JPS622823B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a body fluid filtration device for passing body fluids such as blood.

Obtaining sufficient overflow in body fluid drainage devices, particularly hypermorphic artificial kidneys, presents several challenges. For example, the excess performance depends not only on the properties of the membrane but also on the thickness of the blood layer, ie, the intermembrane thickness, and by making this thinner, the excess amount increases.

However, in the hollow fiber type artificial kidney, there is a limit to reducing the intermembrane thickness, that is, the inner diameter of the fiber. In addition, in stacked artificial kidneys, spacers are used to regulate the thickness of each membrane, making it difficult to set the thickness of each membrane uniformly, resulting in uneven blood flow and loss of membrane area due to the spacers. Ru. Therefore, it is extremely difficult to adjust the interlayer thickness to be thin, and it is impossible to improve the overperformance.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a body fluid filtration device that can uniformly and finely adjust the intermembrane thickness over the entire surface and improve performance. It's about doing.

That is, the present invention comprises: a cylindrical container body with one end open forming an inlet and an outlet for body fluids and an outlet for excess fluid; a laminate of flat membrane units housed within the container body; A piston that can freely adjust the pressure that compresses the laminate from the stacking direction; and an adjustment ring that has an opening for the pressure adjustment piston and is housed in the container main body by being attached to the open end portion of the container main body. The piston maintains liquid tightness with the inner wall of the container, and the membrane unit seals a support with an uneven surface between the upper and lower membranes to make the membrane uneven. The space between these membrane units is used as a body fluid flow path, and the body fluid inlet and outlet are communicated via this flow path, and the filtrate outlet is connected to each membrane. A body fluid filtration device characterized by communicating with the inside of the unit.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Reference numeral 1 in FIG. 1 is a container body of the filtering device, and this container body 1 consists of a cylindrical body with a closed bottom 2.
The bottom portion 2 is provided with an inlet 3 for body fluids located at the center thereof, and an outlet 4 for bodily fluids disposed at a position offset from the center. A plurality of these discharge ports 4 may be provided depending on the case. Further, a body fluid outlet 5 is formed in the side wall of the container body 1. Further, an adjustment ring 6 is screwed into the upper peripheral edge of the container body 1, and presses down a piston 7 housed within the container body 1. This piston 7
A pair of upper and lower O-rings 8 and 9 are attached to the side circumferential surface of the container body 1, and by bringing the O-rings 8 and 9 into close contact with the inner circumferential surface of the container body 1, airtightness is maintained. The piston 7 can be moved up and down. Moreover, the center of the adjustment ring 6 is
A hole is formed through which the piston 7 is pushed by a compression means (not shown).

Furthermore, inside the container body 1, there is a laminate 1 formed by stacking a large number of flat membrane units 11.
2 is accommodated. Each of the above membrane units 11...
... are constructed as shown in FIGS. 2 and 3, respectively. That is, flexible membranes 13 and 14 are overlapped in the shape of a hollow disk, and both the inner and outer edges are welded to form a sealed state, and a thin hollow disk-shaped support 15 is concentrically housed inside the membrane. It is. The support body 15 has a diameter, for example.
It is knitted with about 15 meshes using a thin polyester wire 16 of 0.42 mm, and both the upper and lower surfaces thereof have uneven surfaces 17 and 18, respectively. Therefore, each membrane 1 bonded to the uneven surfaces 17 and 18
3 and 14 are in close contact with each other along the uneven surfaces 17 and 18, so that they can form uneven surfaces.

The membranes 13 and 14 may be made of polyacrylonitrile (trade name of Mitsubishi Rayon Co., Ltd.), for example.
PAN, etc.), polyamide film, polysulfone cellulose acetate film, polyethylene film, polypropylene film, polycarbonate film, etc., but those that can be heat-sealed or high-frequency fused are particularly preferred in terms of processing. The pore size of the membrane can be selected arbitrarily from 3 μm or less, preferably from 20 to 100 Å, depending on the size.

In addition, the membrane unit 11 is formed with a discharge hole 19 extending vertically through the membrane unit 11 at a location opposite to the discharge port 4 for the excess liquid. These discharge holes 19 communicate with each other when the membrane units 11 are stacked, and are connected to the discharge port 4 of the container body 1. Furthermore, the upper and lower peripheral edges of each of the discharge holes 19 are connected to other membrane units 11...
They are bonded to each other by a ring-shaped adhesive sealing material 20 on the periphery of the discharge hole 19. That is, the insides of each membrane unit 11 communicate with each other through their respective discharge holes 19 and are also connected to the discharge port 4 of the container body 1. The adhesive sealing material 20 has sufficient elasticity and does not interfere with the state of the gaps between the membrane units 11. In addition, this adhesive sealing material 2
0... is a material that is non-toxic and has good sealing properties, such as double-sided tape or hot melt.

On the other hand, the hole 21 formed in the center of each membrane unit 11 communicates with each other as shown in FIG. I'm starting to do that. Further, a constant gap 22 is formed between the outer periphery of the laminate 12 and the inner surface of the container body 1, and this gap 22 communicates with the outflow port 5 for body fluid. Since the contact between each membrane unit 11 affects the blood overefficiency, the contact pressure is generally 2 to 100 kg,
The weight is desirably about 5 to 30 kg.

Next, a method of using the above body fluid filtration device will be explained.

First, the laminate 12 of the membrane unit 11 is housed in the container body 1 of the body fluid filtration device, and the laminate 12 is compressed at a certain pressure via the piston 7 by screwing in the adjustment ring 6. In other words, the first
Once it is in the state shown in the figure, it is attached to a holder (not shown). Then, the body fluid inlet 3 and outlet 5 are connected to the blood extracorporeal circulation circuit, and the excess fluid outlet 4 is connected to the discharge line.
Next, priming processing is performed.

Thereafter, the piston 7 is pushed through the opening 10 of the adjustment ring 6 by another pressing means built into the holder to compress the stack 12. Here, the membrane units 11 are in a state of being extremely close to each other. Therefore, while applying negative pressure to the discharge line side, blood is introduced from the inlet 3.

Therefore, the membrane 1 of each membrane unit 11...
3 and 14 form uneven surfaces along the uneven surfaces 17 and 18 of the support body 15. A blood flow path is formed between these closely opposing uneven surfaces, and the blood flows from the holes 21 of each membrane unit 11 in the radial circumferential direction and collects in the gap 22. The body fluid flows out from the outlet 5. Also, when flowing through the flow path between the above-mentioned membrane units 11..., the filtrate is subjected to excessive action, and the filtrate leaks into each of the membrane units 11. It collects at the outlet 4 and is discharged through the outlet 4.

According to the embodiment described above, the thickness of each flow path can be freely selected by adjusting the pressure with which the piston 7 is pressed. Moreover, the membranes 13 and 14 of each membrane unit 11...
Since the surface is uneven along the uneven surfaces 17 and 18, the above-mentioned flow path, that is, even if the inter-membrane thickness is reduced, the flow path is formed and maintained over the entire surface. Therefore,
Partial drift of blood can be prevented.

That is, the interlayer thickness can be made extremely thin while preventing drifting, and can be adjusted to a range that was previously impossible. Thus, its carrying capacity can be increased compared to the membrane area.

The piston 7 also includes a pair of O-rings 8,
Since the container body 1 is slid with respect to the container body 1 through the interposition of the O-ring 9, its movement is more stable than when one O-ring is interposed. Furthermore, the sealing performance against the outside air is improved and the contamination of bacteria is prevented.

Further, since the piston 7 is elastically pressed, the intermembrane thickness is automatically adjusted in accordance with changes in blood flow rate. That is, when the amount of blood inflow increases, the distance between the membranes widens, and when the amount of blood inflow decreases, the distance between the membranes narrows, acting like a safety valve.

Note that the thin wire 1 in the support 15 of the above example
6, the wire diameter d and its opening m are
When the thickness of is t, it is desirable to set it to 3tm10t, td.

That is, in both cases of 3t>m and 10t<m, the excess tends to decrease.

Note that in the above embodiment, a pair of O-rings 8 and 9 are used as the sealing member for the piston 7, but
The present invention is not limited to this, and for example, one O-ring 23 may be used as shown in FIGS. 5 and 6. In this case, a collar 25 is provided on the upper edge of the piston 24 as a measure to prevent contamination with bacteria, and this collar 25 is sandwiched between the container body 1 and the adjustment ring 6.
In this way, since the path from the outside to the O-ring 23 is long and curved, contamination with bacteria can be prevented.

Further, in the above embodiment, as means for elastically biasing the piston 7, pressing via a spring or the like on the holder side is considered, but the present invention is not limited to this. An elastic body may be interposed between the ring 6 and the piston 7 to tighten the adjustment ring 6 and apply a predetermined pressure to the piston 7.

Further, the support in the membrane unit is not limited to a knitted one, and may be any other material, such as a sintered metal or a molded product, as long as its surface is entirely uneven.

Further, instead of the adjusting ring 6, a ring for tightening the piston may be welded to the container body 1, and the piston may be compressed and adjusted by another elastic member.

As explained above, according to the present invention, the intermembrane thickness consisting of the gaps between stacked membrane units can be adjusted to a thinner range that was previously impossible, and a flow path for body fluids is formed as a whole to prevent uneven flow. It can be prevented. Therefore, it is possible to expect a large increase in overcapacity and stable overaction.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
The figure is a sectional view of the membrane unit, and FIG. 3 is a partially cutaway perspective view of the membrane unit.
FIG. 4 is an exploded perspective view of each part, FIG. 5 is a cross-sectional view of a main part showing another embodiment of the present invention, and FIG. 6 is a cross-sectional view showing the main part enlarged. 1... Container body, 2... Bottom, 3... Inflow port,
4...Discharge port, 5...Outlet port, 6...Adjustment ring, 7...Piston, 8, 9...O ring, 10
...Open hole, 11...Membrane unit, 12...Laminated body, 13...Permeable membrane, 14...Permeable membrane, 15...
Support, 16... Thin wire, 17, 18... Uneven surface,
19...Drain hole, 20...Sealing material, 21...Hole, 22...Gap, 23...O ring, 24...
Piston, 25...Brim.

Claims (1)

[Claims] 1 A cylindrical container body with one end open forming an inlet and an outlet for body fluids and an outlet for excess fluid; a laminate of a flat membrane unit housed in the container body; The piston includes a pressure-adjustable piston that compresses from the stacking direction, and an adjustment ring that has an opening for the pressure adjustment piston and is housed in the container main body by being attached to the open end portion of the container main body. maintains liquid tightness with the inner wall of the container, and the membrane unit is formed by sealing a support with an uneven surface between the upper and lower membranes to form irregularities on the membrane, The space between each of these membrane units is used as a flow path for body fluid, and the inlet and outlet for the body fluid are communicated through this flow path, and the outlet for the excess fluid is communicated with the inside of each membrane unit. A body fluid filtration device characterized by: