JPS63234973A - Apparatus for controlling ultrafiltration quantity - 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 (Field of Industrial Application) The present invention relates to an apparatus for continuously and accurately measuring the weight of an ultrafiltrate in, for example, a blood dialysis machine.

[Conventional technology]

Generally, in medical dialysis systems, substances are exchanged between blood and dialysate, and one of the important purposes of this exchange is to remove excess water from the blood.

Conventionally, there has been a device that removes water from the blood flow path, that is, measures and controls the ultrafiltrate, without reducing the efficiency of dialysis, that is, without recirculating the discharged precipitate and supplying fresh dialysate. As a method, for example, JP-A-52-72379
No. 107198/1983, Japanese Patent Application Laid-Open No. 1983-107198
-64059 Publication, and also “Measurement and Control J, 22, [
4], Sho 58-4, p. 388.

Among these, the dialysis apparatus described in Japanese Patent Application Laid-open No. 59-64059 (hereinafter referred to as the conventional apparatus) is the one closest to the present invention, and this conventional apparatus will be explained below with reference to FIG.

This conventional device has a preparation mode, a steady mode, and a measurement mode, and the amount of ultrafiltration is measured by switching the modes in this order.

Fresh dialysate sent from the patient's supply device 4 is introduced into the left ventricle of the metering tank 2 via the solenoid valve v1. This metering tank 2 is divided into the left ventricle and the right ventricle by the inelastic II 3, and the fresh dialysate in the left ventricle is partially accumulated in the left ventricle by moving the membrane 3 to the right ventricle, while the surplus is It is expelled from the left ventricle. Furthermore,
Fresh dialysate is supplied by a liquid pump 5, a flow meter 6, and a constant flow valve v2.
It flows into the dialyzer 1 through the .

The waste dialysate discharged from the dialyzer 1 is sucked by the negative pressure pump 7 and is discharged to the outside of the system through the three-way solenoid valve v5.

Here, the waste dialysate that was in the right chamber of the if ffi tank 3 is pushed out as the membrane 3 moves to the stone chamber, and is similarly discharged out of the system via the solenoid valve v4.

At this time, a blood side pressure sensor (not shown) provided in the blood line (indicated by A and V in the figure) and a dialysate side pressure sensor 9 connected to the dialysate outlet path of the dialyzer 1 are connected. The signals are sent together to the microprocessor 8, and the rotational speed of the negative pressure pump 7, i.e., the dialysate side of the dialyzer 1, is adjusted so that the transmembrane pressure difference between the two corresponds to a preset transmembrane pressure difference. negative pressure is adjusted.

When the left chamber of the double metering tank 2 on the L chamber is filled with fresh dialysate, that is, when the inelastic 1I13 comes into close contact with the right wall, the mode is switched to the steady mode, and the dialyzer 1 The rotational speed of the negative pressure pump 7 is adjusted so that the amount of dialysate passing through the dialysis fluid becomes approximately equal and the crotch pressure difference becomes the set value.

Next, after a certain dialysis time in the steady mode has elapsed, the mode is switched to the ultra-overdose measurement mode.

At this time, the solenoid valve v1 is closed, the three-way solenoid valve v5 is connected to the measuring tank 2 side, and the liquid feeding pump 5 is activated.

Therefore, a closed circulation circuit is formed through the left ventricle of the metering tank 2, the liquid pump 5, the dialyzer 1, and the negative pressure pump 7.

Therefore, the right ventricle of the dialyzer 1 is filled with the same amount of dialysate that was filling the left ventricle, and only the amount of water removed from the blood side in the dialyzer 1 by the negative pressure pump 7 is measured by the manometer. It is accumulated within 10.

The increase in the manometer 10 during this certain period of time is calculated by the head pressure gauge 1.
This was a dialysis device that determined the amount of filtrate above the limit by detecting the amount of filtrate.

[Problem that the invention seeks to solve]

However, the above conventional device has the following problems.

■ The amount of water removed by the conventional device is 211 in 1 minute! The amount of I is very small, ranging from 0.7 ml to 16.71111 ml, and the range of the actual measured amount is wide. Detecting such a small amount of ultrafiltration as a change in the head pressure of the manometer requires a very thin manometer, and errors such as water droplets that adhere to the pipe wall and are not discharged cannot be ignored. Therefore, in order to ensure a wide measurement range for the amount of water removed, the manometer must be long and thin, which not only makes it difficult to store inside the dialysis machine, but also damages nearby electronics if water overflows from the top. It may damage the equipment and cause errors.

■ Conventional equipment causes sudden pressure changes as described below.
It is extremely difficult to sufficiently adjust this using an ultra-overpressure control system, and it is difficult to control the amount of ultrafiltration with high precision.

A. If there is a change in the supply pressure of dialysate by the supply device 4, this will be directly linked to a change in the pressure of the dialysate supply line, resulting in a change in the movement speed of the membrane 3, and furthermore, the piping after the three-way solenoid valve V5 will change. This leads to a change in pressure loss, which in turn causes a fluctuation in the discharge pressure of the negative pressure pump 7.

B. When the mode is switched to the steady mode, the movement of the membrane 3 is stopped, so the pressure in the left chamber of the tank 2, which was conventionally almost atmospheric pressure, suddenly rises to the supply pressure from the feeder supply device 4.

C0 Furthermore, when switching to the metering mode, the solenoid valve v3 is opened, so the pressure in the left chamber of the tank 2 momentarily becomes almost atmospheric pressure, and then the boost pump 5 starts operating.
Large pressure changes occur.

D. In the steady mode, the boost pump 5 is stopped, but this boost pump 5 is difficult to apply to the high ultra-high performance dialyzers that have recently started to be used. This is because in such a dialyzer, the pressure on the dialysate side is also negative, but in conventional devices, the boost pump 5 is stopped, which causes pipe resistance in the dialysate flow path, and also causes the dialysate to become dialysate. This is because stable negative pressure cannot be obtained because the fluid is supplied to the dialyzer only by the pressure of the supply source.

E. In general, the correlation between ultrafiltration pressure and ultrafiltrate amount is not a linear straight line passing through the origin, but an approximate straight line that does not pass through the origin, as seen in Japanese Patent Laid-Open No. 158865/1983. Therefore, the ultra-overpressure calculation formula found in the prior art device publication has problems such as not being able to obtain the desired ultra-overpressure amount.

■ Extreme - Excess amount can be controlled accurately, but because it requires a large number of switching valves and metering pumps with complicated mechanisms, the reliability of the device is lacking and the cost is high.

■ The dialysate is designed to pass through the total volume measuring tank 2, but since the dialysate side flow path of the dialyzer is operated under negative pressure, gas is generated and the dialysate flows through the measuring tank 2 while the dialysate is circulating. No. 2, the ultraviolet-excess amount cannot be accurately measured due to contamination with the right ventricle.

The purpose of the present invention is to solve the problems of the conventional devices mentioned above, especially the low reliability of the water removal measurement method, the difficulty in controlling the ultrafiltration pressure with high accuracy and stability, and the complicated measurement mechanism. etc., the ultrafiltration rate measurement accuracy and reliability are both high.
It is an object of the present invention to provide a small and inexpensive ultra-overflow control device.

[Means for solving problems]

The present invention consists of the following configuration. That is, (1) (a) a dialyzer consisting of a blood flow path, a dialysate flow path, and a dialysis membrane that distinguishes these two flow paths and leads out the ultrafiltrate from the blood flow path to the dialysate flow path; (b) a blood-side pressure detector provided in the blood flow path; (c) a supply liquid cutoff valve that cuts off the supply of dialysate to the dialyzer; and (d) a movable diaphragm that connects the primary chamber. (e) After passing through the supply liquid cutoff valve, one side is branched and connected to the primary chamber of the n volume tank, and the other side is connected to the inlet of the dialyzer. a connected dialysate introduction path; (f) a dialysate-side pressure detector provided in the dialysate introduction path and/or dialysate outlet path of the dialyzer; and (g) a dialysate flow path of the dialyzer. a negative pressure pump that generates negative pressure; (a) a drain cutoff valve that cuts off the discharge of the drained precipitate discharged from the dialyzer; (l) connected to the outlet of the dialyzer, and after passing through the negative pressure pump, one side is branch-connected to the secondary chamber of the metering tank;
The other side is an extreme F consisting of a dialysate lead-out path leading to a drainage shutoff valve.
In the VA amount control device, (e) a constant flow valve provided in the dialysate introduction path; (w) weight measuring means for measuring an ultrafiltration weight between the dialyzer and the drain cutoff valve; An ultra-overcontrol device characterized by comprising:

(2) The weight measuring means includes: (a) a load cell fixed at a fixed height; and (b) a flexible bag-like container suspended from the load cell and having an opening communicating with the atmosphere at its upper end. (c) a flexible tube whose one end is connected to the lower end of the flexible bag-like container and whose other end is connected to the dialysate outlet path; and (d) to process the magic detection value from the load cell. and a weight controller that transmits the detected value to the transmembrane pressure differential control means.

(Function) The constant flow valve of the present invention constantly adjusts the flow rate fluctuation of fresh dialysate that occurs in the primary flow path of the constant flow valve, and adjusts the flow rate of fresh dialysate flowing into the dialyzer to a preset flow rate. Adjust to

Next, the waste dialysate ultrafiltered by the negative pressure pump flows from the dialysate lead-out path into the left ventricle with an equal amount of fresh dialysate stored in the right chamber of the metering tank, and excess waste is removed. The sent liquid, that is, the amount of water removed, flows into the weight measuring means, and the ultrafiltration amount (
The weight of only the water removed (amount of water removed) is measured.

〔Example〕

An embodiment of the present invention will be described in detail using FIGS. 1 to 5.

FIG. 1 shows a flow filter of the apparatus of the present invention, and 21 is a dialyzer, which passes through a blood side flow path A through a dialysis membrane (not shown).
, a dialysate introduction path B which is a flow path from the supply device 22 to the inlet port (not shown) of the dialyzer 21 , and a flow path from the outlet port (not shown) of the dialyzer 21 to the drain cutoff valve 32 . A dialysate outlet channel C is connected thereto.

The dialysate introduction path B is connected to the equipment described below.

That is, the dialysate supply devices 22 and 23, which prepare and prepare fresh dialysate in advance, are supply liquid cutoff valves that are opened and closed by control signals from the switching means 24.

Reference numeral 25 denotes a constant pressure valve for preventing fluctuations in the supply pressure of fresh dialysate by the supply Vc unit 22 from directly affecting the dialyzer 1, and for maintaining the pressure constant. The type of constant pressure valve 25 is a self-cutting pressure regulating valve that operates based on a preset pressure using the internal pressure of the dialysate introduction channel B as a pilot pressure, but it is controlled by a controller (not shown). It is more preferable to use an automatic pressure regulating valve that opens and closes at the same time. 26 is
This pump is a pressure booster pump for further boosting the pressure of the fresh dialysate coming out of the constant pressure valve 25 in order to stably supply it, and its type is preferably a vortex pump, a gear pump, or the like. Reference numeral 27 denotes a measuring tank, which is divided into two by an elastic membrane 28 into a left chamber that temporarily stores fresh dialysate and a stone chamber that temporarily stores discharged analytical solution. Furthermore, after this total ff1lf127, a branch pipe H is connected from the chamber to the dialysate introduction path B between the constant pressure valve 25 and the pressure boost pump 26.
is connected to the left ventricle, and from the left ventricle there is a discharge precipitate flow path C, which will be described in detail later.
A branch E that communicates with is connected. 48 is a constant flow valve for keeping the flow rate of fresh dialysate constant, and has the same structure as the mechanical self-blade flow valve ff114@, which is generally used in the industrial field, regardless of changes in the negative pressure pump 49. ,
The rate of supply of dialysate to the dialyzer 21 (usually 100ml/
min> is controlled to be constant. 29 is a flow meter.

The dialysate outlet path C is a flow path for discharging the discharged analysis liquid and the ultrafiltered liquid in the dialyzer 21 to the outside of the system, and the equipment described below is connected to this flow path C. There is.

That is, 49 is a negative pressure pump for generating negative pressure in the dialysate flow path of the dialyzer 21, 30 is a dialysate pressure sensor that detects this negative pressure, 31 is a blood pressure sensor 40,
This is a microprocessor that sends a control signal to the negative pressure pump 49 in order to keep the pressure difference detected by the dialysate pressure sensor 30 (hereinafter referred to as crotch pressure difference) constant.

Note that the dialysate pressure sensor 30 may be provided in either one or both of the dialysate inlet path B and dialysate outlet path C depending on the required dialysate pressure accuracy. The drained analysis solution side flow path C that has passed through the negative pressure pump 49 joins the branch pipe E at a branch point F, and then a drain cutoff valve that shuts off the drained analysis solution flowing through the drained analysis solution flow path C. 32. Further, reference numeral 24 is a controller 1 to 2 which sends a control signal to the supply liquid cutoff valve 23 and the drained liquid cutoff valve 32, and opens and closes both valves at regular intervals.

Reference numeral 33 denotes a small measuring means for measuring the amount of water removed by ultrafiltration from the blood side flow path A to the dialysate outlet path C via the dialysis membrane.
, a flexible tube 36, and a weight controller 1 to a roller 37.

FIG. 5 is a peripheral view of the measuring bag 35, and FIG.
Figure (B) shows a state in which the water removed liquid flows into the bag from the flexible tube 36 connected to the lower end and is stored therein. Although not particularly shown, the load cell 34 is fixed at a constant height position, and a hook 38 is fixed to the lower movable part. This load cell 34 has a measurement accuracy of ±2 to 4% for a general ultrafiltration amount of 200 to 5000 cc.
It is possible to measure the weight of water removed with moderate accuracy.

The weighing bag 35 is a sealed bag made of a flexible elastic membrane made of silicone rubber, soft vinyl chloride resin, etc., which is suspended from the hook 38 of the load cell 34 and expands freely when the inside is filled with liquid. It's a bag. The flexible tube 36 has one end connected to the lower end of the measuring bag 35 and the other end connected to the dialysate outlet path C, for example.
Flexible tubes such as nylon tubes and silicone tubes. The weight controller 37 is a controller that displays the weight detected by the load cell 34 and issues an alarm signal when the weight exceeds a specified weight.

Next, the operation of this device will be explained based on FIGS. 2(A) to 2(C).

(A> Figure is the preparation mode, which is the preparation stage before transitioning to the steady mode, which is normal ultrafiltration operation. Figure 8 is the steady mode, in which ultrafiltration is performed regularly. Figure 0 is the fixed time period. It is a figure which shows the measurement mode which measures the ultra) filtration amount after elapsed time.

Note that the thick lines in the figure indicate that the dialysate flows in and out in the flow path of each mode.

In the Dongfeng Anyup preparation mode (Fig. A), both the supply liquid cutoff valve 23 and the drain liquid cutoff valve 32 are set to the open state in advance.

The fresh dialysate from the dialysate supply device 22 passes through the supply liquid cutoff valve 23 and is adjusted to a constant liquid supply pressure by the constant pressure valve 25, and then a portion flows to the boost pump 26, but most of it flows through the flow path resistance. The elastic membrane 28 flows into the right chamber of the measuring tank 27, which has a low temperature, through the branch point G and the branch pipe H until it comes into close contact with the left wall of the measuring tank 27.

(In this case, the remaining drained dialysate in the left chamber of the metering tank 27 is passed through the elastic membrane 28 and discharged to the dialysate outlet path C.) When the right chamber is filled with fresh dialysate, the fresh dialysate is The supply pressure is further increased by the boost pump 126, and then the constant flow valve 4
The flow rate into the dialyzer 21 is adjusted at step 8, and flows into the dialyzer 21 via a flowmeter 29.

In this dialyzer 21, the dialysate side flow path C is maintained at a specified negative pressure by the negative pressure pump 49, so an ultrafiltration effect occurs, and the amount of water removed from the blood side flow path is further added to the dialysate. Both flow into the discharged analysis liquid channel C.

At this time, the negative pressure pump 49 is controlled by the microprocessor 31 so that the transmembrane pressure difference matches a preset crotch pressure difference in order to keep the water removal ability of the dialyzer 21 constant.

The discharged precipitate that has passed through the diaphragm die 21 and the negative pressure pump 49 joins the liquid pushed out from the left chamber of the 1tffi tank 27 and is discharged outside the system through the drain cutoff valve 32.

In the steady mode shown in the above figure (B), the supply liquid cutoff valve 23 and the drain liquid cutoff valve 32 are both open, the elastic membrane 28 in the measuring tank 27 is in close contact with the left wall, and the fresh dialysate is kept constant. Constant flow rate and constant transmembrane pressure; this is a mode in which filtration continues.

Measuring mode When ultrafiltration in the steady mode shown in diagram (B) has elapsed for a certain period of time, the supply liquid cutoff valve 23 and drain liquid cutoff valve 32 are closed according to instructions from the microprocessor 31, and the mode shifts to the metering mode shown in diagram (C). do.

While the supply of fresh dialysate from the dialysate supply device 22 is cut off by closing the supply liquid cutoff valve 23, negative pressure from the negative pressure pump 49 is applied to the dialysate outlet path C, so that the metering tank 27 is The fresh dialysate temporarily stored in the right ventricle is supplied to the dialyzer 21 through the branch pipe H1 and the dialysate introduction path B, where it undergoes ultrafiltration. The amount of water removed ultrafiltered from the blood side flow path A to the dialysate flow path and the discharged analytical solution are determined by the drain cutoff valve 3.
2 is closed, the elastic membrane 28 of the measuring tank 27 is pushed to the right, and the drained analyte equal to the fresh dialysate stored in the right ventricle flows into the left ventricle, causing the excess to be drained. The separated solution, ie, the amount of water removed, flows into the measuring bag 35 through the flexible tube 36.

Here, load cell 3 immediately after transitioning to weighing mode
Figure 3 (A> and (
This will be explained in detail based on B).

Point (a) in Figure 3 (8) shows that the dialysate pressure drops instantaneously because the discharge pressure of the negative pressure pump 49 drops the moment the steady mode is switched to the metering mode. .

(The reason is that in the steady mode, there is atmospheric pressure + some flow path resistance of the dialysate lead-out path C including the drain cutoff valve 32,
In the measurement mode, both the primary and secondary sides of the negative pressure pump 49 are shut off, but since there is storage space for the discharged analysis solution in the measurement tank 27 and the measurement bag 35, the flow path resistance is low and the flow resistance increases instantly. This is because the atmospheric pressure drops. ) Therefore, the limit-excess liquid range increases as shown at point (a) in Figure (A>), but the pressure control system follows after a few seconds, so the limit is increased as shown at point (b) in Figure (B). The pressure returns to P.

Then, at point (C) in Figure (A), when the right chamber of the metering tank 27 is completely filled with waste dialysate, the suction side of the negative pressure pump 49 is closed, so there is no excessive negative pressure on the dialyzer 21. Pressure is applied, and excessive ultrafiltration is performed as shown at point (c) in Figure (A>). At the same time, the dialysate pressure also drops instantaneously as shown at point (c) in Figure (B).

Therefore, the figure (A) after several seconds have passed after entering the weighing mode.
If you start measuring from point (b) in ) and measure the weight change of the load cell 340 up to point (d) in figure (A>) before the measuring tank 27 is completely filled with waste dialysate, you will find unnecessary dialysate pressure. It is possible to plan the period for highly accurate water removal while avoiding fluctuations.

The weight detected by the load cell 34 from FIG.

Next, the weight of the weighing bag 35 detected by the load cell 34 is sent to the weight controller 37.

The weight controller 37 controls the weighing bag 3 set in advance.
5 and the actual amount of water removed excluding the tare amount M of the flexible tube 36 itself, and transmits this weight signal to the microprocessor 31. Upon receiving this weight signal, the microprocessor 31 changes the specified negative pressure if the amount of water removed per unit time, that is, the amount of ultrafiltration is an abnormal value. Note that the amount of water removed from the dialyzer 21 is the same volume as that of the right ventricle of the measuring tank 27, so the fresh dialysate stored in the right ventricle of the measuring tank 27 before the steady mode is equivalent to the IJE fluid. flows into the left ventricle, and at the same time, the discharged precipitate equivalent to the amount of water removed flows into the measuring bag 3.
5. Also prepare the transmembrane pressure in this measurement mode.
Since the microprocessor 31 adjusts the differential pressure to be the same as in the steady mode, the amount of ultra-extreme fluid corresponding to the membrane performance of the dialyzer 21 and the crotch differential pressure is transferred to the dialysate outlet path C.

When the metering mode ends, the supply liquid cutoff valve 23 and the drain liquid cutoff valve 32 are opened to shift to the preparation mode, and the fresh dialysate that has passed through the supply liquid cutoff valve 23 flows into the right chamber of the metering tank 27. Therefore, the discharged precipitate filled in the left chamber of the elastic membrane 28 is swept away to the discharged precipitate outlet path C, and the weighing bag 35
Since the internal pressure of the weighing bag 35 is higher than the atmospheric pressure, the removed water stored therein naturally falls into the discharged precipitate outlet path C and is discharged to the outside of the system.

In this way, the above three cycles are repeated one after another,
Normal dialysis occurs.

In the apparatus of the present invention configured as described above, the set transmembrane pressure (TMPs) can be determined from the measured ultrafiltration ffi (Qn) using the following calculation formula.

TMPN =P8n -PDn -A QV =f (Qn) TMPs = (QS /QV)XTMPNHowever, T
MPN: Current transmembrane differential pressure TMPS: Set crotch differential pressure PBn: Current blood side pressure PDn: Current dialysate side pressure A: Dialysate side pressure correction constant Qn: Measured ultrafiltration rate Qv: Qn Correction value QS: Target ultrafiltrate volume □ According to the device of this embodiment, the present invention has the following remarkable effects.

■ By providing the constant pressure valve 25, the dialysate supply device 2
Disturbances such as pressure fluctuations that spread from the dialyzer 2 to the dialyzer 21 and pressure fluctuations in the dialysis flow path due to mode switching can be prevented, and the intermembrane pressure can be controlled with high precision.

■ By providing the constant flow valve 48, the dialysate lead-out path C
Since the amount of discharged precipitate flowing into the pump 49 is approximately constant, stable operation of the negative pressure pump 49 with a constant negative pressure is achieved.

(2) By providing the negative pressure pump 49, it is also possible to perform dialysis in which the dialysate pressure is made negative with respect to atmospheric pressure. This improves the medium molecule removal performance, which inevitably increases the ultrafiltration performance (therefore, a large amount of ultrafiltrate can be obtained with a small pressure difference between the legs), which can solve the problem. .

(2) Furthermore, the number of solenoid valves for switching the dialysate flow path can be reduced from four in the conventional device to only two (supply fluid connection valve 23 and drain fluid cutoff valve 32) in the present invention. Therefore, the device can be simplified.

- Since the amount of water removed is measured by weight detection using the load cell 34, it is possible to measure minute amounts with higher measurement accuracy than conventional dialysis devices. Further, connect the branch pipe E from the dialysate lead-out path C and the branch of the flexible tube 36 to the measuring tank 27 first, and then connect the branch pipe to the measuring bag 35 as shown in FIG. In addition, by branching the branch pipe E from below the dialysate outlet path C, the mixed gas can be preferentially introduced into the metering bag 35 without flowing into the metering tank 27.

■ Since the old issue bag 35 measures weight rather than volume, there is no accuracy window as described above associated with volumetric methods such as liquid level measurement. Conventional devices that measure the liquid level of water head pressure are designed to measure the liquid level by pre-setting a long thin tube that can accommodate the maximum amount of filtration liquid.
In contrast, the apparatus of this embodiment is simply constructed of a flexible film and is therefore easy to handle.Furthermore, the metering bag 35 is expandable and retractable.
B) As shown in the figure, the shape can be freely changed depending on the amount of ultra-extra liquid, and a wide range of liquid amounts can be stored compactly.

Next, FIG. 6 shows a flow filter showing another embodiment of the present invention, which differs from the embodiment shown in FIG. a temperature adjustment device 41 installed on the secondary side of the booster pump 26, a flow switch 42 installed on the secondary side of the constant flow valve 48, and a dialysate outlet point. A gas-liquid separation tank 43 provided at the branch point of the branch pipe E from the path C, and a three-way electromagnetic piece 4 provided in the bypass path I of the drain cutoff valve 32.
4, the upper part of the measuring cylinder 50 is made into a cylindrical shape, and the other devices with the same numbers as in FIG. 1 are the same as in FIG. 1.

The temperature adjustment device 41 includes a heater 45, a temperature detection end 46, and a temperature controller 47, and is used to raise and maintain the temperature of fresh dialysate up to the human body temperature. It is constantly controlled by a temperature controller 47 based on the temperature detected by the temperature detection end 46. The flow switch 42 displays the flow rate of fresh dialysate and issues an alarm if the flow rate exceeds the upper or lower limit of the specified flow rate. The gas-liquid separation tank 43 further improves the performance of gas-liquid separation of the discharged precipitate explained in FIGS. 1 and 4, and has a vertically long cylindrical shape with shadows on the sides. A dialysate lead-out path C from the pressure pump 49 is connected to the measuring cylinder 5 from the top.
A dialysate lead-out path C to 0 is further connected to a branch pipe E that communicates with a measuring tank 27 from the bottom. In addition, the measuring cylinder 50
The upper part of the dialysate is open to the atmosphere, and the gas contained in the dialysate is released to the outside to ensure more reliable drainage.

The three-way solenoid valve 44 is provided in the bypass path I of the drain cutoff valve 32, and in the preparation mode and steady mode, the port (a) is closed together with the drain cutoff valve 32, and the port (b) and the port (b) are closed. C) is opened to ensure that the waste dialysate stored in the bag 35 in the previous measurement mode is discharged out of the system via the bypass path G. In the metering mode, ports (a) and (b) are open, port (c) is closed, and the amount of fluid that is ultrafiltered from the dialyzer 21 is transferred to the bag 3.
It is accumulated within 5. In addition, when switching from the steady mode to the metering mode, immediately before switching, open ports (c), (a) and (b) of the three-way solenoid valve 44, and open the ports (a) and (b) of the three-way solenoid valve 44 from the gas-liquid separation tank 34 to the three-way solenoid valve 44. It is preferable to expel the air stagnant in the bypass path I to the measuring tube 50. Since the three-way solenoid valve 44 is in preparation and in the steady mode, the port of the master cylinder 50 is connected to the discharge side, so even if the discharge pressure becomes higher than atmospheric pressure, the discharged precipitate flows into the measuring cylinder 50. prevent

According to the embodiment device explained in FIG.
In addition to the embodiment device explained in the figures, the following remarkable effects are further layered.

By using the right chamber of the measuring tank 27 as a flow path through which fresh dialysate temporarily passes, the dialysate supply device 22 is normally used after dialysis is completed.
Instead, if a cleaning liquid supply device is temporarily installed, cleaning efficiency in the metering tank 27 can be increased by water cleaning, chemical cleaning, etc.

The temperature adjustment device @ 41 can adjust the temperature of the fresh dialysate to the human body temperature, and the flow switch 42 controls the flow caused by the rupture of the dialysate introduction path B, elastic membrane 28, etc. in the steady mode.
In addition to the decrease, the elastic membrane 28
is in close contact with the right wall of the measuring tank 27, and an abnormal flow rate of fresh dialysate can be detected, such as when fresh dialysate is still flowing even when the training mode is completely completed.

Furthermore, the gas mixed into the gas-liquid separation tank 43 from the dialysate outlet path C along with the waste dialysate floats upward due to the difference in specific gravity, and only the waste dialysate with a higher specific gravity accumulates below. This waste dialysate is stored in the metering tank 27 via the branch pipe E by the discharge pressure of the negative pressure pump 49. On the other hand, the gas in the upper part of the gas-liquid separation 4I43 flows into the measuring cylinder 50 through the bypass path I, ports (a) and (b) of the three-way solenoid valve 44, and is discharged to the outside from the opening at the top of the measuring cylinder. be done.

〔Effect of the invention〕

Since the present invention has the above configuration, the following effects are achieved.

■Since the amount of water removed is measured by weight detection with high measurement accuracy,
A highly accurate and reliable ultra-overflow control device can be obtained compared to the liquid level detection of conventional devices.

Therefore, there is no need to worry about preparing a long and thin manometer, deteriorating measurement accuracy due to droplets adhering to the manometer, overflowing from the upper end, breakage, etc. as in the conventional device.

(2) Since a constant flow valve is provided in the dialysate flow path, the flow rate of fresh dialysate supplied to the dialyzer is stabilized.

As a result, pressure fluctuations in the dialysate side flow path are reduced, the operation of the negative pressure pump becomes quieter, and highly accurate ultrafiltration measurement becomes possible.

■ Abnormal amounts of water removed due to pressure fluctuations in the dialysate flow path that occur when switching from steady mode to metering mode or from metering mode to unit price mode are excluded from the water removal amount measurement target by the action of the Im controller of the weight measuring means. So,
More accurate ultraviolet and filtration rate measurement accuracy can be obtained compared to current devices.

Further, since the weight measuring means is a combination of a load cell, a flexible bag-like container, and a flexible tube, a weight measuring means with high measurement accuracy can be obtained simply and at low cost.

[Brief explanation of the drawing]

Fig. 1 is a flow rotor showing an embodiment of the device according to the present invention, Fig. 2 is an explanatory diagram of its operation, Fig. 3 (A> is a diagram showing the lff1 output value of the load cell, and Fig. 3 (B) is a diagram showing the lff1 output value of the load cell. Figures 4 and 5 are diagrams showing changes in dialysis pressure, Figures 4 and 5 are diagrams explaining the configuration of the weight measuring means, and Figure 6 is a flow filter showing another embodiment of the apparatus according to the present invention. is an explanatory diagram of the operation of a conventional device. Brief explanation of the drawing 2 shows a dialyzer 22: dialysate supply device 23: supply fluid cutoff valve 24: switching means 25: constant pressure valve
26: Boost pump 27: if foot tank
28: Inelastic membrane 29: Flowmeter 30 = Dialysis fluid pressure sensor height 31: Microprocessor 32: Drainage cutoff valve 33: Weight measuring means 34: Load cell 35: Weighing bag 36: Flexible tube 37: Weight controller 38 :Hook 39: Missing number 40:
Blood pressure sensor 41: Temperature adjustment device 42: Flow switch 43: Gas-liquid separator 44: Three-way solenoid valve 45
: Heater 46: Temperature detection end 47: Temperature controller 48: Constant flow valve 49: Negative pressure pump
50: Measuring tube patent applicant Toshi Co., Ltd. (
A) (s) Figure 5

Claims (2)

[Claims] (1) (a) A dialyzer consisting of a blood flow path, a dialysate flow path, and a dialysis membrane that distinguishes these two flow paths and leads out the ultrafiltrate from the blood flow path to the dialysate flow path; (b) A blood-side pressure detector provided in the blood flow path; (c) A supply liquid cutoff valve that cuts off the supply of dialysate to the dialyzer; (d) A movable diaphragm that connects the primary chamber and the secondary chamber. (e) After passing through the supply liquid cutoff valve, one side is branched and connected to the primary chamber of the metering tank, and the other side is connected to the inlet of the dialyzer. (f) a dialysate-side pressure detector provided in the dialysate introduction path and/or dialysate outlet path of the dialyzer; and (g) generating negative pressure in the dialysate flow path of the dialyzer. (h) an intermembrane pump that controls the negative pressure pump so that the transmembrane pressure difference detected by the blood side pressure detector and the dialysate side pressure detector matches a specified transmembrane pressure difference; differential pressure control means; (l) a drain cutoff valve that blocks discharge of waste dialysate discharged from the dialyzer; (v) switching means that intermittently switches the supply liquid cutoff valve and the drain cutoff valve. (l) connected to the outlet of the dialyzer, and after passing through the negative pressure pump, one side is branch-connected to the secondary chamber of the metering tank;
The other is an ultrafiltration rate control device consisting of a dialysate lead-out path leading to a drain cutoff valve, (E) a constant flow valve provided in the dialysate introduction path, and (W) the dialyzer and the drain fluid. 1. An ultrafiltration rate control device comprising: a weight measuring means for measuring an ultrafiltration weight between the cutoff valve and the cutoff valve. (2) The weight measuring means includes: (a) a load cell fixed at a constant height; and (b) a flexible bag-like container suspended from the load cell and having an opening communicating with the atmosphere at its upper end. (c) a flexible tube whose one end is connected to the lower end of the flexible bag-like container and whose other end is connected to the dialysate outlet path; and (d) to process the detected weight value from the load cell. 2. The ultrafiltration amount control device according to claim 1, further comprising a weight controller that transmits the detected value to the transmembrane pressure differential control means.