JPS6348309B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid collection tube used for blood analysis and the like. Body fluids and blood contain many substances such as blood cells, platelets, lymphocytes, various proteins, hormones, lipids, sugars, amino acids, vitamins, and salts. However, blood substances that are generally measured in blood analysis are only a small portion of these substances, and the rest are not only of little use but, in many cases, actually interfere with the measurement.

Conventionally, in the case of blood analysis, substances that would interfere with the measurement were removed from the collected body fluids or blood by centrifugation, filtration, serum separation, protein removal, etc. before the measurement was performed. was, but
The drawback was that it was very complicated and required a lot of cost and effort.

Therefore, the inventors conducted intensive research to overcome the above-mentioned drawbacks, and found that by placing a small-diameter pipe equipped with a selectively permeable membrane at the tip opening into a blood vessel, etc., it is possible to easily obtain the necessary fluid. It was discovered that it is possible to collect

Accordingly, a general object of the present invention is to provide a means for easily collecting body fluids and blood, which do not contain any extraneous substances, directly from a living body.

The main objects of the present invention are: a small diameter pipe having both ends open and one opening covered with a thin film having selective perms; a two-part metal needle longer than the narrow diameter pipe;
The object of the present invention is to provide a liquid collection tube with a plastic sheath for holding the two-part metal needle together.

In addition, if the thin membrane with selective permeability does not allow red blood cells, white blood cells, and platelets to pass through, but allows substances of a smaller size to pass through, only plasma components can be smoothly collected from blood. It is suitable.

In addition, thin films with permselectivity are fibrin,
It is preferable to use a material that does not allow fibrinogen to pass through, but allows a substance with a molecular weight smaller than that of fibrin and fibrinogen to pass through, since it is possible to collect a serum sample that does not contain fibrin or fibrinogen.

It is preferable that the selectively permeable membrane does not allow albumin to pass therethrough, but allows a substance with a molecular weight smaller than albumin to pass therethrough, since a protein-free serum sample can be collected.

Next, an embodiment of the liquid collection tube according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a small-diameter pipe 2 according to the present invention, which has a thin film 1 having permselectivity at its tip opening. This selectively permeable membrane is used to screen out unnecessary organic components in body fluids and blood, and its substance permeability is determined by the physicochemical material of the membrane, but it also depends on the pore size. can also be used as a standard. For example, when collecting only plasma components, a pore size of 0.1 to 1.0 μm is effective for a membrane that does not allow blood cells and platelets to pass through, and when a serum sample that does not contain fibrin or fibrinogen is required, a pore size of 0.05 is effective. ~
A pore size of 0.2 μm and a membrane that does not allow albumin to pass through have a pore size of 30 nÅ or less, respectively.
To collect the fluid, place the distal end with this membrane in the blood vessel or subcutaneously, and apply negative pressure to one open end 5 with a pump or the like, and the pressure difference will cause the fluid to flow through the membrane. It oozes out from the blood vessel into the collection tube.

Although it depends on the site where it is placed, it is desirable that the outer diameter of the small diameter pipe to be placed is φ2 mm or less. 1st
As shown in the figure, only the part to be placed in the living body is made thinner,
It doesn't matter if the suction port on the opposite side is thicker.

FIG. 2 is an exploded view of one embodiment of the aid according to the present invention, which is used when puncturing and indwelling a small-diameter pipe into a blood vessel or subcutaneously in a living body. Two split metal needles 6, 6' longer than the pipe are attached to the outer periphery of the small diameter pipe 2.
It has plastic sheaths 7, 7' on its outer periphery for holding the two-part metal needle together. FIG. 3 shows a state in which the collection tube set of FIG. 2 is integrated and punctured into the blood vessel 9. After puncturing, the sheaths 7, 7' can be torn into pieces by pulling the plastic sheath tabs 8, 8' outward, respectively. When the metal needles 6, 6' are divided into two parts and pulled out, only the inner small-diameter pipe 2 remains in the vessel, as shown in FIG. According to this method, no pressure is applied to the membrane at the tip of the small-diameter pipe during puncturing, so the membrane does not tear.

There is no particular limitation on the method of blocking the opening of a small diameter pipe with the permselective thin film used in the present invention. A method of adhering a membrane from the outside or from the outside of a small diameter pipe, O
Possible methods include sandwiching the tube between rings or the like, or molding the pipe and membrane integrally from the same material and drilling a hole of a desired diameter at the tip.

The membrane is preferably installed at the tip of the small diameter pipe as much as possible. If a body fluid stagnates on the outside of the membrane, the membrane will become clogged and performance will be reduced, so a structure in which the outside surface of the membrane is washed by the flow of body fluid in the blood vessels is preferable.

The material of the small diameter pipe is preferably a material that does not easily cause blood coagulation, such as polyethylene, polypropylene, polysulfone, Teflon, silicone, etc.

According to the liquid collection tube according to the present invention, only the components necessary for blood analysis can be easily collected from blood or the like.

This liquid collection tube can be used not only for measuring blood substances, but also for various other purposes. For example, if a main fluid collection tube is used during blood donation, it will become possible to donate blood in which only plasma is collected.

[Brief explanation of the drawing]

FIG. 1 shows a sectional view of a small diameter pipe according to an embodiment of the present invention. FIG. 2 shows an embodiment of an auxiliary device for puncturing a living body and a collection tube main body. FIG. 3 shows a state in which the liquid collection tube is punctured into a living body. FIG. 4 shows a state in which the puncturing aid is removed after puncturing. 1...Selective permselective thin film, 2...Small diameter pipe, 9
...vascular vessels.

Claims (1)

[Scope of Claims] 1. A small-diameter pipe with both ends open and one opening covered with a permselective thin film, a two-part metal needle longer than the small-diameter pipe, and the two-part metal needle integrated into one body. A liquid collection tube characterized in that it has a plastic sheath for retention. 2. A thin film with selective permeability is used for red blood cells, white blood cells,
2. The liquid collection tube according to item 1, which does not allow passage of platelets but allows passage of substances of a smaller size. 3. The liquid collection tube according to item 1, wherein the permselective thin membrane does not allow fibrin or fibrinogen to pass through, but allows a substance with a molecular weight smaller than fibrin or fibrinogen to pass through. 4. The liquid collection tube according to item 1, wherein the thin membrane having permselectivity does not allow albumin to pass therethrough, but allows a substance with a molecular weight smaller than albumin to pass therethrough.