JP2013248222A - Indwelling needle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an inner unit from receding during a puncture without use of a stopper.SOLUTION: An outer unit 101 includes a shield 20, and a soft outer needle 30 fixed to a front end of the shield. An inner unit 102 includes an inner hub 40 arranged inside the shield, a hard inner needle 50 fixed to a front end of the inner hub, and a tube 60 connected to a rear end of the inner hub. The inner unit is displaced with respect to the outer unit from an initial position where the inner needle protrudes from a leading end of the outer needle, to a receding position where the inner needle is stored inside the shield. The shield includes an outer hub 25 which holds the outer needle, and a cylindrical shield cylinder 21 to which the outer hub is connected. When the inner unit is in the initial position, the inner hub is engaged with the outer hub so that the inner unit cannot move toward the receding position by a reaction force received by the inner needle when a puncture is formed by arranging the inner unit in the initial position.

Description

  The present invention includes a soft outer needle and a hard inner needle, and can puncture a patient with the tip of the inner needle protruding from the tip of the outer needle, and then the inner needle can be retracted from the outer needle. It is related with the indwelling needle apparatus comprised as follows.

  Indwelling needle devices are widely used for treatments such as infusion, blood transfusion, and extracorporeal blood circulation. In such a procedure, if a metal needle is left in the blood vessel, the blood vessel may be damaged. Therefore, an indwelling needle device having a soft outer needle and a hard inner needle is known. With the tip of the inner needle protruding from the tip of the outer needle, the outer needle and the inner needle are punctured into the patient's blood vessel, and then the inner needle is retracted from the outer needle and only the outer needle is left in the patient. The indwelling soft outer needle is unlikely to damage the patient's blood vessels.

  16 is a perspective view of an example of such a conventional indwelling needle device 900 (see, for example, Patent Document 1) as viewed from above, and FIG. 17 is a conventional view along a vertical plane including line 17-17 in FIG. It is arrow sectional drawing of the indwelling needle apparatus 900. FIG. For convenience of explanation, the side where the patient is punctured (the left side of the paper in FIGS. 16 and 17) is called the “front side”, and the opposite side is called the “rear side”.

  The indwelling needle device 900 includes a shield 920 that includes a shield cylinder 921 having a substantially cylindrical shape and an outer hub 925 fixed to one end (front end) thereof. A soft outer needle 930 is fixed to the front end of the outer hub 925. A pair of blades 929a and 929b are provided on the outer peripheral surface of the shield tube 921 near the outer hub 925 side end. The wings 929a and 929b have flexibility and can swing up and down.

  An inner hub 940 is inserted into the lumen of the shield 920. A metal hard inner needle 950 is fixed to the front end of the inner hub 940, and one end of a flexible tube 960 is connected to the rear end of the inner hub 940. The inner needle 950 and the tube 960 communicate with each other via a longitudinal passage 943 that penetrates the inner hub 940 in the front-rear direction.

  The shield tube 921, the outer hub 925, the outer needle 930, and the wings 929a and 929b constitute an outer unit 901 of the indwelling needle device 900. On the other hand, the inner hub 940, the inner needle 950, and the tube 960 constitute an inner unit 902 of the indwelling needle device 900. The inner unit 902 is inserted into the outer unit 901 so as to be movable in the longitudinal direction of the shield 920 (that is, the front-rear direction).

  16 and 17, the inner hub 940 is located on the front end side of the lumen of the shield 920, the inner needle 950 held by the inner hub 940 passes through the outer needle 930, and the tip of the inner needle 950 is the outer needle 930. It protrudes from the tip of the outside. This position of the inner unit 902 relative to the outer unit 901 is referred to as an “initial position”.

  A stopper 970 is used to hold the inner unit 902 in the initial position. FIG. 18 is a perspective view of the stopper 970. An approximately semi-cylindrical insertion portion 972 and a pair of fixing portions 973 extend from the substantially semi-cylindrical base portion 971. The insertion portion 972 is disposed between the pair of fixing portions 973 and these are parallel to each other.

  As shown in FIG. 17, the insertion portion 972 of the stopper 970 is inserted from the rear end of the shield tube 921. By causing the distal end of the insertion portion 972 to collide with the rear end of the inner hub 940 and pushing the inner hub 940 forward, the inner unit 902 can be disposed at the initial position.

  The indwelling needle device 900 is used as follows.

  First, the inner needle 950 and the outer needle 930 are punctured into the patient's blood vessel while the inner unit 902 is held at the initial position (puncturing operation). It is necessary to prevent the inner needle 950 from being stored in the outer needle 930 due to the reaction force that the inner needle 950 receives from the patient during puncturing. For this reason, the puncturing operation needs to be performed while holding the stopper 970. Accordingly, the stopper 970 and the inner unit 902 are not displaced with respect to the outer unit 901, and the inner unit 902 is maintained at the initial position.

  After puncturing the patient's blood vessel with the inner needle 950 and the outer needle 930, the stopper 970 is removed from the shield 920, and then the tube 960 is withdrawn from the shield 920 (retraction operation). The stopper 970 may be removed from the shield 920 at the same time as the tube 960 is pulled out. By pulling out the tube 960, the inner unit 902 moves backward with respect to the outer unit 901, and the inner needle 950 is housed in the shield 920 as shown in FIG. The position of the inner unit 902 with respect to the outer unit 901 shown in FIG. In this state, the indwelling needle device 900 is fixed to the patient using an adhesive tape or the like. Only the soft outer needle 930 is placed while being punctured by the patient.

JP 2011-251081 A

  In the indwelling needle device 900 described above, the stopper 970 is used only to maintain the inner unit 902 at the initial position in the puncturing operation for puncturing the patient with the inner needle 950 and the outer needle 930. The stopper 970 is removed from the shield 920 prior to or together with the backward operation for moving the inner unit 902 toward the backward position.

  However, when only the stopper 970 is removed from the shield 920, there is a risk of misoperation that the user may forget to pull the tube 960 by misunderstanding that the inner unit 902 has been moved to the retracted position. As a result, since the indwelling needle device 900 is placed in the patient with the inner needle 950 protruding from the tip of the outer needle 930, the tip of the hard inner needle 950 may damage the patient's blood vessel.

  In addition, by providing the stopper 970, the number of parts constituting the indwelling needle device 900 increases, and the cost of the indwelling needle device 900 increases.

  Furthermore, the stopper 970 inserted into the shield 920 may fall off the shield 920 due to vibration or the like during the transfer of the indwelling needle device 900.

  Accordingly, it is desirable to allow the inner unit 902 to be maintained at the initial position without using the stopper 970 in the puncturing operation, and to omit the stopper 970.

  An object of the present invention is to provide an indwelling needle device in which an inner unit can be maintained at an initial position without using a stopper in a puncturing operation, and as a result, the stopper is omitted.

  The first indwelling needle device of the present invention includes a shield having a lumen, an outer unit including a soft outer needle fixed to the front end of the shield, and an inner hub disposed in the lumen of the shield. A hard inner needle fixed to the front end of the inner hub, and an inner unit including a tube connected to the rear end of the inner hub. The inner unit moves from the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to a retracted position where the inner needle is housed in the lumen of the shield tube. It is displaced with respect to. The shield includes an outer hub that holds the outer needle and a cylindrical shield tube that is fixed to one end of the outer hub. When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. The inner hub is engaged with the outer hub.

  The second indwelling needle device of the present invention includes an outer unit including a shield having a lumen, a soft outer needle fixed to the front end of the shield, and an inner hub disposed in the lumen of the shield. , An O-ring attached to the inner hub, a hard inner needle fixed to the front end of the inner hub, and an inner unit including a tube connected to the rear end of the inner hub. From the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to the retracted position where the inner needle is housed in the lumen of the shield tube, the O-ring is attached to the shield. The inner unit is displaced relative to the outer unit while sliding on the inner peripheral surface. When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. An O-ring is engaged with the shield.

  The third indwelling needle device of the present invention includes an outer unit including a shield having a lumen, a soft outer needle fixed to a front end of the shield, and an inner hub disposed in the lumen of the shield. A hard inner needle fixed to the front end of the inner hub, and an inner unit including a tube connected to the rear end of the inner hub. The inner unit moves from the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to a retracted position where the inner needle is housed in the lumen of the shield tube. It is displaced with respect to. When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. The inner needle is engaged with the outer unit.

  According to the present invention, when the inner unit is in the initial position, in the first indwelling needle device, the inner hub is engaged with the outer hub, and in the second indwelling needle device, the O-ring is engaged with the shield, In the indwelling needle device 3, the inner needle is engaged with the outer unit. Accordingly, the inner unit does not move toward the retracted position due to the reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. Therefore, the stopper required in the conventional indwelling needle device can be omitted.

FIG. 1 is a perspective view of an indwelling needle device according to Embodiment 1 of the present invention, as viewed from above, with an inner unit in an initial position. 2 is a cross-sectional view of the indwelling needle device according to the first embodiment of the present invention along the vertical plane including line 2-2 in FIG. 3A is a perspective view of an inner hub used in the indwelling needle device according to Embodiment 1 of the present invention, FIG. 3B is a cross-sectional view of the inner hub taken along the plane including line 3B-3B in FIG. 3A, and FIG. 3C. FIG. 3B is a cross-sectional view of the inner hub taken along the plane including the line 3C-3C in FIG. 3A. FIG. 4 is a perspective view seen from above the indwelling needle device according to the first embodiment of the present invention, in which the inner unit is in the retracted position. FIG. 5 is a cross-sectional view of the indwelling needle device according to the first embodiment of the present invention along the vertical plane including line 5-5 in FIG. FIG. 6 is a horizontal cross-sectional view showing the outer hub, the inner hub, and the vicinity thereof when the inner unit is in the initial position in the indwelling needle device according to the first embodiment of the present invention. 7A is a perspective view of the inner hub used in the indwelling needle device according to Embodiment 2 of the present invention, FIG. 7B is a cross-sectional view of the inner hub taken along the plane including line 7B-7B in FIG. 7A, and FIG. 7C. FIG. 7B is a cross-sectional view of the inner hub taken along the plane including the line 7C-7C in FIG. 7A. FIG. 8 is a vertical sectional view showing the outer hub, the inner hub, and the vicinity thereof when the inner unit is in the initial position in the indwelling needle device according to the second embodiment of the present invention. FIG. 9 is a horizontal cross-sectional view showing the outer hub, the inner hub, and the vicinity thereof when the inner unit is in the initial position in the indwelling needle device according to the third embodiment of the present invention. FIG. 10 is a horizontal sectional view showing the outer hub, the inner hub, and the vicinity thereof when the inner unit is in the initial position in another indwelling needle device according to the third embodiment of the present invention. FIG. 11 is a horizontal cross-sectional view showing the outer hub, the inner hub, and the vicinity thereof when the inner unit is in the initial position in the indwelling needle device according to the fourth embodiment of the present invention. FIG. 12 is a horizontal sectional view showing the outer hub, the inner hub, and the vicinity thereof when the inner unit is in the initial position in another indwelling needle device according to the fourth embodiment of the present invention. FIG. 13 is a vertical sectional view showing the outer hub, the inner hub, and the vicinity thereof when the inner unit is in the initial position in the indwelling needle device according to the fifth embodiment of the present invention. FIG. 14 is a cross-sectional view showing the tips of the inner needle and the outer needle and their vicinity when the inner unit is in the initial position in the indwelling needle device according to the fifth embodiment of the present invention. FIG. 15 is a cross-sectional view showing the outer hub and its vicinity when the inner unit is in the initial position in the indwelling needle device according to the sixth embodiment of the present invention. FIG. 16 is a perspective view seen from above of a conventional indwelling needle device in which the inner unit is in the initial position. 17 is a cross-sectional view of the conventional indwelling needle device taken along the vertical plane including line 17-17 in FIG. 18 is a perspective view of a stopper used in the conventional indwelling needle device shown in FIG. FIG. 19 is a cross-sectional view of the conventional indwelling needle device shown in FIG. 16 along the same plane as FIG. 17 with the inner unit in the retracted position.

  The first indwelling needle device of the present invention includes a shield having a lumen, an outer unit including a soft outer needle fixed to the front end of the shield, and an inner hub disposed in the lumen of the shield. A hard inner needle fixed to the front end of the inner hub, and an inner unit including a tube connected to the rear end of the inner hub. The inner unit moves from the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to a retracted position where the inner needle is housed in the lumen of the shield tube. It is displaced with respect to. The shield includes an outer hub that holds the outer needle and a cylindrical shield tube that is fixed to one end of the outer hub. When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. The inner hub is engaged with the outer hub.

  In the first indwelling needle device described above, when the engagement convex portion formed on the inner peripheral surface of the outer hub is fitted into the concave engagement structure formed on the outer peripheral surface of the inner hub, the inner hub is Preferably, the outer hub is engaged. Thereby, the inner hub can be engaged with the outer hub with a simple structure.

  In the first indwelling needle device, it is preferable that an engagement structure that engages with each other when the inner unit is in the initial position is provided in the inner hub and the outer hub. In this case, it is preferable that at least one of the engagement structure provided on the inner hub and the engagement structure provided on the outer hub is continuous along the circumferential direction. Thereby, the inner hub can be engaged with the outer hub regardless of the posture of the inner unit in the rotational direction with respect to the outer unit.

  The second indwelling needle device of the present invention includes an outer unit including a shield having a lumen, a soft outer needle fixed to the front end of the shield, and an inner hub disposed in the lumen of the shield. , An O-ring attached to the inner hub, a hard inner needle fixed to the front end of the inner hub, and an inner unit including a tube connected to the rear end of the inner hub. From the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to the retracted position where the inner needle is housed in the lumen of the shield tube, the O-ring is attached to the shield. The inner unit is displaced relative to the outer unit while sliding on the inner peripheral surface. When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. An O-ring is engaged with the shield.

  In the second indwelling needle device, the shield may include an outer hub that holds the outer needle and a cylindrical shield tube that is fixed to one end of the outer hub. In this case, the O-ring may be engaged with the shield tube. Alternatively, the O-ring may be engaged with the outer hub. Thereby, the O-ring can be engaged with the shield with a simple structure.

  In the second indwelling needle device described above, it is preferable that an engagement convex portion that engages with the O-ring is formed on the inner peripheral surface of the shield. Thereby, the O-ring can be engaged with the shield with a simple structure.

  Said 2nd indwelling needle apparatus WHEREIN: It is preferable that the said engagement convex part is continuing along the circumferential direction. This is advantageous for ensuring high liquid tightness between the O-ring and the shield.

A third indwelling needle device of the present invention includes a shield having a lumen,
And an outer unit including a soft outer needle fixed to the front end of the shield, an inner hub disposed in the lumen of the shield, a hard inner needle fixed to the front end of the inner hub, and An inner unit including a tube connected to a rear end of the inner hub. The inner unit moves from the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to a retracted position where the inner needle is housed in the lumen of the shield tube. It is displaced with respect to. When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. The inner needle is engaged with the outer unit.

  In the above-mentioned third indwelling needle device, when the engaging convex portion formed on the outer peripheral surface of the inner needle is fitted into the concave engaging structure formed on the inner peripheral surface of the outer unit, the inner needle is The outer unit is preferably engaged. Thereby, the inner needle can be engaged with the outer unit with a simple structure.

  In the third indwelling needle device, the inner needle may be engaged with the outer needle when the inner unit is in the initial position. Since the inner needle is engaged with the outer needle, the positional accuracy of the inner unit in the initial position with respect to the outer needle is improved.

  In the third indwelling needle device, the inner needle may be engaged with the shield when the inner unit is in the initial position. In this case, it is preferable that the shield includes an outer hub for holding the outer needle, and a cylindrical shield tube having the outer hub fixed to one end. The inner needle is preferably engaged with the outer hub when the inner unit is in the initial position. Since the inner needle is engaged with the outer hub that holds the outer needle, the positional accuracy of the inner unit in the initial position with respect to the outer needle is improved.

  In the third indwelling needle device, it is preferable that an engagement structure that engages with each other when the inner unit is in the initial position is provided in the inner needle and the outer unit. In this case, it is preferable that at least one of the engagement structure provided on the inner needle and the engagement structure provided on the outer unit is continuous in the circumferential direction. Accordingly, the inner needle can be engaged with the outer unit regardless of the posture of the inner unit in the rotational direction with respect to the outer unit.

  Below, this invention is demonstrated in detail, showing suitable embodiment. However, it goes without saying that the present invention is not limited to the following embodiments. For convenience of explanation, the drawings referred to in the following description show only the main members necessary for explaining the present invention in a simplified manner among the constituent members of the embodiment of the present invention. Therefore, the present invention can include arbitrary components not shown in the following drawings. In addition, the dimensions of the members in the following drawings do not faithfully represent the actual dimensions of the constituent members and the dimensional ratios of the members.

(Embodiment 1)
FIG. 1 is a perspective view seen from above the indwelling needle device 100 according to the first embodiment of the present invention, in which the inner unit is in the initial position. For convenience of the following description, an orthogonal coordinate system is set in which the longitudinal direction of the indwelling needle device 100 is the Z axis, the horizontal axis orthogonal to the Z axis, and the vertical axis are the X axis and Y axis, respectively. The Y-axis arrow side (that is, the upper side in FIG. 1) is called “upper side”, and the opposite side is called “lower side”. However, the “horizontal direction” and the “vertical direction” do not mean the directions when the indwelling needle device 100 is actually used. Further, the side where the patient is punctured (the side of the arrow on the Z axis, that is, the left side of FIG. 1) is called the “front side”, and the opposite side is called the “rear side”. 2 is a cross-sectional view of the indwelling needle device 100 along the vertical plane (YZ plane) including the line 2-2 in FIG.

  The indwelling needle device 100 includes a shield 20. The shield 20 includes a shield cylinder 21 and an outer hub 25 fixed to one end (front end) of the shield cylinder 21. The shield cylinder 21 has a substantially cylindrical shape with a constant inner diameter. A locking protrusion 22 that is continuous in the circumferential direction is formed on the inner peripheral surface of the shield tube 21 in the vicinity of the end (rear end) opposite to the outer hub 25. The outer hub 25 has a substantially funnel shape, and a soft outer needle 30 is fixed to an end (front end) opposite to the shield tube 21. The outer needle 30 has a substantially cylindrical shape. The material of the shield tube 21 and the outer hub 25 is not particularly limited, but is preferably a hard material. For example, polycarbonate, polypropylene, or the like can be used. It is preferable that the shield cylinder 21 and the outer hub 25 be transparent or translucent because the liquid (chemical liquid or blood) in the inner cavity 24 of the shield 20 or the inner hub 40 can be seen through. The material of the outer needle 30 is not particularly limited, but a soft material is preferable. For example, a fluorine resin such as polypropylene, polyurethane elastomer, polytetrafluoroethylene, or the like can be used. It is preferable that the outer needle 30 is transparent or translucent because the liquid (chemical liquid or blood) in the lumen and the inner needle 50 can be seen through. The outer hub 25 and the outer needle 30 may be integrally formed using the soft material described above.

  Reference numerals 29a and 29b are wings extending substantially parallel to the X-axis. The wings 29 a and 29 b are provided on a substantially cylindrical fixing member 28. By attaching the fixing member 28 to the outer peripheral surface of the shield cylinder 21 near the end on the outer hub 25 side, the wings 29 a and 29 b are attached to the shield 20. The material of the blades 29a and 29b is not particularly limited, but a soft material is preferable. For example, polypropylene, vinyl chloride, polyethylene, olefin-based or polystyrene-based thermoplastic elastomers, and the like can be used. The wings 29a and 29b may be formed integrally with the shield 20.

  An inner hub 40 is inserted into the inner cavity 24 of the shield 20 so as to be movable in the longitudinal direction of the shield 20 (that is, the Z-axis direction). A metal hard inner needle 50 is fixed to the front end of the inner hub 40. The inner needle 50 has a substantially cylindrical shape, and the tip is processed sharply. One end of a flexible tube 60 is connected to the rear end of the inner hub 40. The other end of the tube 60 is connected to an infusion circuit for performing infusion, for example. An O-ring 49 is attached to the outer peripheral surface of the inner hub 40. The O-ring 49 is in close contact with the inner peripheral surface of the shield cylinder 21, and in the inner cavity 24 of the shield 20, the drug solution or blood on the outer needle 30 side of the O-ring 49 leaks to the tube 60 side of the O-ring 49. prevent. The material of the inner hub 40 is not particularly limited, but is preferably a hard material. For example, polycarbonate, polypropylene, polyethylene, or the like can be used. The material of the tube 60 is not particularly limited, but is preferably a soft material. For example, a resin material such as vinyl chloride can be used. The material of the O-ring 49 is not particularly limited, but is preferably a flexible material that can be elastically deformed. For example, polyisoprene rubber, silicone rubber, thermoplastic elastomer, or the like can be used.

  3A is a perspective view of the inner hub 40, FIG. 3B is an arrow cross-sectional view of the inner hub 40 along the plane including the line 3B-3B in FIG. 3A, and FIG. 3C is along the plane including the line 3C-3C in FIG. 6 is a cross-sectional view of the inner hub 40 as viewed from the direction of the arrows. The cross section of FIG. 3B and the cross section of FIG. 3C are orthogonal to each other. The inner hub 40 has a front portion 41 having a conical outer surface at one end (front end) and a rear portion 42 having a cylindrical outer surface at the other end. A longitudinal passage 43 passes through the inner hub 40 from the front portion 41 to the rear portion 42 along the central axis 40 a of the inner hub 40. As shown in FIG. 2, the inner needle 50 is inserted into the longitudinal passage 43 from the front portion 41 side and held by the inner hub 40. The rear portion 42 is inserted into the tube 60 and the inner hub 40 and the tube 60 are connected. Thus, the inner needle 50 and the tube 60 are communicated through the longitudinal passage 43 of the inner hub 40.

  An annular groove 44 that is continuous in the circumferential direction is formed on the outer peripheral surface of the inner hub 40 between the front portion 41 and the rear portion 42. As shown in FIG. 2, an O-ring 49 is attached to the annular groove 44.

  A large-diameter portion 45 and a small-diameter portion 46 are formed in this order from the annular groove 44 side between the annular groove 44 and the front portion 41 on the outer peripheral surface of the inner hub 40. The small diameter portion 46 is adjacent to the front portion 41, and the outer diameter of the small diameter portion 46 is smaller than the maximum diameter of the front portion 41 and smaller than the outer diameter of the large diameter portion 45. As shown in FIG. 3C, the maximum diameter portion of the front portion 41, that is, the end edge 41 a on the small diameter portion 46 side of the front portion 41 protrudes outward in the radial direction from the small diameter portion 46. The front portion 41, the small diameter portion 46, and the large diameter portion 45 are formed with a transverse passage 47 that passes through them in the diameter direction (a direction orthogonal to the central axis 40a). The transverse passage 47 intersects and communicates with the longitudinal passage 43.

  Around the rear portion 42, four elastic pieces 48 that are cantilevered are arranged at equiangular intervals with respect to the central axis 40a of the inner hub 40. The elastic piece 48 extends substantially parallel to the central axis 40 a of the inner hub 40. A fitting groove 48 a and a tapered surface 48 b are formed on the surface opposite to the rear portion 42 of the elastic piece 48. The fitting groove 48 a is a recess (groove) along the circumferential direction of the inner hub 40. The tapered surface 48b is adjacent to the fitting groove 48a on the free end side of the elastic piece 48, and forms a part of a conical surface having a large outer diameter on the fitting groove 48a side.

  The shield 20, the outer needle 30 fixed to the shield 20, the wings 29 a and 29 b, and the fixing member 28 constitute an outer unit 101 of the indwelling needle device 100. On the other hand, the inner hub 40, the inner needle 50, and the tube 60 constitute an inner unit 102 of the indwelling needle device 100. The inner unit 102 is inserted into the outer unit 101 so as to be movable in the longitudinal direction of the shield 20 (that is, the front-rear direction).

  In FIG. 1 and FIG. 2, the inner hub 40 is located on the front end side of the inner cavity 24 of the shield 20, the inner needle 50 held by the inner hub 40 penetrates the outer needle 30, and the tip thereof is the tip of the outer needle 30. Protrudes from the outside. This position of the inner unit 102 with respect to the outer unit 101 is referred to as an “initial position” in the present invention.

  FIG. 4 is a perspective view seen from above the indwelling needle device 100 in which the inner unit 102 is in the retracted position. FIG. 5 is a cross-sectional view of the indwelling needle device 100 along the vertical plane (YZ plane) including the line 5-5 in FIG.

  As shown in FIG. 5, when the inner unit 102 is in the “retracted position”, the fitting groove 48a of the inner hub 40 (see FIGS. 3A, 3B, and 3C) and the locking protrusion of the shield tube 21 22 is fitted. Further, the inner needle 50 held by the inner hub 40 is removed from the outer needle 30 and stored in the inner cavity 24 of the shield 20.

  Compared to the initial position (see FIGS. 1 and 2), in the retracted position, the cross-sectional area of the flow path in the outer needle 30 increases by the cross-sectional integral of the inner needle 50, so that the flow rate of the drug solution or blood increases. In the retracted position, the flow path from the outer needle 30 to the tube 60 includes a first flow path that sequentially passes through the inner lumen of the inner needle 50 and the longitudinal passage 43 of the inner hub 40, the inner surface of the shield 20, and the inner needle 50. And the space between each outer surface of the inner hub 40, the transverse passage 47 of the inner hub 40, and the second flow path passing through the longitudinal passage 43 of the inner hub 40 in sequence, so that the drug solution or blood flows at a large flow rate. be able to.

  As described above, in the indwelling needle device 100 according to the first embodiment, the inner unit 102 moves from the initial position shown in FIGS. 1 and 2 to the retracted position shown in FIGS. Can be moved to.

  When puncturing the patient with the indwelling needle device 100, the inner unit 102 must be held in the initial position. In the indwelling needle device 100 of the first embodiment, the inner hub 40 is engaged with the outer hub 25 so that the inner unit 102 at the initial position does not move toward the retracted position.

  The engagement between the inner hub 40 and the outer hub 25 will be described.

  FIG. 6 is a cross-sectional view along the horizontal plane (XZ plane) showing the outer hub 25, the inner hub 40, and the vicinity thereof when the inner unit 102 is in the initial position. As shown in FIG. 6, when the inner unit 102 is in the initial position, the front edge of the large-diameter portion 45 of the inner hub 40 collides with the rear edge of the outer hub 25. The inner unit 102 is positioned with respect to the outer unit 101 in the front-rear direction (Z-axis direction).

  An engaging convex portion 26 a that protrudes toward the small-diameter portion 46 is formed in the region of the inner peripheral surface of the outer hub 25 that the small-diameter portion 46 of the inner hub 40 faces. The engaging convex portion 26 a is continuous with the inner peripheral surface of the outer hub 25 in the circumferential direction so as to surround the inner hub 40. When the engaging protrusion 26 a is fitted into the small diameter portion 46 of the inner hub 40, the inner hub 40 and the outer hub 25 are engaged. When the inner unit 102 in the initial position is moved to the retracted position, the engaging convex portion 26 a of the outer hub 25 collides with the end edge 41 a of the inner hub 40. In order to move the inner unit 102 from the initial position toward the retracted position, it is necessary for the engaging convex portion 26a to move over the end edge 41a of the inner hub 40 and move to the front portion 41 side. For this purpose, it is necessary to apply a relatively large force between the outer unit 101 and the inner unit 102.

  The usage method and operation of the indwelling needle device 100 according to the first embodiment configured as described above will be described.

  The indwelling needle device 100 according to the first embodiment is delivered to a medical institution such as a hospital in a state where the inner unit 102 is disposed at an initial position (FIGS. 1, 2, and 6).

  In the medical institution, as shown in FIGS. 1 and 2, the operator moves the inner needle 50 and the outer needle 30 with the inner unit 102 in the initial position and the inner needle 50 protruding from the tip of the outer needle 30. The patient's blood vessel is punctured (puncture operation). The puncturing operation can be performed by holding the outer unit 101 with a finger. At this time, the inner needle 50 receives a reaction force opposite to the puncturing direction. This reaction force acts to move the inner unit 102 toward the retracted position with respect to the outer unit 101. However, as described above, since the inner hub 40 is engaged with the outer hub 25, the inner unit 102 does not move from the initial position with respect to the outer unit 101.

  Next, with the outer needle 30 punctured by the patient, the inner unit 102 is retracted (retracting operation). For example, while holding the outer unit 101 with one hand (for example, a hand different from the hand holding the outer unit 101 in the puncture operation) so that the outer unit 101 is not displaced with respect to the patient, the tube with the other hand The tube 60 may be pulled out from the outer unit 101 by gripping 60. It is necessary to apply a large tension to the tube 60 so that the engaging convex portion 26a of the outer hub 25 gets over the end edge 41a of the inner hub 40. Thereafter, when the engaging convex portion 26a moves over the end edge 41a of the inner hub 40 and moves to the front portion 41 side, the tube 60 can be pulled out with a relatively small tension. The inner unit 102 moves rearward together with the tube 60. The O-ring 49 slides on the inner peripheral surface of the shield cylinder 21 while maintaining liquid tightness with the shield cylinder 21.

  A locking projection 22 is formed on the inner peripheral surface near the rear end of the shield tube 21. The inner hub 40 moves to the locking protrusion 22, and a tapered surface 48 b (see FIGS. 3A, 3B, and 3 C) formed on the outer surface of the elastic piece 48 of the inner hub 40 slides on the locking protrusion 22. . At this time, the elastic piece 48 is elastically deformed toward the rear portion 42 side. Next, when the taper surface 48b gets over the locking protrusion 22, the elastic piece 48 is elastically recovered, and the locking protrusion 22 is fitted into the fitting groove 48a. Thus, the inner unit 102 moves to the retracted position shown in FIGS.

  In this state, an adhesive tape is applied to the patient's skin from above the outer unit 101, and the indwelling needle device 100 is fixed to the patient. Only the outer needle 30 is indwelled while being punctured by the patient. When the inner unit 102 is in the retracted position, the hard inner needle 50 does not exist in the flexible outer needle 30, so that even if the posture of the indwelling needle device 100 with respect to the patient changes temporarily due to movement of the patient, the outer needle 30 does not damage the patient's blood vessels or the like.

  When the necessary treatment is completed, the adhesive tape that fixes the outer unit 101 is peeled off from the patient, and the outer needle 30 is pulled out from the patient. Even if the tube 60 is pushed and pulled with respect to the outer unit 101, the fitting state between the fitting groove 48a of the inner hub 40 and the locking protrusion 22 of the shield tube 21 is not released. That is, the inner needle 50 cannot protrude again from the tip of the outer needle 30, and the inner unit 102 cannot be pulled out from the outer unit 101. Accordingly, it is possible to prevent the hard inner needle 50 from being punctured by mistake and the used indwelling needle device 100 from being reused by mistake. The used indwelling needle device 100 is discarded.

  As described above, in the indwelling needle device 100 according to the first embodiment, the inner hub 40 is engaged with the outer hub 25 when the inner unit 102 is in the initial position. Therefore, even if the inner needle 50 receives a reaction force in the puncturing operation, the inner unit 102 does not move toward the retracted position and remains at the initial position. Therefore, in order to prevent the inner unit 902 in the initial position from moving toward the retracted position during the puncturing operation, the stopper 970 (FIG. 18) that is essential in the conventional indwelling needle device 900 (FIGS. 16 to 19). However, it is not necessary for the indwelling needle device 100 of the first embodiment.

  As described above, in the indwelling needle device 900 of the related art, there is a risk of misoperation that the internal unit 902 is mistakenly moved to the retracted position by removing the stopper 970 from the shield 920. In contrast, in the first embodiment, there is no stopper. In order to move the inner unit 101 from the initial position to the retracted position, the tube 60 must be pulled out from the outer unit 101. Therefore, the risk of erroneous operation is reduced.

  Further, since no stopper is used, the number of parts constituting the indwelling needle device 100 is reduced, and the cost of the indwelling needle device 100 can be reduced.

  Further, since the inner hub 40 is engaged with the outer hub 25 when the inner unit 102 is in the initial position, vibrations during transfer after the indwelling needle device 100 is shipped with the inner unit 102 in the initial position, etc. Thus, the inner unit 102 is not displaced from the initial position.

  The inner unit 102 in the initial position is engaged with an engaging convex portion 26 a provided on the outer hub 25. An outer needle 30 is held on the outer hub 25. This configuration is advantageous in improving the positional accuracy in the front-rear direction with respect to the outer needle 30 of the inner unit 102 in the initial position.

  As in the above example, in addition to engaging the engaging projection 26 a of the outer hub 25 with the inner hub 40, the front edge of the large-diameter portion 45 of the inner hub 40 is connected to the rear side of the outer hub 25. Restricting the initial position of the inner unit 102 by colliding with the end edge is advantageous for further improving the positional accuracy of the inner unit 102 in the initial position with respect to the outer needle 30 in the front-rear direction.

  By improving the positional accuracy of the inner unit 102 in the initial position relative to the outer needle 30, the protruding length of the inner needle 50 from the outer needle 30 when the inner unit 102 is in the initial position can be managed with high accuracy. Can do.

  Since the engaging convex portion 26 is continuous in the circumferential direction, the inner hub 40 can be engaged with the outer hub 25 regardless of the posture of the inner hub 40 around the central axis 40a in the rotational direction.

  In the above example, the engaging convex portion 26a is continuous along the circumferential direction, but the engaging convex portion 26a may not be continuous in the circumferential direction. For example, the plurality of engaging convex portions 26a may be discretely arranged along the circumferential direction. Or only one engagement convex part 26a discontinuous in the circumferential direction may be arranged.

(Embodiment 2)
In the first embodiment described above, when the inner unit 102 is in the initial position, the engagement protrusion 26a of the outer hub 25 is fitted into the small diameter portion 46 of the inner hub 40, whereby the inner hub 40 and the outer hub 25 are engaged. Combined. In the second embodiment, instead, the inner hub 40 and the outer hub 25 are engaged with each other by fitting the engaging convex portion 26 b of the outer hub 25 into the transverse passage 47 of the inner hub 40. Hereinafter, the indwelling needle device of the second embodiment will be described focusing on differences from the first embodiment.

  7A is a perspective view of the inner hub 40 used in the indwelling needle device of the second embodiment, FIG. 7B is a cross-sectional view of the inner hub 40 along the plane including the line 7B-7B in FIG. 7A, and FIG. It is arrow sectional drawing of the inner hub 40 along the surface containing the 7C-7C line | wire of FIG. 7A. In the inner hub 40 of the second embodiment, the outer diameter of the small diameter part 46 between the front part 41 and the large diameter part 45 is substantially the same as the maximum diameter of the front part 41. The inner hub 40 of the second embodiment is the same as the inner hub 40 of the first embodiment except for the above.

  FIG. 8 is a cross-sectional view along the vertical plane (YZ plane) showing the outer hub 25, the inner hub 40, and the vicinity thereof when the inner unit 102 is in the initial position. As shown in FIG. 8, when the inner unit 102 is in the initial position, the front edge of the large-diameter portion 45 of the inner hub 40 collides with the rear edge of the outer hub 25. The inner unit 102 is positioned with respect to the outer unit 101 in the front-rear direction (Z-axis direction).

  An engaging convex portion 26 b that protrudes toward the transverse passage 47 is formed in the region of the inner peripheral surface of the outer hub 25 that the transverse passage 47 of the inner hub 40 faces. A pair of engaging convex portions 26b are formed so as to face each other in the vertical direction.

  The inner hub 40 and the outer hub 25 are engaged with each other by fitting the engaging convex portion 26 b into the transverse passage 47 of the inner hub 40. When the inner unit 102 in the initial position is moved to the retracted position, the engaging convex portion 26 b of the outer hub 25 collides with the front edge 41 b of the lateral passage 47 of the inner hub 40. In order to move the inner unit 102 from the initial position toward the retracted position, it is necessary for the engaging convex portion 26b to move over the end edge 41b of the inner hub 40 and move to the front portion 41 side. For this purpose, it is necessary to apply a relatively large force between the outer unit 101 and the inner unit 102.

  The usage method of the indwelling needle device of the second embodiment is substantially the same as that of the first embodiment.

  In the puncturing operation, with the inner unit 102 in the initial position and the inner needle 50 protruding from the tip of the outer needle 30 (FIGS. 1, 2, and 8), the inner needle 50 and the outer needle 30 are placed in the patient's blood vessel. Puncture. At this time, the inner needle 50 receives a reaction force in a direction to move the inner unit 102 toward the retracted position with respect to the outer unit 101. However, as described above, since the inner hub 40 is engaged with the outer hub 25, the inner unit 102 does not move from the initial position with respect to the outer unit 101.

  In the next retraction operation, the inner unit 102 is retracted by pulling the tube 60 with the outer needle 30 punctured by the patient. It is necessary to apply a large tension to the tube 60 so that the engaging convex portion 26 b of the outer hub 25 gets over the end edge 41 b of the inner hub 40. Thereafter, when the engaging convex portion 26b moves over the end edge 41b of the inner hub 40 and moves to the front portion 41 side, the tube 60 can be pulled out with a relatively small tension. The tube 60 is pulled to move the inner unit 102 to the retracted position (see FIGS. 4 and 5).

  As described above, in the indwelling needle device of the second embodiment, the inner hub 40 is engaged with the outer hub 25 when the inner unit 102 is in the initial position. Therefore, as in the first embodiment, in the puncturing operation, even if the inner needle 50 receives a reaction force, the inner unit 102 does not move toward the retracted position and remains at the initial position. Therefore, the stopper 970 (FIG. 18) that is essential in the conventional indwelling needle device 900 (FIG. 16 to FIG. 19) is not necessary in the indwelling needle device of the second embodiment.

  Since the stopper is unnecessary, the risk of erroneous operation that may occur with the conventional indwelling needle device 900 provided with the stopper 970 is reduced. Further, the number of parts constituting the indwelling needle device is reduced, and the cost of the indwelling needle device can be reduced. Furthermore, the inner unit 102 is not displaced from the initial position due to vibration during transfer.

  The inner unit 102 in the initial position is engaged with an engaging protrusion 26 b provided on the outer hub 25 that holds the outer needle 30. Therefore, the positional accuracy in the front-rear direction with respect to the outer needle 30 of the inner unit 102 at the initial position is improved. Furthermore, the protruding length of the inner needle 50 from the outer needle 30 when the inner unit 102 is in the initial position can be managed with high accuracy.

  The engaging convex portions 26b are discretely formed in the circumferential direction. Therefore, according to the second embodiment, the engagement structure between the inner hub 40 and the outer hub 25 can also regulate the posture of the inner hub 40 in the rotational direction with respect to the outer hub 25.

  The configuration in which the outer hub 25 and the inner hub 40 shown in the second embodiment are engaged can be combined with the first embodiment.

  In the above example, the two engaging convex portions 26b are arranged to face each other in the vertical direction, but either one of the two engaging convex portions 26 may be omitted.

(Embodiment 3)
In the first and second embodiments described above, when the inner unit 102 is in the initial position, the inner hub 40 and the outer hub 25 are engaged. In the third embodiment, instead of this, when the inner unit 102 is in the initial position, the O-ring 49 attached to the inner hub 40 is engaged with the shield cylinder 21. Hereinafter, the indwelling needle device of the third embodiment will be described focusing on differences from the first embodiment.

  FIG. 9 is a cross-sectional view along the horizontal plane (XZ plane) showing the outer hub 25, the inner hub 40, and the vicinity thereof when the inner unit 102 is in the initial position in the indwelling needle device of the third embodiment. It is. As can be easily understood by comparing with FIG. 6 described in the first embodiment, in the third embodiment, the engagement convex portion 26a (see FIG. 6) formed on the inner peripheral surface of the outer hub 25 in the first embodiment. Not formed. Furthermore, although illustration is omitted, in the third embodiment, the engagement convex portion 26b (see FIG. 8) formed on the inner peripheral surface of the outer hub 25 in the second embodiment is not formed. The inner hub 40 shown in FIG. 9 is the same as the inner hub 40 (see FIGS. 3A to 3C) of the first embodiment, but the inner hub 40 used in the indwelling needle device of the third embodiment is an embodiment. Two inner hubs 40 (see FIGS. 7A-7C) can also be used. Similarly to the first embodiment, when the inner unit 102 is in the initial position, the front edge of the large-diameter portion 45 of the inner hub 40 collides with the rear edge of the outer hub 25, so that the inner unit 102 Is positioned in the front-rear direction (Z-axis direction) with respect to the outer unit 101.

  As shown in FIG. 9, rib-like engagement convex portions 23 a that are continuous in the circumferential direction are formed on the inner peripheral surface of the shield tube 21 in the vicinity of the outer hub 25. When the inner unit 102 is in the initial position, the O-ring 49 attached to the inner hub 40 is in contact with a region on the front side of the engagement convex portion 23a on the inner peripheral surface of the shield tube 21. The engaging projection 23 a is close to the O-ring 49 on the rear side of the O-ring 49 (preferably in contact with the O-ring 49). Thus, when the inner unit 102 is in the initial position, the O-ring 49 and the engaging projection 23a are engaged.

  In order to move the inner unit 102 from the initial position toward the retracted position, it is necessary for the O-ring 49 to move over the engaging convex portion 23a and move to the rear side of the engaging convex portion 23a. When the O-ring 49 gets over the engaging projection 23a, it is necessary to reduce the diameter of the O-ring 49 in the radial direction. Therefore, in order to move the inner unit 102 from the initial position toward the retracted position, it is necessary to apply a relatively large force between the outer unit 101 and the inner unit 102.

  The usage method of the indwelling needle device of the third embodiment is substantially the same as that of the first embodiment.

  In the puncturing operation, the inner needle 50 and the outer needle 30 are placed on the patient while the inner unit 102 is in the initial position and the inner needle 50 protrudes from the distal end of the outer needle 30 (see FIGS. 1, 2, and 9). Puncture blood vessel. At this time, the inner needle 50 receives a reaction force in a direction to move the inner unit 102 toward the retracted position with respect to the outer unit 101. However, as described above, since the O-ring 49 is engaged with the engagement protrusion 23a, the inner unit 102 does not move from the initial position with respect to the outer unit 101.

  In the next retraction operation, the inner unit 102 is retracted by pulling the tube 60 with the outer needle 30 punctured by the patient. It is necessary to apply a large tension to the tube 60 in order to move the O-ring 49 over the engaging convex portion 23a and move it behind the engaging convex portion 23a. Thereafter, when the O-ring 49 moves to the rear side of the engagement convex portion 23a, the tube 60 can be pulled out with a relatively small tension. The tube 60 is pulled to move the inner unit 102 to the retracted position (see FIGS. 4 and 5). In the process in which the inner unit 102 moves from the initial position to the retracted position, the O-ring 49 slides on the inner peripheral surface of the shield cylinder 21 while maintaining liquid tightness with the shield cylinder 21.

  As described above, in the indwelling needle device of the third embodiment, the O-ring 49 is engaged with the shield cylinder 21 when the inner unit 102 is in the initial position. Therefore, as in the first embodiment, in the puncturing operation, even if the inner needle 50 receives a reaction force, the inner unit 102 does not move toward the retracted position and remains at the initial position. Therefore, the stopper 970 (FIG. 18) that is essential in the conventional indwelling needle device 900 (FIG. 16 to FIG. 19) is not necessary in the indwelling needle device of the third embodiment.

  Since the stopper is unnecessary, the risk of erroneous operation that may occur with the conventional indwelling needle device 900 provided with the stopper 970 is reduced. Further, the number of parts constituting the indwelling needle device is reduced, and the cost of the indwelling needle device can be reduced. Furthermore, the inner unit 102 is not displaced from the initial position due to vibration during transfer.

  Since the O-ring 49 is continuous in the circumferential direction, the O-ring 49 and the engaging protrusion 23a can be engaged regardless of the orientation of the inner unit 102 around the central axis 40a in the rotational direction.

  In FIG. 9, when the inner unit 102 is in the initial position, the engaging convex portion 23 a is disposed on the rear side with respect to the O-ring 49, but the present invention is not limited to this. For example, as shown in FIG. 10, when the inner unit 102 is in the initial position, it is in a direction (ie, radial direction) orthogonal to the central axis 40a of the inner hub 40 (see FIGS. 3B, 3C, 7B, and 7C). An engaging convex portion 23 a may be formed at a position facing the O-ring 49. In this case, the engaging protrusion 23a engages with the O-ring 49 while compressing the O-ring 49 in the radial direction. The engaging convex part 23a and the O-ring 49 apply a large pressing force to each other. In order to move the inner unit 102 from the initial position toward the retracted position, it is necessary to overcome the large pressing force and move the O-ring 49 relative to the engaging convex portion 23a. Therefore, the effect of FIG. 10 is the same as that of FIG.

  In FIG. 10, an engagement concave portion into which the engagement convex portion 23 a is fitted may be formed on the outer peripheral surface of the O-ring 49. In this case, in order to move the inner unit 102 from the initial position toward the retracted position, the O-ring 49 is deformed and the engagement concave portion of the O-ring 49 and the engagement convex portion 23a are engaged (fitted). It is necessary to cancel. For this purpose, it is necessary to apply a relatively large force between the outer unit 101 and the inner unit 102. Therefore, also in this case, the same effect as in the case of FIG. In order to securely engage the engagement concave portion of the O-ring 49 and the engagement convex portion 23a, the engagement concave portion formed in the O-ring 49 is preferably continuous in the circumferential direction.

  The configuration in which the O-ring 49 and the shield cylinder 21 shown in the third embodiment are engaged can be combined with the first and second embodiments.

  In the above example, the engaging convex portion 23a is continuous in the circumferential direction, but may be discontinuous in the circumferential direction. That is, the plurality of engaging convex portions 23a may be discretely arranged in the circumferential direction, or only one engaging convex portion 23a discontinuous in the circumferential direction may be arranged. However, from the viewpoint of ensuring liquid-tightness between the O-ring 49 and the shield 20 (especially the shield cylinder 21), it is preferable that the engagement protrusion 23a is continuous in the circumferential direction.

(Embodiment 4)
When the inner unit 102 is in the initial position, the inner hub 40 and the outer hub 25 are engaged in the first and second embodiments described above, and the O-ring 49 and the shield tube attached to the inner hub 40 in the third embodiment described above. 21 engaged. In the fourth embodiment, instead of these, when the inner unit 102 is in the initial position, the O-ring 49 attached to the inner hub 40 is engaged with the outer hub 25. Hereinafter, the indwelling needle device of the fourth embodiment will be described focusing on differences from the first and third embodiments.

  FIG. 11 is a cross-sectional view along the horizontal plane (XZ plane) showing the outer hub 25, the inner hub 40, and the vicinity thereof when the inner unit 102 is in the initial position in the indwelling needle device of the fourth embodiment. It is. As can be easily understood by comparing with FIG. 9 described in the third embodiment, in the fourth embodiment, when the inner unit 102 is in the initial position, the O-ring 49 attached to the inner hub 40 is connected to the outer hub 25. The outer hub 25 is extended rearward so as to be in close contact. On the inner peripheral surface of the outer hub 25, a step 25s formed by changing the inner diameter is formed. A region on the rear side of the step 25s of the outer hub 25 is an extension portion 25e having a relatively larger inner diameter than a region on the front side of the step 25s. The inner peripheral surface of the extension portion 25e (the surface on the side facing the inner hub 40) is a cylindrical surface having an inner diameter substantially the same as the inner diameter of the area behind the extension portion 25e of the shield tube 21. The inner hub 40 shown in FIG. 11 is the same as the inner hub 40 (see FIGS. 3A to 3C) of the first embodiment, but the inner hub 40 used in the indwelling needle device of the fourth embodiment is an embodiment. Two inner hubs 40 (see FIGS. 7A-7C) can also be used. When the inner unit 102 is in the initial position, the front edge of the large-diameter portion 45 of the inner hub 40 collides with the step 25 s of the outer hub 25, so that the inner unit 102 is in the front-rear direction with respect to the outer unit 101. Positioned in (Z-axis direction).

  In the fourth embodiment, the engagement convex portion 26a (see FIG. 6) formed on the inner peripheral surface of the outer hub 25 in the first embodiment is also the engagement convex portion formed on the inner peripheral surface of the outer hub 25 in the second embodiment. Neither 26b (see FIG. 8) nor the engaging projection 23a (see FIGS. 9 and 10) formed on the inner peripheral surface of the shield cylinder 21 in the third embodiment is formed. Instead, the rib-like engagement convex part 23b which continued in the circumferential direction is formed in the internal peripheral surface of the extension part 25e of the outer hub 25. As shown in FIG. When the inner unit 102 is in the initial position, the O-ring 49 attached to the inner hub 40 is in contact with a region on the front side of the engagement convex portion 23b on the inner peripheral surface of the extension portion 25e. The engaging projection 23 b is close to the O-ring 49 (preferably in contact with the O-ring 49) behind the O-ring 49. Thus, when the inner unit 102 is in the initial position, the O-ring 49 and the engaging projection 23b are engaged.

  In order to move the inner unit 102 from the initial position toward the retracted position, it is necessary for the O-ring 49 to move over the engagement convex portion 23b and move to the rear side of the engagement convex portion 23b. When the O-ring 49 gets over the engaging protrusion 23b, it is necessary to reduce the diameter of the O-ring 49 in the radial direction. Therefore, in order to move the inner unit 102 from the initial position toward the retracted position, it is necessary to apply a relatively large force between the outer unit 101 and the inner unit 102.

  The usage method of the indwelling needle device of the fourth embodiment is substantially the same as that of the first embodiment.

  In the puncturing operation, the inner needle 50 and the outer needle 30 are placed on the patient while the inner unit 102 is in the initial position and the inner needle 50 protrudes from the distal end of the outer needle 30 (see FIGS. 1, 2, and 11). Puncture blood vessel. At this time, the inner needle 50 receives a reaction force in a direction to move the inner unit 102 toward the retracted position with respect to the outer unit 101. However, as described above, since the O-ring 49 is engaged with the engagement convex portion 23b, the inner unit 102 does not move from the initial position with respect to the outer unit 101.

  In the next retraction operation, the inner unit 102 is retracted by pulling the tube 60 with the outer needle 30 punctured by the patient. It is necessary to apply a large tension to the tube 60 in order to move the O-ring 49 over the engaging convex portion 23b and move it behind the engaging convex portion 23b. Thereafter, when the O-ring 49 moves to the rear side of the engagement convex portion 23b, the tube 60 can be pulled out with a relatively small tension. The tube 60 is pulled to move the inner unit 102 to the retracted position (see FIGS. 4 and 5). In the process in which the inner unit 102 moves from the initial position to the retracted position, the O-ring 49 maintains the liquid tightness between the shield 20 (that is, the extension portion 25e and the shield tube 21), and the inner periphery of the shield 20 Slide on the surface.

  As described above, in the indwelling needle device according to the fourth embodiment, the O-ring 49 is engaged with the outer hub 25 when the inner unit 102 is in the initial position. Therefore, as in the first embodiment, in the puncturing operation, even if the inner needle 50 receives a reaction force, the inner unit 102 does not move toward the retracted position and remains at the initial position. Therefore, the stopper 970 (FIG. 18) that is essential in the conventional indwelling needle device 900 (FIG. 16 to FIG. 19) is not necessary in the indwelling needle device of the fourth embodiment.

  Since the stopper is unnecessary, the risk of erroneous operation that may occur with the conventional indwelling needle device 900 provided with the stopper 970 is reduced. Further, the number of parts constituting the indwelling needle device is reduced, and the cost of the indwelling needle device can be reduced. Furthermore, the inner unit 102 is not displaced from the initial position due to vibration during transfer.

  The inner unit 102 in the initial position is engaged with an engaging protrusion 23 b provided on the outer hub 25. Therefore, as in the first embodiment, the positional accuracy in the front-rear direction with respect to the outer needle 30 of the inner unit 102 at the initial position is improved. Furthermore, the protruding length of the inner needle 50 from the outer needle 30 when the inner unit 102 is in the initial position can be managed with high accuracy.

  Since the O-ring 49 is continuous in the circumferential direction, the O-ring 49 and the engaging protrusion 23b can be engaged regardless of the orientation of the inner unit 102 around the central axis 40a in the rotational direction.

  In FIG. 11, when the inner unit 102 is in the initial position, the engaging convex portion 23 b is disposed on the rear side with respect to the O-ring 49, but the present invention is not limited to this. For example, as shown in FIG. 12, when the inner unit 102 is in the initial position, it is in a direction (ie, radial direction) orthogonal to the central axis 40a of the inner hub 40 (see FIGS. 3B, 3C, 7B, and 7C). An engaging convex portion 23 b may be formed at a position facing the O-ring 49. In this case, the engaging protrusion 23b engages with the O-ring 49 while compressing the O-ring 49 in the radial direction. The engaging convex portion 23b and the O-ring 49 apply a large pressing force to the other party. In order to move the inner unit 102 from the initial position toward the retracted position, it is necessary to overcome the large pressing force and move the O-ring 49 relative to the engaging convex portion 23b. Therefore, the effect of FIG. 12 is the same as that of FIG.

  In FIG. 12, an engagement concave portion into which the engagement convex portion 23 b is fitted may be formed on the outer peripheral surface of the O-ring 49. In this case, in order to move the inner unit 102 from the initial position toward the retracted position, the O-ring 49 is deformed and the engagement concave portion of the O-ring 49 and the engagement convex portion 23b are engaged (fitted). It is necessary to cancel. For this purpose, it is necessary to apply a relatively large force between the outer unit 101 and the inner unit 102. Therefore, also in this case, the same effect as in the case of FIG. In order to securely engage the engagement concave portion of the O-ring 49 and the engagement convex portion 23b, the engagement concave portion formed in the O-ring 49 is preferably continuous in the circumferential direction.

  The configuration in which the O-ring 49 and the outer hub 25 shown in the fourth embodiment are engaged can be combined with the first and second embodiments.

  In the above example, the engaging protrusions 23b are continuous in the circumferential direction, but may be discontinuous in the circumferential direction. That is, the plurality of engaging protrusions 23b may be arranged discretely in the circumferential direction, or only one engaging protrusion 23b discontinuous in the circumferential direction may be arranged. However, from the viewpoint of ensuring liquid-tightness between the O-ring 49 and the shield 20 (particularly the extension portion 25e), it is preferable that the engagement convex portion 23b is continuous in the circumferential direction.

  In the above example, the extension portion 25e extends further to the rear side than the engagement convex portion 23b. However, the position of the rear end of the extension portion 25e matches the position of the engagement convex portion 23b in the front-rear direction. Also good.

(Embodiment 5)
When the inner unit 102 is in the initial position, the inner hub 40 and the outer hub 25 are engaged in the first and second embodiments described above, and the O-ring 49 and the shield 20 are engaged in the third and fourth embodiments described above. . In the fifth embodiment, instead of these, the inner needle 50 is engaged with the outer needle 30 when the inner unit 102 is in the initial position. Hereinafter, the indwelling needle device of the fifth embodiment will be described focusing on the differences from the first embodiment.

  FIG. 13 is a cross-sectional view along the vertical plane (YZ plane) showing the outer hub 25, the inner hub 40, and the vicinity thereof when the inner unit 102 is in the initial position in the indwelling needle device of the fifth embodiment. It is. As can be easily understood by comparing with FIG. 8 described in the second embodiment, in the fifth embodiment, the engagement convex portion 26b (see FIG. 8) formed on the inner peripheral surface of the outer hub 25 in the second embodiment. Not formed. Furthermore, in the fifth embodiment, the engagement convex portion 26a (see FIG. 6) formed on the inner peripheral surface of the outer hub 25 in the first embodiment is also formed on the inner peripheral surface of the shield tube 21 in the third embodiment. Neither the convex portion 23a (see FIGS. 9 and 10) nor the engaging convex portion 23b (see FIGS. 11 and 12) formed on the inner peripheral surface of the outer hub 25 in the fourth embodiment is formed. The inner hub 40 used in the indwelling needle device of the fifth embodiment is either the inner hub 40 of the first embodiment (see FIGS. 3A to 3C) or the inner hub 40 of the second embodiment (see FIGS. 7A to 7C). It may be. Similarly to the first embodiment, when the inner unit 102 is in the initial position, the front edge of the large-diameter portion 45 of the inner hub 40 collides with the rear edge of the outer hub 25, so that the inner unit 102 Is positioned in the front-rear direction (Z-axis direction) with respect to the outer unit 101.

  FIG. 14 is a cross-sectional view showing the tips of the inner needle 50 and the outer needle 30 and the vicinity thereof when the inner unit 102 is in the initial position in the indwelling needle device of the fifth embodiment. In FIG. 14, only the outer needle 30 is shown as a cross section. As shown in FIG. 14, rib-like engagement convex portions 51 that are continuous in the circumferential direction are formed on the outer peripheral surface near the tip of the inner needle 50. The outer peripheral surface of the inner needle 50 is a cylindrical surface having a constant outer diameter in the longitudinal direction (Z-axis direction) of the inner needle 50 except for the engaging convex portion 51. On the other hand, the inner diameter of the outer needle 30 is not constant in the longitudinal direction of the outer needle 30, and is small in a region (small-diameter region) 33 at a predetermined distance from the tip of the outer needle 30, and behind the small-diameter region 33. Greater than this. On the inner peripheral surface of the small-diameter region 33, a groove-like engaging recess 31 that is continuous in the circumferential direction is formed. When the inner unit 102 is in the initial position, the engaging convex portion 51 of the inner needle 50 is fitted into the engaging concave portion 31 of the outer needle 30. The inner diameter of the outer needle 30 (excluding the engaging concave portion 31) in the small diameter region 33 is preferably the same as or slightly smaller than the outer diameter of the inner needle 50 (excluding the engaging convex portion 51). Accordingly, the outer needle 30 is in close contact with the inner needle 50 in the small diameter region 33. On the other hand, a gap 13 is formed between the outer needle 30 and the inner needle 50 behind the small-diameter region 33.

  When the inner unit 102 is in the initial position, the inner protrusion 50 and the outer needle 30 are engaged with each other by the engagement protrusion 51 being fitted into the engagement recess 31. In order to move the inner unit 102 from the initial position toward the retracted position, it is necessary that the engaging convex portion 51 escapes from the engaging concave portion 31 and further passes through the small diameter region 33 and moves to the outer hub 20 side. is there. When the engaging convex portion 51 passes through the small diameter region 33, the engaging convex portion 51 needs to expand the small diameter region 33 of the outer needle 30. Therefore, in order to move the inner unit 102 from the initial position toward the retracted position, it is necessary to apply a relatively large force between the outer unit 101 and the inner unit 102.

  The method of using the indwelling needle device of the fifth embodiment is substantially the same as that of the first embodiment.

  In the puncturing operation, the inner needle 50 and the outer needle 30 are placed on the patient while the inner unit 102 is in the initial position and the inner needle 50 protrudes from the distal end of the outer needle 30 (FIGS. 1, 2, 13, and 14). Puncture the blood vessels. At this time, the inner needle 50 receives a reaction force in a direction to move the inner unit 102 toward the retracted position with respect to the outer unit 101. However, as described above, since the inner needle 50 is engaged with the outer needle 30, the inner unit 102 does not move from the initial position with respect to the outer unit 101.

  In the next retraction operation, the inner unit 102 is retracted by pulling the tube 60 with the outer needle 30 punctured by the patient. In order to allow the engaging convex portion 51 of the inner needle 50 to escape from the engaging concave portion 31 of the outer needle 30 and to pass through the small-diameter region 33 of the outer needle 30, it is necessary to apply a large tension to the tube 60. Thereafter, when the engaging convex portion 51 comes out of the small-diameter region 33 of the outer needle 30 and moves into the gap 13 between the outer needle 30 and the inner needle 50, the tube 60 can be pulled out with a relatively small tension. . The tube 60 is pulled to move the inner unit 102 to the retracted position (see FIGS. 4 and 5).

  As described above, in the indwelling needle device of the fifth embodiment, the inner needle 50 is engaged with the outer needle 30 when the inner unit 102 is in the initial position. Therefore, as in the first embodiment, in the puncturing operation, even if the inner needle 50 receives a reaction force, the inner unit 102 does not move toward the retracted position and remains at the initial position. Therefore, the stopper 970 (FIG. 18) that is essential in the conventional indwelling needle device 900 (FIG. 16 to FIG. 19) is not necessary in the indwelling needle device of the fifth embodiment.

  Since the stopper is unnecessary, the risk of erroneous operation that may occur with the conventional indwelling needle device 900 provided with the stopper 970 is reduced. Further, the number of parts constituting the indwelling needle device is reduced, and the cost of the indwelling needle device can be reduced. Furthermore, the inner unit 102 is not displaced from the initial position due to vibration during transfer.

  The inner unit 102 in the initial position is engaged with an engagement recess 31 provided in the outer needle 30. Therefore, the positional accuracy in the front-rear direction with respect to the outer needle 30 of the inner unit 102 at the initial position is improved. Furthermore, since the inner needle 50 is engaged with the outer needle 30, the protruding length of the inner needle 50 from the outer needle 30 when the inner unit 102 is in the initial position can be managed with high accuracy.

  Since both the engagement concave portion 31 and the engagement convex portion 51 are continuous in the circumferential direction, the inner needle 50 is engaged with the outer needle 30 regardless of the orientation of the inner unit 102 around the central axis 40a in the rotational direction. be able to.

  The configuration in which the outer needle 30 and the inner needle 50 shown in the fifth embodiment are engaged can be combined with the first to fourth embodiments.

  In the above example, the engaging recess 31 and the engaging protrusion 51 are both continuous in the circumferential direction, but at least one of them may be discontinuous in the circumferential direction. That is, the plurality of engagement recesses 31 and / or the plurality of engagement projections 51 may be arranged discretely in the circumferential direction, or only one engagement recess 31 and / or discontinuous in the circumferential direction. Only one engagement convex portion 51 that is discontinuous in the circumferential direction may be disposed.

(Embodiment 6)
When the inner unit 102 is in the initial position, the inner hub 40 and the outer hub 25 are engaged in the first and second embodiments described above, and the O-ring 49 and the shield 20 are engaged in the third and fourth embodiments described above. In the fifth embodiment, the inner needle 50 and the outer needle 30 are engaged. In the sixth embodiment, instead of these, when the inner unit 102 is in the initial position, the inner needle 50 is engaged with the outer hub 25. Hereinafter, the indwelling needle device of the sixth embodiment will be described focusing on differences from the first embodiment.

  Although illustration is omitted, as in the fifth embodiment, in the sixth embodiment, the engagement convex portion 26a (see FIG. 6) formed on the inner peripheral surface of the outer hub 25 in the first embodiment is also the outer portion in the second embodiment. The engaging convex portion 26b (see FIG. 8) formed on the inner peripheral surface of the hub 25 and the engaging convex portion 23a (see FIGS. 9 and 10) formed on the inner peripheral surface of the shield tube 21 in the third embodiment are also included. Furthermore, the engagement convex part 23b (refer FIG. 11, FIG. 12) formed in the internal peripheral surface of the outer hub 25 in Embodiment 4 is not formed. The inner hub 40 used in the indwelling needle device of the sixth embodiment is any of the inner hub 40 of the first embodiment (see FIGS. 3A to 3C) and the inner hub 40 of the second embodiment (see FIGS. 7A to 7C). It may be. Similarly to the first embodiment, when the inner unit 102 is in the initial position, the front edge of the large-diameter portion 45 of the inner hub 40 collides with the rear edge of the outer hub 25, so that the inner unit 102 Is positioned in the front-rear direction (Z-axis direction) with respect to the outer unit 101.

  FIG. 15 is a cross-sectional view showing the outer hub 25 and its vicinity when the inner unit is in the initial position in the indwelling needle device of the sixth embodiment. As shown in FIG. 15, rib-like engagement convex portions 52 that are continuous in the circumferential direction are formed on the outer peripheral surface of the inner needle 50. The engaging convex portion 52 is a region of the inner needle 50 that is located closer to the inner hub 40 than the outer needle 30 when the inner unit 102 is in the initial position, and is slightly forward from the front end of the inner hub 40. It is formed in the position. The outer peripheral surface of the inner needle 50 is a cylindrical surface having a constant outer diameter in the longitudinal direction (Z-axis direction) of the inner needle 50 except for the engaging convex portion 52. On the other hand, in order to position the outer needle 30 in the front-rear direction, the outer hub 25 is formed with a small-diameter region 25a having a relatively small inner diameter adjacent to a portion that holds the outer needle 30. And the groove-shaped engagement recessed part 27 continuous in the circumferential direction is formed in the internal peripheral surface of the small diameter part 25a.

  When the inner unit 102 is in the initial position, the engagement protrusion 52 of the inner needle 50 is fitted into the engagement recess 27 of the outer hub 25, whereby the inner needle 50 and the outer hub 25 are engaged. In order to move the inner unit 102 from the initial position toward the retracted position, the engaging convex portion 52 needs to escape from the engaging concave portion 27 and further pass through the small diameter region 25a. Therefore, it is necessary to apply a relatively large force between the outer unit 101 and the inner unit 102.

  The usage method of the indwelling needle device of the sixth embodiment is substantially the same as that of the first embodiment.

  In the puncturing operation, with the inner unit 102 in the initial position and the inner needle 50 protruding from the tip of the outer needle 30 (FIGS. 1, 2, and 15), the inner needle 50 and the outer needle 30 are placed in the patient's blood vessel. Puncture. At this time, the inner needle 50 receives a reaction force in a direction to move the inner unit 102 toward the retracted position with respect to the outer unit 101. However, as described above, since the inner needle 50 is engaged with the outer hub 25, the inner unit 102 does not move from the initial position with respect to the outer unit 101.

  In the next retraction operation, the inner unit 102 is retracted by pulling the tube 60 with the outer needle 30 punctured by the patient. In order to allow the engagement convex portion 52 of the inner needle 50 to escape from the engagement concave portion 27 of the outer hub 25 and to pass through the small diameter region 25a of the outer hub 25, it is necessary to apply a large tension to the tube 60. Thereafter, when the engaging convex portion 52 comes out of the small-diameter region 25a of the outer hub 25 and moves into the lumen 24 of the shield 20, the tube 60 can be pulled out with a relatively small tension. The tube 60 is pulled to move the inner unit 102 to the retracted position (see FIGS. 4 and 5).

  As described above, in the indwelling needle device of the sixth embodiment, the inner needle 50 is engaged with the outer hub 25 when the inner unit 102 is in the initial position. Therefore, as in the first embodiment, in the puncturing operation, even if the inner needle 50 receives a reaction force, the inner unit 102 does not move toward the retracted position and remains at the initial position. Therefore, the stopper 970 (FIG. 18) that is essential in the conventional indwelling needle device 900 (FIG. 16 to FIG. 19) is not necessary in the indwelling needle device of the sixth embodiment.

  Since the stopper is unnecessary, the risk of erroneous operation that may occur with the conventional indwelling needle device 900 provided with the stopper 970 is reduced. Further, the number of parts constituting the indwelling needle device is reduced, and the cost of the indwelling needle device can be reduced. Furthermore, the inner unit 102 is not displaced from the initial position due to vibration during transfer.

  The inner unit 102 in the initial position is engaged with an engagement recess 27 provided in the outer hub 25 that holds the outer needle 30. Therefore, the positional accuracy in the front-rear direction with respect to the outer needle 30 of the inner unit 102 at the initial position is improved. Furthermore, the protruding length of the inner needle 50 from the outer needle 30 when the inner unit 102 is in the initial position can be managed with high accuracy.

  Since both the engagement concave portion 27 and the engagement convex portion 52 are continuous in the circumferential direction, the inner needle 50 is engaged with the outer hub 25 regardless of the posture of the inner unit 102 around the central axis 40a in the rotational direction. be able to.

  The configuration in which the outer hub 25 and the inner needle 50 shown in the sixth embodiment are engaged can be combined with the first to fifth embodiments.

  In the above example, both the engagement concave portion 27 and the engagement convex portion 52 are continuous in the circumferential direction, but at least one of them may be discontinuous in the circumferential direction. That is, the plurality of engagement recesses 27 and / or the plurality of engagement projections 52 may be discretely arranged in the circumferential direction, or only one engagement recess 27 and / or discontinuous in the circumferential direction. Only one engagement convex portion 52 that is discontinuous in the circumferential direction may be disposed.

  The above first to sixth embodiments are merely examples. The present invention is not limited to Embodiments 1 to 6 above, and can be modified as appropriate.

  The engaging structures that engage with each other and are respectively provided in the outer unit 101 and the inner unit 102 when the inner unit 102 is in the initial position are not limited to the first to sixth embodiments. The position where the engagement structure is provided, the shape, the number, and the like can be arbitrarily changed. In the first and second embodiments, the outer unit 101 is provided with an engaging convex portion, and the inner unit 102 is provided with a concave engaging structure that engages with the engaging convex portion. A concave engagement structure that engages with the engagement convex portion may be provided on the outer unit 101. In the fifth and sixth embodiments, the inner needle 50 is provided with an engaging convex portion, and the outer unit 101 is provided with a concave engaging structure that engages with the engaging convex portion. A concavity may be provided, and the outer unit 101 may be provided with a convex engagement structure that engages with the engagement recess.

  The cross-sectional shape of the engaging protrusions 23a, 23b, 26a, 26b, 51, 52 is not limited to the above embodiment. The cross-sectional shape of the engaging projections 23a, 23b, 26a, 26b, 51, 52 and the protruding height (projection amount) are for the reaction force received by the inner needle 50 during the puncturing operation and for moving the inner unit 102 during the retracting operation. Can be set in consideration of the force required for the operation.

  When the inner unit 102 is in the initial position, the inner unit 102 and the outer unit 101 may be engaged at a plurality of portions.

  The configurations of the outer unit 101 and the inner unit 102 can be arbitrarily changed within the scope of the present invention.

  For example, a large-area planar portion may be provided on the outer surface of the shield 20 so that the indwelling needle device can be easily grasped, and an uneven shape for preventing slipping may be formed.

  The fitting structure between the hub 40 and the shield 20 in the retracted position may have a configuration other than the above. Alternatively, the fitting structure may be omitted.

  The wings 29a and 29b and the fixing member 28 that are attached to the outer unit 101 may be omitted.

  In the first to sixth embodiments, the front end of the large-diameter portion 45 of the inner hub 40 is caused to collide with the outer hub 25, thereby restricting the forward position of the inner unit 102 with respect to the outer unit 101. However, the forward position of the inner unit 102 at the initial position may be regulated by bringing the inner unit 102 and the outer unit 101 into contact with each other at locations other than those described above. The front and rear positions of the inner unit 102 at the initial position may be regulated using the engaging structures that are provided in the outer unit 101 and the inner unit 102 and engage with each other.

  In the above description, the indwelling needle device of the present invention is used for hemodialysis. However, the use of the indwelling needle device of the present invention is not limited to this, and is used for any application in which an indwelling needle device such as infusion or blood transfusion is used. can do.

  The field of use of the present invention is not particularly limited, and can be widely used as an indwelling needle device for performing treatments such as infusion, blood transfusion, and extracorporeal blood circulation. Especially, it can utilize preferably as an indwelling needle apparatus for hemodialysis.

DESCRIPTION OF SYMBOLS 100 Indwelling needle apparatus 101 Outer unit 102 Inner unit 20 Shield 21 Shield cylinder 23a Engagement convex part 24 Shield inner cavity 25 Outer hub 26a, 26b Engagement convex part (engagement structure)
27 Engaging recess (engaging structure)
30 Outer needle 31 Engaging recess (engaging structure)
40 Inner hub 46 Small diameter part (engagement structure)
47 Transverse path (engagement structure)
49 O-ring 50 Inner needle 51, 52 Engagement convex part (engagement structure)
60 tubes

Claims (13)

An outer unit including a shield having a lumen and a soft outer needle fixed to the front end of the shield;
An inner hub disposed within the lumen of the shield, a rigid inner needle secured to the front end of the inner hub, and an inner unit including a tube connected to the rear end of the inner hub;
The inner unit moves from the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to a retracted position where the inner needle is housed in the lumen of the shield tube. An indwelling needle device that is displaced relative to
The shield includes an outer hub for holding the outer needle, and a cylindrical shield tube having the outer hub fixed to one end.
When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. An indwelling needle device, wherein an inner hub is engaged with the outer hub.   The engagement projection formed on the inner peripheral surface of the outer hub is fitted into a concave engagement structure formed on the outer peripheral surface of the inner hub, whereby the inner hub is engaged with the outer hub. Item 2. The indwelling needle device according to item 1. An engagement structure that engages with each other when the inner unit is in the initial position is provided in the inner hub and the outer hub,
The indwelling needle device according to claim 1 or 2, wherein at least one of the engagement structure provided on the inner hub and the engagement structure provided on the outer hub is continuous along a circumferential direction. An outer unit including a shield having a lumen and a soft outer needle fixed to the front end of the shield;
An inner hub disposed in the lumen of the shield, an O-ring attached to the inner hub, a rigid inner needle fixed to the front end of the inner hub, and a rear end of the inner hub An inner unit including a tube,
From the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to the retracted position where the inner needle is housed in the lumen of the shield tube, the O-ring is attached to the shield. An indwelling needle device in which the inner unit is displaced relative to the outer unit while sliding on the inner peripheral surface,
When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. An indwelling needle device, wherein an O-ring is engaged with the shield. The shield includes an outer hub for holding the outer needle, and a cylindrical shield tube having the outer hub fixed to one end.
The indwelling needle device according to claim 4, wherein the O-ring is engaged with the shield tube. The shield includes an outer hub for holding the outer needle, and a cylindrical shield tube having the outer hub fixed to one end.
The indwelling needle device according to claim 4, wherein the O-ring is engaged with the outer hub.   The indwelling needle apparatus in any one of Claims 4-6 in which the engagement convex part engaged with the said O-ring is formed in the said internal peripheral surface of the said shield.   The indwelling needle device according to claim 7, wherein the engagement convex portion is continuous along a circumferential direction. An outer unit including a shield having a lumen and a soft outer needle fixed to the front end of the shield;
An inner hub disposed within the lumen of the shield, a rigid inner needle secured to the front end of the inner hub, and an inner unit including a tube connected to the rear end of the inner hub;
The inner unit moves from the initial position where the inner needle penetrates the outer needle and protrudes from the tip of the outer needle to a retracted position where the inner needle is housed in the lumen of the shield tube. An indwelling needle device that is displaced relative to
When the inner unit is in the initial position, the inner unit does not move toward the retracted position due to a reaction force received by the inner needle when the inner unit is placed at the initial position and punctured. An indwelling needle device, wherein an inner needle is engaged with the outer unit.   An engagement convex portion formed on the outer peripheral surface of the inner needle is fitted into a concave engagement structure formed on the inner peripheral surface of the outer unit, whereby the inner needle is engaged with the outer unit. Item 10. The indwelling needle device according to item 9.   The indwelling needle device according to claim 9 or 10, wherein the inner needle is engaged with the outer needle when the inner unit is in the initial position.   The indwelling needle device according to any one of claims 9 to 11, wherein the inner needle is engaged with the shield when the inner unit is in the initial position. An engagement structure that engages with each other when the inner unit is in the initial position is provided in the inner needle and the outer unit,
The indwelling needle according to any one of claims 9 to 12, wherein at least one of the engagement structure provided on the inner needle and the engagement structure provided on the outer unit is continuous along a circumferential direction. apparatus.

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