer wall of the housing part 133, the outer wall of the housing part 133 serves as a guide when the inner needle 111 is pulled out. For this reason, the inner needle 111 cannot be greatly tilted and can be pulled out straight, and unintentional detachment of the needle tip protector 151 can be made difficult to occur. Further, since the inner needle 111 cannot be greatly tilted and can be pulled out straight, it is possible to reduce the burden on the patient when the inner needle 111 is withdrawn.

  Below, each member of the indwelling needle 100 of this embodiment is demonstrated in detail.

  The inner needle 111 is a hollow needle and can be formed of a known material such as stainless steel, aluminum, titanium, or an alloy containing these. The needle tip 111a provided at the distal end portion of the inner needle 111 may be tapered so that the outer diameter gradually decreases toward the distal end, so that the living body can be punctured easily and with low irritation.

  The inner needle 111 is provided with a drop-off preventing portion 118 that protrudes from other portions at a distance from the needle tip 111a. The drop-off prevention part 118 may be provided at a position corresponding to the length of the cylindrical part 152 so that the needle point 111a of the inner needle 111 can be accommodated in the cylindrical part 152 of the needle point protector 151. From the viewpoint of enabling smooth puncturing, it is preferable that the drop-off prevention unit 118 is provided at a certain distance from the needle tip 111a. If the drop prevention part 118 is provided in the vicinity of the needle tip 111 a, the drop prevention part 118 protrudes from the outer needle 131. When the patient's blood vessel is punctured while the drop-off prevention part 118 protruding from the other part of the inner needle 111 is exposed from the outer needle 131, the protruded drop-off prevention part 118 is caught on the patient's skin and the like to cause pain. There is a fear. Therefore, it is preferable that the drop-off prevention unit 118 is provided so as to be covered with the outer needle 131.

  The drop-off prevention part 118 may have a maximum width so that it can pass through the front end side opening 152a of the cylindrical part 152 and cannot pass through the rear end side opening 152b. The drop-off prevention unit 118 can be provided by crushing a predetermined position of the inner needle 111. Further, the fall prevention unit 118 may be configured by fixing another member at a predetermined position of the inner needle 111. The member to be fixed can be metal, resin, elastic material, or the like. As a fixing method, welding, pressure bonding, adhesion using an adhesive, or the like may be selected according to the material of the member. The drop-off prevention part 118 may be a part in which a part of the outer periphery protrudes or a ring-shaped part having a large outer diameter. Furthermore, the drop-off prevention part 118 may be formed by making the diameter larger than the rear end side in the entire front end side of the predetermined position of the inner needle 111.

  The inner needle hub 112 provided at the rear end portion of the inner needle 111 protrudes from the substantially cylindrical pedestal portion 113 in which the rear end portion of the inner needle 111 is fixed in an embedded state and the front end portion of the pedestal portion 113, and is accommodated. It has a substantially cylindrical cover portion 114 that fits around the outer wall of the portion 133, and a substantially cylindrical connector portion 115 that protrudes from the rear end portion of the pedestal portion 113. The inner needle 111 can be fixed to the inner needle hub 112 by fitting, caulking, fusing, bonding with an adhesive, or the like. The rear end portion of the inner needle 111 is exposed at the rear end portion of the pedestal portion 113, and the lumen of the inner needle 111 is communicated with the internal space of the connector portion 115. The inner needle hub 112 can be a resin molded product in which the pedestal 113, the cover 114, and the connector 115 are integrated. If the inner needle hub 112 is made transparent or semi-transparent so that the inside can be visually confirmed, it is possible to confirm blood flashback.

  The inner needle cap 116 can be removably assembled to the opening of the connector portion 115. The inner needle cap 116 may be a stepped cylindrical synthetic resin member provided with a step portion at an axially intermediate portion. The end portion on the small diameter side of the inner needle cap 116 can be liquid-tightly connected to the opening of the connector portion 115. The large-diameter side opening of the inner needle cap 116 can be connected to a syringe or the like. A ventilation filter 117 can be provided in the opening on the small diameter side of the inner needle cap 116 so that blood does not leak when the indwelling needle 100 is punctured into the blood vessel of the patient. The ventilation filter 117 may be a filter that transmits gas but blocks liquid. For example, a sintered porous body, a hydrophobic nonwoven fabric or other porous body can be used.

  The outer needle 131 can be formed into a hollow needle shape having moderate flexibility. For example, the outer needle 131 can be formed of various soft resins such as ethylene-tetrafluoroethylene copolymer (ETFE), polyurethane, polyether amide, or polypropylene. Further, for the same reason as the needle tip 111a of the inner needle 111, the distal end portion 131a of the outer needle 131 can also be tapered so that the outer diameter gradually decreases toward the distal end. Note that one or more through holes may be provided in the distal end portion 131a of the outer needle 131 as necessary so that the fluid can be efficiently distributed to the outer needle 131.

  A substantially cylindrical outer needle hub 132 is provided at the rear end portion of the outer needle 131. The lumen of the outer needle 131 and the inside of the outer needle hub 132 are in communication. The outer needle 131 can be fixed to the outer needle hub 132 by fitting, caulking, fusing, bonding with an adhesive, or the like. In the present embodiment, the outer needle hub 132 includes a housing 135, a tube 136, an outer needle connector 137, and a housing portion 133.

  The casing 135 is fixed to the rear end portion of the outer needle 131. The outer needle connector 137 is a connector for connecting other medical instruments, and the inner peripheral surface of the outer needle connector 137 can be a female luer taper. An external thread can be provided on the outer periphery near the rear end of the outer needle connector 137 in order to ensure connection with other medical devices. The housing 135 and the outer needle connector 137 are connected by a tube 136. The tube 136 can be a resin tube having elasticity.

  The accommodating portion 133 is connected to the rear end portion of the outer needle connector 137. In the present embodiment, a connecting portion 138 that connects to the outer needle connector 137 is provided on the distal end side of the accommodating portion 133. A tubular protrusion that is fluid-tightly connected to the female luer taper of the outer needle connector 137 is provided at the distal end of the connecting portion 138. A guide wall is provided so as to cover the tubular protrusion, and a female screw that can be screwed with a male screw provided on the outer needle connector 137 is provided inside the guide wall. An elastic packing 141 that seals the rear end of the outer needle connector 137 is provided at the rear end of the tubular protrusion. The elastic packing 141 is provided with a slit so that the inner needle 111 can be passed therethrough. Further, when the inner needle 111 is pulled out, the slit is closed and the seal is maintained. In addition, although the example provided with the two elastic packings 141 was shown, the elastic packing 141 may be one piece and may be three or more pieces. Further, the connecting portion 138 may have any configuration as long as it can be connected to the outer needle connector 137.

  On the rear end side of the accommodating portion 133, a recess 133a capable of accommodating the needle tip protector 151 is provided. A third magnetic member 163 is provided in the recess 133a. The third magnetic member 163 engages the needle tip protector 151 by attractive force between at least one of the first magnetic member 161 and the second magnetic member 162 when the needle tip protector 151 is accommodated in the recess 133a. What is necessary is just to provide in the position which can be made to do. In the present embodiment, the third magnetic member 163 is provided on the surface serving as the bottom surface of the recess 133 a so as to face the first magnetic member 161. For this reason, when the needle tip protector 151 is housed in the recess 133 a of the housing portion 133, the needle tip protector 151 is moved to the housing portion 133 by the attractive force generated between the first magnetic member 161 and the third magnetic member 163. Engaged.

  The recess 133a and the needle tip protector 151 satisfy the relationship of L2-L1 <L3. For this reason, there is very little fear that a finger etc. will inadvertently touch the needle tip protector 151 accommodated in the recess 133a. Further, by setting L2−L1 ≦ 0, it is possible to further reduce the possibility that a finger or the like touches the needle tip protector 151.

  Further, the cover portion 114 of the inner needle hub 112 is fitted on the side wall of the relatively long accommodating portion 133. Since the side wall of the accommodating portion 133 and the cover portion 114 function as a guide when the inner needle 111 is pulled out, it is easy to pull out the inner needle 111 straight. In order to enhance the function as a guide, it is better to lengthen the cover portion 114, and the length of the cover portion 114 may be the same as the length of the accommodating portion 133. However, the length of the cover part 114 does not have to be longer than the length of the accommodating part 133. Preferably, the length of the cover portion 114 can be equal to or longer than the length of the portion of the inner needle 111 protruding from the outer needle 131 in a state where the indwelling needle 100 is assembled. By doing so, when the needle is withdrawn, the cover portion 114 is externally fitted into the accommodating portion 133 until at least the inner needle 111 is accommodated in the outer needle 131. For this reason, the cover part 114 works like a guide, and the needle can be pulled straight without significantly tilting the inner needle 111. As a result, unintentional detachment of the needle tip protector 151 can be made difficult to occur. Moreover, since the needle can be pulled straight without being greatly inclined, the burden on the patient can be reduced.

  In addition, the needle tip protector is covered with the housing portion 133 and the cover portion 114, and the risk of a finger or the like touching the needle tip protector 151 inadvertently can be greatly reduced.

  In the present embodiment, an example in which the accommodating portion 133 is separable from other members of the outer needle hub 132 is shown. It is easier to connect a tube or the like to the outer needle hub 132 when the accommodating portion 133 is separable. However, as long as a tube or the like can be connected, the accommodating portion 133 may be integrated with other members of the outer needle hub 132 or may not be separated.

  In the present embodiment, the configuration in which the elastic packing 141 that prevents the backflow of blood from the outer needle 131 is provided in the connection portion 138 is shown. However, the elastic packing 141 may be provided as necessary and may not be provided. Further, another member provided with the elastic packing 141 may be inserted between the outer needle connector 137 and the accommodating portion 133. Further, the elastic packing 141 may be provided in the outer needle connector. FIG. 7 shows an example of an outer needle connector 137 </ b> A provided with an elastic packing 141. When the outer needle connector 137A is provided with the elastic packing 141, when a tube or the like is connected to the rear end portion of the outer needle connector 137, a pusher 145 and a pusher are provided for expanding the elastic packing 141 and opening the passage. It can be set as the structure provided with the pusher guide 146 which prevents the child 145 from falling off. Other configurations may be used as long as the passage is opened when a tube or the like is connected. In the case where the elastic packing 141 is provided on the outer needle connector 137A side, the elastic packing 141 may not be provided on the accommodation portion 133 side, but the elastic packing 141 may also be provided on the accommodation portion 133 side.

  In the present embodiment, the outer needle hub 132 is configured such that the housing 135 and the outer needle connector 137 are connected by the tube 136. By providing the tube 136, there is an advantage that the degree of freedom of arrangement of the outer needle connector 137 is improved. In addition, the tube 136 can be clamped to prevent the liquid from flowing. However, as shown in FIG. 8, it may be a case 135A in which the case and the outer needle connector are integrated. In this way, the advantage that the outer needle hub 132 can be reduced in size can be obtained. Although the configuration in which the elastic packing 141 is provided in the housing 135A is shown, the elastic packing 141 may not be provided in the housing 135A.

  The cylindrical portion 152 of the needle tip protector 151 can be formed of resin or the like. The diameter of the distal end side opening 152a of the cylindrical portion 152 is such that the drop prevention portion 118 of the inner needle 111 can pass through. The diameter of the rear end side opening 152b may be slightly larger than the diameter of the other part of the inner needle 111 because the drop-off preventing part 118 cannot pass through. The diameter of the rear end side opening 152b may be set by providing a ring-shaped member at the rear end of the cylindrical portion 152. The ring-shaped member can be a member such as a resin or a metal whose inner diameter is smaller than the maximum width of the drop-off preventing portion 118. An absorber that absorbs blood or the like may be provided in the cylindrical portion 152. For example, the absorber can be a porous member such as a sponge.

  Of the first magnetic member 161, the second magnetic member 162, and the third magnetic member 163, the one that is a magnet is not particularly limited, but may be a sumakoba magnet, an alnico magnet, a neodymium magnet, a ferrite magnet, or the like. .

  Of the first magnetic member 161, the second magnetic member 162, and the third magnetic member 163, the magnetic body may be any magnetic body that is attracted to the magnet. Stainless steel or the like can be used from the viewpoint of corrosion resistance.

  Although the shape of the 1st magnetic member 161 and the 3rd magnetic member 163 is not specifically limited, It can be set as columnar shape or prismatic shape. The shape of the second magnetic member 162 may be any shape as long as the distal end side opening 152a can be closed. For example, if a thin disk shape or the like is used, the inside of the closing portion passage 156 can be moved smoothly. Moreover, you may provide a recessed part in the position where the needle | hook tip 111a of the 2nd magnetic member 162 contact | abuts. By engaging the needle tip 111a with the recess, it is possible to make it difficult for the needle tip 111a accommodated in the needle tip protector 151 to be displaced.

  In the present embodiment, the configuration in which the first magnetic member 161 and the third magnetic member 163 are attracted to each other is shown, but the second magnetic member 162 and the third magnetic member 163 may be attracted. In this case, the third magnetic member may be provided at a position facing the second magnetic member 162 in a state where the second magnetic member 162 is at the initial position. In this way, when the needle tip 111a is accommodated and the second magnetic member 162 slides toward the first magnetic member 161, the second magnetic member and the third magnetic member 163 do not face each other, and the needle The engagement between the tip protector 151 and the accommodating portion 133 is weakened. For this reason, the engagement between the needle tip protector 151 and the housing portion 133 can be released with a weaker force than before the front end portion of the inner needle 111 is housed in the needle tip protector 151. The third magnetic member 163 may be provided at a position that attracts both the first magnetic member 161 and the second magnetic member 162. The third magnetic member 163 may be a magnet when the magnetic member to be attracted is a magnet, or may be a magnetic body other than the magnet, and the magnetic member to be attracted is a magnetic body other than the magnet. Is a magnet.

  Although the example which arrange | positions the 3rd magnetic member 163 in the part used as the bottom face of the recessed part 133a was shown, you may arrange | position the 3rd magnetic member 163 in the part used as the side surface of the recessed part 133a. In this case, the first magnetic member 161 or the second magnetic member 162 and the third magnetic member 163 may be disposed so as to face each other in the radial direction.

  What is necessary is just to arrange | position the thing which is a magnet among the 1st magnetic member 161, the 2nd magnetic member 162, and the 3rd magnetic member 163 so that the mutually opposite magnetic poles may oppose.

  In the present embodiment, the cross-sectional shape of the large diameter portion of the cylindrical portion 152 is not a circle but a substantially D shape. By making the tip part of the cylindrical part 152 into such a non-circular shape, the needle tip protector 151 is accommodated in the concave part 133a in a fixed direction. For this reason, it becomes easy to accommodate the needle tip protector 151 in the recess 133a by aligning the first magnetic member 161 or the second magnetic member 162 with the position of the third magnetic member 163. Concavities and convexities that engage with each other may be provided on the distal end surface of the needle tip protector 151 and the bottom surface of the recess 133a. You may provide the unevenness | corrugation etc. which mutually engage in the side surface of the needle | hook tip protector and the recessed part 133a. With this configuration, the alignment of the needle tip protector 151 is further facilitated. When providing unevenness, the cross-sectional shape of the large diameter portion may be circular. Further, the mechanism that facilitates the alignment of the needle tip protector 151 may have another configuration. A mechanism that facilitates the alignment of the needle tip protector 151 may be provided as necessary, and may not be particularly provided.

  The cross-sectional shape of the large diameter portion is not limited to a substantially D shape, and may be a circular shape or an elliptical shape, or a shape having a plurality of sides such as a hexagonal shape or a quadrangular shape. The cross-sectional shape of the small-diameter portion as well as the large-diameter portion may be a shape other than a circle.

  By making the cylindrical part 152 into a stepped cylindrical shape having a large-diameter part and a small-diameter part, it is possible to increase the distance L3 between the concave part 133a and the needle tip protector 151 at the rear end part of the concave part 133a. There is. However, the cylindrical portion 152 may be a cylindrical shape having no step or another cylindrical shape.

  The recess 133a only needs to be able to accommodate the needle tip protector 151. There is a gap between the needle tip protector 151 and the side wall, and the concave tip 133a can be configured not to hold the needle tip protector 151. In this case, since the side wall of the recess 133a and the side surface of the needle tip protector 151 are not in contact with each other, the resistance when the inner needle 111 is pulled out does not increase even if the recess 133a is provided. However, the side wall of the recess 133a and the side surface of the needle tip protector 151 can be fitted so that the needle tip protector 151 can move smoothly. With such a configuration, the needle tip protector 151 is less likely to be detached before the inner needle 111 is completely pulled out.

  The indwelling needle of the present disclosure is useful as an indwelling needle or the like because the inner needle can be easily pulled out and the protector is unlikely to be carelessly detached.

DESCRIPTION OF SYMBOLS 100 Indwelling needle 111 Inner needle 111a Needle tip 112 Inner needle hub 113 Base part 114 Cover part 115 Connector part 116 Inner needle cap 117 Vent filter 118 Fall-off prevention part 131 Outer needle 131a Tip part 132 Outer needle hub 133 Accommodating part 133a Recess 135 Housing Body 135A Housing 136 Tube 137 Outer needle connector 137A Outer needle connector 138 Connection part 141 Elastic packing 145 Pusher 146 Pusher guide 151 Needle tip protector 152 Cylindrical part 152a Front end side opening part 152b Rear end side opening part 153 Closure part 156 Closure portion passage 161 First magnetic member 162 Second magnetic member 163 Third magnetic member

Claims (6)

An inner needle,
An outer needle through which the inner needle can be inserted;
An outer needle hub provided at a rear end portion of the outer needle, and a needle tip that is detachably engaged with the outer needle hub when the inner needle is inserted in a state where the inner needle is inserted through the outer needle. With a protector,
The needle tip protector has a front end side opening portion and a rear end side opening portion, and a cylindrical portion into which the inner needle is inserted and a front end portion of the inner needle are accommodated inside the cylindrical portion. And a closing part that closes the tip side opening,
The inner needle has a drop-off preventing part that can pass through the front end side opening and cannot pass through the rear end side opening,
The outer needle hub includes an accommodating portion having a recess capable of accommodating the needle tip protector,
When the length of the side wall of the concave portion is L1, the length of the needle tip protector is L2, and the distance between the concave portion and the needle tip protector at the rear end portion of the concave portion is L3, the relationship of L2-L1 <L3 is established. Fill, indwelling needle.   The indwelling needle according to claim 1, wherein L2-L1 is 0 or less.   The indwelling needle according to claim 1 or 2, wherein the outer needle hub and the needle tip protector are detachably engaged with each other or by an attractive force between the magnet and the magnetic body. The closing portion slides toward the first magnetic member when the distal end of the inner needle is accommodated in the first magnetic member provided at the distal end of the tubular portion and the inner needle. And a second magnetic member that closes the tip side opening,
The outer needle hub has a third magnetic member provided on the rear end side,
At least one of the first magnetic member and the second magnetic member is a magnet;
In a state where the inner needle is inserted into the outer needle, the needle tip protector is caused by the attraction force between at least one of the first magnetic member and the second magnetic member and the third magnetic member. The indwelling needle according to claim 1, which is detachably engaged with the outer needle hub. An inner needle hub provided at the rear end of the inner needle;
The inner needle hub has a cover portion that is provided at a distal end portion and is fitted on the side wall of the housing portion,
The length of the said cover part is an indwelling needle of any one of Claims 1-4 which is more than the length of the part which protrudes from the said outer needle of the said inner needle.   The indwelling needle according to any one of claims 1 to 5, wherein the accommodating portion is separable from other portions of the outer needle hub.

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