JPH0245063A - Body fluid filter device - Google Patents

Abstract

PURPOSE:To prevent the generation of the agglutination and solidification of blood cell components and to obtain sufficient plasma separability by bringing the body fluid admitted from a body fluid inflow port into contact with a body fluid filter body to filter the same, then introducing the fluid to a filtration residue outlet and introducing the filtrate separated by the body fluid filter body to a filtrate outflow port. CONSTITUTION:A blood flow passage which is the body fluid flow passage to pass the blood admitted from the blood inflow port 3 of a housing 2 between a plasma separating membrane 4 and blood flow passage forming bodies 17, 18 and to introduce the blood to the blood outflow port and the plasma flow passage which is the filtrate flow passage to pass the plasma filtered by the membrane 24 between the rear surface of the plasma separating membrane and a plasma flow passage forming body 13 and to introduce the plasma to plasma outflow ports 8a, 8b are formed in a plasma separator 1. A blood outflow port 4 is provided to the central part of the front surface 2a of the housing 2. The blood admitted into the housing flows into a blood inflow part 20 which is the annular space formed by the outer periphery of a plasma separating body 15 and the inside wall of the housing 2; thereafter, the blood flows between the membrane 14 and the bodies 17, 18 toward the center of the plasma separating body. The shearing speed is lowest in the outer peripheral part and is highest in the central outlet part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a body fluid filtration device that filters body fluids using a filtration membrane;
For example, the present invention relates to a plasma separation device that filters blood and separates it into concentrated red blood cells and plasma.

[Prior Art] As a body fluid filtration device that filters body fluid using a filtration membrane, there is, for example, a plasma separation device that filters blood and separates it into blood cells and plasma. This device includes a hollow fiber type and a flat membrane type, and many membrane materials and shapes have been proposed. Compared to hollow fiber type plasma separators, flat membrane type plasma separators allow a wider selection of membrane shapes and blood flow path shapes; disk-shaped (Japanese Patent Application Laid-Open No. 58-50963) and rectangular shapes have been proposed. has been done. In particular, a flat membrane disc-shaped plasma separator is a form that can easily provide an appropriate pressure loss and shear rate. In order to achieve a uniform flow of blood within the device, this disc-shaped plasma separator introduces blood through a blood inlet provided at the center of the top or bottom of the cylindrical container, and flows through the disc-shaped flat membrane. Blood is configured to flow radially on the membrane surface from the central opening toward the outer periphery.

[Problems to be Solved by the Invention] However, such conventional flat membrane disc-shaped plasma separation devices cannot be used in actual clinical use or in-incubation using heparinized blood.
In vitro filtration experiments, an increase in pressure loss occurs in the plasma separation device due to adhesion, aggregation, and coagulation of blood cell components, resulting in a significant drop in plasma separation performance and the occurrence of hemolysis, which may prevent proper plasma separation. Ta.

Regarding this point, as a result of repeated studies to elucidate the mechanism, (1)
It has become clear that if the shear rate defined by the formula is too large, or if the shear rate changes within the plasma separation device are too large, this can easily trigger the occurrence of adhesion, aggregation, and coagulation of blood cell components. .

S: shear rate QB: blood flow rate a: blood flow path b: blood flow path thickness It is known that the above shear rate has a positive correlation with plasma separation ability. Therefore, in order to suppress the occurrence of adhesion, aggregation, and coagulation of blood cell components, it is possible to increase the thickness of the flow channel or make the inside of the blood flow channel larger (for example, by increasing the inner diameter), but this decreases the plasma separation ability. This has the disadvantage of inviting This point has also been taken into consideration in the design of conventional disc-shaped plasma separators. , efforts have been made to set the channel thickness. Nevertheless, the reality is that the above-mentioned problems still remain.

The present invention can be used in plasma separation devices that have sufficient plasma separation ability and are less prone to increase in pressure loss due to adhesion, aggregation, and coagulation of blood cell components compared to conventional circular stacked plasma separation devices. The present invention aims to provide a body fluid filtration device.

[Means for solving the problem 1] What achieves the above purpose is a body fluid inlet, a filtrate outlet,
a cylindrical housing formed by a top surface, a bottom surface and a cylindrical side wall, and a filtration residual liquid outflow port; a plurality of body fluid filter bodies stacked in the housing; and a body fluid inflow from the body fluid inflow port. a body fluid flow path that guides the body fluid that has been filtered by contacting the body fluid filter body to the filtration residual liquid outlet after being filtered; and a filtrate flow path that guides the filtrate separated by the body fluid filter body to the filtrate outlet. , the filtration residual liquid outflow port is provided in at least one of the central portion of the top surface or the bottom surface of the housing, and the body fluid inflow port is provided in a peripheral portion of the top surface or bottom surface of the housing, or This is a body fluid filtration device provided on a cylindrical side wall.

Further, in the body fluid filtration device, for example, the body fluid inlet is a blood inlet, the filtrate outlet is a plasma outlet, and the filtrate residual liquid outlet is a concentrated red blood cell outlet. It is a device. Furthermore, it is preferable that the body fluid inlet is provided at a position within 2CjI from the outermost periphery of the top or bottom surface of the /% housing. Furthermore, the body fluid filtration membrane body has an outer diameter of 8 to +5 cm.
It has a round shape with a diameter of 1.5 to 5.5 mm in the center. O
It has a circular opening of cx, and the ratio of the diameter of the opening to the outer diameter is preferably 1:3 to 6. moreover,
It is preferable that the body fluid filtration body comprises a filtrate flow path forming body, a body fluid filtration membrane enclosing the filtrate flow path forming body, and a body fluid flow path forming body provided between the body fluid filtration membranes. . Furthermore, it is preferable that the body fluid inlet is provided in the cylindrical side wall of the housing so as to be parallel to a tangential direction of the body fluid filtered in the housing.

The body fluid filtration device of the present invention will be explained in detail using the drawings.

FIG. 1 is an exploded perspective view showing an embodiment in which the body fluid filtration device of the present invention is applied to a plasma separation device. FIG. 2 is a cross-sectional view of the plasma separation device of FIG. 1.

The body fluid filtration device 1 of the present invention has a body fluid inlet 3, a liquid outlet ga, 8b, and a filtration residual liquid outlet 4, and has an upper surface portion 2a,
A cylindrical housing 2 formed by a bottom surface portion 2b and a cylindrical side wall portion 2c, a plurality of body fluid filter bodies 15 stacked in the housing 2, and a body fluid flowing in from the body fluid inlet 3 into the body fluid filter body 15. After contact and filtration, the body fluid flow path leads to the filtration residual liquid outflow port 4, and the filtrate flow path leads the filtrate separated by the body fluid filter body 5 to the filtrate outflow ports 8a, 8b, and the filtration residual liquid outflow port 4 is provided in at least one of the center portions of the top surface portion 2a and the bottom surface portion 2b of the housing 2, and the body fluid inlet 4 is provided in the peripheral portion of the top surface portion 2a or the bottom surface portion 2b of the housing 2, or in a cylindrical shape. Side wall part 2c
It is provided in

The body fluid filtration device 1 of the present invention will be explained using an example in which it is applied to the plasma separation device shown in FIGS. 1 and 2.

The plasma separator 1 includes a housing 2 and a plurality of plasma separators 15 stacked inside the housing 2 to form a body fluid filter.
It consists of

The housing 2 includes an inlet 3 for blood, which is a bodily fluid to be filtered;
It consists of a cylindrical casing having an outlet 4 for concentrated red blood cells, which is the filtrate residual liquid, and an outlet 8a, 3b for plasma, which is the filtrate, and a bottom plate 9 that seals the opening of the cylindrical casing. As shown in FIG. 1, the bottom plate 9 has an O-ring lO on the side surface.

The plasma separator I5 is formed by a plasma separator 11114, a blood channel forming body 17, and a plasma channel forming body 13. Then, two upper and lower circular plasma flow path forming bodies 13 made of a screen mesh are provided with an opening 11 in the center communicating with the blood outflow port 4 and plasma passage holes 12 communicating with the plasma outflow ports 8a and 8b near the periphery. The peripheral part of the plasma separation membrane 14 and the peripheral part of the central opening are heat-sealed.
A plasma separation membrane unit is formed by sealing with adhesive or the like and pasting a sealing material around the outer periphery of the plasma passage hole. Here, the circular plasma flow path forming body 13 is not limited to the above-mentioned mesh as long as it can secure a flow path for plasma.

A center opening 11 and a [f[1ff1 passage hole 12] corresponding to each unit were provided between the plurality of plasma separation membrane units, and a large number of convex portions were provided on both sides (however, the A circular blood flow path forming body 17 whose outer periphery is flat is disposed. In addition, above the top and below the bottom of the plasma separation membrane unit, there are openings and passage holes corresponding to the central opening and plasma passage holes of the separation membrane unit, and a large number of convex portions on one side ( However, the outer periphery of the passage hole is flat.) The circular blood flow path forming body 18 is brought into contact with the convex portion thereof in contact with the separation membrane unit. A plasma separator 15 is formed by the plasma separation membrane unit and the blood flow path forming body. A plurality of sets of plasma separators 15 are stacked and inserted into the housing 2, and the bottom plate 9 is pressed to fit into the housing 2, and a liquid-tight state is achieved by the O-ring IO. Further, due to the above-mentioned pressing, the plasma separation membrane unit and the blood flow path regulator are 1. The passage holes are liquid-tightly connected by a sealing material 16 at their outer peripheries, and the passage holes communicate with each other.

Therefore, in this plasma separator 1, blood flowing from the blood inlet 3 of the housing 2 flows between the plasma separation membrane 14 and the blood flow path forming body 17, 18, and a body fluid flow path is formed to reach the blood outflow port. and a filtrate flow path in which plasma filtered by the plasma separation membrane 14 flows between the back surface of the plasma separation membrane and the plasma flow path forming body 13 and reaches plasma outlet ports 8 a and 8 b. A plasma flow path is formed.

In the plasma separator 1 of the present invention, a blood outflow port 4 is provided at the center of the top surface 2a of the housing 2, and a blood inflow port 3 is provided at the periphery of the top surface 2a of the housing 2.
is provided, so that the blood that has flowed into the plasma separator 1 first flows into the blood inflow part 20, which is an annular space formed by the outer periphery of the plasma separator 15 and the inner wall of the housing 2, and then undergoes plasma separation. Membrane 14 and blood flow path forming bodies 17 and 18
and flows toward the center of the plasma separator. By doing so, the plasma separation membrane exhibits sufficient plasma separation ability within an appropriate pressure drop range that does not damage blood cell components, does not apply an excessively high shear rate, and further filtration. The economic loss of the membrane can be kept low, and therefore the increase in pressure loss due to adhesion, aggregation, and coagulation of blood cell components can be kept low, and stable plasma separation can be performed.

In conventional disk-shaped plasma separators, blood flows radially from the center of the circle toward the outer periphery. At this time, as is clear from the above equation (1), the shear rate is highest at the central inlet and lowest at the outer periphery. This relationship is schematically shown in FIG. 4 by a solid line (B). On the other hand, if the blood flows uniformly from the outer circumference to the center of the circle as in the present invention, the shear rate will be the smallest at the outer circumference and the largest at the central outlet, but the blood flow rate will be lower than the membrane surface. Considering that plasma is separated during the process of flowing over the top and gradually decreases from the inlet to the outlet, the relationship is as shown by the dotted line in Figure 4 (
A), and the change in shear rate is smaller than before. Therefore, in the plasma separator of the present invention, it is possible to suppress the increase in pressure loss due to adhesion, aggregation, and coagulation of blood cell components to a low level without impairing the plasma separation ability at all.

Furthermore, the blood inlet 3 is located on the upper surface 2a of the housing 2 (
It may be provided on the lower surface 2b. Similarly, the blood outlet 4 may also be provided on the lower surface 2b of the housing 2.

The blood inlet 2 is provided at a distance from the inner wall of the housing 2 within 3 GII, preferably within 2 am, and more preferably within 0.5 cm. Also, 2c
In the case where the blood inflow section 20, which is an annular space formed between the inner wall of the housing 2 and the plasma separator 15, is provided at a position separated by +v or more, the blood is separated from the plasma separation membrane to form a blood flow path. This allows for reliable flow in the vertical direction between the body and the body. However, since the priming volume of the plasma separator becomes large, it is preferable to provide the priming volume within 2 CIi.

In addition, as the plasma separation membrane 3, cellulose esters such as organic acid esters such as cellulose nitrate and cellulose acetate,
Synthetic resin membranes such as polypropylene, polyethylene, and polycarbonate (30 to 200 μm in thickness are formed by known methods such as phase separation, extraction, stretching, and charged particle irradiation), and have an average pore diameter of 0. The diameter is approximately 1 to 1 μm, preferably 0°1 to 0.8 μm.

Further, the circular filter membrane 14 has a diameter of 1.5 to 5 cm at the center.
m, preferably with a circular opening of 2-3 cm, with an outer diameter of 8-1.5 cm, preferably 10-] 2 cm concentric circles, with a ratio of the opening diameter to the outer diameter of 1:3-1 ;6 is preferred.

The blood flow path forming bodies 17 and 18 form blood flow paths with the plasma separation membrane 14, and have a large number of protrusions. Its Young's modulus is 1, OX 10' to 2.
OX 10 dyne/cm2, preferably 1,
OX 1.0' ~ 1゜OX 10 dyne/am'
It is made of material. The reason for this is that when the separator is pressed to easily narrow and relax the blood flow path, the flow path plastically restores itself, making it easier to obtain a desired filtration membrane.

Examples of materials having a Young's modulus within this range include low density polyethylene, silicone, isoprene rubber, butyl rubber, styrene-phtadiene rubber (SBR), and ethylene-vinyl acetate copolymer resin (EVA). Further, the surface hardness of the blood flow path forming body provided with the convex portion is 10
Those having a Shore A hardness of ~100' are desirable. The convex portions of the blood flow path forming bodies 17 and 18 are connected to the plasma separation membrane 1 here.
4 to prevent deformation and ensure a blood flow path in the gap between the protrusions.

The height of this convex portion is preferably 50 to 500 μm,
In particular, those with a shoulder diameter of 100 to 250 μm are preferred. The reason for this is that it is difficult to adjust the channel thickness below 5ca shoulder, and
This is because when μπ is exceeded, the deformation is large and errors are likely to occur, and the shear rate cannot be increased. Also,
The distance between the bottoms of these convex portions is preferably 100 to 2,000 μm, particularly preferably 400 to gooμm. Also,
The ratio of the radius of the bottom of the protrusions, the length of a diagonal line or one side, and the distance between the protrusions is preferably 1:1 to 1:3.

Further, as an embodiment of the pond of the plasma separator 1, for example, the one shown in FIG. 3 is also preferable.

The difference between the embodiment shown in FIG. 3 and that shown in FIG.
The blood inflow port 3 is provided in the cylindrical side wall 2c of the housing 2, and the configuration of the plasma separator.

In this embodiment, a circular plasma flow channel forming body 17 made of a screen mesh or a nonwoven fabric having an opening 11 in the center and plasma passage holes 12 near the periphery is used. A membrane unit is formed by sandwiching two plasma separation membranes I4 so as to face the flow path, and sealing the periphery thereof and the periphery of the central opening. A sealing material 16 is placed between the membrane units at the center opening corresponding to the unit, the plasma passage hole, and the outer periphery of the plasma passage hole.
A flat plate-shaped blood flow path forming body 17 to which blood flow path forming body 17 is attached is disposed, and the membrane unit and blood flow path forming body 17 are brought into a liquid-tight state by the sealing material 16.

The protrusions 14a of the plasma separation membrane 14 support the plasma separation membrane with the blood flow path forming body 17 provided on the upper part thereof to prevent deformation, and prevent blood flow in the gaps between the protrusions 14a. This is to secure roads. This protrusion 14a is
Height I (is 2θ ~ 200 μm, bottom diameter R is 100 ~ 1
000tt, w, the distance between the apexes of the protrusion is 300-20
00μ shoulder, the area occupied by the protrusion on the entire membrane surface is 3
It is preferable that it is 20%. More preferably, the height H is 50 to 100 μm, and the shoulder 1 bottom diameter R is 200 to 500 μm.
μ shoulder, the distance between the peaks of the protrusions is 500 to 1000 μ shoulder, and the area occupied by the protrusions is 5 to 15% of the entire membrane surface.
It is desirable that

The plate-shaped blood flow path forming body 17 is preferably made of a hard material with a Brinell hardness (JIS Z2243) of 10 or more, and has a thickness T of 10 to 200 μm, and preferably 20 to 50 μm. Materials having Brinell hardness within this range include polyethylene, boropropylene, polyester, polycarbonate, and the like. Also,
The circular filtration membrane 14 has a circular opening in the center with a diameter of 1.5 to 5 cm, preferably 2 to 3 cm, and an outer diameter of 8 to 1 cm.
5 ca, preferably 10 to 12 cx concentric circles, and the ratio of opening diameter to outer diameter is preferably 1:3 to 1:6.

Moreover, as the plasma flow path forming body 13, those mentioned above can be suitably used.

By using a plasma separation membrane having protrusions on its surface as described above, the plasma separation device can be downsized. Furthermore, by providing a hard blood flow channel forming body on the top of the plasma separation membrane with protrusions and setting the shape of the protrusions as described above, it is possible to form a highly uniform and stable thin-layer blood flow channel. high plasma separation performance.

In the embodiment shown in FIG. 3, the blood inlet 3 is connected to the side wall 2c of the housing 2 so as to be parallel to the tangential direction of the plasma separation membrane 14 (parallel to the tangential direction of the side wall of the housing 2). It is provided.

Further, the shape of the plasma inlet 3 may be such that it extends in the radial direction (orthogonally) to the cylindrical side wall 2c of the housing 2, as shown in FIG. 4. In this case, since the blood is introduced perpendicularly to the side surface of the laminated disc-shaped flat membrane, the effect of preventing blood cell component aggregation and coagulation at the blood inlet portion is slightly reduced. Therefore, as described above, when providing a blood inlet in the side wall 2C of the housing, it is preferable to have a shape as shown in FIG. 3.

In the above explanation, the explanation is given using an example in which the extracorporeal filtration device is applied to a plasma separation device, but the application is not limited to this, for example, it can be applied to a device for removing pathogenic macromolecules from plasma components, a device for removing medium molecular weight substances, etc. can.

[Function] Next, an example in which the function of the body fluid filtration device of the present invention is applied to a plasma separation device will be described with reference to FIGS. 1, 2, and 6. FIG. 6 is a circuit diagram showing an extracorporeal circulation circuit equipped with a plasma separation device.

Blood removed from a human body or a blood container (not shown) is introduced from a circuit port 30 by a liquid feeding pump 31, passes through a chamber 32, and is introduced from a blood inlet 3 of the plasma separation device 1. The blood that has flowed into the plasma separation device 1 flows into the blood inflow part 20, which is an annular space shown in FIG. The plasma that has been filtered and permeated through the separation membrane 14 flows between the plasma channel forming bodies 13, passes through the plasma passage hole 12, and flows out from the plasma outflow ports 8a and 3b. The plasma collection container 3 has an outflow rate controlled by a filtering body fluid pump 34.
It is collected in 5. On the other hand, concentrated red blood cells, which are the residual liquid after filtration, are discharged from the blood outlet 4, passed through the chamber 36, and returned to the human body or the +m liquid container from the circuit outlet 37. In addition, 38 and 39 degrees 40 in the figure are pressure gauges.

[Example] The present invention will be explained in detail below.

(Example 1) The membrane unit consisted of two circular polypropylene filtration membranes (average pore diameter 0.6 μm, membrane thickness 130 μm, outer diameter 110 μm).
Ox, a convex part 20zm between the centers, and two openings with an inner diameter of 6 mm at opposite positions located 15 mm apart from the outer periphery at the center), and apertures 29 as a plasma flow path forming body.
0μm, thickness 125μm, outer diameter 94xm, center opening 2
Sandwich two sheets of polyester screen mesh having two openings with an inner diameter of 6jIII at opposing positions at a distance of 12x from the outer periphery to the center of the waste, and heat seal the outer periphery and center opening of the separation membrane. Created by.

The blood flow path forming body used was made of polypropylene and had a thickness of 1 inch and had a number of protrusions of 120 μl in height and 300 μl in diameter on its surfaces (front and back) at regular intervals. The membrane unit and the blood flow path forming body are laminated alternately using a hot melt adhesive as a sealing material, and the upper and lower surfaces of the membrane unit have a height of 120 mm on one side only.
A plasma separator was prepared by providing a blood flow channel forming body made of polypropylene having a thickness of 1 inch and having a large number of convex portions having a diameter of 300 μR at regular intervals. As a housing,
A cylindrical casing made of polycarbonate (outer diameter 112xm, inner diameter 1106x, depth 3gjIjI), with a blood outflow port (inner diameter 5zx) and two plasma outflow ports (inner diameter 5x) in the center of the top surface.
), and as shown in FIG. 2, a blood inlet with an inner diameter of 5 mm was provided at a distance of 3H from the inner wall of the housing.

After the plasma separator was housed in the housing, a polycarbonate bottom plate having a silicone rubber O-ring on the side surface was inserted to create the plasma separator of the present invention. The effective membrane area of this plasma separator was 0.353+''.

(Example 2) The housing was a cylindrical case made of polycarbonate (outer diameter 112zi, inner diameter 1106z, depth 38I),
A blood outflow port (inner diameter 5 mm) and two plasma outflow ports (inner diameter 5111i) are provided at the center of the upper surface, and as shown in FIG. A plasma separator of the present invention was prepared in the same manner as in Example 1, except that (2) a liquid inlet having an inner diameter of 5 mm was used. The effective membrane area of this plasma separator is 0.3
5m".

(Example 3) The housing is a cylindrical casing made of polycarbonate (outer diameter 112 x m, inner diameter 106 mm, depth 38 I) with a blood outflow port (inner diameter 5RN>) and two plasma outflow ports (inner diameter 51111), and as shown in FIG. 4, the procedure was the same as in Example 1, except that a blood inlet with an inner diameter of 5 x y was provided at approximately the center of the cylindrical side wall of the housing and perpendicular to the side wall. The plasma separator of the present invention was created using the following steps.

The effective membrane area of this plasma separator was 0.35x''.

(Comparative Example 1) The housing is a cylindrical case made of polycarbonate (outer diameter 112+yx, inner diameter 106iz, depth 38zx).
A blood inlet (inner diameter 5xx), two plasma outlet ports (inner diameter 5jIII) are provided at the center of the upper surface, and a blood inlet with an inner diameter of 5mm is provided approximately in the center of the cylindrical side wall of the housing and perpendicular to the side wall. A plasma separation device of a comparative example was produced in the same manner as in Example 1 except that a plasma separator was used. The effective membrane area of this plasma separator was 0°354''.

(Comparative example 2) The same housing as in Comparative Example 1 was used.

The membrane unit consists of two circular polypropylene filtration membranes (average pore size 0.6 μl, membrane thickness 130 μl, outer diameter 100 μl).
+yx, central opening 10x*, two openings with an inner diameter of 5MjI in opposing positions located 15xm apart from the outer periphery in the center), between which the plasma flow path shape - as a formed body, the opening is 290μ shoulder, the thickness is 125μ11 Two pieces of polyester screen mesh L having an outer diameter of 94xz, a central opening of 18ix, and two openings of inner diameter 6xx at opposite positions spaced from the outer circumference to the center of the shoulders are sandwiched, and the outer circumference and center of the separation membrane are It was created by heat sealing the opening.

The blood flow channel forming body used was made of polypropylene and had a thickness of 1 m and had a number of convex portions having a height of 120 μl and a diameter of 300 μl at regular intervals on its surfaces (front and back surfaces). The membrane unit and the blood flow IM forming body are laminated alternately using hot melt adhesive as a sealing material, and the upper and lower surfaces of the membrane unit have a height of 1 on one side only.
A plasma separator of a comparative example was prepared using a plasma separator provided with a blood flow channel forming body made of polypropylene having a thickness of IIN and having a large number of protrusions of 20 μm and 300 μm in diameter at regular intervals. The effective membrane area of this plasma separator is 0.
It was 35x'.

(Experiment) Using the plasma separator of Examples 1 to 3 and Comparative Examples 1 and 2 above, the hematocrit value was 40% and the temperature was 37%.
Heparinized bovine blood at °C was flowed in at a flow rate of 100 FIQ per minute, plasma filtration ff1QF was measured, and the pressure drop increase ΔPD was determined for 60 minutes after the start of filtration.

Note that the pressure loss at the start of filtration was 30xxH9 in all cases. Each experiment was performed three times and the average was determined. The results are shown in Table 1.

Table 1 In Examples 1.2 and 3, plasma separation performance equivalent to that of Comparative Example 1 was observed, and the increase in pressure drop was small (stable plasma separation could be performed. In Example 3, in Experiment 3, A slight increase in pressure loss was observed.

In Comparative Example 1, blood was introduced through the central opening, and an increase in pressure loss was observed twice out of three experiments.

In Example 3, since the inner diameter was small, the shear rate at the blood inlet (center opening) was high, resulting in an increase in pressure loss and a decrease in plasma separation ability.

[Effects of the Invention] The body fluid filtration device of the present invention has a body fluid inlet, a filtrate outlet, and a filtration residual liquid outlet, and has a cylindrical housing formed by a top surface, a bottom surface, and a cylindrical side wall. , a plurality of body fluid filter bodies layered in the housing, and a body fluid flow path that guides the body fluid flowing in from the body fluid inlet to the filtration residual liquid outlet after contacting the body fluid filter body and filtering the body fluid. It has a filtrate flow path that guides the filtrate separated by the body fluid filter to the filtrate outflow port, and the filtration residual liquid outflow port is provided in at least one of the center portion of the top surface portion or the bottom surface portion of the housing. , the body fluid inlet is provided on the periphery of the top or bottom surface of the housing, or on the cylindrical side wall, and the body fluid that flows into the body fluid filtration device first passes through the outer periphery of the body fluid filter. After flowing into the blood inlet, which is an annular space formed by the inner wall of the housing, the blood flows toward the center of the body fluid filter. For this reason, sufficient body fluid filtration ability is expressed within an appropriate pressure loss range that does not damage the body fluid filtration body, and an excessively high shear rate is not applied, and furthermore, economic loss of the filtration body is kept low. This enables stable plasma separation to be performed while suppressing increases in pressure loss due to adhesion, aggregation, and coagulation of body fluid components.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing one embodiment of the body fluid filtration device of the present invention, FIG. 2 is a sectional view of the body fluid filtration device shown in FIG. 1, and FIG. FIG. 4 is a partial sectional view of another embodiment of the body fluid filtration device of the present invention, and FIG. 5 is a partial sectional view of another embodiment of the body fluid filtration device of the present invention. 6 is a diagram showing the relationship between length and shear rate, and FIG. 6 is a circuit diagram for explaining the operation of the body fluid filtration device of the present invention. DESCRIPTION OF SYMBOLS 1...Plasma separator, 2...Housing 3...Blood inlet, 4...Blood outlet 8a, gb...Plasma outlet, 9...Bottom plate 10...O ring, 13... Plasma flow path forming body 14... Plasma separation membrane, 15... Plasma separation body, 16... Seal material, 17... Blood flow path regulating body FIG.

Claims (6)

[Claims] (1) A cylindrical housing having a body fluid inlet, a filtrate outlet, and a filtration residual liquid outlet, and formed by a top surface, a bottom surface, and a cylindrical side wall; a body fluid filter body, a body fluid flow path that guides the body fluid flowing in from the body fluid inlet to the body fluid filter body after contacting the body fluid filter body and filtering the body fluid, and then guiding the body fluid to the filtration residual liquid outlet; a filtrate flow path leading to a filtrate outflow port, the filtration residual liquid outflow port is provided on at least one of the top surface portion or the center portion of the bottom surface portion of the housing, and the body fluid inflow port is provided on the top surface of the housing. 1. A body fluid filtration device, characterized in that it is provided on the peripheral edge of the bottom surface or the cylindrical side wall. (2) The body fluid filtration device is a plasma separation device in which the body fluid inlet is a blood inlet, the filtrate outlet is a plasma outlet, and the filtrate residual outlet is a concentrated red blood cell outlet. The body fluid filtration device according to claim 1. (3) The body fluid filtration device according to claim 1 or 2, wherein the body fluid inlet is provided at a position within 2 cm from the outermost periphery of the top or bottom surface of the housing. (4) The body fluid filtration membrane has a circular shape with an outer diameter of 8 to 15 cm, and has a circular opening in the center with a diameter of 1.5 to 5.0 cm. and the outer diameter is 1
The body fluid filtration device according to any one of claims 1 to 3, wherein the ratio is 3 to 1:6. (5) The body fluid filtration body is composed of a filtrate flow path forming body, a body fluid filtration membrane enclosing the filtrate flow path forming body, and a body fluid flow path forming body provided between the body fluid filtration membranes. Claim 1
5. The body fluid filtration device according to any one of 4 to 4. (6) The body fluid inlet is provided in the cylindrical side wall of the housing so as to be parallel to the tangential direction of the body fluid filter housed in the housing.
The body fluid filtration device according to any one of the above.