JP3981978B2 - Blood collection needle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a blood collection needle. More specifically, one end of the blood collection needle is punctured into a subject's blood vessel, the other end is inserted into a vacuum blood collection tube, and the inside of the blood vessel communicates with the inside of the vacuum blood collection tube. The present invention relates to a blood collection needle used for collecting blood in an amount corresponding to negative pressure. According to the blood collection needle of the present invention, it is possible to confirm a so-called flashback in which one end is punctured into the vein of the subject before the other end is inserted into the vacuum blood collection tube.
[0002]
[Prior art]
Conventionally, blood collection needles having a mechanism capable of confirming flashback before attaching a vacuum blood collection tube during blood collection using a vacuum blood collection tube have been proposed.
As such a blood collection needle, for example, a substantially cylindrical hub, a needle tube having a sharp cutting edge extending from both axial ends of the hub, and an inner diameter much larger than the outer diameter of the needle tube, In addition, there is a blood collection needle composed of a bottomed cylindrical elastic cap fitted to the hub so as to surround one end of the needle tube (for example, see Patent Document 1). The blood collection needle is provided with a vent hole in the hub for allowing the inside of the elastic cap to communicate with the external atmosphere, and an air permeable blood impermeable filter is provided at the external port of the vent hole. When the blood collection needle punctures one end of the blood collection needle into a subject's vein, blood flows into the blood collection needle and air inside the blood collection needle is externally passed through an air permeable blood impermeable filter. The flashback can be confirmed by exiting. As the air permeable blood impermeable filter, a membrane filter or a sintered filter is used.
However, when the elastic cap is compressed when the vacuum blood collection tube is connected to the blood collection needle, there is a possibility that the blood filled in the elastic cap is pressurized and blood leaks from the filter portion or the like.
[0003]
On the other hand, in order to prevent blood leakage when a vacuum blood collection tube is connected, a blood collection needle having an air chamber formed in the hub has also been developed (see, for example, Patent Document 2). In the blood collection needle, blood flowing into the blood collection needle when one end of the blood collection needle is punctured into the subject's vein does not flow into the air chamber, and the pressure rises due to compression of the elastic cap when the vacuum blood collection tube is connected. The collected blood flows into the air chamber. Accordingly, since the blood pressure inside the blood collection needle does not increase due to the connection of the vacuum blood collection tube, leakage of blood from the filter portion or the like can be effectively prevented.
However, such a blood collection needle needs to be provided with an air chamber inside the hub, and the structure of the hub is complicated and large, so that there is a problem that it is difficult for medical personnel to use.
[0004]
[Patent Document 1]
Japanese Patent Publication No. 7-32766 [Patent Document 2]
Japanese Patent No. 3086024 [0005]
[Problems to be solved by the invention]
In view of the above circumstances, it is an object of the present invention to provide a compact blood collection needle that has no risk of blood leaking from a filter portion or the like when a vacuum blood collection tube is connected, has a simple hub structure, and is easy to use by medical personnel.
[0006]
[Means for Solving the Problems]
As a result of diligent investigations to solve the above-mentioned problems, the present inventor has formed an internal volume of an elastic cap that surrounds one end of the needle tube into a minimum size that allows confirmation of flashback, thereby obtaining a vacuum. It has been found that the increase in the pressure of blood filling the elastic cap at the time of blood vessel connection can be minimized and leakage of blood from the filter portion can be prevented, and the present invention has been achieved.
[0007]
That is, the present invention
(1) a needle tube having a sharp cutting edge at the distal end and the proximal end, a hub that is a hollow tubular body that is extrapolated to the needle tube, the distal end portion being fixed to the needle tube, and a proximal end side of the hub, The elastic cap has an inner diameter that can be in close contact with the outer surface of the needle tube, and can cover the portion exposed to the proximal end from the hub of the needle tube in a liquid-tight manner. At least one groove that communicates with the inside of the needle tube is provided via a blade edge on the proximal end side of the needle tube, and a passage that communicates the inside of the needle tube with the external atmosphere is formed in the hub via a groove on the inner surface of the elastic cap. A blood collection needle provided with an air permeable blood impermeable filter at an external port of the passage,
(2) The groove according to (1), wherein the groove extends from the distal end side to the proximal end side of the elastic cap over the entire length of the elastic cap.
(3) The blood collection needle according to (2), wherein the groove extends linearly in the axial direction of the needle tube,
(4) Furthermore, the inner surface of the elastic cap is provided with an air reservoir that does not directly communicate with the inside of the needle tube but communicates with the passage. (1) to (3) Blood collection needle,
(5) The blood reservoir according to (4), wherein the air reservoir extends linearly in the axial direction of the needle tube from the distal end side toward the proximal end side except for the proximal end portion of the elastic cap.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the blood collection needle of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings, but the present invention is not limited to these descriptions.
FIG. 1 is a longitudinal sectional view showing an embodiment of the blood collection needle of the present invention, and FIG. 2 is a longitudinal sectional view of an elastic cap of the blood collection needle shown in FIG. FIG. 4 is a longitudinal sectional view showing another embodiment of the elastic cap of the blood collection needle of the present invention. FIG. 7 is a longitudinal sectional view showing another embodiment of the blood collection needle of the present invention.
The blood collection needle 1 of the present invention includes a needle tube 2 having sharp cutting edges 21 and 22 at the distal end and proximal end, a hub 3 externally inserted into the needle tube 2, and an elastic cap attached to the proximal end side of the hub 3. 4.
In the blood collection needle 1 of the present invention, the distal end refers to the side that punctures the patient (left side in the figure), and the proximal end refers to the side that punctures the vacuum blood collection tube (not illustrated) (right side in the figure).
[0009]
The needle tube 2 in the present invention is a hollow tube, and sharp cutting edges 21 and 22 are formed at the distal end and the proximal end thereof. The cutting edge 21 has an inclined blade surface in order to reduce the piercing resistance when piercing a patient's blood vessel and the cutting edge 22 is pierced into a rubber stopper fitted in the opening of the vacuum blood collection tube. Yes.
Examples of the material of the needle tube 2 include metal materials such as stainless steel, aluminum, titanium, and alloys thereof.
[0010]
A hub 3 is externally attached to the needle tube 2 at an intermediate portion thereof. The hub 3 is a hollow tube and is formed by injection molding or the like. The inner diameter of the hub 3 is slightly larger than the outer diameter of the needle tube 2 so that the needle tube 2 can be inserted.
The hub 3 is preferably made of a transparent or translucent material for easily confirming flashback, and specifically, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polymethylpentene, polycarbonate, polyacrylonitrile, ABS. It is formed from a resin or the like.
The tip of the hub 3 is airtightly fixed to the needle tube 2 using, for example, an adhesive S. As the adhesive S, an epoxy curing agent, a UV curing adhesive, or the like is used. The adhesive S may be used so as to fill a part of the gap between the hub 3 and the needle tube 2 as shown in FIG.
[0011]
One or more ribs 31 may be provided on the outer periphery of the distal end portion of the hub 3. The rib 31 is for engaging with a cap (not shown) attached to the blood collection needle 1 before use in order to protect the cutting edge 21 of the blood collection needle 1, and the blood collection needle within the blood collection needle cap. It also has the effect of preventing 1 from rotating. A screw portion 32 may be provided on the outer periphery of the base end portion of the hub 3. The threaded portion 32 can be screwed into a holder (not shown) for holding the vacuum blood collection tube in a state where the cutting edge 22 of the blood collection needle 1 is inserted into the vacuum blood collection tube.
[0012]
The blood collection needle 1 shown in FIG. 1 has a structure in which the hub 3 is composed of two members so that an air permeable blood impermeable filter 5 described later can be held by fitting. Specifically, the hub 3 includes a hub main body 33 and an elastic cap connection member 34, and the elastic cap connection member 34 is inserted into and integrated with a base end portion of the hub main body 33.
A locking portion 341 may be formed at the base end portion of the elastic cap connecting member 34 in order to lock the elastic cap 4 described later in an airtight manner so that it cannot be detached.
[0013]
The elastic cap 4 that is locked to the locking portion 341 of the elastic cap connecting member 34 has a bottomed cylindrical shape, and a portion of the needle tube 2 exposed from the hub 3 to the proximal end side is liquid-tight. It is formed in a size that can be covered. The elastic cap 4 has an inner diameter that can be in close contact with the outer surface of the needle tube 2.
Examples of the material of the elastic cap 4 include natural rubber, synthetic rubber such as isoprene rubber and silicon rubber, and elastomer. Further, the elastic cap 4 may be transparent or translucent so that flashback can be easily confirmed.
[0014]
At least one groove 41 is provided on the inner surface of the elastic cap 4. The groove 41 extends over the entire length of the elastic cap 4 from the distal end side to the proximal end side of the elastic cap 4, and preferably extends linearly in the axial direction of the needle tube 2. The groove 41 communicates with the inside of the needle tube 2 via the blade edge 22 on the proximal end side of the needle tube 2 and flows into the needle tube 2 when the blade edge 21 on the distal end side of the needle tube 2 is punctured into the blood vessel of the patient. The blood can flow from the blade edge 22 on the proximal end side of the needle tube 2 into the proximal end portion of the elastic cap 4 and further into the groove 41.
FIG. 3 is a cross-sectional view of the elastic cap 4 shown in FIG. As the shape of the groove 41, for example, one having a square cross section as shown in FIG. The size of the groove 41 shown in FIG. 3 is preferably a width of 0.1 to 1.0 mm and a depth of 0.05 to 0.5 mm, more preferably a width of 0.2 to 0.4 mm and a depth of 0.1 to 0.2 mm. The groove 41 may have a semicircular cross section in addition to the quadrangular cross section as shown in FIG. 3, or the lumen cross section itself of the elastic cap 4 may be partially connected to the needle tube 2. You may form in the ellipse which does not contact | connect.
The size and number of the grooves 41 are arbitrarily set within a range that does not impair the object of the present invention to minimize the internal volume of the elastic cap 4.
[0015]
The needle tube 2, the hub main body 33, and the elastic cap connection member 34 are assembled so as to form a passage 35 that allows the groove 41 provided on the inner surface of the elastic cap 4 to communicate with the external atmosphere. For example, as shown in FIG. 1, the passage 35 includes a gap between the elastic cap connecting member 34 and the needle tube 2, a gap between the needle tube 2 and the hub main body 33, a gap between the hub main body 33 and the elastic cap connecting member 34, and a hub. It is formed from a gap between the main body 33 and the elastic cap 4. The gap forming the passage 35 may be provided in the entire outer periphery of the needle tube 2 or may be provided in a part of the outer periphery of the needle tube 2 such as two in the vertical direction. The gap forming the passage 35 may be of a size that allows air and blood to pass through by venous pressure, but the cross-sectional area of the gap is preferably 10 ⁻² mm ² or more. The shape of the gap forming the passage 35 is not particularly limited, but is provided in a ring shape around the needle tube 2, and the difference between the outer diameter and the inner diameter of the ring is 0.05 mm or more. Is preferred.
[0016]
An air permeable blood impermeable filter 5 is disposed at the opening to the outside atmosphere of the passage 35. The air permeable blood impermeable filter 5 is cylindrical and has an arbitrary shape and size in accordance with the shape and size of the passage 35. The air permeable blood impermeable filter 5 is not particularly limited as long as it has pores that allow gas to pass but not liquid such as a membrane filter and a sintered filter, but preferably polyethylene, polypropylene, poly It is a sintered body made of methyl methacrylate, polystyrene, or the like, and more preferably contains a water-absorbing polymer that swells when contacted with blood and closes the pores of the sintered body. Examples of the water-absorbing polymer include starch and acrylate, and the content thereof is preferably 5 to 30% with respect to the total weight of the sintered filter.
In the blood collection needle 1 shown in FIG. 1, the filter 5 is disposed at the opening of the passage 35 by fitting three members, the hub main body 33, the elastic cap connecting member 34 and the elastic cap 4. On the other hand, the blood collection needle 1 of the present invention may have the hub 3 made of a single member as shown in FIG. 7, in which case the air permeable blood impermeable filter 5 is provided in the passage 35. It arrange | positions by welding to an opening part.
[0017]
As shown in FIG. 4, the blood collection needle 1 of the present invention is provided with an air reservoir 42 that does not directly communicate with the inside of the needle tube 2 but communicates with the passage 35 on the inner surface of the elastic cap 4. Good.
5 is a cross-sectional view of the elastic cap shown in FIG. 4 taken along line BB, and FIG. 6 is a cross-sectional view of the elastic cap shown in FIG. 4 taken along line CC. For example, as shown in FIGS. 4 to 6, the air reservoir 42 has a rectangular cross section extending in the axial direction of the needle tube 2 from the distal end side to the proximal end side except for the proximal end portion of the elastic cap 4. Grooves are raised. The shape of the air reservoir 42 is not particularly limited as long as the blood that has flowed into the needle tube 2 when the cutting edge 21 on the distal end side of the needle tube 2 is punctured into the blood vessel of the patient does not flow.
The air reservoir 42 is a portion into which blood whose pressure has increased due to compression of the elastic cap 4 can flow when the cutting edge 22 on the proximal end side of the needle tube 2 is inserted into the vacuum blood collection tube. By having the air reservoir 42, the blood collection needle 1 of the present invention has no risk of blood leaking from the air permeable blood impermeable filter 5 or the like when the vacuum blood collection tube is connected.
[0018]
The blood collection needle 1 of the present invention is used by piercing the patient's vein with the cutting edge 21 on the distal end side of the needle tube 2 in a state in which a holder (not shown) is screwed into the screw portion 32 of the hub 3. At this time, the air in the needle tube 2 passes through the groove 41 provided on the inner surface of the elastic cap 4 via the cutting edge 22 on the proximal end side of the needle tube 2 and flows into the passage 35 and then passes through the air permeable blood. It escapes to the outside through the permeable filter 5, and at the same time, blood flows into the needle tube 2. The blood that has flowed into the needle tube 2 passes through the groove 41 provided on the inner surface of the elastic cap 4 via the blade edge 22 on the proximal end side of the needle tube 2 and flows into the passage 35. The mouth is blocked by an air-permeable blood-impermeable filter 5. The blood collection needle 1 can confirm flashback by visually observing the blood flowing into the elastic cap 4 or the hub 3 from the outside.
[0019]
After confirming the flashback, the blood collection needle 1 of the present invention is configured such that the cutting edge 22 on the proximal end side of the needle tube 2 is inserted into the vacuum blood collection tube and blood flows into the vacuum blood collection tube at the same time as the blood collection is performed. The elastic cap 4 is compressed by a rubber stopper provided at the opening of the vacuum blood collection tube. The compression of the elastic cap 4 causes the blood in the groove 41 to increase in pressure and be pushed out into the passage 35. However, since the blood collection needle 1 of the present invention has a small internal volume, the blood whose pressure has increased. Therefore, there is no possibility that the air permeable blood impermeable filter 5 is damaged or blood leaks. Further, if the air reservoir 42 is provided on the inner surface of the elastic cap 4, a part of the blood in the groove 41 whose pressure is increased by the connection of the vacuum blood collection tube flows into the air reservoir 42. Furthermore, blood leakage can be prevented.
[0020]
【The invention's effect】
The blood collection needle of the present invention is easy to mold and manufacture because it is not necessary to form an air chamber inside the hub. Therefore, it is possible to provide a blood collection needle that is simple in structure and compact and easy to use for medical personnel. In addition, the blood collection needle of the present invention has no risk of blood leaking from an air permeable blood impermeable filter or the like when a vacuum blood collection tube is connected.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a blood collection needle of the present invention.
FIG. 2 is a longitudinal sectional view of an elastic cap of the blood collection needle shown in FIG.
FIG. 3 is a cross-sectional view of the elastic cap shown in FIG. 2 taken along line AA.
FIG. 4 is a longitudinal sectional view showing another embodiment of the elastic cap of the blood collection needle of the present invention.
5 is a cross-sectional view of the elastic cap shown in FIG. 4 taken along the line BB.
6 is a cross-sectional view of the elastic cap shown in FIG. 4 taken along the line C-C.
FIG. 7 is a longitudinal sectional view showing another embodiment of the blood collection needle of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Blood collection needle 2 Needle tube 21, 22 Cutting edge 3 Hub 35 Passage 4 Elastic cap 41 Groove 5 Air-permeable blood impermeable filter

Claims (5)

A needle tube having a sharp cutting edge at the distal end and the proximal end; a hollow tube externally inserted into the needle tube, the distal end of which is fixed to the needle tube; and a proximal end of the hub; An elastic cap having an inner diameter that can be in close contact with the surface and capable of liquid-tightly covering a portion of the needle tube that is exposed from the hub to the base end side; There is provided at least one groove communicating with the inside of the needle tube via the end edge, and a passage is formed in the hub for communicating the inside of the needle tube with the external atmosphere via the groove on the inner surface of the elastic cap. A blood collection needle in which an air permeable blood impermeable filter is provided at an external opening of the passage. The blood collecting needle according to claim 1, wherein the groove extends over the entire length of the elastic cap from the distal end side to the proximal end side of the elastic cap. The blood collecting needle according to claim 2, wherein the groove extends linearly in the axial direction of the needle tube. The blood collection needle according to any one of claims 1 to 3, wherein an air reservoir is provided on an inner surface of the elastic cap so as not to communicate directly with the inside of the needle tube but communicate with the passage. The blood collection needle according to claim 4, wherein the air reservoir extends linearly in the axial direction of the needle tube from the distal end side toward the proximal end side except for the proximal end portion of the elastic cap.

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