JPS60194960A - Humors filter apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Background Art (Field of the Invention) The present invention relates to a body fluid filtration device that passes body fluids such as collapsing fluid, ascites, and pleural effusion through a filtration membrane to separate filtrate such as plasma.

(Prior Art and its Problems) Conventionally, as this type of body fluid filtration device, there is one shown in FIG. 1, for example. This device includes a side plate 3 having a body fluid inlet 41 and a filtrate outlet 2, and a filtrate outlet 4.
A square frame-shaped backing part 6b is provided between the side plate 5 having a
A flow path forming plate 6 with a void 6a formed inside thereof, a filtration membrane 7,
A filtrate flow path forming plate 8 provided with a backing portion 8b is placed on the periphery of the mesh filtrate flow path portion 8a, and these are pressed and fixed in a liquid-tight manner. In this device, body fluids such as blood flowing from the body fluid inlet port 1 are filtered through the filtration membrane 7 through the gap 6a, and blood cell components are passed from the body fluid outlet port 2 and through the filtrate flow section 8a to the filtrate outlet port. They are each discharged from section 4.

However, this device had the following problems in terms of characteristics at 1 mm. In other words, in this type of body fluid filtration device, it is known that the thinner the body fluid flow path, the greater the rupture velocity of the filtration membrane at the front of the membrane, resulting in better filtration characteristics, as shown in Figure 1. In the device, by reducing the thickness of the flow path forming plate 6, it is possible to reduce the thickness of the flow path in the gap 6a through which body fluid flows. However, since the filtration membrane 7 is easily deformed, the body fluid flow path formed in the void 6a cannot maintain a uniform flow path thickness set by the film thickness of the flow path forming plate 6, resulting in large variations, for example. Even if the channel thickness is set to 300 microns, an error of about ±100 microns will occur. Therefore, even if the flow path forming plate 6 is formed extremely thin in this device, it is difficult to secure a desired filtration amount, and the variation is significant.

In order to eliminate the drawbacks of such filtration devices.

Filtration membranes are abutted via rubber gaskets each having three parallel channels on both sides of an elongated manifold plate having a blood inlet at one end and a blood outlet at the other end, and these filtration membranes are provided with a plasma filtrate inlet. A filtration device formed by pressing a collecting plate has been proposed [Trans, Am,
Soc, Arltif, Intern.

Organs, XXIV, 2l-28 (1978
) ]. however.

In such a device, since the flow path is long compared to the flow path width, pressure loss is large, which poses a practical problem.

and at least one void-like filtration chamber bordering the filtration medium on at least one side, below which a filtrate discharge member is arranged, and having an inlet for the medium to be filtered and an outlet for the waxy material concentrated by the filtration. An ultrafiltration device particularly suitable for blood filtration consisting of a base layer of fabric of fiber mesh having an internal diameter of 2.5 mm or less and a thickness of 0.1 to 0.5 mm, An ultrafiltration device is known (British Patent No. 1.555.389) which is arranged between the two.

However, since such devices are used for ultrafiltration, they are subject to large negative pressures, and there is a structural limit to reducing the thickness of the flow path, so the rupture speed of the filtration membrane at the front of the machine is small.
It has the disadvantage that it tends to become clogged when proteins, blood cells, etc. adhere to the membrane surface.

This clogging causes blood to stagnate, causing problems of blood damage such as hemolysis and coagulation.

The body fluid filtration device illustrated in FIG. 1 will be explained with reference to FIG. 2. If the width of the membrane flow path is a, the length of the flow path is taken, the thickness of the flow path is b, and the blood flow path is 98117 seconds, then the plasma separation flow rate QF is the in-flight rupture velocity between the blood and the membrane surface γ = 6QIIl
ab2 and membrane area S=a depends on the statement, QF=IX(γ”)
It is known that there is a relationship of XS (I and J are coefficients determined experimentally). Therefore, if you want to increase the filtration rate QF as much as possible, either increase the cutting speed γ at the front of the machine, or
In a body fluid filtration device, increasing the filtration pressure causes hemolysis, which is damage to red blood cells, so it is necessary to suppress the filtration pressure to the minimum necessary level. Therefore, the flow path resistance (pressure loss) within the body fluid filtration device cannot exceed a certain value.

By the way, the pressure loss ΔP is ΔP= 12Q++ J&9
/ab 3 (71 is the viscosity of the fluid), which is more than 0, so in order to increase the filtration it There was a limit to reducing the area.
This is the theoretical background for what has been said in the description of the prior art, such as in FIG. In the present invention, the body fluid filtration membrane and its rotating means are rotated relative to each other to solve the problem of the prior art.

IT, OBJECT OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and its purpose is to increase the contact surface between the liquid and the separation membrane by relatively rotating the body fluid separation membrane in the body fluid. While applying shear to the centrifuge → 11y, the shear rate can be freely changed independently of the pressure loss, compared to the separation of body fluids. Therefore, it is an object of the present invention to provide a rotary body fluid filtration device in which the membrane area can be significantly reduced compared to a laminar flow type, and which is advantageous in economical priming polyurethane and the like.

According to the present invention, the above-mentioned object includes a housing having an internal space and a body fluid inlet and a body fluid outlet communicating with the body fluid, and a body fluid separating membrane having a body fluid separating membrane rotatably housed in the internal space of the housing. This is achieved by a body fluid filtration device comprising: a membrane unit; and a body fluid filtration device configured to filter body fluid supplied to the internal space of the housing by the body fluid separation membrane unit rotating relative to the housing. .

Further, according to the present invention, the above object includes a housing having an internal space and a body fluid inlet and a body fluid outlet communicating with the housing, and a body fluid separation membrane rotatably housed in the internal space of the housing. The body fluid separation device comprises a body fluid separation membrane unit and a means for rotating the body fluid separation membrane unit or the housing, and the body fluid supplied to the internal space of the housing is rotated relative to the housing. This is achieved by a body fluid filtration device characterized in that it is configured to filter through a membrane unit 1.

(1) Specific structure of the invention A preferred embodiment of the rotary body fluid filtration device of the present invention shown in the accompanying drawings will be described in detail below, using blood as a representative example of the body fluid. Similar parts in the various examples below are designated using the same numbers.

As shown in FIG. 3, a rotary body fluid filtration device 10 of the present invention
are roughly divided into a housing 11, a plasma separation membrane unit 13 that is rotatably housed in a space 12 defined within the housing 11, and a plasma separation membrane unit 13 that is housed in a housing 11.
and means 14 for rotating within the space 12 of.

The housing 11 preferably consists of side parts 11a and llb, defining a space 12 between these parts. The upper housing part 11a has a blood inlet 15 and a blood outlet 16 communicating with the space 12 and further includes a rotation means 1.
4 has a sleeve 18 with a central through hole 17 for passage of the blood plasma, and this sleeve 18 is provided with a plasma outlet 20 having a flow path 19. A four portion 21 is provided in the lower housing portion ttb at a position corresponding to the through hole 17 of the sleeve 18. The housing 11 is preferably made of hard plastic such as polymethyl methacrylate, polystyrene, or polycarbonate.

The plasma separation membrane unit 13 includes a separation membrane 22 and its portion 11.
space 28 for supporting the i & membrane 22 and for the plasma flow path.
A spacer 23 is provided to form a spacer 23. The separation membrane 22 is made of a microporous membrane such as cellulose acetate, nitrocellulose, polycarbonate, or nylon having a pore diameter of 0.1 to 1.0, and the spacer 23 is made of a sintered body of plastic, glass, metal, etc. Consists of screen mesh, non-woven fabric, etc., the former is heat-sealed to the latter,
They are integrated using methods such as high-frequency sealing, ultrasonic sealing, and bonding with adhesives.

The plasma separation membrane unit 13 described above is the /\Using 1
The 0-rotation means 14 is housed in the space 12 of 1 and is rotated relative to the housing 11 by the rotation means 14 supported by a support (not shown).
4, and a drive means 26 for rotating this rotating shaft 24 via a transmission 25. The rotating shaft 24 passes through the through hole 17 of the sleeve 18 and is seated on the four parts 2, which are bearings, of the lower housing part 11b, and the rotating shaft 24 and the housing part 11
A and ttb and the sleeve 18 are rotatably supported by a sealing material 27 such as an O-ring in a sealed state. Joined.Rotary shaft 14
A flow path 30 formed in the center of the plasma outlet 20 communicates the flow path 19 of the plasma extraction port 20 with the plasma flow path space 28 of the plasma fraction 111&+1fJ unit 13, and allows the plasma separated by the membrane 22 to flow through the space 28. It is configured such that it can be taken out via channel 30 and channel 19. The rotating shaft 24 is preferably made of a metal such as stainless steel, a hard material such as tetrafluoroethylene, polycarbonate, etc.
6 can be any arbitrary number.

Note that the rotating means is not limited to the mechanical ones described in section 1 and below, but magnetic or electromagnetic induction types can also be used. The rotation method may be constant speed rotation or pulse rotation. Then, the separation membrane unit and the housing may be configured to rotate relative to each other.

FIG. 4, FIG. 5, and FIG. 6 show other configuration examples of the rotary body fluid filtration device of the present invention.

In the configuration shown in FIG. 4, the plasma separation membrane unit 13 is composed of two membrane units 13a and 13b, and the plasma flow path spaces 28a and 28b of both membrane units are connected to the rotating shaft 2.
The structure is substantially the same as that shown in FIG. 1, except that it communicates with a flow path 30 formed inside 4. Note that the number of the membrane units may be two or more. Further, it is preferable to interpose a spacer 48 between each membrane unit (13a and 13b in the figure) in order to prevent blood from rotating together with the membrane unit.

In the configuration shown in FIG. 5, the plasma separation membrane unit 13 is not configured as a disk type unit as shown in FIGS. 3 and 4, and the plasma separation membrane 22 is attached around the cylindrical spacer 31. However, the separated plasma is taken out through the internal space 32 of the cylindrical spacer 31.

The structure shown in FIG. 6 is a modification of the one shown in FIG. 5, in which the cylindrical spacer 31 shown in FIG. 5, the separated plasma is removed through the interior space 32 of the cylindrical spacer 22. In this case, the housing 11 has a top portion 11c, an outer peripheral portion li
d and a bottom part lie, a sleeve 18 is provided on the top part lie, and a blood inflow/outflow part is provided on the outer peripheral part 15.1.
6 is provided with four parts 21 in the bottom part lie.

(8) Specific operation of the invention Next, the operation of the rotary body fluid filtration device of the invention will be briefly explained.

Blood is supplied from the blood inlet 15 and enters the space 12 of the housing 11, where the drive means 26 changes the speed a25.
and contacts the plasma separation membrane unit 13 which is being rotated via the rotation shaft 24. Since the plasma separation membrane unit 13 rotates with respect to the blood, the contact area between the blood and the membrane 22 is considered to be apparently significantly larger than in the conventional case where the membrane 22 is stationary. In addition, the boundary layer peeling stress between the blood and the membrane surface, which is mainly based on the wall shear rate, increases dramatically.

Here, boundary layer peeling stress is defined. In other words, in general, the closer to the membrane surface the higher the density of blood cells is, and the further away from the membrane surface the lower the density of blood cells. In order to avoid concentration, a force is required to move the blood cells away from the membrane surface, and this is called boundary layer peeling stress. The larger this force is, the more blood cells are prevented from concentrating on the membrane surface, the clogging of the membrane is reduced, and stable filtration efficiency is maintained over a long period of time.

In this way, the blood contacts the membrane 22 of the membrane unit 13 in a state where the contact surface area between the blood and the membrane 22, the wall shear rate between the blood and the membrane surface, and the boundary layer peeling stress are increased.
A larger amount of the plasma to be separated enters the plasma separation space 28 through the membrane 22, and is further taken out through the flow path 30 inside the rotating shaft 24 and the flow path 19 in the plasma collection 11 and 20. The blood from which the plasma has been separated is discharged from the blood outlet 16.

Note that the connection between the flow path 30 of the rotating shaft 14 and the T path 19 of the plasma extraction port 20 is protected in a sealed state by a sealing material 27, so that it can be separated from mixing with blood or contamination from the outside. blood plasma is protected.

The above operation is the same for FIGS. 3 to 6.

In order to confirm the function and effect of the rotary body fluid filtration device of the present invention, a test circuit as shown in FIG. 7 was constructed and a test was conducted. In FIG. 7, 10 is the body fluid filtration device of the present invention, 40 is a constant temperature layer, 41 is a magnetic stirrer, 42 is heparinized blood, 43 is a pump, 44 is a channel for monitoring blood inflow pressure, 145 is a meter, 46 is filtered plasma, 4
7 is a channel for monitoring blood outflow pressure - 248 is a meter. The blood used was live blood + heparin (eoo.

Unit 7 Sentence) Ten anticoagulant ACD blood 50d/1 (citric acid + sodium citrate + glucose) and heparinized bovine blood 42 kept at 37°C in a thermostatic chamber 40 is pumped through a pump 43 at a rate of Qa=lOOIllI/min. and motor 2
Blood was filtered using the body fluid filtration device io of the present invention which was rotated at a rotation speed of 6, and the filtered plasma was observed as QF (III).

The body fluid filtration device 10 of the present invention subjected to the filtration test has (I) a disk-shaped plasma fraction of 111:M units as shown in FIGS. 3 and 4, and a membrane area of 241.5
cnf (II) A membrane having a cylindrical plasma separation membrane unit as shown in FIGS. 5 and 6 and having a membrane area of 94 Ud was used. Plasma separation capacity is the amount of plasma filtration per unit membrane area (
119!101f), and the results are shown in the graph of FIG. As is clear from this graph, body fluid m
It was found that the plasma separation capacity, that is, the plasma filtration rate, increases as the rotation speed of the membrane unit increases, and when the membrane unit is kept stationary without rotating as in the conventional case (
In other words, it can be seen that the plasma separation ability is significantly superior to that obtained when the rotation speed is 0).

Although the above explanation has mainly focused on plasma separation, the present invention is not limited to plasma separation, but can also be used as an apparatus for filtering (including ultrafiltration, etc.) separating components of body fluids such as ascites and pleural fluid. Available for use.

(1) Specific Effects of the Invention As is clear from the above, the rotary body fluid filtration device of the present invention provides many advantages over the conventional static type as described below.

(1) Traditionally, it prevents membrane clogging and decreases in filtration efficiency,
When trying to increase the boundary layer peeling stress by increasing the shear rate in order to increase the amount of filtration, the pressure drop inevitably increases and hemolysis may occur, but according to the present invention, the pressure drop and shear rate can be reduced. Since these can be controlled independently, the boundary layer peeling stress can be increased without causing hemolysis, and a high filtration rate can be maintained. Furthermore, since the pressure loss and the shear rate can be made independent, the design conditions, usage conditions, and scope of the device can be made wider than in the past.

(2) In the body fluid filtration device of the present invention, since the body fluid separation membrane unit is rotated relative to the opposite liquid, there are apparently more opportunities for contact between blood and the body fluid separation membrane, that is, the membrane area is the same. However, the same effect as increasing the membrane area can be obtained, and the boundary layer peeling stress based on the shear rate between the body fluid and the membrane surface also increases. For this reason, the conventional body fluid separation membrane unit is 11 minutes faster than a static laminar flow type.
11M area can be significantly reduced.

(3) As mentioned in (2), since the area of the separation membrane can be significantly reduced, it is possible to downsize the body fluid filtration device, reduce the plumbing capacity, and reduce costs. ) and the membrane becomes smaller, minimizing fluid contamination and damage.

(4) Compared to conventional body fluid filtration devices, the blood filling capacity inside the device can be made extremely small, so the effect on blood can be reduced, and the blood & amount is, for example, 50%.
- 50011I can be selected since the risk of hemolysis occurring over a wide range is small. Also put into the blood
It has the advantage that only a small amount of anticoagulant is required.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a conventional body fluid filtration device. The t52 diagram is a diagram for explaining the separation ability of body fluid separation membranes,
3 and 4 are cross-sectional views of a body fluid filtration device of the present invention having a disc-shaped separation membrane unit, and FIGS. 5 and 6 are sectional views of a body fluid filtration device of the present invention having a cylindrical separation membrane unit. A cross-sectional view, FIG. 7 is a circuit diagram used to test the body fluid separation ability, and FIG. wS8 is a graph showing the results of a test conducted using the testing apparatus of FIG. 7. Explanation of symbols 1...Body fluid inlet, 2...Filtration residual liquid outlet, 3.5...Side plate, 4...Filtrate flow Outlet part, 6... Channel forming plate, 6a...
...Gap, 6b...Backing part, 7...
...filtration membrane, 8...filtrate flow path forming plate, 8a.
...filtrate channel section, 8b...backing section, 10...body fluid filtration device of the present invention, 11...
...Housing, 12...Space, 13...
...Membrane unit, 14...Rotating means, 15...Blood inlet, 16...Blood outflow 1'', 17...Through hole , 18...
Sleeve, 19...Flow path, 20...Plasma extraction port, 21...Recess, 22...Separation membrane, 23...Spacer , 24...Rotating shaft, 25...Transmission, 26...Driving means, 27...Sealing material, 28...Plasma flow Road space, 29... Projection, 30...
...Flow path, 31...Cylindrical spacer, 32...
...Internal space, 40... Constant temperature chamber, 41...
... Stirrer, 42 ... Heparinized bovine blood, 4
3...Pump, 44...Chamber for blood inflow pressure monitoring, 45.48...Meter, 46...Filtered plasma, 47...・To the blood outflow pressure monitor channel -148... Spacer Patent applicant Masaharu Watanabe Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 7

Claims (4)

[Claims] (1) A housing having an internal space and a body fluid inlet and a body fluid outlet communicating with the housing, and a body fluid separation membrane unit having four membranes of body fluid molecules rotatably housed in the internal space of the housing, The body fluid supplied to the internal space of the housing is rotated relative to the housing +iiij body fluid fraction 1! A body fluid filtration device characterized in that it is configured to perform filtration using an I-membrane unit. (2) The body fluid separation membrane unit includes a body fluid separation membrane and the body fluid g.
The body fluid filtration device according to claim 1, comprising a spacer supporting the lI 11M. (3) a housing having an internal space and a body fluid inlet 1 and a body fluid outlet communicating therewith; a body fluid separation membrane unit having a body fluid separation membrane rotatably housed in the internal space of the housing; a separation membrane unit or a means for rotating the housing, and the body fluid supplied to the internal space of the housing is configured to be filtered by the body fluid separation membrane unit rotating relative to the housing. A body fluid filtration device characterized by: (4) The body fluid separation membrane unit comprises a body fluid separation membrane and a spacer that supports the body fluid separation membrane.
The body fluid filtration device described in Section 1.