JPH0260659A - Body fluid filter device - Google Patents

Abstract

PURPOSE:To obtain the body fluid filter device which has a small priming volume and is reduced in size by constituting filtrate flow passages between the bag-shaped filtration films constituting the body fluid flow passages. CONSTITUTION:The body fluid filter device has the construction consisting in interposing plural sheets of the bag-shaped filtration films between filtrate flow passage forming bodies 5 or alternately stacking these films to provide the filtrate flow passages, housing these filtration films into the body case of the body fluid filter device provided with a body fluid inflow port 1, a body fluid outflow port 2 and a filtrate outflow port 3, and adhering a cap 10 via an O-ring 11 to the body case by ultrasonic sealing or adhesive agent. Each of the bag-shaped filtrate films 9 is formed by positioning two sheets of the filtration films 6 provided integrally with projecting parts on one surface so as to hold a diskshaped flat spacer 7 between the films in such a manner that the respective projecting parts face each other on the inner side and sealing the ends of the two filtration films to form the films to a bag shape. The bony fluid flow passages 21 are formed therein. The projecting parts have preferably 30 to 200mum, more particularly preferably 50 to 100mum height of the projecting parts. The flat plate spacer has preferably 10 Brinell hardness and 10 to 200mum thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a filtration device for separating body fluids, and particularly to a filtration device for filtering blood to separate blood cells and plasma.

[Prior Art] Conventionally, plasma separation devices for separating blood have been used in medical fields such as plasma exchange therapy. Centrifugal separators and membrane separators are known as such plasma separators, and membrane separators are particularly widely used because of their ease of equipment and operation. Typical membrane separation devices are hollow fiber type and flat membrane type, and compared to the hollow fiber type, the material of the filtration membrane can be selected from a wider range, the membrane is highly stable, and the filtration module is It has the advantage that the shape can be selected from a wide range and that a compact and high-performance plasma separation device can be designed.

As such a flat membrane type plasma separator, Japanese Patent Application Laid-open No. 57-1980
A filtration device having a structure in which a large number of porous filtration membranes formed in a bag shape with a support sandwiched between two porous membranes are stacked with a blood flow path regulating plate interposed between them, as disclosed in Publication No. 25857. It has been known. Although this structure can be made smaller by making the blood flow path regulating plate thinner, there is a limit to this. Therefore, as shown in Fig. 3, instead of the flow path regulating plate having the unevenness, unevenness is provided on the surface of the bag-shaped porous filtration membrane, and a large number of the bag-shaped filtration membranes are connected to each other through an extremely thin flat plate spacer. Attempts have been made to stack them. In this plasma separation device, blood flows in through a body fluid inlet 1 and is filtered through a bag-like filtration membrane, so that plasma flows out as a filtrate through a filtrate outlet, and an unfiltered solution flows out through a body fluid outlet 3. It's structured. However, such improvements are still insufficient.

In addition, when only plasma is collected during blood donation using a plasma separator, in order to ensure the safety of the donor and to prevent the separated plasma from being diluted with the briming solution, the blood side briming volume of the blood separator must be It is desirable to reduce the However, with the device having the above structure, it is difficult to reduce the blood side briming volume.

[Problems to be Solved by the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a miniaturized body fluid filtration device with a small briming volume.

[Means for Solving the Problems] The body fluid filtration device of the present invention includes a plurality of bags each having a body fluid outflow hole and a body fluid inflow hole in a filtration device body case provided with a body fluid inlet, a body fluid outlet, and a filtrate outlet. The body fluid inlet of the body case is communicated with the body fluid inlet of each bag-shaped filtration membrane, and the body fluid outlet of the body case is communicated with the body fluid outlet of each bag-shaped filtration membrane. In the body fluid filtration device, the bag-like filtration membrane is a bag-like filtration membrane that constitutes a body fluid flow path, and a filtrate flow path is configured between each bag-like a-filtration membrane.

In the body fluid filtration device of the present invention, body fluid flows directly from a body fluid inlet into a bag-like filtration membrane having a cavity for a body fluid flow path, and in this bag-like filtration membrane, the filtrate that has been filtered and comes out of the bag-like filtration membrane is passed through the body. It has a path through which the body fluid flows out through the filtrate outflow port of the case, and a path through which unfiltered body fluid flows out from the bag-like filtration membrane through the body fluid outflow port.

The bag-shaped filtration membrane is formed by interposing two filtration membranes each having a large number of protrusions on opposing surfaces with a flat spacer interposed so that both sides of the membranes are in contact with the protrusions.

The height of the protruding portion is preferably 30 to 200 μm, particularly preferably 50 to 100 μm. The height of this protrusion is an important factor that defines the thickness of the body fluid flow path. From the viewpoint of filtration engineering, if the height of the convex portion is less than 20 μm, the body fluid flow path becomes too thin and pressure loss tends to increase, and if it exceeds 200 μm, the shear rate cannot be increased. Therefore, there is a tendency that sufficient body fluid filtration cannot be obtained.

Although it is desirable that this height be constant, it is not necessarily limited, and the height may change stepwise along the flow direction of the body fluid.

Further, the distance between the individual convex portions on the surface of the filtration membrane is one of the important factors for forming a uniform and stable body fluid flow path. In other words, if the distance between the protrusions is less than 300 μm, the effective membrane area will decrease and the pressure loss will increase excessively, whereas if the distance between the convex portions exceeds 2000 μm, the membrane will be slightly distorted and bent, resulting in a uniform and stable membrane. It becomes difficult to secure a flow path for body fluids, and sufficient performance cannot be obtained. From this, the distance between the convex parts is preferably 300 to 2000 μm, particularly 500 to 2000 μm! 000 μm is preferred. The distribution state of the convex parts is
Although it is preferable that the thickness be uniform over the entire surface of the filtration membrane, it is not particularly limited as long as it does not inhibit the uniform flow of body fluids.

If the average diameter of the convex portion is less than 100 μm, it is difficult to support and form a uniform flow path, and if it exceeds 1000 μm, the occupied area tends to become too large.
0 to 1000 μm is preferable.

As for the manufacturing method of the filtration membrane with self-containing rooster-shaped parts, when forming the filtration membrane, the filtration membrane is formed on a metal roll in which the convex part pattern is carved as an intaglio, and the filtration membrane material is applied to the membrane surface. A method of forming convex portions made of the same material as , a method of applying resin to the concave portions of a metal roll in which the convex pattern is carved as an intaglio, and irradiating this onto a smooth filter membrane, or a screen printing plate. Examples include a method in which a convex pattern is printed on a smooth filtration membrane using an ultraviolet ray or electron beam curable resin, and then the pattern is cured by irradiation with ultraviolet rays or an electron beam, but there are no particular limitations. It is not something that will be done.

The flat spacer is preferably hard in order to ensure a uniform and stable body fluid flow path. The hard material here means that when it comes into contact with the protrusions on the membrane surface,
This refers to a material that virtually does not cause deformation such as denting, and has a Brinell hardness of 10 or more. Materials with Brinell hardness in this range include polyethylene, polypropylene,
Polyester, polycarbonate, etc. are preferred.

The Brinell hardness is determined by the following formula according to JIS 22243.

π Dh HB: Brinell hardness (Kg/B2) p: Weight of n4 ball (K9) D = Diameter of steel ball (a) d: Diameter of hollow (am) h: Depth of hollow (rut) If the thickness of the flat flow path regulating body is less than 10 μm, it is difficult to support and form a uniform body fluid flow path, and if it exceeds 200 μm, the device tends to become larger.
The thickness is preferably 0 to 200 μm, particularly preferably 20 to 60 μm.

Materials used for this flat spacer include body fluids,
Particularly preferred are polyethylene, polypropylene, polyester, polycarbonate, etc., which have excellent compatibility with blood.

[Function] Since the body fluid inflow path, which was conventionally provided outside the bag-like filtration membrane, is provided inside the bag-like filtration membrane as the body fluid flow path /lt1 in the body fluid filtration device of the present invention, The routes of body fluids within the device differ as follows. That is, in the conventional body fluid filtration device, body fluid first flows into a body fluid inflow path provided outside the bag-like filtration membrane, and then in the filtration membrane, the filtered filtrate passes through the bag-like a-filtration membrane and the filtrate outflow port. While the unfiltered body fluid is discharged through the body fluid outlet channel and the body fluid outlet. In contrast, in the body fluid filtration device of the present invention, the body fluid first flows from the body fluid inlet into the body fluid inlet path inside the bag-like a-filtration membrane, and then the filtrate filtered by the filtration membrane is transferred to the filtrate flow path and the filtrate outlet. , while unfiltered body fluid flows out through the body fluid channel and the body fluid outlet.

Furthermore, in the present invention, the briming solution such as physiological saline, which is conventionally filled outside the bag-like filtration membrane in the main body case, is filled inside the bag-like filtration membrane, so its volume is reduced.

[Example] EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples.

FIG. 1 is a diagram showing the configuration of a separation device according to an embodiment of the present invention, and FIG. 2 is a sectional view thereof. In FIGS. 1 and 2, the body fluid filtration device includes a body fluid inlet 1 and a body fluid outlet 2.
A plurality of bag-shaped filtration membranes are stacked alternately with a filtrate flow path forming member 5 interposed therebetween, and a filtrate flow path is provided and stored in a body fluid filtration device main body case 20 in which a filtrate outlet 3 is provided. However, it has a structure in which the lid 1o is bonded via an O-ring 11 by ultrasonic sealing or adhesive.

The bag-like filtration membrane 9 includes two filtration membranes 6 each having a protrusion integrally provided on one side, with a circular flat spacer 7 sandwiched between the two filtration membranes 6 so that the protrusions face each other inwardly. The ends of both filtration membranes are sealed to form a bag.
A body fluid flow path 21 is formed inside thereof. The filtrate channel forming body 5, the filtration membrane 6, and the flat spacer 7 are respectively a body fluid inflow hole 5a, a 6a, and a body fluid outflow hole 5b, 6b.

7b. The peripheral edges of each body fluid inflow hole and body fluid outflow hole are sealed and communicated with a sealing agent 8, for example, a hot melt adhesive, and the body fluid inflow path 12 and the body fluid outflow path 1 are connected to each other.
3 is formed.

The body fluid filtration M6 has an average pore diameter of 0.6 μm and a membrane thickness of 130
A predetermined pattern of ultraviolet curable resin (manufactured by Dainippon Ink Co., Ltd., product name: Daicure MV) is printed on one side of a μm polypropylene porous flat membrane using a screen plate, and the filtration membrane is immediately irradiated with ultraviolet rays. By curing the resin pattern, the height is 70 μm and the bottom diameter is 300 μm.
Uniform convex portions with an interval of 750 μm and an occupied area of 15% are formed.

The body fluid flow path forming body 5 is made of polypropylene nonwoven fabric having a basis weight of 215 g/m2, a wire diameter of 3 denier, and a thickness of 150 μm.
It is used in layers.

Further, as the flat plate spacer, a biaxially stretched polypropylene film having a thickness of 60 μm is used.

The filtration device main case 20 has a diameter of 108mm and a thickness of 6.5cm.
M, and the number of laminated bag-like filtration membranes 9 is 11. Also,
The filtration membrane 6 and body fluid channel forming body 5 have a diameter of 1041 m, and the flat spacer has a disc shape with a diameter of 968 m. On the other hand, the dimensions of the conventional product used as a comparative example are that the body fluid filtration device body case 20 has a diameter of 106 run and a thickness of 6.5 m, the filtration membrane 6 has a diameter of 104 m, a central opening diameter of 22 am, and a flat plate shape. The spacer has a diameter of 104B.

Its central opening has a diameter of 22 m, and the body fluid flow path forming body has a diameter of 98 fl and a central opening of 30 mm.

The briming volume of the body fluid filtration device of the present invention having the above shape was 13111, whereas the briming volume of the comparative example was 18M.

Furthermore, a filtration experiment of ACD and heparinized blood (hematocrit 40%) was conducted using this body fluid filtration device. Heparinized blood flows into the filtration device at a flow rate of 50 m/min, and the height of the filtrate outlet is adjusted so that the pressure of the solution at the body fluid outlet and the filtrate outlet is equal, and the filtrate outflow amount for one minute is measured. As a result, Comparative Example 20xtl 1 minute, Example 22ml
1 minute, the device of the present invention showed superior body fluid separation performance compared to the conventional device.

[Effects of the Invention] The body fluid filtration device of the present invention can reduce the amount of priming solution on the body fluid side compared to conventional body fluid filtration devices without deteriorating its performance, thereby improving safety. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a body fluid filtration device according to an embodiment of the present invention, FIG. 2 is a sectional view of a body fluid filtration device according to an embodiment of the present invention, and FIG. 3 is a diagram showing a conventional example. 1 is a cross-sectional view of the body fluid filtration device shown in FIG. DESCRIPTION OF SYMBOLS 1... Body fluid inlet, 2... Body fluid outlet, 3... Filtrate outlet, 7... Flat spacer, 9... Bag-shaped filtration membrane, 20... Filtration device main body case

Claims (4)

[Claims] (1) A plurality of bag-shaped filtration membranes each having body fluid inflow holes and body fluid outflow holes are stacked and housed in a filtration device body case provided with a body fluid inlet, a body fluid outlet, and a filtrate outlet. A body fluid filtration device in which the body fluid inlet of the membrane and the body fluid inlet of the main body case are communicated, and the body fluid outlet of each bag-shaped filtration membrane and the body fluid outlet of the main body case are communicated, wherein the bag-shaped filtration membrane is A body fluid filtration device characterized in that a body fluid flow path is formed inside the body fluid filtration device, and a filtration flow path is formed between each bag-like filtration membrane. (2) The bag-shaped filtration membrane is formed by interposing two filtration membranes having a plurality of protrusions integrally on opposing surfaces with a flat spacer interposed so that both sides of the membranes are in contact with the protrusions. The body fluid filtration device according to claim 1. (3) The body fluid filtration device according to claim 2, wherein the height of the convex portion of the protruding portion is 30 to 200 μm. (4) The body fluid filtration device according to claim 3, wherein the flat spacer has a Brinell hardness of 10 or more and a thickness of 10 to 200 μm.