JP3242461B2 - Method for collecting residual liquid in the filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering residual liquid in a filter.

[0002]

2. Description of the Related Art Conventionally, a filter has been incorporated into a blood transfusion set, for example, to remove microaggregates from blood to be transfused, or a blood purification system to remove a predetermined substance from blood. It is used for various purposes, such as being set in a circuit of No.

[0003] In the case of using the above filters, in each case, blood or the like is introduced into the filter by a head, and blood is passed through the filter by the pressure generated by the head to separate impurities and the like by filtration.

However, in the above-described filter filtration method, even if the filtration of a liquid such as blood is completed, the liquid permeated into the filter medium of the filter or contained in the separated filtered material must be recovered. Can not. For this reason, in a processing device having a filter in a circuit, there is a problem that the amount after treatment is smaller than the amount of liquid before treatment.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of recovering liquid from a filter with high efficiency when a filter is used.

[0006]

This and other objects are achieved by the present invention (1) described below. Also, (2),
(3) is preferable.

(1) A filter having a liquid supply line, a filter medium connected to the liquid supply line and having a filter medium and a deformable housing for accommodating the filter medium, and a filter directly or at a liquid outlet of the filter. A circuit having a pump connected indirectly is formed, and in a state in which communication between the inside of the filter and the outside is closed, the inside of the filter is sucked by the pump, and the pressure difference between the outside air pressure and the inside pressure of the filter is caused by the housing. A method for recovering the residual liquid in the filter, comprising: deforming the housing so as to reduce the volume of the housing, contracting the filter medium by deforming the housing, and collecting the residual liquid in the filter medium.

(2) After the pressure in the filter is reduced by suction of the liquid remaining in the filter, the blockage is released, gas is sucked into the filter, and the liquid remaining in the filter is collected. A method for recovering residual liquid in the filter according to the above.

(3) The filter medium has a bag shape, and a spacer having a gas inflow space therein is provided inside the filter medium and / or between the filter medium and the inner wall of the housing. The method for recovering residual liquid in a filter according to 1) or 2).

[0010]

In the filter, the liquid flowing from the liquid supply line is filtered. The filter is configured to be deformable, and the processed liquid is drawn out of the filter from the liquid outlet of the filter by suction of the liquid sending pump. After the supply of the liquid from the liquid supply line is completed, if the suction by the liquid supply pump is further continued in a state where the liquid inflow port is closed, the volume of the housing is reduced, so that the filter medium and the separated precipitate ( (Agglomerates) are squeezed out, and the remaining liquid is squeezed out of them, and the remaining liquid is derived and efficiently collected.

At this time, the inside of the filter is in a reduced pressure state. When the inside of the filter is further communicated with the outside air from this state, the air rapidly flows into the filter and is impregnated in the pores of the filter medium of the filter. The residual liquid can also be recovered, and the recovery rate is further improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method for recovering residual liquid in a filter according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a circuit diagram of a plasma purification system 1 using the method for recovering residual liquid in a filter of the present invention.

[0013] The plasma purification system 1, the plasma bag 2, a filter 3, a pump P _1, the chamber 4, the dialyzer 5, the pump P _2, reservoir bag 6, and a pressure gauge 7.

The plasma bag 2 contains plasma components separated from blood collected from a patient. In the plasma bag 2, a flocculant as a plasma protein fraction separating agent is previously put, and the plasma introduced into the plasma bag 2 causes the plasma in the plasma bag 2 due to the action of the flocculant. High molecular weight protein components are precipitated. The outlet of the plasma bag 2 is connected to the liquid inlet 31 of the filter 3 via a connection tube 91. The plasma bag 2 and the connection tube 91 constitute a liquid supply line to the filter 3.

The filter 3 is for removing the precipitate. This filter 3 is shown in FIGS.
As shown in FIG.
And a liquid outlet 32, and a bag-shaped sheet-like filter medium 33 is housed in the housing 30. An opening 331 communicating with the liquid inlet 31 provided in the housing 30 is formed in the filter medium 33.

The housing 30 is formed so as to be deformable, and a material for forming the housing 30 is, for example, a flexible resin material such as polyvinyl chloride, polyurethane, polyethylene vinyl, polyethylene vinyl acetate (EVA) or the like. , And, polypropylene, polyethylene, polycarbonate, polyvinyl chloride, those formed to some extent a thin hard material such as a hard resin such as acrylic, such as translucent or transparent, so that the inside can be confirmed with the naked eye, Desirably.

The housing 3 is made of a hard material as described above.
0, the housing 30 is deformed and the volume of the housing 30 is sufficiently reduced by the deformation.
And the size of the gap in the housing 30 in the natural state. The size varies depending on the material. For example, in the case of polypropylene, the thickness is about 2 mm or less, and the distance between the sheets in the natural state when the housing 30 is composed of two sheets is 5% of the diagonal line of the housing 30. It is preferable to set the following. In the case of acrylic resin, the thickness is about 2mm, 3% for the length of the diagonal line
It is preferable that

As shown in FIG. 3, the housing 30 has a rectangular shape as a whole, and a liquid inlet 31 and a liquid outlet 32 are respectively formed at or near a diagonal corner of the housing 30. It is desirable to be located at a position. Thereby, the filtering ability of the filter medium 33 and the removal and recovery of the impregnating liquid described later can be more uniformly exerted.

As shown in FIG. 2, the plasma containing the precipitate flowing from the liquid inlet 31 of the filter 3 is supplied to the opening 331.
Pass through the inside of the bag-shaped filter medium 33, the precipitate is filtered out when passing through the filter medium 33 to become purified plasma, and further formed between the inner surface of the housing 30 and the outer surface of the filter medium 33. And flows out of the liquid outlet 32.

As the filter medium 33 in the present embodiment formed in a bag shape, for example, a material in which an aggregate of fibers is formed in a sheet shape is suitably used. The fibrous body is formed by knitting synthetic fibers such as nylon, polypropylene and polyester, and may be, for example, a nonwoven fabric or a woven fabric in which synthetic fibers are uniformly stacked. The fiber may be in any form, such as a fiber composed of one or more long fibers, or a fiber in which many short fibers are entangled.

The fiber diameter is preferably from 0.1 to 20.
It is about μm, more preferably about 1 to 5 μm. The bulk density of the filter medium 33 is preferably 0.1 to 1 g / cm ³ , more preferably 0.3 to 0.6 g / cm ^3. Or bulky ones.

Examples of the filter medium 33 include, in addition to the above, porous materials such as sintered bodies, polyurethane, polypropylene, and polyethylene. The filter medium used varies depending on the size and physical quantity of the material to be filtered.

Spacers 35a and 35b are superposed on the outer and inner surfaces of the bag-shaped filter medium 33. The spacers 35a and 35b are, for example, woven fabrics,
It is made of a material having good air permeability and liquid permeability, such as a nonwoven fabric and a mesh. These spacers 35a, 35
b, as described later, lowers the pressure in the housing 30 to bring the inner wall of the housing 30 and the filter medium 33 into close contact with each other.
After the plasma is squeezed out, when the liquid inflow side is opened and air is allowed to flow in, the air can easily flow into the space of the filter medium 33.

In order to exert such an effect, it is preferable that the spacers 35 a and 35 b are a fibrous body having a coarser mesh than the filter medium 33. In this way, a sufficient inflow space for air to flow in is secured between the fibers of the spacers 35a and 35b, and the above-described effect is effectively exerted. When the spacer is a nonwoven fabric, the thickness is preferably about 20 to 1000 μm, the basis weight is about 10 to 250, and more preferably about 20 to 40.

The inlet of the chamber 4 is connected to the liquid outlet 32 of the filter 3 via a connection tube 92. When the plasma in the filter 3 is collected, air mixed with the plasma is separated in the chamber 4. Further, a pressure gauge 7 is connected to the chamber 4.

At the outlet of the chamber 4, a connecting tube 9 is provided.
The suction port of a pump P ₁ as a liquid sending pump is connected via 3. With this pump P ₁ , the plasma is drawn out of the plasma bag 2 and guided into the filter 3. In the present invention, omitting the chamber 4, connected to the inlet of the liquid outlet 32 and the pump P ₁ of the filter 3 is tube 9
3 may be directly connected. The pump P ₁
Is connected to the plasma inlet of the dialyzer 5 via a connection tube 94.

The dialyzer 5 removes excess coagulant remaining in the filtered plasma. The dialyzer 5, dialysate through the pump P ₃ from the reservoir 11, for example 400
The liquid is sent at a flow rate of about 600 ml / min and discharged into the storage tank 12. Plasma fluid outlet of the dialyzer 5 is connected to the suction port of the pump P ₂ via the connecting tube 95,
Discharge port of the pump P ₂ is connected to a reservoir bag 6.

Here, specific examples of the pumps P ₁ and P ₂ include a roller pump for the pump P ₁ , a roller pump and a centrifugal pump for the pump P ₂ , and among them, the roller pump is particularly preferable. . Moreover, the pump P ₁ is preferably also serves as a pump for liquid feed. This is because the circuit becomes simple.

A pressure gauge can be connected to the connection tube 94. The pressure in the dialyzer 5 is measured by this pressure gauge, and the detected value is input to the control means. The control means, and controls the driving of the pump, so that the pressure in the dialyzer 5 based on the detected value is maintained to a proper value, the pump P ₂ (discharge amount) adjusting the rotational speed It can also be configured. Further, between the dialyzer 5 and the pump P _2, or, between the pump P ₂ and the collection bag 6 may be provided with a conductivity sensor, by said transmission Shirubedo sensor, excess flocculant in the dialyzer 5 It is also possible to continuously check whether or not bubbles have been removed, and to detect bubbles.

The constituent materials of the connection tubes 91 to 96 are preferably flexible and capable of easily closing the inner cavity by being crushed from the outside. For example, polyvinyl chloride, polyethylene, polypropylene, PET, PBT And thermoplastic elastomers such as a polyester, ethylene-vinyl acetate copolymer, polyurethane, polyester elastomer, and styrene-butadiene-styrene copolymer. Among them, polyvinyl chloride is particularly preferable. If each connecting tube is made of polyvinyl chloride, sufficient flexibility and flexibility can be obtained, so that it is easy to handle, and is particularly suitable for closing with a clamp or the like. In addition, bag 2, filter 3, chamber 4, dialyzer This is because the bondability with No. 5 or the like becomes good.

Next, a method for recovering the residual liquid in the filter according to the present invention applied to the plasma purification system 1 having the above configuration will be described. By driving the pump P _1, the plasma in the plasma bag 2 flows into the filter 3 through the connection tube 91. Precipitate 20 already precipitated in plasma bag 2
The high molecular weight protein component as the filter material 3 of the filter 3
The plasma containing the coagulant remaining in the filter 3 and being filtered out flows from the filter 3 into the chamber 4. In the chamber 4, the plasma mixed with the air bubbles mixed in the plasma is separated. Dialyzer 5 plasma bubbles are separated by a discharge force of the pump P ₁
Sent to In the dialyzer 5, excess coagulant remaining in the plasma is removed.

The plasma flocculant dialyzer 5 has been removed, it is fed to the reservoir bag 6 by the pump P _2. As described above, the plasma containing the precipitate in the plasma bag 2 is purified by the filter 3 and the dialyzer 5, and is sequentially sent to the storage bag 6 and collected. When all the plasma has flowed out of the plasma bag 2, the connection tube 91 is closed by a closing means such as the clamp 15, for example.

As the closing means, a film having a bubble point can be used instead of the clamp.
That is, such a membrane is provided on the liquid inlet side, and after filtration, the membrane is sucked at a pressure below the bubble point in a wet state. Then, further to suck the plasma in the filter 3 continues the operation of the pump P _1.

As the pressure in the filter 3 is reduced by suction, the housing 30 is deformed and its volume is reduced. Inside the bag-shaped filter medium 33 in the filter 3, a precipitate 20 of the filtered plasma is accumulated, and the plasma is filtered by the filter medium 3.
3 and soaks in the precipitate 20 and remains.

As the residual plasma in the filter 3 is aspirated, the shape of the housing 30 is deformed in the direction of reducing the volume as described above, and as shown in FIGS. The bag-shaped filter medium 33 is sandwiched from both sides by a pair of opposing inner walls, and the volume of the filter medium 33 itself is reduced and squeezed. Due to the deformation of the housing due to the decompression, the plasma that has permeated into the voids of the filter medium 33 or into the precipitate 20 is squeezed out and collected.

Although a sufficient recovery rate can be obtained by the steps described above, in the present invention, the recovery rate can be further improved by performing the following operation. When the pressure in the filter 3 is sufficiently reduced, for example, -50
~ -600mmHg, preferably -100 ~ -400mm
When the pressure reaches about Hg, the clamp 15 closing the connection tube 91 is removed, and the air remaining in the plasma bag 2 flows into the filter 3.

In addition to the above, another air inflow path may be provided in the filter 3 so that air flows in from the air inflow path. In this case, it is preferable to provide a hydrophobic filter or a bacteria removing filter in the air inflow path.

The outside air rushes into the housing 30 due to the difference between the internal pressure of the filter 3 and the external pressure. In addition, the filter medium 33 is compressed by the housing 30 and expands from the contracted state so as to return to the original size, and the gap in the filter medium 33 expands to the original size. At this time, the housing 30
Since the outside air flows into the inside of the filter medium 33 vigorously, the outside air flows into the space of the expanding filter medium 33, and the plasma remaining in the space is blown off to the filtrate side.

The plasma detached from the filter medium 33 is supplied to the liquid outlet 3
Collected after 2nd grade. As described above, the plasma remaining in the filter 3, particularly, the plasma impregnated in the filter medium 33 can also be recovered, and the recovery rate is improved.

As described above, after the pressure in the filter 3 is reduced, the interior of the filter 3 is communicated with the outside air to restore the pressure. By the action, the plasma remaining in the filter medium 33 or the like can be uniformly removed and collected from almost the entirety of the filter medium 33.

Further, by the action of the spacers 35a and 35b, the outside air which flows vigorously reaches the entire surface of the filter medium 33 uniformly and quickly, and the effect of improving the recovery rate is further reinforced.

The method of communicating the inside of the filter with the outside air is not limited to the cutting of the connection tube 91 or the like. For example, the connection portion of the connection tube 91 with the plasma bag 2 or the filter 3 may be removed, or the connection tube 91 or the like may be removed. Communication that can be communicated by opening a cock (not shown) or the like installed in the middle of the housing, forming an opening by breaking a part of the housing 30, or breaking the housing 30 without a tube. This can be achieved by connecting the air inflow passage closed by means, and breaking the communication means. Further, it can be carried out by putting a necessary amount of air in the bag 2 in advance.

As described above, when air is introduced and collected after the pressure in the filter 3 is reduced, air bubbles may be mixed with the suctioned and recovered plasma. You. Accordingly, the plasma in the filter 3 can be continuously collected by the chamber 4 to the extent that the air flowing into the filter 3 flows into the chamber 4 together with the plasma, and the collected amount of the plasma can be increased as much as possible.

After depressurizing the inside of the filter 3, the timing of opening the inside of the filter 3 to the outside is, for example, a predetermined value of the pressure gauge 7 connected to the chamber 4 (for example, about -50 to -600 mmHg described above). The pump P
It is also possible to configure so that ₁ is stopped or notified by notification means such as a buzzer or a lamp.

When the internal pressure of the filter 3 decreases, air in the plasma bag 2 slightly enters, and air bubbles are easily generated in the plasma. By detecting the generated air bubbles, the negative pressure of the filter 3 having the negative pressure is detected. It may be configured to measure the opening timing. In this case, the connecting tube 9
A bubble detecting means for detecting bubbles in the blood plasma can be attached to 2.

As the bubble detecting means, for example, an optical sensor for detecting the presence or absence of bubbles based on the amount of transmitted light can be used. A bubble detection signal from the bubble detection means may be input to the control means, and the timing may be notified by the notification means.

On the other hand, in the dialyzer 5, each of the pumps P ₁ and P ₂ is so controlled as to prevent substances contained in the dialysate, such as endotoxin, which adversely affect the living body from flowing into the plasma. It is preferable that the discharge amounts Q ₁ and Q ₂ are set so that Q ₁ ≧ Q ₂ .

[0048] Also as described above, when being forcibly sucking the blood plasma from inside the filter 3, with a decrease in the pressure in the filter 3, the discharge amount from the pump P ₁ is lowered,
In the control means, in accordance with the decrease of the discharge amount it can also be configured to control the rotation of the pump P _2.

[0049] That is, when the discharge amount of the pump P ₁ is lowered, the pressure in the circuit between the pump P ₁ and the pump P ₂ is decreased, detecting the drop in pressure gauge 8 for detecting the pressure in the dialyzer 5 Then, the detected value is input to the control means. Control means controls the rotational speed of the pump P ₂ based on the input values from the pressure gauge. In addition, by providing a flow meter for detecting the discharge amount of the pump P _1, the pump P ₂ based on the detection value
May be configured to control the discharge amount.

As described above, the plasma purification system 1 configured as described above is configured to send plasma from the plasma bag 2 to the storage bag 6, but the liquid supply line is configured by the plasma bag 2 and the connection tube 91. It is not limited to what is done.
As another configuration example of the liquid supply line, for example, a plasma separator that separates blood collected from a blood vessel of a patient into blood cell components and plasma, and the plasma protein fraction separation into the plasma separated by the plasma separator A liquid supply line having a mixing container for mixing and dissolving the agent may be used.

According to the method of the present invention, the efficiency of recovering a liquid such as plasma from the filter 3 is significantly improved. In particular, it is particularly effective to use the method of the present invention for a filter using a filter medium having a small pore size having a high ratio of remaining in a liquid filter medium, or when performing filtration of a highly viscous liquid. . In the above description, the liquid includes blood or blood components, or a concentrated solution thereof, a fractionated liquid, or the like.

The method of the present invention is not limited to the plasma purification system 1 described above, but may be any filter used for filtering a liquid. Other types, for example, a circuit using a filter, a blood filter for blood transfusion, and a transfusion solution may be used. It can be used for a filter, and can also be used when used alone.

[0053]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. The following circuits were respectively constructed, and the recovery rate from the filter was compared under each recovery condition.

I. Circuit components <Filter A> The filter described in the above specific configuration was used (FIGS. 2 to 5).・ Housing material: Polyvinyl chloride (soft type) ・ Maximum filling capacity: 250ml ・ Filter material: Material Nylon 30 / Polyester 70 Fiber diameter 1-5μm Fiber shape Linear Bulk density 0.4g / cm ³ Filtration area 400cm ²・ Spee Sir: non-woven fabric material nylon bulk density 0.2g / cm ³

<Liquid pump> Roller pump: Roller rotation speed 11 rpm: Tube inner diameter 3.5 mm

<Plasma bag> A plasma bag heated at 37 ° C. to dissolve a coagulant and containing 360 ml was used. Plasma: Bovine blood was obtained by centrifugation. Coagulant: sodium chloride 84 g glycine 53.2 g

II. Circuit Configuration The plasma bag was connected to the liquid inlet of each of the filters A, and the liquid pump was connected to the liquid outlet of the filter A.

III. Recovery method The plasma in the plasma bag was collected at 30 ml /
Suctioned and filtered at min. When the plasma in the plasma bag was emptied, the following method was performed as a method for recovering the plasma from inside the filter A, the filtrate discharged from the pump was recovered, and the amount was measured.

Example 1: In the circuit of filter A, when the plasma bag is empty, the tube connecting the plasma bag and filter A is clamped (closed) to prevent air from flowing into filter A. Perform squeezing, remove the clamp when the filter internal pressure became -250 mmHg, let the air in the plasma bag flow in, stop the pump when air bubbles came out continuously for more than 1 minute from the liquid outlet The recovered amount was measured.

Example 2 In the circuit of the filter A, when the plasma bag was emptied, the tube connecting the plasma bag and the filter A was clamped (closed) and squeezed while preventing the air from flowing into the filter A. The pump was stopped when the internal pressure of the filter became -250 mmHg, and the amount recovered was measured.

COMPARATIVE EXAMPLE 1 In the circuit of filter A, collection was performed by operating a pump without suddenly flowing air into filter A without clamping between the plasma bag and the tube connecting filter A. When air bubbles continuously came out from the liquid outlet for one minute or more, the pump was stopped and the amount recovered was measured.

IV. Example 1 Table 1 shows the values obtained in Examples and Comparative Examples as described above.

[0063]

[Table 1]

As shown in Table 1, Examples 1 and 2
It is clear that the recovery rate of the plasma was better than that of the comparative example, and the values were significantly different. In particular, in Example 1, the collection efficiency is extremely good.

[0065]

As described above, according to the method for recovering residual liquid in a filter of the present invention, the efficiency of recovering a liquid such as plasma from the filter is significantly improved. In particular, the effect is remarkable for a filter using a filter medium having a small pore size, which has a high ratio remaining in the liquid filter medium, or when filtering a highly viscous liquid.

Further, when a method of recovering liquid by flowing outside air is used, the recovery rate is further improved. In this method, if a filter having a spacer is used,
The effect of the outside air inflow is further exhibited.

On the other hand, in the present invention, since the inside of the filter is depressurized by using the liquid feed pump installed in the circuit, there is no need to separately provide a dedicated decompression means or the like, and the circuit configuration does not become complicated. .

[Brief description of the drawings]

FIG. 1 is an overall circuit diagram of a plasma purification system embodying the present invention.

FIG. 2 is a sectional side view of a housing, a liquid inlet, and a liquid outlet when the filter is performing a filtering action.

FIG. 3 is an overall perspective view of the filter in a state where the filter is exerting a filtering action.

FIG. 4 is a cross-sectional side view of a housing, a liquid inlet, and a liquid outlet when the filter is depressurized and squeezed.

FIG. 5 is an overall perspective view of the filter in a state where the filter is depressurized and squeezed.

[Explanation of symbols]

1 Plasma Purification System 2 Plasma Bag 3 Filter 30 Housing 31 Liquid Inlet 32 Liquid Outlet 33 Filter Material 331 Opening 34 Space 35a, b Spacer 4 Chamber 5 Dialyzer 6 Storage Bag 7 Pressure Gauge 91-96 Tube 11,12 reservoir 15 clamp 20 precipitates P ₁ to P ₃ pump

Continuation of the front page (56) References JP-A-4-135568 (JP, A) JP-A-53-137595 (JP, A) JP-A-49-12691 (JP, A) Jpn. (U, U) Shokai 49-134697 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) A61M 1/34

Claims (3)

(57) [Claims] 1. A filter having a liquid supply line, a filter medium connected to the liquid supply line and having a filter medium and a deformable housing for accommodating the filter medium, and a liquid outlet directly or indirectly connected to the liquid outlet of the filter. A circuit having a pump connected to the filter, and in a state in which communication between the inside of the filter and the outside is closed, the inside of the filter is sucked by the pump, and the housing is caused by a pressure difference between an outside air pressure and an inside pressure of the filter. A method for recovering a residual liquid in a filter, comprising deforming the housing so as to reduce the volume thereof, contracting the filter medium by deforming the housing, and collecting the residual liquid in the filter medium. 2. The method according to claim 1, wherein after the pressure inside the filter is reduced by suction of the liquid remaining in the filter, the blockage is released, gas is sucked into the filter, and the liquid remaining in the filter is recovered. How to collect residual liquid in the filter. 3. The filter medium has a bag shape, and a spacer having a gas inflow space therein is provided inside the filter medium and / or between the filter medium and the inner wall of the housing. Or the method for recovering residual liquid in the filter according to 2.