JPH04364831A - Blood sampling needle - Google Patents

Abstract

PURPOSE:To provide a blood sampling needle which enables the checking of flashback very easily and quickly. CONSTITUTION:This needle has a roughly cylindrical hub 2 having a transparent or semi-transparent part, a cannula 41 which is extended separately from both axial ends of the hub 2 while having a sharp tip with a path inside and a bottomed elastic chip fitted liquid tight into the hub 2 wrapping one extension end of the cannula 41. The hub 2 is provided with an axial communication hole 13 with is loaded with the cannula 41 to fix, an air hole to make an internal cavity part E of the bottomed elastic chip communicate with an external changed area and a ventilating filter 7 which interrupts the passage of the air hole and has a pore 19 interposed almost vertically to the direction of the hub axis so as to let a gas pass but not to let a liquid pass.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a blood collection needle, in particular, a blood collection needle that communicates one specimen source such as blood in a venous blood vessel with one or more specimen storage chambers such as vacuum blood collection tubes that have been subjected to negative pressure in advance. The present invention relates to a blood collection needle that enables multiple specimen collection.

0002

2. Description of the Related Art Conventionally, in conducting clinical tests, blood sampling units that are capable of collecting blood multiple times with a single puncture have been frequently used. For example, as shown in FIG. 4, this unit includes a blood collection needle 100 including cannulas 120 and 130 provided at both ends of a hub 110, an elastic tip 135 attached to surround the cannula 130, and It consists of a cylindrical holder 200 to which the needle 100 is fixed, and a blood collection tube 300 that is inserted into the holder 200 and is previously set to negative pressure. When collecting blood, first, the holder 200 and the blood collection needle 100 are assembled in advance and integrated, and the cannula 120 side is punctured into the venous blood vessel to secure the venous blood vessel. After that, the blood collection tube 300 is pushed into the holder, and the rubber stopper 310 is closed using the cannula 130.
Blood collection is started by penetrating the blood collection tube 3.
Blood collection is completed when the pressure inside 00 and the venous pressure are balanced.

However, in such conventional vacuum blood sampling systems, there is no place for the gas inside the cannula and the elastic tip to escape during venipuncture, making it impossible to confirm so-called flashback. Therefore, there is sometimes a risk that blood collection may be started while the cannula is still inside the body after being dislodged from the vein.

To solve this problem, Japanese Patent Publication No. 2-21809 has already proposed a needle assembly equipped with a mechanism for confirming flashback.

[0005]

[Problems to be Solved by the Invention] However, this device has a ventilation device as a communication path provided inside the hub,
The structure is extremely complicated, including a compressed annular sleeve that is inserted into a communication path in the device and has material properties that swell with moisture, and there is a problem that it cannot be mass-produced at a low cost. Further, in this case, negative pressure is applied to the sleeve housed in the housing chamber when blood is collected, resulting in insufficient sealing with the outside, resulting in a lack of safety. Also, there is a lot of dead volume. In order to solve these problems, the present applicant has already proposed a blood collection needle that has an extremely simple structure and can also confirm flashback (Japanese Patent Application No. 2-264219).

The present invention is a further improvement of such a blood collecting needle, and its purpose is to provide a blood collecting needle which not only has a simple structure but also allows flashback to be confirmed extremely easily and quickly.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a substantially cylindrical hub having a transparent or semi-transparent portion, a hub extending from both axial ends of the hub, and The hub has a cannula having a sharp tip with a passage therein, and a bottomed elastic tip that is fluid-tightly fitted to the hub so as to surround one extending end of the cannula. an axial communication hole for inserting and fixing the cannula; a ventilation hole for communicating the inner cavity of the bottomed elastic tip with the external atmosphere; The air permeability filter is provided with a permeable filter having pores arranged substantially perpendicularly thereto and allowing gas to pass therethrough but not allowing liquid to pass therethrough.

[0008]

[Embodiment] An embodiment of the blood sampling needle of the present invention will be described below with reference to FIG. The blood collection needle 1 of the present invention includes a substantially cylindrical hub 2, cannulas 41 and 45 extending from both ends of the hub 2 in the axial direction, and the hub surrounding the extending end of one cannula 45. The elastic tip 50 has a cylindrical shape with a bottom and is fluid-tightly fitted to one end of the tip 2.

A cannula 41 inserted into the hub 10,
45 is integrated in this embodiment, and the internal passage 40 communicates with it in the axial direction, and both ends thereof have a sharp tip shape. Such cannulas 41 and 45 are
When inserted into a communication hole 13 of a hub 10, which will be described later, it is fixed with various adhesives S or the like.

The hub 2 is composed of two members, and in this embodiment is formed by fitting a first hub member 10 and a second hub member 30. The first hub member 10 has a communication hole 13 that penetrates in the central axis direction, a pore 19 that is continuous along the axial direction of the communication hole 13, and a pore 1
9, and a flange 21 extending outward from the liquid reservoir 20b.

The communication hole 13 is connected to the cannula 41 as described above.
, 45 are holes into which cannulas 41, 45 are inserted.
The inner diameter is slightly larger than the outer diameter. Usually, the difference in diameter is about 0.05 to 0.30 mm.

A fine hole 19 is connected to such a communicating hole 13.
is formed, and this pore 19 is substantially separated from the communicating hole 13 by the cannula 45. And pore 1
9 forms a part of a ventilation hole which will be described later. The pores 19 can have various cross-sectional shapes, such as a semicircle, and have an average diameter of about 0.3 to 3 mm. Such pores 19 communicate with cylindrical liquid reservoirs 20a and 20b.

[0013] The liquid reservoirs 20a and 20b are mainly formed by the pores 1.
9 and an external hole 39, which will be described later, and to create a liquid pool to facilitate confirmation of flashback. There is no particular restriction on the shape of the liquid reservoirs 20a, 20b as long as they fulfill such a function. These liquid reservoirs 20a and 20b also form part of the ventilation hole, as will be described later.

An annular flange portion 21 is formed in communication with the outer peripheral surface of the liquid reservoir portion 20b.
A ring-shaped fitting convex portion 21a is formed on the joint surface. Thereby, the second hub member 30 is fitted through a plate-shaped air permeable filter 7, which will be described later. Note that a seat 21b for receiving the ventilation filter 7 and the second hub member 30 is provided on the fitting convex portion 21a.

The first hub member 10 is normally provided with a threaded portion 15 on the outer periphery of the approximately central portion of its main body, and this threaded portion 15 has a mouth portion (FIG. 4) of a holder 200, which is one unit of the blood collection unit. ) are screwed together. moreover,
A locking portion 17 is formed at the rear end of the first hub member 10 to lock the elastic chip 50 in a fluid-tight manner. The locking portion 17 is not particularly limited as long as it has a shape that prevents the elastic tip 50 from easily detaching.In the case of this embodiment, an example thereof is a locking protrusion 17a protruding like a jaw.
It is equipped with

The elastic tip 50 engaged with the locking portion 17 has a cylindrical shape with a bottom portion 51 and a lumen portion E serving as a space surrounding the second cannula 45 . This elastic tip 50 is attached to the second cannula 45 during blood collection.
Therefore, a suitable degree of elasticity is required so that it can be resealed even after being temporarily perforated.

[0017] Examples of the material used include synthetic rubber and elastomer. Among these, those having transparent or semi-transparent properties are preferred so that flashback can be confirmed. The dimensions of such elastic tips are usually
The length is about 10 to 30 mm, and the outer diameter is about 1 to 3 mm.

By the way, the second hub member 30 fitted into the first hub member 10 has a cannula 41,
It has an axial communication hole 33 for inserting the cannula 45, and a cannula fixing hole 35 provided at the distal end of the cannula. (At this time, the gap between the communicating hole 33 and the cannula 41 is usually filled with adhesive S slightly) to fix the cannula 41, 45.

The second hub member 30 has an annular flange portion 31, and this flange portion 31 has a ring-shaped fitting recess 31a, and the first hub member is inserted into this recess 31a. 10 fitting convex portions 21a are fitted and fixed. The mode of fixation is simple adhesion,
Methods such as fusion bonding are used. Furthermore, four external holes 39 are penetrated through a portion of the flange portion 31 (FIG. 2). Then, when the first hub member 10 and the second hub member 30 are fitted, the external hole 39 of the flange portion 31 is communicated with the liquid reservoir portion 20b via the breathable filter 7.

The plate-shaped ventilation filter 7 blocks the passage of the ventilation hole and is interposed approximately perpendicularly to the hub axis direction. That is, in the case of this embodiment, the air permeable filter 7 is interposed at the substantially perpendicular joint surface between the first hub member 10 and the second hub member 30. More specifically, the flat surface of the breathable filter is interposed at an angle of 70 to 110 degrees with respect to the hub axis direction. Outside this range, the filter becomes a nuisance, causing the inconvenience that flashback cannot be confirmed easily and quickly.

[0021] The breathable filter 7 has pores that allow gas to pass through but do not allow liquid to pass through. This filter is preferably water repellent and is made of fluorocarbon resin such as Teflon or PP, PE, etc. Contains olefin resin. Such a filter 7 is sealed inside the hub by fitting, ultrasonic waves, heat, or the like. The pore diameter of the filter 7 is 0.2 to 5 μm, more preferably 1 to 3 μm,
The thickness is 5-50 μm, preferably 7-16 μm. This filter may have a two-layer structure using a reinforcing material as described later.

As described above, the bottomed cylindrical elastic tip 50
A ventilation hole that communicates the inner cavity E with the external atmosphere is formed by the pore 19, the liquid reservoirs 20a and 20b, and the external hole 39.

That is, the ventilation hole is installed such that one end 19a thereof is located at the rear end of the first hub member 10 and communicates with the inner cavity E of the elastic chip 50, and the other end of the ventilation hole is located at the rear end of the first hub member 10. Hole 39 communicates with the outside atmosphere.

By the way, the distal end of the cannula 41 inserted into the communication hole 33 on the second hub member 30 side and the distal end of the cannula 45 on the first hub member 10 side are connected to a vein when collecting a sample, respectively. One analyte source, such as blood within a blood vessel, and a analyte reservoir, such as a so-called vacuum blood collection tube, are punctured.

[0025] The hub 2 is usually formed by injection molding, especially the first hub member 1 on the rubber chip side.
0 is also to make it easier to confirm flashbacks.
It is considered to be a transparent or semi-transparent material. Specific examples include resin materials such as polypropylene, polyethylene, polystyrene, polystyrene terephthalate, polymethylpentene, polycarbonate, polyacrylonitrile, and ABS. The assembled hub 2 has a length of 10 to 3
0 mm, and the outer diameter is about 5 to 15 mm. The two hub members 10, 30 are assembled by fitting, ultrasound, heat, adhesive, or the like.

In this embodiment, a structure is adopted in which the pore 19 and the liquid reservoirs 20a, 20b forming part of the ventilation hole are connected to the axial communication hole 13. That is, when the cannula is inserted into the communication hole 13, a part of the outer periphery of the cannula forms part of the ventilation hole. As a result, the outer diameter of the locking portion 17 for locking the elastic tip 50 can be reduced, and the communication hole can be easily formed by injection molding.

[0027] Apart from this, the shape of the ventilation hole is shown in Fig. 2.
As shown in the second embodiment, a hole 99 may be formed separated from the axial communication hole 13 by a certain partition wall. Next, a third embodiment of the present invention will be described based on FIG. 6. The structure of this third embodiment is fundamentally different from those of the first and second embodiments described above, as shown in FIG. The point is that an air chamber 20c is provided at the top. Note that the shape of this air chamber 20c is preferably approximately ring-shaped. This configuration is made to prevent the possibility of blood leaking from the filter 7 when a large amount of blood flows into the elastic chip 50 due to flashback. That is, for example, if there is extremely little air in the hub, the pressure applied to the filter 7 will become extremely high when a large amount of blood flows into the elastic tip 50, and blood may leak from the filter 7. Despite the possible disadvantages, the air chamber 20 of the present invention
By providing c, the above-mentioned inconvenience can be avoided.

Note that the external hole 39 in this case is
There are four provided on the second hub member 30 along the outer periphery of the hub member 1 (FIG. 7). The filter 7 is reinforced with a reinforcing material 80 to prevent the filter 7 from being bent. The reinforcing material 80 is made of a material whose surface is hydrophilic, for example, polyester (approximately 200 mesh) made hydrophilic by plasma treatment. In the blood collection needle of the third embodiment, blood that has passed through the communication hole 13 flows toward the filter 7 and the reinforcing material 80, but does not enter the air chamber 20c. When blood reaches the filter 7 and the reinforcing material 80, the filter 7 becomes wet, making it difficult for air to pass through. This makes it possible to secure a large amount of air within the air chamber 20c. In this way, the air chamber 20c
The air inside acts as a cushion, preventing blood from leaking from the filter 7. Note that the air chamber 20
A tip 29a of the partition wall 29 forming the partition wall 29 has a tapered shape that widens outward toward the filter 7. This makes it easier to apply the filter 7.

Air chamber 20c as shown in FIG.
It is preferable that the inner diameter r1 in the outer hole 39 is approximately the same as the outer diameter r2 in the outer hole 39, and particularly larger than the outer diameter r2. If r1<r2, blood flows into air chamber 2
The air easily enters into the air chamber 20c, resulting in a disadvantage that the amount of air in the air chamber 20c becomes small.

[0030]

Functions and Effects of the Invention The functions of the blood sampling needle of the present invention described above will be explained. As shown in FIG. 3, the threaded portion 15 provided on the outer periphery of the hub 2 of the blood collection needle 1 is screwed into the opening of the holder 200, so that the blood collection needle and the holder 200 are integrated. In this state, the first cannula 41 of the blood collection needle is punctured into the blood vessel V. Then, the blood in the blood vessel V flows into the first cannula 4.
It flows from the inner hole of the first cannula through the inner hole of the second cannula into the inner hole E of the elastic tip, further rises inside the ventilation hole, and stops at the air permeable filter 7. At this time, flashback can be easily confirmed by forming the hub 2 from a transparent or semi-transparent material. In particular, in the case of the present invention, since the plate-shaped breathable filter is interposed substantially perpendicularly to the hub axis direction, flashback can be confirmed extremely easily and quickly.

When the present inventors actually conducted an experiment to confirm flashback, 5 cm aq. Flashback was confirmed very easily and quickly even at low venous pressure. In addition, since the air chamber 20c is provided adjacent to the ventilation hole, the pressure applied to the filter is relaxed by the blood pushed out from the elastic tip contracted by the blood collection tube, and blood does not leak from the filter. There is no.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing a blood collection needle as a first embodiment of the present invention.

FIG. 2 is a view taken along the line II-II in FIG. 1;

FIG. 3 is a partial cross-sectional view showing a blood collection needle according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram for explaining the action of the blood collection needle of the present invention.

FIG. 5 is an exploded perspective view of the blood collection unit.

FIG. 6 is a partial cross-sectional view showing a blood collection needle according to a third embodiment of the present invention.

FIG. 7 is a view taken along the line VII-VII in FIG. 6;

[Explanation of symbols]

1...Blood collection needle 2...Hub 7...Breathable filter 10...First hub member 13...Communication hole 19...Pore 20a, 20b...liquid pool 20c...Air chamber 30...Second hub member 39...External hole 41,45...cannula 50...Elastic tip E...Inner cavity

Claims (5)

[Claims] 1. A substantially cylindrical hub having a transparent or translucent portion, each extending from both axial ends of the hub,
and a cannula with a sharp tip having a passageway therein;
and a bottomed elastic tip that is fluid-tightly fitted to the hub so as to surround one extending end of the cannula, and the hub has an axial communication hole for inserting and fixing the cannula. and a vent hole that communicates the inner cavity of the bottomed elastic tip with the outside atmosphere, and a gas passage that blocks the passage of the vent hole and is interposed in a direction substantially perpendicular to the hub axis direction. 1. A blood collection needle comprising: a breathable filter having pores that do not allow liquid to pass through. 2. An air chamber is formed in communication with the ventilation hole to further secure air within the hub, and the air chamber is separated from the ventilation hole by a partition wall protruding in the hub axial direction. The blood collection needle according to claim 1, characterized in that: 3. The blood collection needle according to claim 2, wherein the partition wall has a tip end tapered outward toward the air-permeable filter. 4. The hub includes two members, the hub members are joined together, and a joining surface is provided substantially perpendicular to the hub axis direction;
The blood collection needle according to any one of claims 1 to 3, characterized in that a breathable filter is interposed on the joint surface. 5. The air permeable filter has a flat surface interposed at an angle of 70 to 110 degrees with respect to the hub axis direction. Blood collection needle.