JPS6338465A - Blood purifying apparatus - Google Patents

Abstract

(57) [Abstract] 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 a blood purification device based on ultrafiltration. The present invention also relates to a blood purification device that can be automatically adjusted.

``Prior Art'' As is well known, in artificial dialysis treatment for renal failure, dialysate is supplied from a dialysate supply source to a dialyzer connected to the patient's arteries and veins, and after dialysis is completed, the dialysate is The liquid is drained as it is.

On the other hand, in a dialysis machine, in addition to dialysis of waste products contained in the blood of a person who is imitating, water in the blood of the person who is similar is ultrafiltered to the dialysate side through a dialysis membrane, and the dialysate is sent to the dialyzer. The outlet side (drainage) flow rate increases by the amount of ultrafiltered water compared to the artificial flow rate.

In such artificial dialysis treatment, it is important to remove not only waste products from the blood but also excess water.
On the other hand, if the water removed by ultrafiltration (water removal>ri) increases, it will be necessary to supplement the water later.

Therefore, confirmation and adjustment of water removal 1 during artificial dialysis is important.

By the way, this water removal 1 is determined by the pressure difference between the blood and dialysate acting through the dialysis membrane in the dialyzer and the performance of the dialyzer, and varies depending on these pressure differences and the performance of the permeation Fr5. Therefore, such an X! The analyzer has
-Jl in dialysis times! A mechanism that can accurately determine the amount of body fluid removed over several hours from the start to the end of analysis is essential.

As a blood purification device equipped with such a mechanism, a device having the structure shown in Fig. 4 is conventionally known (Japanese Patent Publication No. 61-5
No. 735).

In the figure, blood is drawn out from a patient to a blood outlet l, sent to a blood pump 4 of a dialyzer 3 by a blood pump 2, and after substance exchange in the dialyzer 3, a throttle valve 6 is inserted from a blood outlet 5. After that, the blood returns to the patient via the blood return lower.

The blood pressure inside the d3 fold 4S is adjusted by the throttle valve 6, and the difference between this pressure and the dialysate side pressure causes ultrafiltration 1! (
Water removal m) is determined. Note that the reference numeral 8 is a blood pressure indicator.

On the other hand, the dialysate is supplied from the vibrator 9, and the stop valve IQ
, flow meter 11, throttle valve! 2, three-way switching solenoid valve 13
leading to. The solenoid valves 13 , 14 are operated by a timer 15 , and the dialysate is sent from the solenoid valve 13 to the solenoid valve 14 via a dialysate metering pump 16 .

The dialysate metering pump 16 is configured to alternately repeat liquid feeding and draining at regular intervals by the operation of electromagnetic valves 13 and 14. In this liquid feeding cycle of the pump 16, the dialysate is supplied by the pump 16? ! is sent from the first valve 13 via the electromagnetic valve 14 to the dialysate volume 17 of the dialyzer 3, and after substance exchange in the dialyzer 16, it is stored in the metering container 20 through the outlet 18 and the negative pressure pump 19.

The throttle valve 21 and the negative pressure pump (dialysate metering pump) 19 are
aFr? Since it is provided to apply a negative pressure to the dialysate in the dialysate 53, the negative pressure is adjusted by the throttle valve 21, and the pressure is indicated by the pressure gauge 22.

Next, in the drain cycle, the liquid stored in the metering container 20 is drawn out from the pipe 23 by the pump 16 and discharged to the drain port 24 via the electromagnetic valves 13, 14. At this time, the delivery of dialysate is stopped. In addition, valve 25
is used for draining the measuring container 20.

In the above configuration, the measuring container 20 stores 1, which is the sum of the dialysate sent for a certain period of time by the pump 16 and the water removed by the dialyzer 16 for the same certain period of time, and in the next cycle, the same pump is pumped for the same certain period of time. Drain by 16. Therefore, if short-term fluctuations in the flow rate of the pump 16 can be ignored, a total of 1 container 2
At 0, only the amount of water removed remains.

"Problems to be Solved by the Invention" By the way, the conventional blood purification apparatus described above has the following problems.

That is, in the blood purification apparatus having the above configuration, when the liquid removal valve is controlled by the blood pump 16 and the throttle valve 6, and the negative pressure pump 19 and the calibration valve 21, the dialysis rate set by each of the pumps and the throttle valve is There is a problem that the actually obtained liquid removal area is hotter than the theoretically obtained liquid removal m due to the differential pressure between the liquid side and the blood side.

Regarding this problem, the present inventors conducted repeated decolorization experiments and came to the following findings.

In other words, it was found that the actual amount of water removed above the theoretical amount was not removed from the patient's blood, but the total amount of dialysate was reduced by that amount. As for the cause of this, we conducted several experiments and found that the decrease in the total amount of dialysate is instantaneous when each solenoid valve 13, 14 is switched by an electric signal, but there is a time when all solenoid valves are open. It has been found that at this moment, the dialysate present in each pipe of the dialysate supply system and dialysate discharge system becomes deaf, and at this time, excess dialysate is sucked out.

Therefore, the above-mentioned conventional blood purification apparatus still has the problem that the liquid removal 1 cannot be accurately measured and controlled.

"Means for Solving the Problems" The blood purification device of the present invention has a cylinder in which a liquid suction port is formed at one end of the side corner and a liquid drain port is formed at the other end. Two pistons whose length is longer than the distance between the liquid suction port and the liquid drain port are housed in series and movably, and each piston is movable separately and at the same time spaced apart from each other by a predetermined distance. One dialysate pump in the device is composed of a metering pump that can be synchronized while maintaining the same, and all solenoid valves are omitted to simplify the device. .

"Operation" According to the constant pump having the above configuration, it can be operated as follows. First, when sucking liquid, one piston is fixed in front of the liquid suction port, and the other piston, which was initially in contact with this piston, is moved a predetermined distance toward the liquid drain port (the distance between the liquid suction and drain ports). smaller distance).

At this time, dialysate is sucked between the two pistons. Then, the two pistons are moved in the direction of the drain port while maintaining the distance between them. During this interlock, when the liquid suction port is open, the other liquid drain port is reliably blocked by the other piston, and conversely, when the liquid drain port is open, one piston is This means that the liquid port is blocked. As soon as the other piston passes through the drain port, stop and fix it. Subsequently, one piston is moved toward the other fixed piston until it abuts. Thereby, the dialysate filled between each piston can be led out from the drain port. Therefore, by using this metering piston, the accurate supply and discharge of dialysate and the blocking of each flow path in between can be ensured without using a large number of solenoid valves that take up installation space and are difficult to control. It is possible,
As a result, the amount of liquid removed can be accurately controlled.

Next, the present invention will be explained in more detail with reference to Examples.

``Example'' As shown in FIG. 1, the features of the blood purification apparatus of this example are as follows:
0a and 30b, and the solenoid valve was completely omitted.

As shown in FIG. 2(a), the metering pump 30a (30b) has two pistons 32 in a cylindrical cylinder 31.
a132b is slidably housed, and the capacity is variable. A liquid suction port 31a is provided at one end of the outer peripheral surface of the cylinder 31, and a liquid drain port 31 is provided at the other end.
b is drilled. Further, the pistons 32a132b have the same dimensions, and the length dimension is the same as that of the liquid supply port 31a.
The distance e is set longer than the distance e between the drain port 31b and the drain port 31b. These pistons are individually driven by motors or the like, and are set to be driven synchronously by electric signals. To explain the method of driving the pump 30a (30b) using this motor, first, when sucking liquid, one piston 32a is moved to the liquid suction port 3.
1a, and move the other piston 32b, which was initially in contact with this one piston 32a, by a predetermined distance (a distance smaller than the distance Q between the liquid suction and low liquid drainage ports) in the direction of the liquid drain port 31b [ FIG. 2(b)→(a)]. At this time,
Dialysate is sucked between the two pistons 32a, 32b. Then, the two pistons 32a and 32b are moved in the direction of the drain port 31b while maintaining that distance.

In this way, the other piston 32b is connected to the drain port 31a.
As soon as it finishes passing through, it stops and becomes fixed. Subsequently, as shown in FIG. 2(c), one piston 32a moves toward the other fixed piston 32b until it comes into contact with it. As a result, each piston 32a, 3
The dialysate filled between 2b can be led out from the drain port 31b. After the dialysate has been discharged, the piston 32a
When the pistons 32b and 32b come into contact with each other, the pistons 32a continue to move until they finish passing through the liquid supply port 31a. This completes the operation of the pump 30a (30b), and this process is repeated thereafter.

During this operation, the liquid suction port 31a and the liquid drain port 31b are blocked at the same time, or at least one of them is blocked. That is, when the liquid suction port 31a is open, the other liquid drain port 31a is reliably blocked by the other moving piston 32b, and conversely, when the liquid drain port 31b is open, The moving piston 32a is blocking the liquid suction port 31a.

In the apparatus of this embodiment, one pump 30a of two dialysate metering pumps 30a and 30b having the above-mentioned configuration and function.
The pumps 30a and 30b are set to a predetermined volume 1 (amount of water removed) smaller than the other pump, and these pumps 30a and 30b are used by connecting to each pipe as shown in FIG. That is, in one pump 30a, the dialysate supply pipe 9 is connected to the liquid suction port 31.
Piping 3 that connects to a and connects the drain port 31b to the throttle valve 21.
3 to the dialysate port 17 of the dialyzer 3. In the other pump 30b, a pipe 33 connected to the dialysate outlet 18 of the dialyzer 3 is connected to the liquid suction port 31a, and a drain pipe 35 is connected to the drain port atb. In addition,
The pistons 32a and 32b are set by a control device (not shown) so that the piston operations are performed in synchronization with each other half a cycle apart.

In the blood purification apparatus of the present invention having the above configuration, first, one piston 32a of one pump 30a is connected to the liquid supply port 31a.
The piston 22 is stopped in front of the other piston 22.
b toward the drain port 31b. On the other hand, in the other pump 30b, the other piston 32b is connected to the drain port 3.
1b, one piston 32a near the liquid supply port 31a is moved toward the other piston 32b, and then the abutted piston 32a,
32b is returned to its initial state. This blocks supply of dialysate and discharge of used dialysate, while supplying dialysate to one pump 30a and discharging waste fluid from the other pump 30b. When filling of one pump 30a with dialysate is completed, next, one pump 30a is filled with dialysate.
In this case, one piston 3 near the liquid suction port 31a
2a is moved toward the other piston 32b that is stopped near the drain 031b. Thereby, the dialysate in one pump 30a is supplied to the dialyzer 3. At the same time, in the other pump 30b, the liquid supply port 31
One piston 32a is stopped near a, the other piston 32b is moved toward the drain port 31, and the same amount of used dialysate as the dialysate supplied to the dialyzer 3 is pumped into the other pump 30b. Inhale. In this way, the operation of supplying and discharging the dialysate is repeated, and the difference between the amount of dialysate supplied and the amount of dialysate discharged becomes the amount of water removed.

In the above embodiment, as shown in FIG. 3, the pumps 30a and 30b are adjusted to have the same capacity, and the pump 30a1 is connected to the piping 34 in front of the other pump 30b.
If a small-capacity pump (water removal pump) 36 having the same structure as 30b is provided and configured to draw with a slight negative pressure, the amount of water removed can be directly measured using this small-capacity pump 36.

"Effects of the Invention" As explained above, according to the blood purification device of the present invention, it is possible to accurately supply dialysate without using a large number of solenoid valves that take up a large installation volume and are difficult to control. It is possible to reliably perform the discharge and to shut off each flow path in between, and as a result, the amount of liquid removed can be accurately controlled.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the blood purification device of the present invention, FIG. FIG. 4 is a block diagram showing another embodiment of the blood purification apparatus of the present invention, and FIG. 4 is a block diagram of a conventional blood purification apparatus. 2... Blood circulation pump, 3... Dialyzer, 30a, 30b... Dialysis liquid juice 1 pump, 31.
...Cylinder, 31a...Cylinder suction port, 31b...
...Cylinder drain port, 32a, a2b...
...Piston, 33...Piping (dialysate supply side piping), 34...Piping (dialysate drainage side piping), 3
5...Drain pipe, 36...Water removal pump, Q...Distance between liquid suction port and drain port, L.
・・・・・・Piston length dimension.

Claims (1)

[Claims] A dialysate supply side piping of a dialyzer that brings blood and dialysate into contact through an ultrafiltration membrane and transfers waste products and water from the blood to the dialysate, and a drain of the dialyzer. A dialysate metering pump is provided on each of the liquid side piping, and a liquid suction port is formed at one end of the outer peripheral surface, and a liquid drainage port is formed at the other end of the cylinder. Two pistons whose length is longer than the distance between the and the drain port are housed in series and movably, and each of the pistons is movable separately and at the same time interlocks with each other while maintaining a predetermined distance. A blood purification device characterized in that the dialysate metering pump is constituted by a metering pump configured to be able to perform the following steps.