JPS644331Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a plasma collector, and particularly to a plasma collector for efficiently obtaining plasma for blood tests.

Conventionally, as a method for collecting plasma components for blood tests, a method of centrifuging collected blood has been used. However, this method requires a long time to separate plasma, is not applicable to the blood of patients with hemolytic diseases, and has drawbacks such as the inability to return separated and removed blood cell components to the body. Furthermore, as described in Japanese Utility Model Application Publication No. 51-162582, a simple plasma collector is also known, which selectively extracts only plasma components by installing a filter member inside the syringe barrel or between the syringe barrel and the syringe needle. There is. However, since this plasma collector also collects plasma components after taking blood out of the body, blood cell components that do not pass through the membrane cannot be returned to the body, and the piston of the syringe forcefully collects plasma components by suction. Therefore, careful manipulation was required to prevent hemolysis. Furthermore, as seen in Utility Model Application Publication No. 55-40860, a blood sampling port was created by removing part of both sides of the tip of the injection needle, and a tube with a closed tip and through which plasma components passed was inserted into the injection needle. A plasma collector is known in which only plasma components are selectively extracted from blood using a suction device provided at the rear end of a tube. Although this plasma collector has the advantage of being able to selectively collect only the plasma component from the blood, it also has the advantage of forcibly collecting plasma components by suction using the piston of the syringe. Careful operation was required.

The present invention improves these drawbacks by attaching filters to the tip and rear openings of the cannula, providing a plasma component outlet at the rear end of the filter, and forming a cannula formed by the two filters. The inside of the cannula is filled with a fibrous material that separates plasma components from blood using capillary action, and the blood introduced into the cannula through a filter attached to the opening at the tip of the cannula is separated into blood cells using the fibrous material. This plasma collector is characterized in that it separates plasma components into blood plasma components and blood plasma components, and allows the separated plasma components to flow out from a plasma component outlet at the rear end of the cannula.

According to the plasma collector of the present invention, since plasma components are collected using the capillary action of the fibrous material filled in the cannula, the piston of the syringe barrel,
No forced suction using a vacuum container, etc. is required. Therefore, there is no need to worry about hemolysis of blood cell components. Furthermore, since plasma components are collected with the cannula introduced into the blood vessel, the amount of blood cell components that are discarded can be reduced.

Next, an embodiment of the plasma collector of the present invention will be explained with reference to the drawings. FIG. 1 is a cross-sectional view of a plasma collector, in which filters 4 and 6 are attached to the tip and rear openings of the cannula 3.
The inside of the cannula formed by 6 is filled with fibrous material 5. The filter 4 attached to the opening at the tip of the cannula is intended to prevent the fibrous material filled inside the cannula from flowing out into the blood vessels. It can be anything. Further, the filter 6 attached to the rear end opening of the cannula is usually the same filter as the filter 4, for example, a mesh body made of polyester or the like. A plasma component outlet 7 is provided at the rear end of the cannula.

The fibrous material used in the present invention has the role of moving only plasma components to the outlet 7 by capillary action, and also has the role of a filter that separates blood into blood cell components and plasma components. The shape of the fibrous material may be any shape as long as it fulfills these two roles, and examples thereof include long fibers, short fibers, nonwoven fabrics, and woven fabrics. Among these, short fibers and long fibers are preferably used. Although it is preferable that the fibrous material is densely packed in the cannula 3, it is not necessary to fill the cannula 3 densely, as long as the fibrous material is filled to the extent that a desired amount of plasma components can be taken out. It is necessary to select a material for the fibrous material that has little blood adhesion and does not cause blood coagulation. Examples include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, regenerated cellulose, cellulose acetate, polyacrylonitrile, and polyester. It is also possible to use these fibrous materials that have been surface-treated with a hydrophilic acrylic resin (for example, polyhydroxyethyl methacrylate polymer) that has high blood affinity.

As the cannula 3, an ordinary conduit made of polyethylene or polypropylene can be used, but since the cannula is introduced into a blood vessel, it is necessary to select a material that has little blood adhesion and does not cause blood coagulation.

Next, another embodiment of the present invention will be explained with reference to FIG. FIG. 2 shows a filter to be attached to the opening at the tip of the cannula 3, in which a hollow fiber membrane 8 having a large number of holes 9 in the membrane wall is joined to the opening at the tip of the cannula, and the cannula and the hollow fiber membrane are communicated with each other. Further, the tips of the hollow fibers are closed with epoxy resin 10 or the like to prevent the fibrous material 5 from flowing out into the blood. The micropores 9 provided in the hollow fiber membrane 8 may have a size that allows blood to freely flow in and out. The length of this hollow fiber membrane cannot be determined unconditionally since it varies depending on the amount of plasma components to be collected, but it is 5 mm to 20 cm, preferably 1 to 15 cm. Furthermore, it is necessary to select a material for the hollow fiber membrane that has little blood adhesion and does not cause blood coagulation. For example, materials similar to those of the fibrous material described above can be used. Hollow fiber 8 and cannula 3 are bonded with various adhesives,
Usually, they are fixed and communicated with an adhesive having excellent blood affinity (for example, a silicone adhesive or a cyanoacrylate adhesive).

Next, a method for collecting plasma components from blood using the plasma collector shown in FIG. 1 will be explained with reference to FIG. 3. First, the injection needle 1 is punctured into the blood vessel 10, and an adhesive tape (not shown) is placed on the fixing device 2 provided at the end of the injection needle 1 to fix the injection needle to the body surface.
Next, the cannula 3 is gently inserted into the injection needle, and its tip is positioned within the blood vessel and left as is for a while. Then, the blood introduced into the cannula is separated by the capillary action of the fibrous material 5 and flows out from the outlet 7. Plasma components flowing out from the outlet 7 attached to the rear end of the cannula 3 are collected into a collection container (not shown) or the like. When the collection of the desired plasma component is completed, the cannula 3 is removed from the injection needle 1, and then the injection needle 1 is removed from the blood vessel, thereby completing the collection of the plasma component. Through such operations, only plasma components can be easily collected without causing hemolysis or loss of blood cell components.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the plasma collector of the present invention, FIG. 2 is a longitudinal sectional view showing another example, and FIG. 3 is a cross-sectional view of the plasma collector of the present invention. It is a sectional view showing a state of use. 1... Syringe needle, 2... Fixture, 3... Cannula, 4... Filter, 5... Fibrous material, 6...
Filter, 7... Outlet, 8... Hollow fiber membrane, 9... Hole.

Claims (1)

[Scope of utility model registration request] Filters are attached to the tip and rear openings of the cannula, and a plasma component extraction port is provided at the rear end of the cannula. The cannula is filled with a fibrous material that separates plasma components, and the cannula is introduced into the blood vessel through an injection needle punctured into the blood vessel, and the cannula is introduced into the cannula through a filter attached to the opening at the tip of the cannula. 1. A plasma collection device characterized by separating collected blood into blood cell components and plasma components using a fibrous material, and causing the separated plasma components to flow out from a plasma component outlet at the rear end of a cannula.