JP3108679B2 - Blood collection needle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood sampling needle, in particular, a sample source such as blood in a venous blood vessel, and a sample storage chamber such as a vacuum blood sampling tube which has been pre-pressurized and communicates with one or more blood sampling needles. The present invention relates to a blood collection needle that enables a sample to be collected twice.

[0002]

2. Description of the Related Art Conventionally, in performing a clinical test, a blood sampling unit that enables a plurality of blood samplings with a single puncture has been frequently used. This unit includes, for example, as shown in FIG. 4, a blood collection needle 100 provided with canulas 120 and 130 provided at both ends of a hub 110 and an elastic tip 135 attached so as to surround the canula 130, and the blood collection needle 100. It is composed of a cylindrical holder 200 to which the needle 100 is fixed, and a blood collection tube 300 which is inserted into the holder 200 and has a negative pressure in advance. Then, at the time of blood collection, first, the holder 200 and the blood collection needle 100 are previously assembled and integrated, and the cannula 120 side is punctured into the venous blood vessel to secure the venous blood vessel. Thereafter, the blood collection tube 300 is pushed into the holder, and the rubber stopper 310 is
To start blood collection, and blood collection tube 3
Blood collection is completed in a state where the internal pressure and the venous pressure are balanced.

[0003] However, in such a conventional vacuum blood collection system, there is no place for escape of gas inside the cannula and the inside of the elastic chip at the time of venipuncture, and it is impossible to confirm so-called flashback. For this reason, there is a danger that blood collection may be started while the vein is outside the vein and the cannula remains in the body.

In order to solve such a problem, Japanese Patent Publication No. 21809/1990 proposes a needle assembly already provided with a mechanism capable of confirming flashback.

[0005]

However, this device has a ventilation device as a communication passage provided inside the hub,
There is a problem that the configuration is extremely complicated, such as having an annular compressed sleeve that has a material characteristic of being swollen by moisture and inserted into a communication passage in the device, and cannot be mass-produced at low cost. Further, in this case, a negative pressure is applied to the sleeve housed in the housing chamber at the time of blood collection, and the seal with the outside is insufficient, so that safety is lacking. There are also many dead volumes. In order to solve such a problem, the present applicant has already provided a blood collection needle having a very simple structure and capable of confirming flashback, i.e., a hub having a ventilation hole for communicating the inner cavity of the elastic tip with the external atmosphere. There has been proposed a blood collection needle provided inside, and further provided with a gas permeable filter that blocks a passage of a vent from the outside.

[0006] When blood is collected using a blood collection needle, since there is an individual difference in the blood pressure value and the like of the blood collected, a large amount of blood flows into the elastic chip at once by flashback. Can occur. In this case, since the pressure applied to the ventilation filter increases instantaneously, blood may leak from the ventilation filter. The above proposal does not take this point into consideration.

The present invention has been made on the basis of such a situation. The purpose of the present invention is not only to ensure the confirmation of flashback with a simple configuration, but also to realize a large amount of flashback at once in the elastic chip by flashback. It is an object of the present invention to provide a blood collection needle that can prevent blood leak from the ventilation filter even when the blood flows into the ventilation filter and the pressure applied to the ventilation filter increases very quickly.

[0008]

In order to solve such a problem, the present invention includes a cannula extending from both ends in the axial direction of a substantially cylindrical hub, and has one extending end of the cannula. In a blood collection needle surrounded by a bottom-shaped elastic tip, the hub has a ventilation hole communicating the inner cavity of the bottomed elastic tip with an external atmosphere, and further communicates with the ventilation hole. And an air chamber for preventing a rapid pressure increase in the hub, and a gas permeable filter formed so as to block the passage of the air hole from the external atmosphere.

[0009]

In a more preferred embodiment, the cannula is integrated and has openings only at both ends.

In a more preferred embodiment, the air chamber is formed in a ring shape.

According to the present invention, the air chamber is provided even if a large amount of blood flows into the elastic chip at one time due to flashback, and the internal air does not instantaneously escape to the outside through the ventilation filter. This acts as a cushion for buffering the pressure, thereby preventing a sudden high pressure from being applied to the gas permeable filter.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the blood collection needle of the present invention will be described below with reference to FIG.

The blood collection needle 1 of the present invention has a substantially cylindrical hub 2.
And a cannula 41, 45 extending from both ends in the axial direction of the hub 2, and a bottomed cylinder liquid-tightly fitted to one end of the hub 2 so as to surround the extending end of one cannula 45. And a resilient tip 50 in the shape of a letter.

The cannula 41 inserted into the hub 10,
In the case of the present embodiment, reference numeral 45 is integrated, and the inside thereof is communicated with the internal passage 40 in the axial direction, and both ends thereof have a sharp tip shape. That is, the cannulas 41 and 45 are formed of a single integrated cylinder, and there are no openings other than both ends. Such cannulas 41 and 45 are fixed by various adhesives S or the like while being inserted into a communication hole 13 of the hub 10 described later.

The hub 2 is composed of two members, and in this embodiment, is formed by fitting the first hub member 10 and the second hub member 30 together.

The first hub member 10 has a communication hole 13 penetrating therethrough in the central axis direction, a small hole 19 provided in the communication hole 13 along the axial direction, and a communication hole with the small hole 19. Liquid reservoirs 20a and 20b.

The communication hole 13 is provided with the cannula 4 as described above.
1, 45 are holes for inserting cannula 41, 4
The inner diameter is slightly larger than the outer diameter of 5. Usually, the diameter difference is about 0.05 to 0.30 mm.

The fine holes 19 are connected to the communication holes 13 and
Are formed, and the pores 19 are substantially separated from the communication holes 13 by a cannula 45. And pore 1
9 forms a part of a vent hole described later. Various shapes such as a semicircle can be adopted as the cross-sectional shape of the pore 19, and the average diameter thereof is about 0.3 to 3 mm. Such pores 19 communicate with the cylindrical liquid reservoirs 20a and 20b.

The liquid reservoirs 20a and 20b mainly include the fine holes 1
9 and an external hole 39 to be described later, and a role of forming a liquid pool and facilitating confirmation of flashback. There is no particular limitation on the shape of the liquid reservoirs 20a and 20b as long as they fulfill such a function. The liquid reservoirs 20a and 20b also form a part of the vent as described later.

An air chamber 20c is formed on the outer peripheral surface of the liquid reservoir 20b via a partition 29 so as to communicate with the vent hole. It is preferable that the shape of the air chamber 20c be substantially ring-shaped. Such an air chamber 20
The reason for providing c is to prevent the possibility of blood leaking from a filter 7 described later when a large amount of blood flows into the elastic chip 50 by flashback.
That is, for example, if the air in the hub is extremely small, the pressure applied to the filter 7 when a large amount of blood flows into the elastic tip 50 becomes extremely high, and blood may leak from the filter 7. Although inconvenience may occur,
The inconvenience can be avoided by providing the air chamber 20c of the present invention.

The outer peripheral surface of the air chamber 20c is formed by a flange 21. The flange 21 is fitted to a second hub member 30 described later.

Further, the first hub member 10 is generally provided with a screw portion 15 on the outer periphery of a substantially central portion of the body portion of the main body, and the screw portion 15 has an opening ( FIG. 4) is screwed.
Further, the elastic tip 5 is provided at the rear end of the first hub member 10.
A locking portion 17 for locking the O in a liquid-tight manner is formed. The locking portion 17 is not particularly limited as long as the elastic tip 50 cannot easily be detached.
In the case of the present embodiment, as an example, a jaw-shaped locking projection 17a is provided.

The elastic tip 50 engaged with the locking portion 17 has a cylindrical shape having a bottom portion 51 and has a lumen E as a space surrounding the second cannula 45. The elastic tip 50 is used for the second cannula 45 during blood collection.
Therefore, even after being temporarily pierced, appropriate elasticity is required so that it can be resealed again.

Examples of the material used include synthetic rubber and elastomer. Among them, those having a transparent or translucent property so that flashback can be confirmed are preferable. The dimensions of such elastic tips are usually
It has a length of about 10 to 30 mm and an outer diameter of about 1 to 3 mm.

The second hub member 30 fitted to the first hub member 10 has a cannula 41,
45 has an axial communication hole 33 for inserting the cannula 45, and a cannula fixing hole 35 provided at the end thereof. With the cannula 41, 45 inserted, the adhesive S is inserted into the cannula fixing hole 35. (At this time, the adhesive S is usually slightly filled in the gap between the communication hole 33 and the canula 41) to fix the canulas 41 and 45.

The second hub member 30 has an annular flange portion 31 which is fixed to the flange portion 21 of the first hub member 10 as shown in the figure. I have. As a mode of the fixation, a simple method such as adhesion or fusion is used. Furthermore, the flange 3
Four external holes 39 are penetrated in a part of 1 (FIG. 2). Then, the first hub member 10 and the second hub member 3
When 0 is fitted, the external hole 39 of the flange portion 31 is communicated with the liquid pool portion 20b via the air permeable filter 7 described later.

In the case of this embodiment, the plate-shaped air-permeable filter 7 is interposed so as to be substantially perpendicular to the hub axis direction and fixed to the second hub member 30 so as to block the passage of the air hole. ing.

The gas permeable filter 7 has pores which allow gas to pass therethrough and do not allow liquid to pass therethrough. The filter preferably has water repellency and is made of a fluororesin such as Teflon or a resin such as PP or PE. It is configured to contain an olefin resin. Such a filter 7 is sealed inside the hub by fitting, ultrasonic waves, heat or the like. Filter 7
Has a pore size of 0.2 to 5 μm, more preferably 1 to 3 μm.
m, the thickness is 5 to 50 μm, preferably 7 to 16 μm. The gas permeable filter 7 may have a two-layer structure using a reinforcing material as described later.

As described above, the bottomed cylindrical elastic tip 50
The ventilation hole for communicating 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 vent hole is located 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 tip 50. The hole 39 communicates with the outside atmosphere.

The distal end of the cannula 41 inserted into the communication hole 33 on the second hub member 30 and the distal end of the cannula 45 on the first hub member 10 are respectively connected to the vein at the time of specimen collection. A sample source such as blood in a blood vessel and a sample storage chamber such as a so-called vacuum blood collection tube are punctured.

The hub 2 is usually formed by injection molding, and especially the first hub member 1 on the rubber chip side.
0 is to make it easy to confirm flashback,
It is made of a transparent or translucent material. Specific examples include resin materials such as polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polymethylpentene, polycarbonate, polyacrylonitrile, and ABS. The dimensions of the assembled hub 2 are 10 to 3 in length.
0 mm and an outer diameter of about 5 to 15 mm. The two hub members 10 and 30 are fitted or assembled by ultrasonic waves, heat, an adhesive, or the like.

In this embodiment, a configuration is adopted in which the pores 19 and the liquid reservoirs 20a and 20b which form part of the ventilation holes are connected to the axial communication holes 13. That is, when the cannula is inserted into the communication hole 13, a part of the outer periphery of the cannula constitutes a part of the ventilation hole. Thus, the outer diameter of the locking portion 17 for locking the elastic chip 50 can be reduced, and the communication hole can be easily formed by injection molding.

In addition, the form of the ventilation hole may be such that a hole is formed apart from the axial communication hole 13 at a predetermined interval. The substantial function as the communication hole is the same.

In the embodiment shown in FIG. 1, the gas permeable filter 7 is reinforced by a reinforcing member 80 to prevent the gas permeable filter 7 from bending. As the reinforcing material 80, a material having a surface hydrophilicity, for example, polyester (about 200 mesh) hydrophilized by plasma treatment is used. In the blood collection needle of the present invention having such an embodiment, the blood that has passed through the communication hole 13 flows toward the air-permeable filter 7 and the reinforcing member 80, but does not enter the air chamber 20c. When the blood reaches the air permeable filter 7 and the reinforcing member 80, the air permeable filter 7 gets wet, and it becomes difficult for air to pass through. At this time,
A lot of air can be secured in the air chamber 20c. Thus, the air in the air chamber 20c functions as a cushion, and blood does not leak from the air permeable filter 7. In addition, it is preferable that the tip portion 29a of the partition wall 29 forming the air chamber 20c has a tapered shape that spreads outward toward the air permeable filter 7. Thereby, the gas permeable filter 7 is easily wetted.

Further, as shown in FIG. 1, the inner diameter r1 of the air chamber 20c is preferably substantially the same as the outer diameter r2 of the outer hole 39, particularly preferably larger than the outer diameter r2. When r1 <r2, the blood easily enters the air chamber 20c, and
This is because there is a disadvantage that the amount of air in 0c is small.

[0038]

According to the present invention, there is provided a blood collection needle provided with a cannula extending from both ends in the axial direction of a substantially cylindrical hub and one extending end of the cannula surrounded by a bottomed elastic tip. The hub has a ventilation hole for communicating the inner cavity of the bottomed elastic tip with an external atmosphere, and further communicates with the ventilation hole to prevent a rapid pressure increase in the hub. And an air chamber, and a gas permeable filter formed so as to block the passage of the air hole from the external atmosphere.

Therefore, even if a large amount of blood flows into the elastic chip at one time due to flashback and the internal air does not escape to the outside through the air-permeable filter instantaneously, the air chamber is provided. Acts as a cushion for buffering the pressure, the pressure applied to the air permeable filter is relieved, and blood does not leak from the air permeable filter.

[Brief description of the drawings]

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

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a schematic diagram for explaining the operation of the blood collection needle of the present invention.

FIG. 4 is an exploded perspective view of the blood collection unit.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 ... Blood collection needle 2 ... Hub 7 ... Air-permeable filter 10 ... First hub member 13 ... Communication hole 19 ... Pores 20a, 20b ... Liquid reservoir 20c ... Air chamber 30 ... Second hub member 39 ... External hole 41, 45: Cannula 50: Elastic tip E: Internal cavity

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 5/15

Claims (3)

(57) [Claims] 1. A blood collection needle comprising: a cannula extending from both ends in the axial direction of a substantially cylindrical hub; and one extending end of the cannula surrounded by a bottomed elastic tip.
The hub is provided with a ventilation hole for communicating the inner cavity of the bottomed elastic tip with the external atmosphere, and further communicates with the ventilation hole to prevent a sudden pressure increase in the hub. A blood collection needle having a chamber and a gas permeable filter formed so as to block a passage of a vent from an external atmosphere. 2. The blood collection needle according to claim 1, wherein the cannula is integrated and has openings only at both ends. 3. The blood collection needle according to claim 1, wherein the air chamber has a ring shape.