JPH0513455U - Body fluid filter - Google Patents

Abstract

(57) [Abstract] [Purpose] A hemofiltration device capable of preventing deformation of the housing itself without increasing the thickness of the housing and thereby not reducing the filtration efficiency even if the internal pressure inside the housing rises. To provide. A blood filtering device (1) having a filter medium (3) housed in a housing (2) having a blood inlet (2a), a plasma outlet (2b) and a blood outlet (2c), the housing (2) having a bottomed tubular shape. A space A for accommodating the filter medium 3 is formed between the first casing member 21 and the first casing member 22, and the first casing member 21 and the second casing member 22 are held so as to keep the space A liquid-tight. Are fixed, and the first casing member 21 and the second casing member 22 are fixed at their peripheral portions and at central portions provided apart from the peripheral portions, respectively. Hemofiltration device.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a body fluid filtering device. More specifically, the present invention relates to a body fluid filtration device represented by a blood filtration device that separates blood fluid into plasma and blood cells with a filter medium.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, a hemofiltration device for separating blood into plasma and blood cells by a filter medium has been disclosed.

The structure of a conventional hemofiltration device is shown in FIG.

That is, in the blood filtering device 100, the lid 112 is inserted and fixed to the cylindrical body 111 having the blood inlet 114a, the blood outlet 114b, and the plasma outlets 114c and 114c via the O-ring 113. In the housing 114, a plurality of membrane units 118 including a filtration membrane 117 with protrusions and a plasma flow channel forming member 116 for forming a plasma flow channel, and a blood flow channel between these membrane units 118 are secured. It is configured to accommodate a plurality of flow path restricting bodies 120.

[0005]

[Problems to be solved by the device]

 However, the above-described hemofiltration device 100 is configured such that the housing 114 is simply inserted into and fixed to the cylindrical body 111 with the lid 112 via the O-ring 113. Therefore, when the internal pressure inside the housing 114 rises, the housing 114 itself is deformed and the filtration efficiency is extremely lowered. It is also possible to increase the wall thickness of the housing 114 in order to prevent the deformation of the housing 114 itself, but in that case, the device itself becomes large, which causes a problem in operability. It was

Therefore, according to the present invention, the deformation of the housing itself can be prevented without increasing the wall thickness of the housing, and thus the filtration efficiency does not decrease even if the internal pressure inside the housing rises. The purpose is to provide a device.

[0007]

[Means for Solving the Problems]

 The present invention which solves the above problems has the following configurations (1) to (3). (1) A body fluid filtering device in which a filter medium is housed in a housing having a body fluid inlet, a filtrate outlet, and a body fluid outlet, wherein the housing includes a first casing member having a bottomed tubular shape, and A space for containing the filter medium is formed between the first casing member and the first casing member, and the first casing member and the second casing member are fixed so as to keep the space liquid-tight. The second casing member is a hemofiltration device characterized in that the peripheral portions thereof and the central portion provided apart from the peripheral portion are fixed.

(2) A first protrusion is formed at or near the center of the second casing member, and the first protrusion is provided at or near the center of the bottom of the first casing. The bodily fluid filter according to item 1, wherein a second convex portion that can be fitted is formed, and the central portion or the vicinity thereof is fixed by fitting the first convex portion and the second convex portion. Over device.

(3) The second casing member has a bottomed tubular shape, a third convex portion is formed on the outer surface of the side wall thereof, and the third casing is formed on the inner surface of the side wall of the first casing member. A fourth convex portion that can be fitted with the third convex portion is formed, and by fitting the third convex portion and the fourth convex portion, the first casing and the second casing are made liquid-tight via a seal member. The body fluid filtering device according to item 1 or 2, which is configured to be fixed.

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 and 2.

FIG. 1 is a longitudinal sectional view showing a structure of a plasma filtration device according to a preferred embodiment of the present invention, and FIG. 2 is a transverse sectional view taken along the line A-A ′ in FIG.

That is, the plasma filtration device 1 according to the present embodiment comprises a filter medium 3 housed in a housing 2 having a blood inlet 2a, a plasma outlet 2b and a blood outlet 2c. A space for accommodating the filter medium 3 is formed between the first casing member 21 having a bottom cylindrical shape and the first casing member 21, and the first casing member 21 and the first casing member 21 are arranged so as to keep the space liquid-tight. The second casing member 22 is fixed, and the first casing member 21 and the second casing member 22 are fixed at their peripheral edge portions and the central portion provided apart from the peripheral edge portion. It is characterized by.

As the material forming the housing 2, synthetic resins such as polypropylene, polycarbonate, polystyrene, polymethylmethacrylate, and metals such as glass and stainless can be used, but polypropylene and polycarbonate that can be autoclaved and are easy to handle. Particularly preferred.

As shown in FIG. 1, the filter medium 3 housed in the housing 2 is composed of a bag-shaped filter membrane 31 with protrusions and a plasma channel forming body 32 housed inside the filter membrane 31. It is composed of a plurality of membrane units 33 and a plurality of spacer plates 34 which are interposed between the plurality of membrane units 33 and form blood flow paths.

More specifically, the filter medium 3 has a circular plasma flow path forming body 32 including a screen mesh having an opening 35 in the center and a filtered plasma passage hole 36 in the vicinity of the peripheral edge, which is formed on the blood flow path side. The membrane unit 33 is obtained by sandwiching the upper and lower circular filtration membranes 31, 31 having a large number of microprotrusions, and sealing the peripheral edge thereof, and the filtered plasma passage hole 36 corresponding to the membrane unit 33. The spacer plates 34 having the above-mentioned structure are alternately arranged. The membrane unit 33 and the spacer plate 34 are integrally fixed by a sealing material 37. In the figure, the filter medium 3'accommodated on the right side does not have the filtration plasma passage hole 36, and has a structure in which the membrane units 33 and the spacer plates 34 are alternately arranged.

As the filter membrane 31 constituting the filter medium 3, a cellulose ester such as an organic acid ester such as cellulose nitrate or cellulose acetate, a synthetic resin membrane such as polypropylene, polyethylene, or polycarbonate is subjected to a phase separation method, an extraction method, a stretching method, The film is formed by a known method such as a charged particle irradiation method and has an average pore size of about 0.1 to 1 μm.

The height of the fine protrusions of the filtration membrane 31 is preferably 20 to 200 μm, and the ratio of the fine protrusions to the entire membrane area 31 is preferably 3 to 20%.

As a method of forming such fine protrusions on the membrane, when the filtration membrane 31 is manufactured, the filtration membrane 31 is formed on a metal roll in which the convex portion pattern of the fine protrusions is engraved as an intaglio plate, and the filtration membrane 31 is filtered. A method of forming protrusions of the same material as the membrane 31 itself, a method of filling resin into the concave portions of a metal roll engraved with the convex pattern as an intaglio and transferring this onto the filtration membrane 31, or a screen printing plate A method of printing a convex pattern on the filter membrane 31 using an ultraviolet or electron beam curable resin and then irradiating it with ultraviolet rays or an electron beam to cure the resin can be used.

The spacer plate 34 is preferably made of a material having a Brinell hardness of 10 or more. Examples of such a material include polyethylene, polypropylene, polyester and polycarbonate. Further, the thickness of the spacer plate 34 is preferably about 10 to 200 μm.

The configuration of the filter medium 3 is not limited to the above-mentioned configuration, and for example, minute protrusions may be formed on the upper and lower surfaces of the spacer plate 34 and the minute protrusions may not be provided on the filtration membrane 31.

Thus, the housing 2 forms a space A for accommodating the filter medium 3 between the first casing member 21 having a bottomed cylindrical shape and the first casing member 21, and the space A is filled with liquid. The second casing member 22 is fitted to the first casing member 21 so as to hold it tightly.

At the bottom of the first casing member 21, a blood inflow port 2 a, a plasma outflow port 2 b communicating with the filtered plasma passage hole 36, and blood containing blood cell components that have not passed through the filter medium 3 flow out. A blood outlet port 2c is formed for this purpose.

Around the blood inlet 2 of the first casing member 21, as shown in FIG. 2, a plurality of first convex portions 21a to 21a radially arranged with the blood inlet 2a as a center. 21d is formed.

The tips of the first convex portions 21a to 21d are formed with first taper portions 211a to 211d so as to facilitate fitting with the second convex portions 22a to 22d of the second casing member 22, which will be described later. Has been done.

Further, at the base end of each of the first tapered portions 211a to 211d, a first fitting is made so as to be able to be fitted to each of second fitting portions 222a to 222d of each of second convex portions 22a to 22d described later. Joint parts 212a to 212d are formed,

The second casing member 22 has a cylindrical shape with a bottom that is slightly smaller than the first casing member, and the second convex portion 21 a to 21 d that can be fitted to the center of the inner bottom portion of the second casing member 22. The convex portions 22a to 22d are formed.

The tips of the respective second convex portions 22a to 22d are formed into second taper portions 221a to 221d so as to be easily fitted into the respective second convex portions 21a to 21d of the first casing member 21. Has been done.

Further, at the base ends of the second taper portions 221a to 221d, the second fitting portions 212a to 212d of the second convex portions 22a to 22d are fitted with the second fitting portions so that they can be fitted together. Parts 222a to 222d are formed,

Therefore, the first convex portion 21a and the second convex portion 22a (fitting portion a), the first convex portion 21b and the second convex portion 22b (fitting portion b), the first convex portion 21c and the second convex portion. The first casing member 21 and the second casing member 22 are formed by fitting the portion 22c (fitting portion c) and the first convex portion 21d and the second convex portion 22d (fitting portion d) in a wedge shape. Are fitted and fixed at their central portions.

The blood flowing in from the blood inlet 2 is supplied to the filter medium 3 through the fitting parts a to d.

Next, the fitting of the peripheral portion of the housing will be described.

An annular third convex portion 21e is formed in the vicinity of the peripheral edge portion of the first casing member 21, and the tip of the third convex portion 21e has a fourth convex portion 22 of the second casing member, which will be described later. The third taper portion 211e is formed so as to be easily fitted with e.

A third fitting portion 212e is formed at the base end of the tapered portion 211e so as to fit with a fourth fitting portion 222e of a fourth convex portion 22e described later.

In the vicinity of the peripheral edge of the second casing member 22, a fourth convex portion 22e that can be fitted with the third convex portion 21e is formed.

The tip of the fourth convex portion 22e is formed as a fourth tapered portion 221e so that the fourth convex portion 22e can be easily fitted into the third convex portion 21e of the first casing member 21.

A fourth fitting portion 222e is formed at the base end of the fourth tapered portion 221e so as to fit with the third fitting portion 212e of the third convex portion 21e.

Therefore, by fitting the third convex portion 21e and the fourth convex portion 22e in a wedge shape, the tip end of the side wall of the second casing member 22 is inserted through the 0-ring 4 made of silicone or the like. It is configured to be in close contact with the inner bottom surface of the first casing member 21. As a result, the first casing member and the second casing member are liquid-tightly fitted at their peripheral portions.

As described above, in the body fluid filtering device according to the present invention, since the first casing member 21 and the second casing member 22 are fixed near the central portion and the peripheral portion, the internal pressure inside the housing 2 is reduced. Even if it rises, the deformation of the housing 2 itself can be prevented, and thus the filtration efficiency is not reduced.

In the present invention, the method of fixing the first casing member 21 and the second casing member 22 is not limited to the fitting of the convex member and the convex member. You may use the fitting by.

Further, the side walls of the first casing member 21 and the second casing member 22 are adhered to each other, and a convex portion is formed at the center of the inner bottom portion of each of the first casing member 21 and the second casing member. Fixing may be performed by adhering the tips of the parts together. Examples of such an adhesion method include ultrasonic fusion, high frequency fusion, heat fusion, and organic solvent adhesion. As the material of the housing 2, it is necessary to apply the material according to each of the above-mentioned bonding methods.

Further, the positions where the respective first convex portions 21a to 21d and the respective second convex portions 22a to 22d are provided do not necessarily have to be provided in the central portion of the respective casings, and even if they are in the vicinity thereof, they are substantially disposed. The same effect can be obtained.

Further, although the present embodiment has been described on behalf of a hemofiltration device, the present invention is not limited to this, and if the body fluid is treated with a filter medium, for example, an artificial dialyzer or the like. Can also be applied to.

Next, the present invention will be described in detail by showing examples.

[0044]

【Example】

 Example The body fluid filtration device shown in FIG. 1 was produced as follows.

On the blood contact surface of a polypropylene flat membrane having an average pore diameter of 0.6 μm and a film thickness of 130 μm, an ultraviolet curable resin (Dainippon Ink and trade name Daikya MV) was used in a predetermined manner using a screen plate. The pattern was printed, and the resin was immediately cured by irradiating the filter membrane with ultraviolet rays to form minute projections having a height of 70 μm and an area occupancy of 15% on the filter membrane.

A polypropylene non-woven fabric (Mitsui Petrochemical; PK-103) was used as the plasma flow path forming body, and the filtration membrane was formed into a bag shape by heat sealing (140 ° C., 2 seconds). A plasma channel forming body was housed to prepare a membrane unit.

As the spacer plate, a polypropylene plate having a Brinell hardness of 40 (outer diameter 102 mm, thickness 50 μm) was used, which was interposed between the membrane units and fixed using a hot melt adhesive as a sealing material. It was The central opening was set to 22 μm. Then, these are housed inside a first casing shown below, and the second casing is fitted with an O-ring made of silicone rubber interposed therebetween to make the inside of the housing liquid-tight, and A plasma filtration device was manufactured. The effective membrane area of this plasma filtration device was 0.16 mm ² .

First casing: Polycarbonate bottomed cylinder (thickness 3 mm) Inner bottom diameter 106 mm, depth 7 mm Blood inlet diameter φ4.0 mm Plasma outlet diameter φ2.5 mm Blood outlet diameter φ3.5 mm <First convex portion > Thickness 1.25 mm Angle of taper part is about 30 ° Four pieces are arranged at intervals of 30 ° on the circumference of 15 mm in diameter centered on the blood inlet. <Third convex portion> Thickness 2.00 mm Angle of taper portion is about 30 ° Arranged on a circle having a diameter of 108 mm around the blood inlet. Second casing: Polycarbonate bottomed cylinder (thickness 3 mm) Inner bottom diameter 110 mm, depth 11 mm <Second protrusion> Thickness 1.00 mm Tapered part angle approx. 28 ° Diameter centered on blood inlet Four pieces are arranged at intervals of 30 ° on the circumference of 19 mm. <Fourth convex part> Thickness 2.00 mm Angle of taper part is about 26 ° Arranged on the circumference of 111 mm in diameter centered on the blood inlet.

[Comparative Example] The same casing as that of the example was used except that the first casing did not have the first convex portions, and the second casing did not have the third convex portions. Using the same as in Example, a plasma filtration device having only the peripheral edge fixed was obtained. The filter medium used was the same as in the practical example. The effective membrane area of this plasma filtration device was 0.16 mm ² .

The following experiments were conducted using the plasma filtration devices of Examples and Comparative Examples.

<Water Pressure Resistance Test> The plasma outlet and the blood outlet of the plasma filtration devices of Examples and Comparative Examples were closed, physiological saline was poured from the blood inlet to change the water pressure inside the housing, The change in the thickness of the housing itself was measured. The results are shown in Table 1. The values in the table indicate the change in thickness (mm) from the initial state. Table 1 Pressure (mmHg) 0 50 100 150 200 250 Example 0 0.01 0.02 0.02 0.04 0.05 Comparative example 0 0.44 0.87 1.29 1.70 2.10

<Plasma Separation Performance Test> 200 ml of blood was fed into the plasma filtration devices of Examples and Comparative Examples while pressurizing at 100 mmHg, and plasma separation operation was performed. The results are shown in Table 2. The experiment was performed using three plasma filtration devices. The values in the table indicate the average value ± deviation. Table 2 Filtration time (sec) Serum volume (ml) Example 222 ± 8.0 80.5 ± 1.5 Comparative example 139 ± 4.3 36.9 ± 15.6

From the results shown in Table 1, it was confirmed that the plasma filtration device of the present invention favorably suppresses the deformation of the housing due to the increase in the internal pressure of the housing, as compared with the plasma filtration device of the comparative example.

Further, from the results of Table 2, it is clear that the plasma filtration device of the present invention has a remarkably large amount of collected plasma as compared with the plasma filtration device of the comparative example. This is because the plasma filtration device of the comparative example deforms the housing due to the application of internal pressure during plasma filtration, resulting in excessive gaps between the inner wall of the housing and the membrane unit and between the membrane unit and the spacer. It seems that there is a large amount of blood that is not involved in serum filtration. As a result, although the filtration time has been shortened as a result, the amount of collected plasma has become extremely small. On the other hand, in the plasma filtration device of the present invention, since the deformation of the housing is suppressed as much as possible, an ideal blood flow path is formed, and thus it is understood that a high level of plasma separation efficiency is achieved.

[0055]

[Effect of the device]

 As described above in detail, the blood filtering device according to the present invention is a body fluid filtering device in which a filter medium is housed in a housing having a body fluid inlet, a filtrate outlet, and a body fluid outlet. A space for accommodating the filter medium is formed between a first casing member having a bottomed tubular shape and the first casing member, and the first casing member and the second casing are configured to keep the space liquid-tight. A member is fixed, and the first casing member and the second casing member are fixed at their peripheral portions and at a central portion provided apart from the peripheral portion, respectively. Therefore, even if the internal pressure inside the housing rises, the deformation of the housing itself can be prevented, and thus high filtration efficiency can be exhibited.

A first convex portion is formed at or near the central portion of the second casing member, and the first convex portion is fitted at or near the central portion of the bottom portion of the first casing. If the second convex portion that can be fitted is formed and the central portion or the vicinity thereof is fixed by fitting the first convex portion and the second convex portion, it is possible to use the first casing member. The second casing member is more firmly fixed to the second casing member, and thus high filtration efficiency can be exhibited.

Further, the second casing member has a bottomed tubular shape, a third protrusion is formed on the outer surface of the side wall thereof, and the third convex portion is formed on the inner surface of the side wall of the first casing member. A fourth convex portion that can be fitted with the convex portion is formed, and by fitting the third convex portion and the fourth convex portion, the first casing and the second casing are fixed in a liquid-tight manner via a seal member. According to this structure, the first casing member and the second casing member are more firmly fixed to each other, whereby high filtration efficiency can be exhibited.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a plasma filtration device according to a preferred embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line A-A ′ in FIG.

FIG. 3 is a cross-sectional view showing the structure of a conventional plasma filtration device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma filtration device 2 Housing 2a Blood inflow port 2b Plasma outflow port 2c Blood outflow port 21 1st casing member 22 2nd casing member 21a-21d 1st convex part 211a-211d 1st taper part 212a-212d 1st fitting part. 22a-22d 2nd convex part 221a-221d 2nd taper part 222a-222d 2nd fitting part 21e 3rd convex part 211e 3rd taper part 212e 3rd fitting part 22e 4th convex part 221e 4th taper part 222e 4th 4 Fitting part 3 Filter material 31 Filtration membrane 32 Plasma flow path forming body 33 Membrane unit 34 Spacer plate 4 O-ring

Claims (3)

[Scope of utility model registration request] 1. A body fluid filtering device in which a filter medium is housed in a housing having a body fluid inlet, a filtrate outlet, and a body fluid outlet, the housing comprising a first casing member having a bottomed tubular shape, A space for accommodating the filter medium is formed between the first casing member and the first casing member, and the first casing member and the second casing member are fixed so as to keep the space liquid-tight, the first casing member The blood filtering device is characterized in that the peripheral portion and the central portion provided apart from the peripheral portion are fixed to the second casing member and the second casing member, respectively. 2. A first convex portion is formed at or near a central portion of the second casing member, and is fitted to the first convex portion at or near a central portion of a bottom portion of the first casing. The body fluid filtering device according to claim 1, wherein a second convex portion which can be fitted is formed, and the central portion or the vicinity thereof is fixed by fitting the first convex portion and the second convex portion. 3. The second casing member has a bottomed tubular shape, a third convex portion is formed on the outer surface of the side wall, and the inner surface of the side wall of the first casing member is formed.
A fourth convex portion that can be fitted with the third convex portion is formed, and by fitting the third convex portion and the fourth convex portion, the first casing and the second casing are connected to each other via a seal member. The body fluid filtering device according to claim 1 or 2, which is configured to be tightly fixed.