HK1182038B - Indwelling needle device - Google Patents

Description

Indwelling needle device

Technical Field

The present invention relates to an indwelling needle (indwelling needle) device which includes a soft outer needle and a hard inner needle, and which is configured to be capable of puncturing a patient with the tip of the inner needle protruding from the tip of the outer needle, and then to be capable of retracting the inner needle from the outer needle.

Background

Indwelling needle devices are widely used for transfusion, blood transfusion, extracorporeal blood circulation, and the like. Since there is a possibility that a blood vessel is punctured when a metal needle is left in the blood vessel, patent document 1 discloses an indwelling needle device which includes a soft outer needle and a hard inner needle and which can puncture the blood vessel of a patient with the tip of the inner needle protruding from the tip of the outer needle, and then can retract the inner needle from the outer needle.

Fig. 8A is a cross-sectional view showing the distal end of the inner needle 920 protruding from the distal end of the outer needle 910 and its vicinity in the indwelling needle device disclosed in patent document 1. A side hole 921 is formed on the outer circumferential surface of the inner needle 920. In the state of fig. 8A, after the inner needle 920 and the outer needle 910 are sequentially inserted into the blood vessel of the patient, blood 930 of the patient flows through the inner needle 920 and flows through the side hole 921 of the inner needle 920 and the gap 925 between the inner needle 920 and the outer needle 910. If the outer needle 910 is made of a transparent or translucent material, blood flowing through the gap 925 can be visually confirmed, and flashback (flash back) of blood can be easily confirmed. In addition, since the gap 925 is filled with blood of the patient in addition to the lumen of the inner needle 920, priming (priming) operation is facilitated in hemodialysis, for example, and the risk of blood mixed with air returning to the patient can be reduced.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2006-297062

Summary of the invention

Problems to be solved by the invention

In hemodialysis, if the opening at the tip of the needle comes into contact with the inner wall of a blood vessel, the flow rate of blood decreases. In order to secure a blood flow path in an indwelling needle device for hemodialysis, a side hole is usually provided in the outer peripheral surface of a needle.

However, if a side hole 911 is formed in the outer peripheral surface of the outer needle 910 of the indwelling needle device shown in fig. 8A as shown in fig. 8B, there is a problem as follows: when puncturing a blood vessel of a patient, blood 930 of the patient enters a gap 925 between the inner needle 920 and the outer needle 910 through the side hole 921 of the inner needle 920 from the inner needle 920, and further leaks to the outside through the side hole 911 of the outer needle 910.

In fig. 8B, even if the side hole 921 of the inner needle 920 is closed, blood of the patient enters the gap 925 between the inner needle 920 and the outer needle 910 through a hub (not shown) connected to the base end (not shown) of the inner needle 920 from the inner needle 920, and further leaks to the outside through the side hole 911 of the outer needle 910.

Disclosure of Invention

An object of the present invention is to solve the above-described problems and provide an indwelling needle device in which a side hole is formed in an outer needle so that a blood flow path is ensured when the outer needle is indwelling in a blood vessel of a patient, and a gap between an inner needle and the outer needle is filled with blood, whereby a priming operation can be easily performed and blood does not leak from the side hole of the outer needle at the time of puncture.

Means for solving the problems

The indwelling needle device of the present invention includes: a sheath having an inner cavity; a soft outer needle fixed to the tip of the sheath; a bush disposed in the inner cavity of the sheath and movable in a longitudinal direction of the sheath; and an inner needle fixed to the front end of the hub. The hub is displaced between an initial position in which the hub is located on the distal end side of the lumen of the sheath and the inner needle penetrates the outer needle and projects from the distal end of the outer needle to the outside, and a retracted position in which the hub is located on the rear end side of the lumen of the sheath and the inner needle is housed in the lumen of the sheath.

The outer needle has a 1 st side hole penetrating through its outer circumferential surface. The inner needle has a 2 nd side hole penetrating through an outer peripheral surface thereof. When the hub is at the initial position, an inner peripheral surface of a region including the 1 st side hole of the outer needle is in close contact with an outer peripheral surface of the inner needle, and the 2 nd side hole is positioned on the hub side of a region where the inner peripheral surface of the outer needle is in close contact with the outer peripheral surface of the inner needle.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, since the 1 st side hole is formed in the outer needle, when the outer needle is inserted into a blood vessel of a patient and indwelling, even if the opening at the distal end of the outer needle comes into contact with the inner wall of the blood vessel and is closed, a blood flow path can be ensured.

Further, when the hub is at the initial position, the 2 nd side hole of the inner needle is closer to the hub side than the region where the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle are in close contact, so that the priming operation, that is, the gap between the inner needle and the outer needle can be filled with blood easily through the 2 nd side hole.

Further, when the hub is at the initial position, the inner peripheral surface of the region including the 1 st side hole of the outer needle is in close contact with the outer peripheral surface of the inner needle, so that blood does not leak from the 1 st side hole.

Drawings

Fig. 1 is a perspective view of an indwelling needle device according to an embodiment of the present invention with a hub in an initial position.

FIG. 2A is a sectional view of an indwelling needle device according to an embodiment of the present invention, taken along a plane including line 2A-2A of FIG. 1.

FIG. 2B is a sectional view of the indwelling needle device according to the embodiment of the present invention taken along the plane including the line 2B-2B in FIG. 1.

Fig. 3A is a perspective view of a hub incorporated in an indwelling needle device according to an embodiment of the present invention. FIG. 3B is a plan view, in cross-section, of the bushing taken along a plane containing line 3B-3B of FIG. 3A, and FIG. 3C is a side view, in cross-section, of the bushing taken along a plane containing line 3C-3C of FIG. 3A.

Fig. 4 is a perspective view of a stopper used in the indwelling needle device according to the embodiment of the present invention.

FIG. 5 is a sectional view showing the distal ends of the outer needle and the inner needle and the vicinity thereof when the hub is at the initial position in the indwelling needle device according to the embodiment of the present invention.

FIG. 6 is a perspective view of an indwelling needle device in accordance with an embodiment of the present invention with the hub in a retracted position.

FIG. 7A is a sectional view in a plan view of an indwelling needle device according to an embodiment of the present invention, taken along a plane including line 7A-7A of FIG. 6.

FIG. 7B is a sectional view of the indwelling needle device according to the embodiment of the present invention taken along the plane including line 7B-7B of FIG. 6, as seen from the side.

Fig. 8A is a sectional view showing the distal end of the inner needle protruding from the distal end of the outer needle and its vicinity in the conventional indwelling needle device. FIG. 8B is a cross-sectional view showing a virtual indwelling needle device in which a side hole is formed in the outer needle of the indwelling needle device shown in FIG. 8A.

Detailed Description

In the indwelling needle device according to the present invention, it is preferable that, when the hub is in the initial position, a gap is formed between the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle on the sheath side of the region where the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle are in close contact with each other, and the 2 nd-side hole communicates with a space between the outer surface of the hub and the inner surface of the sheath via the gap. Thus, when the hub is at the initial position, the priming operation for filling the space between the outer surface of the hub and the inner surface of the sheath with blood can be easily performed through the 2 nd side hole, in addition to the gap between the inner needle and the outer needle.

Preferably, when the bush is in the initial position, the 1 st side hole does not communicate with the 2 nd side hole. This can more reliably prevent leakage of blood from the 1 st side hole.

Preferably, when the hub is at the initial position, a gap is formed between the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle on the sheath side of the region where the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle are in close contact with each other, and the 1 st side hole does not communicate with the gap. This can more reliably prevent blood in the gap between the inner needle and the outer needle from leaking through the 1 st side hole.

The present invention will be described in detail below while showing preferred embodiments. However, the present invention is not limited to the following embodiments. For convenience, only the main components necessary for the description of the present invention among the constituent components of the embodiments of the present invention will be shown in simplified form in the drawings referred to in the following description. Therefore, the present invention may include any constituent elements not shown in the following drawings. The dimensions of the components in the drawings below do not faithfully represent the dimensions of the actual constituent components, the dimensional ratios of the components, and the like.

Fig. 1 is a perspective view of an indwelling needle device 10 according to an embodiment of the present invention with a hub in an initial position. FIG. 2A is a sectional view of the indwelling needle device 10 taken along a plane including the line 2A-2A in FIG. 1, and FIG. 2B is a sectional view of the indwelling needle device 10 taken along a plane including the line 2B-2B in FIG. 1, taken along a side of the same. In the present invention, the side that penetrates the patient (left side of the paper in fig. 2A and 2B) is referred to as the "front side", and the opposite side is referred to as the "rear side".

The indwelling needle device 10 includes a sheath 20. The jacket 20 has a jacket tube 21 and an outer bush 25 fixed to one end (front end) of the jacket tube 21. The sheath tube 21 has a substantially cylindrical shape with a constant inner diameter. An engagement projection 22 continuous in the circumferential direction is formed on the inner circumferential surface of the sheath tube 21 near one end (rear end) opposite to the outer bush 25. The outer hub 25 has a substantially funnel shape, and a soft outer needle 30 is fixed to an opposite end (tip) of the sheath tube 21. The outer needle 30 has a substantially cylindrical shape, and a pair of 1 st side holes 31 penetrating through the outer peripheral surface thereof are formed near the distal end thereof. A pair of 1 st side holes 31 communicate with the lumen of the outer needle 30. The material of the sheath tube 21 and the outer liner 25 is not particularly limited, but is preferably a hard material, and for example, polycarbonate, polypropylene, or the like can be used. It is preferable if sheath cylinder 21 and outer liner 25 have transparency or light transmission properties to allow blood and liner 40 within its lumen to be seen through. The material of the outer needle 30 is preferably a soft material, although not particularly limited, and for example, a fluorine-containing resin such as polypropylene, a polyurethane elastomer, polytetrafluoroethylene, or the like can be used. It is preferable if the outer needle 30 has transparency or light transmittance to see through blood in its lumen and the inner needle 50. Further, the outer hub 25 and the outer needle 30 may be integrally formed using the soft material.

Reference numerals 29a, 29b denote wings. The wings 29a and 29b are provided on the substantially cylindrical fixing member 28. The wings 29a and 29b are attached to the sheath 20 by fitting the fixing member 28 around the outer peripheral surface of the sheath tube 21 near the end of the outer liner 25. The material of the flaps 29a and 29b is preferably a soft material, although not particularly limited, and for example, a thermoplastic elastomer such as polypropylene, ethylene chloride, polyethylene, olefin, or polystyrene can be used. The wings 29a and 29b may be integrally formed with the sheath 20.

The bush 40 is inserted into the lumen of the sheath 20 so as to be movable in the longitudinal direction (i.e., the front-rear direction) of the sheath 20. A hard inner needle 50 made of metal is fixed to the front end of the hub 40, and one end of a tube 60 made of resin is connected to the rear end of the hub 40. The other end of the tube 60 is connected to a blood circuit for performing hemodialysis, for example. An O-ring 49 is attached to the outer peripheral surface of the bush 40. The O-ring 49 is closely attached to the inner peripheral surface of the sheath tube 21 to prevent blood in the lumen of the sheath 20 on the outer needle 30 side of the O-ring 49 from leaking to the tube 60 side of the O-ring 49. The inner needle 50 has a substantially cylindrical shape, and a 2 nd side hole 51 penetrating the outer peripheral surface thereof is formed near the sharp distal end thereof. The 2 nd side hole 51 communicates with the lumen 52 of the inner needle 50. The material of the bush 40 is preferably a hard material, although not particularly limited, and for example, polycarbonate, polypropylene, polyethylene, or the like can be used. The material of the tube 60 is preferably a soft material, although not particularly limited, and for example, ethylene chloride or the like can be used.

Fig. 3A is a perspective view of the bushing 40, fig. 3B is a plan view of the bushing 40 taken along a plane including line 3B-3B of fig. 3A, and fig. 3C is a side view of the bushing 40 taken along a plane including line 3C-3C of fig. 3A. The bush 40 has a front portion 41 at one end (front end) and a rear portion 42 at the other end, and the front portion 41 has a conical surface-shaped outer surface and the rear portion 42 has a cylindrical surface-shaped outer surface. The longitudinal passage 43 extends longitudinally through the liner 40 from the front portion 41 to the rear portion 42 along the central axis 40a of the liner 40. As shown in fig. 2A and 2B, the inner needle 50 is inserted into the longitudinal passage 43 from the front portion 41 side and held by the hub 40. The rear portion 42 is inserted into the tube 60 and the bushing 40 is connected to the tube 60. Thus, the inner needle 50 and the tube 60 communicate with each other through the longitudinal passage 43 of the hub 40.

An annular groove 44 continuous in the circumferential direction is formed on the outer circumferential surface of the bush 40 between the front portion 41 and the rear portion 42. As shown in fig. 2A and 2B, an O-ring 49 is mounted in the annular groove 44.

A large diameter portion 45 and a small diameter portion 46 are formed on the outer peripheral surface of the bush 40 in this order from the annular groove 44 side between the annular groove 44 and the front portion 41. The small diameter portion 46 has a relatively smaller outer diameter than the large diameter portion 45, and is adjacent to the front portion 41. A transverse path 47 that traverses the small diameter portion 46 in the radial direction (the direction perpendicular to the central axis 40 a) is formed in the small diameter portion 46. The transverse path 47 intersects and communicates with the longitudinal path 43.

Around the rear portion 42, 4 elastic pieces 48 supported by the one side are arranged at equal angular intervals with respect to the central axis 40a of the bush 40. The elastic piece 48 extends substantially parallel to the central axis 40a of the bush 40. A fitting groove 48a and a tapered surface 48b are formed on one surface of the elastic piece 48 opposite to the rear portion 42. The fitting groove 48a is a recess (groove) along the circumferential direction of the bush 40. The tapered surface 48b is adjacent to the free end side of the elastic piece 48 with respect to the fitting groove 48a, and constitutes a part of a conical surface having a larger outer diameter on the fitting groove 48a side.

In fig. 1, 2A, and 2B, the liner 40 is located on the front end side of the lumen of the sheath 20. In the present invention, this position of the liner 40 relative to the sheath 20 is referred to as an "initial position". In the initial position, the inner needle 50 held by the front portion 41 of the hub 40 penetrates the outer needle 30, and the tip thereof is exposed to the outside from the tip of the outer needle 30. The lumen 52 of the inner needle 50 communicates with the tube 60 via the longitudinal passage 43 of the hub 40, and communicates with the space 12 between the outer surface of the hub 40 and the inner surface of the sheath 20 on the tip side of the O-ring 49 and the gap 13 (see fig. 5 described later) between the outer peripheral surface of the inner needle 50 and the inner peripheral surface of the outer needle 30 via the transverse passage 47 of the hub 40.

The stopper 70 is used in order to maintain the bushing 40 at the initial position. Fig. 4 is a perspective view of the stopper 70. The stopper 70 includes: a substantially semi-cylindrical base end portion 71, a substantially semi-cylindrical insertion portion 72, and a pair of gripping portions 73. The insertion portion 72 and the pair of gripping portions 73 are erected in parallel on the base end portion 71 with the insertion portion 72 sandwiched between the pair of gripping portions 73.

As shown in fig. 1, 2A and 2B, the insertion portion 72 of the stopper 70 is inserted into the gap between the sheath cylinder 21 and the tube 60 from the rear end of the sheath cylinder 21. When the stopper 70 is inserted as far as possible into the sheath 20, the front end of the insertion portion 72 collides with the rear end of the elastic piece 48 of the bush 40, the large diameter portion 45 of the bush 40 collides with the rear end of the outer bush 25, and the bush 40 is disposed at the initial position in the inner cavity of the sheath 20. At this time, the pair of gripping portions 73 of the stopper 70 are positioned on both sides of the sheath tube 21 of the sheath 20.

Fig. 5 is a sectional view showing the front ends of the outer needle 30 and the inner needle 50 and the vicinity thereof when the hub 40 is in the initial position. Unlike fig. 2A, in fig. 5, only the outer needle 30 is shown as a cross-section in order to clearly show the positions of the 1 st and 2 nd side holes 31 and 51. As shown in fig. 5, the inner diameter of the outer needle 30 is not constant in the longitudinal direction of the outer needle 30, but is small in a predetermined region 33 from the tip of the outer needle 30, and is large on the rear side of the region 33. Therefore, in the region 33, the inner peripheral surface of the outer needle 30 is in close contact with the outer peripheral surface of the inner needle 50, and a gap 13 is formed between the inner peripheral surface of the outer needle 30 and the outer peripheral surface of the inner needle 50 on the rear side of the region 33. In the present invention, the region 33 is referred to as a "close contact region". The 1 st side hole 31 is formed in the close contact region 33. In addition, when the bushing 40 is in the initial position, the 2 nd side hole 51 is located on the rear side of the close contact region 33. As a result, the 2 nd side hole 51 communicates with the gap 13. On the other hand, the 1 st side hole 31 does not communicate with the 2 nd side hole 51, and also does not communicate with the gap 13.

The method of using and the operation of the indwelling needle device 10 of the present embodiment configured as described above will be described below.

As shown in fig. 1, 2A and 2B, the indwelling needle device 10 is configured to hold the hub 40 at the initial position by sandwiching the pair of gripping portions 73 of the stopper 70 with 2 fingers. Since the pair of gripping portions 73 is easily elastically deformed and closely attached to the outer peripheral surface of the sheath tube 21, the indwelling needle device 10 can be stably held. In this state, the inner needle 50 protruding from the distal end of the outer needle 30 is inserted into a blood vessel of the patient. Although the inner needle 50 receives a reaction force at the time of puncturing, the rear end (elastic piece 48) of the hub 40 holding the inner needle 50 abuts against the front end of the insertion portion 72 of the stopper 70, and therefore the inner needle 50 and the hub 40 cannot be displaced relative to the sheath 20.

The deeper the 1 st side hole 31 of the outer needle 30 enters into the blood vessel, the deeper the inner needle 50 and the outer needle 30 are punctured.

By inserting the leading end of the inner needle 50 into the blood vessel, the blood of the patient flows into the lumen 52 of the inner needle 50 from the opening of the leading end of the inner needle 50. As is apparent from fig. 2A and 2B, the blood flowing into the lumen 52 of the inner needle 50 passes through the lumen 52 of the inner needle 50 and the longitudinal passage 43 of the hub 40 in this order and flows into the tube 60. The blood flowing into the lumen 52 of the inner needle 50 flows into the gap 13 (see fig. 5) between the inner peripheral surface of the outer needle 30 and the outer peripheral surface of the inner needle 50 through the 2 nd side hole 51 of the inner needle 50, and flows into the tube 60 through the space 12 between the outer surface of the hub 40 and the inner surface of the sheath 20, the transverse passage 47 of the hub 40, and the longitudinal passage 43 of the hub 40 in this order.

In this way, at the time of puncture, in addition to the lumen 52 of the inner needle 50, the space 12 between the gap 13 between the inner peripheral surface of the outer needle 30 and the outer peripheral surface of the inner needle 50 and the space 12 between the outer surface of the hub 40 and the inner surface of the sheath 20 are also filled with blood, and therefore, the priming operation can be performed easily and quickly.

In addition, since the 1 st side hole 31 of the outer needle 30 is formed in the close contact region 33, even if the gap 13 is filled with blood, the blood does not leak out to the outside through the 1 st side hole 31 during the puncture.

If the outer needle 30 and/or the sheath 20 have transparency or translucency, flashback of blood due to puncture can be visually confirmed.

The retainer 70 is then pulled out of the sheath 20, simultaneously or subsequently pulling the tube 60 from the sheath 20. Since the hub 40 is connected to the distal end of the tube 60, the hub 40 and the inner needle 50 held by the hub move rearward relative to the sheath 20 by pulling the tube 60.

A locking protrusion 22 is formed on the inner circumferential surface near the rear end of the sheath tube 21. The bush 40 moves to the locking projection 22, and the tapered surface 48b formed on the outer surface of the elastic piece 48 of the bush 40 slides on the locking projection 22. At this time, the elastic piece 48 is elastically deformed to the rear portion 42 side. Then, when the tapered surface 48b passes over the locking projection 22, the elastic piece 48 elastically returns, and the locking projection 22 is fitted into the fitting groove 48 a. The position of the bush 40 relative to the sheath 20 when the fitting groove 48a is fitted to the locking projection 22 is referred to as a "retracted position" in the present invention.

Fig. 6 is a perspective view of the indwelling needle device 10 with the hub 40 in the retracted position. FIG. 7A is a sectional view of the indwelling needle device 10 taken along the plane including the line 7A-7A in FIG. 6, and FIG. 7B is a sectional view taken along the side of the indwelling needle device 10 taken along the plane including the line 7B-7B in FIG. 6.

As shown in fig. 7A and 7B, when the bush 40 is at the retracted position, the fitting groove 48a (see fig. 3A, 3B, and 3C) of the bush 40 is fitted to the locking projection 22 of the shield tube 21. The inner needle 50 held by the hub 40 is pulled out of the outer needle 30 and is accommodated in the inner cavity of the sheath 20.

In this state, the adhesive tape is adhered to the skin of the patient from the wings 29a and 29b, and the indwelling needle device 10 is fixed to the patient. Only the outer needle 30 is left in a state of piercing the patient.

In the retracted position, the cross-sectional area of the flow path in the outer needle 30 is increased by the cross-sectional area of the inner needle 50 as compared to the initial position (see fig. 1, 2A, and 2B), and thus the flow rate of blood is increased. In the retracted position, since two flow paths, i.e., the 1 st flow path and the 2 nd flow path, are provided as the flow paths from the outer needle 30 to the tube 60, blood can flow at a relatively large flow rate, the 1 st flow path passes through the lumen 52 of the inner needle 50 and the longitudinal through passage 43 of the hub 40 in this order, and the 2 nd flow path passes through the space 12 between the inner surface of the sheath 20 and the outer surfaces of the inner needle 50 and the hub 40 in this order, the transverse through passage of the hub 40, and the longitudinal through passage 43 of the hub 40 in this order.

In the retreated position, the hard inner needle 50 is not present inside the soft outer needle 30, and therefore, even if the posture of the indwelling needle device 10 with respect to the patient changes due to the patient's movement or the like, the outer needle 30 does not damage the blood vessel or the like of the patient.

Since the 1 st side hole 31 is formed near the distal end of the outer needle 30, even if the distal end opening of the outer needle 30 is closed by contact with the inner wall of the blood vessel, blood can flow through the 1 st side hole 31. Therefore, a blood flow path can be always ensured, and a decrease in blood flow rate can be prevented.

After the required treatment is completed, the tape to which the wings 29a and 29b are fixed 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 against the sheath 20, the fitting state between the fitting groove 48a of the bush 40 and the locking projection 22 of the sheath tube 21 is not released. That is, the hub 40 and the outer needle 30 cannot be pulled out from the sheath 20 by projecting the inner needle 50 from the distal end of the outer needle 30 again. Therefore, erroneous puncture of the hard inner needle 50 and erroneous reuse of the used indwelling needle device 10 are prevented. The used indwelling needle device 10 is discarded.

The above embodiments are merely illustrative, and the present invention is not limited to the above embodiments and can be modified as appropriate.

For example, in the above-described embodiment, the number of the 1 st side holes 31 is 2, but the present invention is not limited thereto, and may be 1 or 3 or more. The shape, size, circumferential arrangement position, and the like of the 1 st side hole 31 are also not particularly limited. However, the 1 st side hole 31 needs to be formed in the close contact region 33 and is not formed on the sheath 20 side of the close contact region 33.

In the above embodiment, the number of the 2 nd side holes 51 is 1, but the present invention is not limited thereto, and may be 2 or more. The shape, size, circumferential arrangement position, and the like of the 2 nd side hole 51 are not particularly limited. However, the 2 nd side hole 51 needs to be formed at a position that can communicate with the gap 13 (see fig. 5) when the bushing 40 is at the initial position. When the bushing 40 is in the initial position, if the 1 st lateral hole 31 is in communication with the 2 nd lateral hole 51, a portion of the 2 nd lateral hole 51 may also be present within the hug zone 33. From the viewpoint of priming operation in which the gap 13 between the inner needle 50 and the outer needle 30 is filled with blood, when the hub 40 is in the initial position, the 2 nd side hole 51 is preferably provided in the vicinity of the adhesion region 33.

The stopper 70 may have a configuration other than the above embodiment as long as the bush 40 can be held at the initial position. Alternatively, instead of the stopper 70, a fitting structure for fitting the bush 40 in the initial position into the sheath 20, for example, may be provided on the bush 40 and the sheath 20.

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

In the above description, the indwelling needle device of the present invention is used for hemodialysis, but the application of the indwelling needle device of the present invention is not limited thereto, and the indwelling needle device can be used for any application using the indwelling needle device such as infusion or blood transfusion.

The embodiments described above are only for the purpose of clarifying the technical contents of the present invention, and the present invention is not limited to the specific examples described above, and can be implemented by various modifications within the spirit of the present invention and the scope described in the claims, and the present invention should be broadly construed.

Industrial applicability

The field of use of the present invention is not particularly limited, and the present invention can be widely used as an indwelling needle device for performing a treatment such as infusion, blood transfusion, extracorporeal blood circulation, or the like. In particular, it can be suitably used as an indwelling needle device for hemodialysis.

Description of the symbols

10 remaining needle device

13 gap between outer peripheral surface of inner needle and inner peripheral surface of outer needle

20 sheath

21 sheath cylinder

25 outer liner

30 outer needle

31 st hole

33 area of close contact

40 liner

50 inner needle

51 No. 2 side hole

60 tube

70 stop dog

Claims (4)

1. An indwelling needle device comprising:

a sheath having an inner cavity;

a soft outer needle fixed at the front end of the sheath,

a bushing disposed in the lumen of the sheath and movable in a longitudinal direction of the sheath;

an inner needle fixed to the front end of the bush; and

a tube connected to a rear end of the bushing,

a longitudinal passage and a transverse passage are formed in the hub, the longitudinal passage communicating the inner needle and the tube, the transverse passage traversing the hub in a diameter direction and communicating with the longitudinal passage,

the hub is displaced between an initial position in which the hub is located on a front end side of the lumen of the sheath and the inner needle passes through the outer needle and projects from a front end of the outer needle to the outside, and a retracted position in which the hub is located on a rear end side of the lumen of the sheath and the inner needle is housed in the lumen of the sheath,

the outer needle is formed with a 1 st side hole penetrating through the outer circumferential surface thereof,

a 2 nd side hole penetrating the outer circumferential surface of the inner needle is formed,

when the bush is at the initial position, the inner peripheral surface of the region including the 1 st side hole of the outer needle is closely attached to the outer peripheral surface of the inner needle, the 2 nd side hole and the inner peripheral surface of the outer needle are closer to the hub side than the region where the outer peripheral surface of the inner needle is in close contact therewith, and a 1 st flow path and a 2 nd flow path are formed, the 1 st flow path being a flow path from the distal end opening of the inner needle to the tube through the lumen of the inner needle and the longitudinal passage of the hub in this order without passing through the 2 nd side hole, the 2 nd flow path is a flow path from the distal end opening of the inner needle to the tube through the 2 nd side hole, a gap between the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle, a space between the outer surface of the hub and the inner surface of the sheath, the transverse path of the hub, and the longitudinal path of the hub in this order.

2. The indwelling needle device of claim 1,

when the hub is at the initial position, a gap is formed between the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle on a side closer to the sheath than the region where the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle are in close contact with each other, and the 2 nd side hole communicates with a space between the outer surface of the hub and the inner surface of the sheath via the gap.

3. The indwelling needle device of claim 1,

when the bushing is in the initial position, the 1 st lateral hole is not in communication with the 2 nd lateral hole.

4. The indwelling needle device of claim 1,

when the hub is at the initial position, a gap is formed between the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle on a side closer to the sheath than the region where the inner peripheral surface of the outer needle and the outer peripheral surface of the inner needle are in close contact, and the 1 st side hole does not communicate with the gap.