JP2000262628A - Intravenous needle assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intravenous needle assembly capable of reducing punc ture resistance and preventing coring by an inner needle. SOLUTION: The intravenous needle assembly has an outer needle 2 which is an intravenous needle and the inner needle 4 which is used by being inserted into this outer needle 2. The inner needle 4 is composed of a solid member and has a sharp needle tip 41 at its front end. A chamfered part 44 is formed along the longitudinal direction of the inner needle 4 from near the base end (root part) of the needle tip 41 on the outer peripheral surface of the inner needle 4. The chamfered part 44 forms a flow passage for blood and allows the inflow of the blood between the inner needle 4 and the size reducing part 21 of the outer needle 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indwelling needle assembly for puncturing a blood vessel and indwelling it during, for example, infusion.

[0002]

2. Description of the Related Art When infusion is performed on a patient, an indwelling needle connected to an infusion line is punctured into a blood vessel of the patient and is indwelled. Such an indwelling needle is constituted by a hollow outer needle, and when puncturing a blood vessel of a patient, a hollow inner needle (needle tube) having a sharp needle tip at a distal end is inserted into a lumen of the outer needle. ,
The puncture operation is performed with the needle tip protruding from the tip of the outer needle.

[0003] When the inner needle reaches the inside of the blood vessel, the blood that has flowed through the opening of the needle tip flows through the lumen of the inner needle and into the transparent housing attached to the base end of the inner needle ( Flashback). Thereby, it can be confirmed that the inner needle has secured the blood vessel.

At this point, by slightly advancing the inner needle and the outer needle, the distal end of the outer needle is inserted into the blood vessel.

However, in the conventional indwelling needle assembly,
Since the inner peripheral surface of the distal end portion of the outer needle is in close contact with the outer peripheral surface of the inner needle, blood does not flow between the outer needle and the inner needle. It could not be confirmed visually by flashback.

For this reason, after confirming that the inner needle has secured the blood vessel, an operation of advancing the inner needle and the outer needle a delicate distance has been performed according to the feeling and experience of the operator. The distance between the needle and the tip of the outer needle is slightly different depending on the type, size, manufacturer, etc. of the indwelling needle assembly, and there is also a difference in the thickness of the patient's blood vessel. This is not always done, and the puncture position of the outer needle into the blood vessel may be too shallow or too deep.

Further, since the inner needle is formed of a hollow needle tube and has an opening at the needle tip, when piercing the needle tip of the inner needle into the skin, the penetration resistance is large, and the coring (corresponding to living tissue) Small pieces). In particular, a small piece of living tissue generated by coring is clogged in the lumen of the inner needle, blood circulation in the inner needle is obstructed, or it cannot be confirmed that the inner needle has secured a blood vessel by the above-described flashback, Alternatively, there is a problem that it takes a long time for this confirmation.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an indwelling needle assembly capable of reducing piercing resistance and preventing coring by an inner needle, and furthermore, an indwelling needle (outer needle) is used to cut a blood vessel. It is an object of the present invention to provide an indwelling needle assembly that allows the user to visually confirm that it has been secured.

[0009]

This and other objects are achieved by the present invention which is defined below as (1) to (15).

(1) An indwelling needle assembly comprising a hollow outer needle and an inner needle which is inserted into a lumen of the outer needle and has a sharp needle tip at a distal end, wherein the inner needle has at least An indwelling needle assembly, wherein the needle tip is closed.

(2) An indwelling needle assembly comprising: a hollow outer needle; and an inner needle that is inserted into a lumen of the outer needle and has a sharp needle tip at a distal end, wherein the inner needle is solid. An indwelling needle assembly characterized by comprising:

(3) The indwelling needle assembly according to the above (1) or (2), wherein a gap serving as a blood flow path is formed in at least a portion of the outer peripheral portion of the inner needle which is in close contact with the outer needle.

(4) The indwelling needle assembly according to the above (3), wherein the gap is formed by a concave portion which is recessed inward from the outer peripheral surface of the inner needle.

(5) The indwelling needle assembly according to (4), wherein the length of the recess in the longitudinal direction of the inner needle is 1 mm or more.

(6) The indwelling needle assembly according to the above (4) or (5), wherein the concave portion is formed along the longitudinal direction of the inner needle from near the base of the needle tip.

(7) The indwelling needle assembly according to any one of (4) to (6), wherein the recess is a chamfered portion formed by chamfering.

(8) The concave portion is a groove (4).
The indwelling needle assembly according to any one of (6) to (6).

(9) The indwelling needle assembly according to any one of the above (4) to (8), wherein the recess is formed by plastically deforming the inner needle.

(10) The indwelling needle assembly according to the above (9), wherein the plastic deformation is performed by press working.

(11) The indwelling needle assembly according to the above (1) or (2), wherein at least a portion of an outer peripheral portion of the inner needle that is in close contact with the outer needle is roughened.

(12) The indwelling needle assembly according to the above (1) or (2), wherein a void serving as a blood flow path is formed in at least a portion of the inner peripheral portion of the outer needle that is in close contact with the inner needle. .

(13) At the distal end of the outer needle, there is provided a reduced diameter portion whose inner diameter is reduced and which is in close contact with the inner needle, and a gap serving as a blood flow path is formed on the inner peripheral surface of the reduced diameter portion. The indwelling needle assembly according to the above (1) or (2), wherein is formed.

(14) The above-mentioned (12) or (1), wherein the gap is constituted by a concave portion recessed from the inner peripheral surface of the outer needle.
The indwelling needle assembly according to 3).

(15) The indwelling needle assembly according to any one of (1) to (14), wherein the needle tip has an inclined blade surface.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an indwelling needle assembly of the present invention will be described.
A detailed description will be given based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of the indwelling needle assembly of the present invention, and FIG. 2 is a plan view showing the configuration near the tip of the inner needle in the indwelling needle assembly shown in FIG. 3 is FIG.
FIG. 4 is a cross-sectional view taken along the line AA in FIG. 2, FIG. 4 is a cross-sectional view taken along the line BB in FIG. 2, and FIG. is there. In the following description, the right side in FIGS. 1, 2, 3 and 5 is referred to as a “proximal end”, the left side is referred to as a “distal end”, and the same applies to other drawings.

As shown in FIGS. 1 and 2, the indwelling needle assembly 1 of the present invention has an outer needle 2 which is an indwelling needle, and an inner needle 4 which is used by being inserted into the outer needle 2. are doing.

A hub 3 is fixed to the proximal end of the outer needle 2 in a liquid-tight manner. The hub 3 is made of a transparent or translucent resin, and the visibility of the inside 31 is ensured.

As shown in FIG. 5, the distal end of the outer needle 2 has a reduced diameter portion 21 whose inner diameter is reduced.
The inner diameter of the reduced diameter portion 21 is set to be substantially equal to or slightly smaller than the outer diameter of the inner needle 4 described later, and the inner needle 4 is inserted into the inner cavity of the outer needle 2 and the needle tip 41 is In a state where the outer needle 2 protrudes from the distal end opening 23 (hereinafter, this state is referred to as an “assembled state”), the inner peripheral surface of the reduced diameter portion 21 is
It is configured to be in close contact with the outer peripheral surface of.

The inner diameter of the portion of the outer needle 2 closer to the proximal end than the reduced diameter portion 21 is larger than the outer diameter of the inner needle 4. A predetermined gap 22 is formed between the outer peripheral surface and the outer peripheral surface. This gap 22 becomes a blood flow path.

The distal end of the outer needle 2 has a tapered shape whose outer diameter gradually decreases toward the distal end. This makes it possible to puncture the living body easily and in a minimally invasive manner.

The constituent material of the outer needle 2 is not particularly limited, but various soft resins such as ethylene-tetrafluoroethylene copolymer (ETFE), polyurethane and polyether nylon resin are preferable.

It is preferable that all or a part of the outer needle 2 has visibility. Further, an X-ray contrast agent such as barium sulfate or barium carbonate may be blended in the constituent material of the outer needle 2 to provide a contrast function.

The inner needle 4 is made of a metal material such as stainless steel, aluminum or aluminum alloy, titanium or titanium alloy, or, for example, polyphenylene sulfide, polybutylene terephthalate (polyester), polyether ether ketone, polyimide, polycarbonate And a solid member made of a hard resin such as a cyclic olefin copolymer. A sharp needle tip 41 is formed at the tip of the inner needle 4. The needle tip 41 has a blade surface 42 inclined at a predetermined angle with respect to the axis of the inner needle 4.
have.

Since the inner needle 4 is constituted by a solid member,
Since there is no opening in the needle tip 41, when the inner needle 4 is punctured into the living tissue, puncture resistance is reduced, pain is reduced, and coring is prevented.

Further, since the blade surface 42 is formed on the needle tip 41, piercing resistance is further reduced and pain is reduced. The method of forming the blade surface 42 is not particularly limited, and for example, can be performed according to an ordinary method by cutting, grinding, polishing, laser processing, or the like.

As shown in FIG. 1, the length of the inner needle 4 is set to such a length that at least the needle tip 41 protrudes from the distal end opening 23 of the outer needle 2 when assembled.

At the proximal end of the inner needle 4, a hub (housing)
5 is fixed in a liquid-tight manner. At the tip of this hub 5,
A connecting portion 51 having a reduced diameter is formed. Generally, the connecting portion 51 of the hub 5 is located within the proximal opening of the hub 3 in an assembled state.

As the constituent materials of the hub 3 and the hub 5,
For example, polyethylene, polypropylene, polyolefins such as ethylene-vinyl acetate copolymer, polyurethane, polystyrene, polymethyl methacrylate,
Examples thereof include polycarbonate, polybutadiene, polyamide, and polyester.

The inner needle 4 is formed with a concave portion which is recessed inward from the outer peripheral surface. In this embodiment, a predetermined portion of the inner needle 4 is chamfered as the recess as shown in FIGS. More specifically, a strip-shaped chamfered portion which is flatly cut out at least in a portion of the outer peripheral portion of the inner needle 4 which is in close contact with the outer needle 2, that is, a portion which faces the reduced diameter portion 21 of the outer needle 2 in an assembled state. 43 are formed.

The chamfered portion 43 is provided on the blade surface 42 of the needle tip 41.
A length b is formed along the longitudinal direction (axial direction) of the inner needle 4 from the vicinity of the base end (root) on the side.

The shape and size of the chamfered portion 43 are not particularly limited as long as the shape and dimensions can cover the contact portion between the inner needle 4 and the outer needle 2. In the case of the configuration shown, the length b
Is preferably 1 mm or more, more preferably about 1 to 65 mm, and still more preferably about 2 to 40 mm. Further, the maximum depth a of the chamfered portion 43 is preferably about 0.01 to 0.8 mm, more preferably about 0.03 to 0.3 mm. Since the inner needle 4 is formed of a solid member, the strength is higher than the hollow needle, and the maximum depth a can be increased. Therefore, a sufficient cross-sectional area of the blood flow path can be ensured. Can be.

The chamfered portion 43 can be formed at an arbitrary position on the circumference of the outer periphery of the inner needle.
The cutting surface 42 of the needle tip 41 is
It is preferable to be located near the base (jaw) on the side. When the indwelling needle is punctured into the living body, the puncture is usually performed with the blade surface 42 facing upward. Therefore, by providing the chamfered portion 43 at such a position, the blood in the flash bag 44 is removed.
There is an advantage that the state of passing through can be easily visually recognized.

The inner needle 4 has a chamfered portion (recess) 4 as described above.
3, a gap 44 serving as a blood flow path is formed inside the reduced diameter portion 21 in the assembled state, and the distal end opening 23 of the outer needle 2 and the gap 22 are formed through the gap 44.
Communicate with each other to form a continuous blood flow path.

The greatest advantage of forming the concave portion by chamfering is that its processing and formation are easy. The details will be described below.

The chamfered portion 43 is formed by, for example, grinding,
The polishing can be performed by plastic processing such as polishing, laser processing, etching, and pressing. For example, when a groove is formed at the same position instead of the chamfered portion 43 by grinding or polishing, the relative movement of the grindstone with respect to the workpiece is set vertically,
It is necessary to control in the three-dimensional directions of width and depth. On the other hand, when the chamfered portion 43 of this embodiment is formed by the same method, since the chamfered portion 43 has a flat shape, the relative movement direction of the grindstone is controlled by the length of the inner needle 4. Only the two-dimensional direction of the direction and the depth direction is sufficient. In addition, a plurality of inner needles 4 can be arranged in a state where the direction of the blade surface 42 of the inner needles 4 and their tip positions are aligned, and chamfering can be performed on these at the same time.

Accordingly, the chamfered portion 43 can be formed by a processing device having a simpler configuration, the processing accuracy is high, and the plurality of inner needles 4 can be collectively chamfered, so that productivity is improved. Dramatically improved.

When the inner needle 4 is made of a resin material,
The chamfered portion 43 is formed at the same time when the inner needle 4 is formed (for example, injection molded).
And the method of forming the chamfered portion 43 by heat molding can be performed, and therefore, the inner needle 4 having the concave portion such as the chamfered portion 43 can be easily manufactured.

Next, how to use the indwelling needle assembly 1 (operation).
An example will be described. [1] As shown in FIG. 1, the outer needle 2 and the inner needle 4 are assembled in advance. In such an assembled state of the indwelling needle assembly 1, the needle tip 41 projects from the distal end opening 23 of the outer needle 2,
The axial area of the reduced diameter portion 21 is included in the chamfered portion 43 of the inner needle 4.

It is preferable that this step has already been completed when the indwelling needle assembly 1 is used (when the packaging material is opened).

[2] The assembled inner needle 4 and outer needle 2 are percutaneously punctured into a blood vessel (vein or artery) of the patient. At this time, since an opening is not formed in the needle tip 41, piercing resistance is low and coring is also prevented.

After the needle tip 41 of the inner needle 4 is punctured into a blood vessel,
When the inner needle 4 and the outer needle 2 are further advanced by a small distance, the outer needle 2
Is inserted into the blood vessel. As a result, blood flows through the distal end opening 23, passes through the gap 44, flows toward the proximal end of the gap 22, and is introduced into the interior 31 of the hub 3. The flashback can be visually recognized by the outer needle 2 and the hub 3 having visibility. This makes it possible to know that the distal end of the outer needle 2 has secured a blood vessel.

[3] Thereafter, the outer needle 2 alone is further moved in the blood vessel and introduced to a predetermined indwelling position.
Is held down with one hand, the hub 5 is gripped with the other hand and pulled in the proximal direction, and the inner needle 4 is pulled out of the outer needle 2.

[4] An infusion line is connected to the hub 3 via a connector (not shown), the outer needle 2 and the hub 3 are fixed with an adhesive tape or the like, and the infusion is supplied. Thus, the infusion is injected into the blood vessel of the patient via the outer needle 2.

FIGS. 6 and 7 are perspective views showing the configuration of the distal end of the inner needle according to another embodiment of the indwelling needle assembly of the present invention, and the vicinity of the distal end in an assembled state of the inner needle and the outer needle. It is a longitudinal cross-sectional view which shows a structure of. Hereinafter, the embodiment shown in these figures will be described focusing on differences from the embodiment shown in FIGS.

As shown in FIG. 6, a rough surface is formed on the outer peripheral surface of the distal end portion of the inner needle 4 to form a rough surface 45, that is, a surface having many minute irregularities. .
Formed part (formation area) of this rough surface 45 in the longitudinal direction of the inner needle
Is substantially the same as the chamfered portion 43.

As shown in FIG. 7, in the assembled state, the rough surface 45 formed on the inner needle 4 is located at the portion facing the reduced diameter portion 21 of the outer needle 2 and Region.

The indwelling needle assembly having such a structure that the inner needle 4 has the rough surface 45 is also used in the same manner as that of the above embodiment. In this case, in the step [2], when the distal end of the outer needle 2 is inserted into the blood vessel, the blood flows into the distal opening 2.
3, passes through a number of minute concave portions in the rough surface 45, and then flows toward the proximal direction through the gap 22, and is introduced into the interior 31 of the hub 3. Then, the flashback can be visually recognized by the outer needle 2 and the hub 3 having visibility, whereby it is possible to know that the distal end of the outer needle 2 has secured a blood vessel.

The rough surface 45 can be formed only on a part of the outer circumference of the inner needle in the circumferential direction. However, in order to secure as large an area as the blood flow path on the rough surface 45 as possible, As shown in the figure, the inner needle is preferably formed all around the outer circumference.

The roughness of the rough surface 45 is not particularly limited.
The center line average roughness Ra specified in JIS B0601 is 1
It is preferably about 0 to 500 μm, and 50 to 200 μm.
More preferably, it is about μm. With such a roughness, rough surface processing is easy and rough surface 4
5 can sufficiently secure the flow of blood.

The greatest advantage of providing the rough surface 45 is that its processing and formation are easy. The details will be described below.

The rough surface 45 can be formed by, for example, masking a region other than the rough surface forming portion of the inner needle 4 and then performing sand blasting, shot blasting, etching or the like.

Further, a plurality of inner needles 4 are arranged in a state where the direction of the blade surface 42 of the inner needles 4 and their tip positions are aligned, and rough surface processing is simultaneously performed on these by the above-described processing method. Can greatly improve productivity.

FIGS. 8 and 9 are a perspective view and a plan view, respectively, showing the configuration of the distal end portion of the inner needle according to another embodiment of the indwelling needle assembly of the present invention, and FIG. FIG. 11 is a cross-sectional view taken along line C-D in FIG. 9, and FIG. 12 is a vertical cross-sectional view showing a configuration near the distal end in an assembled state of the inner needle and the outer needle. Hereinafter, the embodiment shown in these figures will be described focusing on differences from the embodiment shown in FIGS.

As shown in FIGS. 8 to 12, a groove 46 extending along the longitudinal direction of the inner needle 4 is formed on the outer peripheral surface of the distal end of the inner needle 4. The formation portion (formation region) of the groove 46 in the longitudinal direction of the inner needle is substantially the same as the chamfered portion 43.

As shown in FIG. 12, in the assembled state,
The groove 46 formed in the inner needle 4 is located at a portion facing the reduced diameter portion 21 of the outer needle 2 and includes an axial region of the reduced diameter portion 21.

In this case, as shown in FIG. 11, both edges 47 of the groove 46, that is, the vicinity of the boundary between the groove 46 and the outer peripheral surface of the inner needle 4 are rounded (so-called R-shaped). ) Is preferred. If the edge portion 47 is sharply sharpened, the inner surface of the outer needle 2 may be damaged when the inner needle 4 is inserted through the outer needle 2.
If the 7 is rounded, such an inconvenience does not occur.

The grooves 46 are formed, for example, by grinding,
Although it may be formed by a method such as laser processing or etching, it is preferably formed by plastically deforming the inner needle 4 by plastic working, in particular, by pressing the inner needle 4. This allows grinding,
Compared to the case where the groove 46 is formed by laser processing or the like, the groove 4
It is difficult for sharp edges to be formed on both side portions of the edge portion 6. Even if secondary processing such as polishing or deburring is not performed to round the edge portion, the edge portion is rounded. The groove 46 having 47 can be easily formed.

As shown in FIG. 9, the groove 46 is formed from the vicinity of the base end (root) of the blade surface 42 by a length d along the axial direction of the inner needle 4.

The shape and dimensions of the groove 46 are not particularly limited.
Any material can be used as long as it can cover the contact portion between the inner needle 4 and the outer needle 2. In the case of the configuration shown, the maximum depth c of the groove 46 is set.
Is preferably about 0.01 to 0.8 mm, and 0.03 to
About 0.3 mm is more preferable, and the length d is preferably 1 mm or more, more preferably about 1 to 65 mm, and 2 to 4 mm.
About 0 mm is more preferable. The width e of the groove 46 is
It is preferably about 0.05 to 1.6 mm, and 0.1 to 1.0 mm.
mm is more preferable.

The cross-sectional shape, maximum depth, width and the like of the groove 46 may be the same or may vary along the longitudinal direction of the inner needle 4. For example, the groove 46 may have a portion (particularly a proximal portion) whose maximum depth and / or width gradually decreases (or increases) in the proximal direction.

The groove 46 is not limited to a linear one as shown, but may be a curved one, a meandering one or a spiral one.

A plurality of grooves 46 may be formed. In this case, the positions of the grooves 46 may be parallel to each other, may be arranged at a predetermined angle, or may be crossed. Anything may be used. Further, one groove 46 may be branched into a plurality of grooves in the middle.

According to the above-described plastic working, even a plurality of such grooves 46 or grooves 46 having a complicated shape can be easily formed.

The indwelling needle assembly having such a configuration that the inner needle 4 has the groove 46 is also used in the same manner as in the above embodiment. In this case, in the step [2], when the distal end of the outer needle 2 is inserted into the blood vessel, the blood flows into the distal opening 23.
And flows through the inside of the groove 46,
Flows toward the proximal direction, and is introduced into the interior 31 of the hub 3. Then, the flashback can be visually recognized by the outer needle 2 and the hub 3 having visibility, whereby it is possible to know that the distal end of the outer needle 2 has secured a blood vessel.

FIG. 13 is a longitudinal sectional view showing the configuration of the distal end portion of the inner needle according to another embodiment of the indwelling needle assembly of the present invention, and FIG.
FIG. 14 is a sectional view taken along line EE in FIG. 13. Hereinafter, the embodiment shown in these figures will be described focusing on differences from the embodiment shown in FIGS.

As shown in FIGS. 13 and 14, the inner needle 4
Is formed of a hollow tubular member, but its tip end, that is, the needle tip 41 is closed (having a closing portion 49). Thereby, the same effect as that of the inner needle 4 made of a solid member can be obtained.

The inner needle 4 having such a hollow and closed distal end can be reduced in weight as compared with the inner needle 4 made of a solid member having the same outer diameter.

In the illustrated configuration, the closing portion 4 of the inner needle 4 is
9 is formed integrally with the tubular member constituting the inner needle 4, but is not limited to this. For example, another member or another material is embedded in the lumen of the inner needle 4 to seal the lumen. Is also good.

The inner needle 4 has the same groove 4 as described above.
6 are formed. Inner needle 4 in the portion where groove 46 is formed
A protruding portion 48 that protrudes into the lumen of the inner needle 4 is formed on the inner side surface of the inner needle 4. As a result, as shown in FIG. 14, the wall thickness of the tube of the inner needle 4 is substantially equal between the portion where the groove 46 is formed and the other portion, that is, substantially the entire wall including the portion where the groove 46 is formed. It is constant. For this reason, there is no reduction in strength in the portion where the groove 46 is formed, and even if the tube of the inner needle 4 is relatively thin, deformation or breakage in the portion where the groove 46 is formed can be effectively prevented.

In the illustrated example, a projection 48 projecting into the lumen of the inner needle 4 is formed on the inner surface of the inner needle 4 in the portion where the groove 46 is formed. It may not be.

FIG. 15 is a longitudinal sectional view showing the structure near the distal end in an assembled state according to another embodiment of the indwelling needle assembly of the present invention, and FIG. 16 is a sectional view taken along line FF in FIG. is there. Hereinafter, the embodiment shown in FIGS.
The following mainly describes differences from the embodiment shown in FIGS.

In this indwelling needle assembly, the inner needle 4 is a normal one in which the chamfered portion 43, the rough surface 45 or the groove 46 is not formed. At least one groove (gap) 24 extending in the longitudinal direction of the outer needle 2 is formed on the inner peripheral surface of the reduced diameter portion 21 of the outer needle 2 as a concave portion recessed from the inner peripheral surface. In FIG. 16, four grooves 24 are formed at 90 ° intervals (see FIG. 16). The groove 24 forms a gap with the outer peripheral surface of the inner needle 4 and functions as a blood flow path.

Although the depth f of the groove 24 is not particularly limited,
Usually, about 0.01-0.8 mm is preferable, and 0.03
It is more preferably about 0.3 mm.

The indwelling needle assembly having such a configuration that the outer needle 2 has the groove 24 is also used in the same manner as in the above embodiment. In this case, in step [2], when the distal end of the outer needle 2 is inserted into the blood vessel, blood flows through the distal end opening 23, passes through each groove 24, and then turns the gap 22 in the proximal direction. And flows into the interior 31 of the hub 3. Then, the flashback can be visually recognized by the outer needle 2 and the hub 3 having visibility, whereby it is possible to know that the distal end of the outer needle 2 has secured a blood vessel.

The greatest advantage of providing the groove 24 serving as a blood flow path on the outer needle 2 side is that its processing and formation are easy. The details will be described below.

The outer needle 2 is a tubular member, and since its constituent material is a resin material as described above, it can be manufactured by extrusion molding (or injection molding). According to this molding method, the groove 24 can be formed at the same time when the outer needle 2 is molded, and there is no additional manufacturing process. In particular, groove 2
The shape, size, arrangement pattern, and the like of 4 can be arbitrarily set according to the shape of the die (the base from which the molten resin comes out) of the extruder.

The formation of the groove 24 on the outer needle 2 is easier than forming the inner needle 4 made of metal.

It is needless to say that various conditions relating to the groove 24, such as the shape, dimensions, arrangement pattern, and forming method of the groove 24, are not limited to those described above.

Although the indwelling needle assembly of the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to this, and each member constituting the indwelling needle assembly has the same function. Can be replaced with any structure that can exhibit the following.

Further, the concave portion formed in the inner needle 4 has been described with the chamfered portion 43 and the groove 46, and the concave portion formed in the outer needle 2 has been described with the groove 24, but the type and form of the concave portion are as follows. It is not limited to these.

The chamfered portion 43, the rough surface 45,
The groove 46, the groove 24 and the like may be formed at a portion other than the close contact portion between the outer needle 2 and the inner needle 4, and may be formed over substantially the entire length of the outer needle 2 or the inner needle 4, for example.

Further, in the present invention, the inner needle and the outer needle may not be formed with a concave portion (chamfered portion 43, grooves 46, 24, etc.), a roughened surface, etc., serving as a blood flow path.

[0094]

As described above, according to the indwelling needle assembly of the present invention, the needle tip of the inner needle is closed, so that when puncturing a living tissue, piercing resistance is reduced and pain is caused. And coring by the inner needle can be prevented.

When a space serving as a blood flow path is provided between the inner needle and the outer needle, it can be confirmed by flashback of blood that the outer needle has secured a blood vessel. In particular, by ensuring a sufficient cross-sectional area of the void, it is possible to quickly (in a short time) confirm that the outer needle has secured a blood vessel. Therefore, the puncture operation of the indwelling needle into the blood vessel can be performed easily and accurately.

Further, the indwelling needle assembly of the present invention is easy to manufacture and process and has high processing accuracy. In particular, when a plurality of inner needles are processed at the same time, or when the outer needles are manufactured by extrusion molding, the production efficiency is high, and there is no increase in the number of manufacturing steps.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an indwelling needle assembly of the present invention.

FIG. 2 is a plan view showing the configuration near the distal end of an inner needle in the indwelling needle assembly shown in FIG.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along line BB in FIG. 2;

FIG. 5 is a vertical cross-sectional view showing a configuration near a distal end portion in an assembled state.

FIG. 6 is a perspective view showing a configuration of a tip portion of an inner needle according to another embodiment of the indwelling needle assembly of the present invention.

FIG. 7 is a vertical cross-sectional view showing a configuration near a tip end in an assembled state.

FIG. 8 is a perspective view showing a configuration of a distal end portion of an inner needle according to another embodiment of the indwelling needle assembly of the present invention.

FIG. 9 is a plan view showing a configuration of an inner needle tip portion according to another embodiment of the indwelling needle assembly of the present invention.

FIG. 10 is a sectional view taken along line CC in FIG. 9;

FIG. 11 is a sectional view taken along line DD in FIG. 9;

FIG. 12 is a vertical cross-sectional view showing a configuration near a distal end portion in an assembled state.

FIG. 13 is a longitudinal sectional view showing a configuration of a distal end portion of an inner needle according to another embodiment of the indwelling needle assembly of the present invention.

14 is a sectional view taken along line EE in FIG.

FIG. 15 is a longitudinal sectional view showing a configuration near the distal end in an assembled state according to another embodiment of the indwelling needle assembly of the present invention.

16 is a sectional view taken along line FF in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Indwelling needle assembly 2 Outer needle (indwelling needle) 21 Reduced diameter part 22 Gap 23 Tip opening 24 Groove 3 Hub 31 Inside 4 Inner needle 41 Needle tip 42 Blade surface 43 Chamfered portion 44 Void 45 Rough surface 46 Groove 47 Edge portion 48 Projecting part 49 Closing part 5 Hub 51 Connecting part

Claims (15)

[Claims] 1. An indwelling needle assembly comprising: a hollow outer needle; and an inner needle that is inserted into a lumen of the outer needle and has a sharp needle tip at a distal end, wherein the inner needle is at least a needle. An indwelling needle assembly, wherein the tip is closed. 2. An indwelling needle assembly comprising: a hollow outer needle; and an inner needle that is inserted into a lumen of the outer needle and has a sharp needle tip at a distal end, wherein the inner needle is a solid needle. An indwelling needle assembly comprising a member. 3. The indwelling needle assembly according to claim 1, wherein a void serving as a blood flow path is formed in at least a portion of the outer peripheral portion of the inner needle which is in close contact with the outer needle. 4. The indwelling needle assembly according to claim 3, wherein the gap is formed by a concave portion which is recessed inward from an outer peripheral surface of the inner needle. 5. The length of the recess in the longitudinal direction of the inner needle is 1 mm.
The indwelling needle assembly according to claim 4, which is as described above. 6. The indwelling needle assembly according to claim 4, wherein the concave portion is formed along a longitudinal direction of the inner needle from near a base of the needle tip. 7. The indwelling needle assembly according to claim 4, wherein the recess is a chamfer formed by chamfering. 8. The method according to claim 4, wherein the recess is a groove.
The indwelling needle assembly according to any one of the above. 9. The indwelling needle assembly according to claim 4, wherein the recess is formed by plastically deforming the inner needle. 10. The indwelling needle assembly according to claim 9, wherein the plastic deformation is performed by press working. 11. A roughened surface of at least a portion of an outer peripheral portion of the inner needle which is in close contact with the outer needle.
Or the indwelling needle assembly according to 2. 12. The indwelling needle assembly according to claim 1, wherein a void serving as a blood flow path is formed in at least a portion of the inner peripheral portion of the outer needle that is in close contact with the inner needle. 13. A tip portion of the outer needle has a reduced diameter portion whose inner diameter is reduced and closely adheres to the inner needle, and a void serving as a blood flow path is formed on an inner peripheral surface of the reduced diameter portion. The indwelling needle assembly according to claim 1 or 2, which is formed. 14. The indwelling needle assembly according to claim 12, wherein the gap is formed by a concave portion which is recessed from an inner peripheral surface of the outer needle. 15. The indwelling needle assembly according to claim 1, wherein an inclined blade surface is formed at the needle tip.