JP2021062067A - Fluid replacement device of hemodialysis device - Google Patents

Abstract

To reliably execute fluid replacement even when pressure of a blood circuit 3 fluctuates.SOLUTION: A fluid replacement passage 5 for supplying a replacement fluid to a blood circuit 3 during dialysis treatment is communicated with a dialysis fluid supply passage 14 and the blood circuit 3. First flow amount throttle means MV1 is provided in the dialysis fluid supply passage 14 in the downstream of a connection part 22 of the dialysis fluid supply passage 14 and the fluid replacement passage 5, and second flow amount throttle means MV2 is provided in the fluid replacement passage 5. Control means executes control to cause the pressure of the connection part 22 to be predetermined pressure or higher by controlling the first flow amount throttle means MV1, and executes control to cause the flow amount of the replacement fluid flowing through the fluid replacement passage 5 to be a target value by controlling the second flow amount throttle means MV2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fluid replacement device for a hemodialysis device, and more particularly to a fluid replacement device for a hemodialysis device provided with a flow flow throttle means instead of a fluid replacement pump.

Conventionally, as a fluid replacement device for a hemodialysis device, a fluid replacement device for a hemodialysis device provided with a flow throttle means instead of a fluid replacement pump is known (Patent Document 1).
That is, the replacement solution device of the blood dialysis machine is a dialyzer that performs blood dialysis, a dialysate supply passage that supplies fresh dialysate to the dialyzer, and a dialysate that collects used dialysate that has passed through the dialyzer. A dialysate circuit consisting of a passage, a blood circuit consisting of an arterial passage for supplying blood to the dialyzer and a venous passage for discharging blood from the dialyzer, and a supplementary fluid passage connecting the dialysate supply passage and the blood circuit. A first flow throttle means for adjusting the flow rate of the dialysate supply passage, which is provided in the dialysate supply passage on the downstream side of the connection portion between the dialysate supply passage and the supplementary liquid supply passage, and the first flow throttle means. A control means for controlling the above is provided, blood is circulated through the dialyzer to purify the blood, and the pressure on the upstream side of the first flow squeezing means is increased by the first flow squeezing means. The dialysate is supplemented into the blood circuit via the replacement fluid passage.

Japanese Unexamined Patent Publication No. 2015-80595

Since the replacement fluid device of the hemodialysis apparatus described in Patent Document 1 is provided with a flow flow limiting means in the dialysate supply passage instead of the replacement fluid pump provided in the replacement fluid passage, blood is compared with the one provided with the replacement fluid pump. There is an advantage that the fluid replacement device for the dialysis machine can be manufactured at low cost, but on the other hand, there is a risk that reliable fluid replacement cannot be performed.
For example, in the case of a patient with high blood pressure, the pressure of the blood circuit is higher than that of a patient with low blood pressure, but when the pressure of the blood pressure circuit is high, the pressure difference between the pressure of the blood pressure circuit and the pressure of the connection portion is high. Becomes smaller. When the pressure difference between the two becomes small, the amount of replacement fluid flowing from the dialysate supply passage to the blood circuit decreases, and if the pressures of the two become the same, the replacement fluid does not flow at all. Another example of high pressure in the blood circuit is when the feed rate of the blood pump is set large in order to improve the dialysis efficiency.
In this way, the blood pressure and the blood pump feed amount are different for each patient, so the pressure of the blood circuit is different for each patient, but the pressure of the blood circuit is high when treating a patient with high blood pressure or for some other reason. In some cases, there was a risk that the amount of replacement fluid flowing from the dialysate supply passage to the blood circuit would be too small.
In view of such circumstances, the present invention provides a fluid replacement device for a hemodialysis device capable of performing fluid replacement more reliably than in the past.

The invention of claim 1 comprises a dialyzer for performing blood dialysis, a dialysate supply passage for supplying fresh dialysate to the dialyzer, and a dialysate recovery passage for collecting used dialysate that has passed through the dialyzer. A blood circuit including a dialysate circuit, an arterial passage for supplying blood to the dialyzer, and a venous passage for discharging blood from the dialyzer, a replacement fluid circuit connecting the dialysate supply passage and the blood circuit, and the above. A first flow squeezing means for adjusting the flow rate of the dialysate supply passage and the first flow squeezing means, which are provided in the dialysate supply passage on the downstream side of the connection portion between the dialysate supply passage and the supplementary liquid supply passage, are controlled. With control means,
Blood is circulated through the dialyzer to purify the blood, and the pressure on the upstream side of the first flow drawing means is increased by the first flow drawing means to enter the dialysate into the blood circuit through the replacement fluid passage. In the fluid replacement device of the hemodialysis device that is designed to replenish the fluid
The replenishment passage is provided with a second flow rate throttle means for adjusting the flow rate of the replenishment passage, and the control means is provided with a replenishment flow rate setting means for inputting a target value of the flow rate of the replenisher flowing through the replenishment passage.
The control means controls the first flow rate throttle means so that the pressure at the connection portion becomes equal to or higher than a predetermined value, and controls the second flow rate throttle means so that the flow rate of the replacement fluid becomes a target value. It is characterized by.

According to the invention of claim 1, the first flow rate throttle means is controlled so that the pressure at the connection portion is equal to or higher than a predetermined value, and the second flow rate throttle means is controlled so that the flow rate of the replacement fluid becomes a target value. Therefore, even if the pressure of the blood circuit fluctuates, it is possible to obtain the effect that more reliable replacement fluid can be performed as compared with the conventional case.

The circuit diagram which shows one Example of this invention. The circuit diagram for demonstrating the adjustment of the 1st flow rate throttle means MV1 and the 2nd flow rate throttle means MV2.

Hereinafter, the present invention will be described with reference to the illustrated examples. In FIG. 1, the hemodialysis apparatus 1 is connected to a dialyzer 2 to flow blood, and a blood circuit 3 connected to the dialyzer 2 to flow dialysate. The dialysate circuit 4 is provided with a replenishment passage 5 for connecting the blood circuit 3 and the dialysate circuit 4.
The blood circuit 3 is composed of an arterial passage 7 connected to a patient's blood vessel to supply blood to the dialyzer 2 and a venous passage 8 for returning blood from the dialyzer 2 to the patient.
The arterial side passage 7 is provided with a puncture needle 7A that punctures the patient's blood vessel at one end thereof, and the other end is connected to the entrance of the dialyzer 2, and the arterial side passage 7 is opened and closed in order from the puncture needle 7A. A clamp 9, a pressure sensor PA, and a blood pump 10 for delivering blood are provided.
One end of the venous passage 8 is connected to the outlet of the dialyzer 2, and a puncture needle 8A for puncturing a patient's blood vessel is provided at the other end, and a drip chamber is provided on the downstream side of the dialyzer 2. D1 is arranged, and a pressure sensor PV is provided in the drip chamber D1.

The dialysate circuit 4 is provided with a first dialysate chamber 11 and a second dialysate chamber 12 for accommodating dialysate, and the first dialysate chamber 11 and the second dialysate chamber 12 are supplied with liquid. The fresh dialysate supplied through the passage 13 is stored, the fresh dialysate is supplied to the dialyzer 2 through the dialysate supply passage 14, and the used dialysate discharged from the dialyzer 2 is dialysate. It is designed to be collected through the collection passage 15 and discharged to the outside of the device through the drainage passage 16.
The first dialysate chamber 11 and the second dialysate chamber 12 have the same shape, and the inside is divided into two chambers by a flexible diaphragm, and one of them is a supply chamber 11A, 12A for accommodating fresh dialysate. The other is a collection chamber 11B and 12B for collecting the used dialysate.

A liquid supply passage 13 and a dialysate supply passage 14 are branched and connected to the supply chambers 11A and 12A of the first dialysate chamber 11 and the second dialysate chamber 12, respectively, and the liquid supply passage 13 is branched. Liquid supply valves V1 and V2 are provided in the provided passage, and supply valves V3 and V4 are provided in the branched passage of the dialysate supply passage 14. Further, the dialysate recovery passage 15 and the drainage passage 16 are branched and connected to the recovery chambers 11B and 12B, respectively, and recovery valves V5 and V6 are provided in the branched passages of the dialysate recovery passage 15. , Drainage valves V7 and V8 are provided in the branched passages of the drainage passage 16.

The liquid supply passage 13 is provided with a fresh dialysate supply device (not shown) on the upstream side thereof, and the supply pressure of the fresh dialysate supplied from the fresh dialysate supply device is the pressure sensor PG1. It is made possible to measure by.
The dialysate supply passage 14 is provided with a first dialysate filter F1 and a second dialysate filter F2, each of which is an endotoxin cut filter for purifying the dialysate, on the downstream side of the second dialysate filter F2. Is provided with various components 21 including a concentration sensor for detecting the concentration of dialysate.

The replacement fluid passage 5 is branched from the dialysate supply passage 14 on the downstream side of the various component 21, and the first flow rate throttle means MV1 is connected to the dialysate supply passage 14 on the downstream side of the connection portion 22 of both passages 5 and 14. And the flow meter 23 and the on-off valve V9b are sequentially provided.
From the upstream side, the dialysate recovery passage 15 includes an on-off valve V19, a pressure sensor PD, various components 24 including a concentration sensor, an air degassing tank 25 for removing air bubbles in the dialysate, and used ones. A liquid feed pump 26 for sending dialysate to the collection chambers 11B and 12B of the first dialysate chamber 11 and the second dialysate chamber 12 and a pressure sensor PG3 are provided.

The dialysate supply passage 14 and the dialysate recovery passage 15 are connected by a bypass passage 31, and an on-off valve V9a is provided in the bypass passage 31. The bypass passage 31 includes a dialysate supply passage 14 between the flow meter 23 provided in the dialysate supply passage 14 and the on-off valve V9b, a pressure sensor PD provided in the dialysate recovery passage 15, and various components 24. It communicates with the dialysate recovery passage 15 between them.
A water removal passage 32 is connected to the downstream side of the liquid feed pump 26, and a required amount of used dialysate is discharged to the drain passage 16 via the water removal pump 33 provided in the water removal passage 32. It has become like. Further, the gas removed by the degassing tank 25 is discharged to the drainage passage 16 by the degassing passage 35 provided with the degassing valve V9.

The replacement fluid passage 5 is provided with a second flow throttle means MV2, an on-off valve V36b, and a replacement fluid passage connection port 36 from the upstream side. When shown by the solid line in FIG. 1, the replacement fluid passage 5 is provided. , Connected to the venous passage 8 between the outlet of the dialyzer 2 and the drip chamber D1.
However, the replacement fluid passage 5 may be connected to the arterial passage 7 between the blood pump 10 and the inlet of the dialyzer 2, as shown by the dotted line in FIG.
Further, as the flow rate limiting means MV1 and MV2, those using a diaphragm valve are preferable. In the flow rate throttle means using a diaphragm valve, the flow path area is increased or decreased by increasing or decreasing the lift amount of the diaphragm valve with respect to the valve seat, so that there is no sliding part that comes into contact with the liquid and foreign matter is contained in the dialysate. This is because there is no risk of contamination.

By the way, the hemodialysis apparatus 1 is controlled by a control means (not shown), and the control means is provided with a replacement fluid flow rate setting means (not shown) for inputting a target value of the flow rate of the replacement fluid flowing through the replacement fluid passage 5. It is provided.
As the replacement fluid flow rate setting means, several configurations can be adopted.
First, even if the replacement fluid flow rate setting means is configured by the touch screen or the physical button provided on the control means and the operator manually inputs the target value via the touch screen or the physical button. Good.
Secondly, the replacement fluid flow rate setting means includes a card reading means, which is pre-recorded in various external storage means such as an IC card (RFID), an SD card, and a compact flash (registered trademark) by the card reading means. It may read the target value.
Thirdly, the replacement fluid flow rate setting means includes a communication means, and a target value transmitted from a central monitoring device (preferably a PC) connected by the communication means via a communication means such as a local network (LAN). May be read, and may also have the above-mentioned first to third configurations.
In short, the replacement fluid flow rate setting means may have any configuration as long as the target value of the flow rate of the replacement fluid flowing through the replacement fluid passage 5 can be input to the control means.

Further, the target value of the replacement fluid flow rate by the replacement fluid flow rate setting means is set as follows, for example.
As an example, when a replacement fluid time of 4 hours and a total fluid replacement volume of 2.4 (~ 72) L are given, the replacement fluid flow rate setting means becomes a flow rate of 100 (~ 300) ml / min based on these values. Set the replacement fluid flow rate so as to.
At this time, in response to a command to the replacement fluid flow rate setting means, the replacement fluid flow rate setting means divides the replacement fluid time into predetermined time intervals, for example, every 20 minutes, and creates a replacement fluid profile in which the replacement fluid volume in each section is set. be able to. For example, it is possible to create a replacement fluid profile such that the amount of replacement fluid is small in the first half and the second half and is large in the middle stage.
In this case, the replacement fluid flow rate setting means shall make the total value of the replacement fluid amount in each section the total replacement fluid amount, and calculate the replacement fluid flow rate for each section from the replacement fluid amount in each section and the time for each section. become. Then, the control means will perform control based on the target value set in each section.

In the above configuration, when hemodialysis is performed, fresh dialysate is supplied from the liquid supply passage 13 to the supply chamber 11A of the first dialysate chamber 11, and used dialysis stored in the recovery chamber 11B. The liquid is discharged into the drainage passage 16. At the same time, when the used dialysate is discharged from the dialyzer 2 by the liquid feed pump 26 and collected in the recovery chamber 12B of the second dialysate chamber 12, the supply chamber 12A of the second dialysate chamber 12 is accompanied by this. The fresh dialysate is supplied to the dialyzer 2.
Subsequently, by switching the open / closed states of the liquid supply valves V1 and V2 and the drainage valves V7 and V8 and the supply valves V3 and V4 and the recovery valves V5 and V6, fresh dialysate is supplied to the supply chamber 12A of the second dialysate chamber 12. Is supplied, the used dialysate is drained from the collection chamber 12B, fresh dialysate is supplied from the supply chamber 11A of the first dialysate chamber 11 to the dialyzer 2, and the used dialysate is collected in the collection chamber. It is collected in 11B. By repeating this alternately, the fresh dialysate is continuously supplied to the dialyzer 2, and the used dialysate is collected from the dialyzer 2.
Then, when the used dialysate is collected from the dialyzer 2 into the collection chambers 11B and 12B, a part of the used dialysate is discharged from the dialysate collection passage 15 to the drainage passage 16 by the water removal pump 33. , The amount of used dialysate collected can be made larger than the amount of fresh dialysate supplied to the dialyzer 2, and excess water can be removed from the blood.

When fluid replacement is performed during the above hemodialysis, the on-off valve V36b is opened and a part of the dialysate supplied from the dialysate supply passage 14 to the dialyzer 2 is passed through the fluid replacement passage 5. It comes to be supplied to the blood circuit 3.
At this time, a control means (not shown) for controlling the hemodialysis apparatus 1 adjusts the opening degree of the first flow rate squeezing means MV1 and the second flow squeezing means MV2 so that the opening degree is appropriate, and the required amount of replacement fluid is surely supplied. It is designed to be supplied to the blood circuit 3.
Hereinafter, preparatory adjustment before the start of dialysis regarding control of the first flow rate throttle means MV1 and the second flow rate throttle means MV2 by the control means will be described.

First, the on-off valve V36b of the replenishment passage 5 is closed, and the total amount of dialysate from the dialysate chamber 11 or 12 is collected from the dialysate supply passage 14 via the dialyzer 2 by the liquid feed pump 26. Set so that the flow rate when flowing into is a predetermined flow rate.
At this time, the volumes of the first dialysate chamber 11 and the second dialysate chamber 12 are the same and known, and each is 100 ml as an example.
Further, the delivery time of the dialysate from one of the dialysate chambers 11 or 12 can be detected by using the pressure sensor PG3. That is, the time when the liquid transfer from one chamber is completed can be detected by detecting the pressure wave (water hammer) generated when the diaphragm in the chamber reaches the right side shown in FIG. 1 by detecting with the pressure sensor PG3. it can. Therefore, when the liquid feeding in the other chamber is completed, each recovery valve and the drain valve V5 to V8 are switched to set the liquid feeding start time in one chamber, and the completion of the liquid feeding in the one chamber is detected by the pressure sensor PG3. The time up to the time when the liquid is sent can be detected as the liquid feeding time.
Therefore, the flow rate can be calculated from the above 100 ml and the liquid feeding time, and here, the flow rate is set to 700 ml / min.
When the flow rate is set to 700 ml / min in this way, the control means sends the liquid so that the flow rate becomes 700 ml / min, and more specifically, the liquid feeding time at which the flow rate becomes 700 ml / min can be obtained. The pump 26 is feedback controlled.

Next, when the total flow rate of 700 ml / min is passed through the first flow rate throttle means MV1, the control means has, for example, the pressure of the connection portion 22, that is, the inlet pressure Pin of the first flow rate throttle means MV1 is 50 kPa (≈). The pressure loss coefficient ζmv1 of the first flow rate throttle means MV1 is set so as to be 375 mmHg).
The reason why the upstream pressure Pin is set to 50 kPa is that the upper limit of the pressure of the blood circuit 3 is generally set to 300 mmHg during dialysis treatment, and the upper limit of the pressure is detected by the pressure sensor PA or PV provided in the blood circuit 3. This is because the control means is set to issue an alarm as an abnormality occurs. That is, if the upstream pressure Pin of the connection portion 22 is maintained at 50 kPa, the pressure of the connection portion 22 can be reliably maintained higher than the pressure of the blood circuit 3 when the fluid replacement passage 5 is opened, whereby the fluid replacement fluid can be maintained. It can be executed reliably.

The pressure loss coefficient ζmv1 of the first flow rate throttle means MV1 is set as follows.
In FIG. 2, Pin is the inlet pressure of the first flow rate throttle means MV1 (pressure of the connection portion 22), and Pout is the outlet pressure of the first flow rate throttle means MV1. The pressure on the downstream side of the first flow throttle means MV1 can be detected by the pressure sensor PD, and the outlet pressure of the first flow throttle means MV1 is the detected value of the pressure sensor PD, the pressure loss due to the on-off valve V19, and the dialysis. It is the sum of the pressure loss due to the vessel 2, the pressure loss due to the on-off valve V9b, and the pressure loss due to the flow meter 23. Strictly speaking, there is a pressure loss based on the length of the pipeline from the outlet of the first flow rate throttle means MV1 to the pressure sensor PD and the bend, but the loss is small and is omitted here. If it is desired to calculate the pressure with higher accuracy, these losses may be taken into consideration.
The inlet pressure Pin of the first flow rate throttle means MV1 is obtained by adding the pressure loss of the first flow rate throttle means MV1 to the outlet pressure Pout of the first flow rate throttle means MV1.

Since each of the above pressure losses can be calculated by a conventionally known calculation method, the outlet pressure Pout of the first flow rate throttle means MV1 can be calculated by calculation if the detected value of the pressure sensor PD is known. These pressure losses are constant values when the flow rate is constant at 700 ml / min.
If the outlet pressure Pout of the first flow rate throttle means MV1 can be calculated, the pressure loss required for the first flow rate throttle means MV1 is large from the difference between the outlet pressure Pout and the required inlet pressure Pin (50 kPa). Can be calculated.
This calculation is calculated as follows.
Q = U × A ... (1)
ΔP = Pin-Pout = ζ × ρ × U 2/2 ··· (2)
Here, Q is the flow rate, U is the average flow velocity, A is the cross-sectional area, ΔP is the pressure difference, ζ is the pressure loss coefficient, and ρ is the fluid density.
Assuming that the flow rate Qd flowing to the dialyzer 2 side before replenishment is the same as the total flow rate Qt (700 ml / min) and the cross-sectional area on the downstream side of the first flow rate throttle means MV1 is Ad (known value), the formula ( From 1), the average flow velocity Ud flowing to the dialyzer 2 side can be calculated. Since the fluid density ρ is known, if these are substituted into the equation (2), the required pressure loss coefficient ζmv1 of the first flow rate throttle means MV1 can be obtained from the required pressure loss ΔP of the first flow rate throttle means MV1. Is calculated.
When the magnitude of the pressure loss coefficient ζmv1 of the first flow rate throttle means MV1 is obtained, the control means controls the opening degree of the first flow rate throttle means MV1 using the pressure loss coefficient ζmv1 as a parameter, thereby controlling the opening degree of the first flow rate throttle means MV1. The inlet pressure Pin of the flow rate throttle means MV1 is controlled to the predetermined value of 50 kPa described above.

After that, the control means confirms by using the pressure sensor PG3 that the inlet pressure Pin of the first flow rate throttle means MV1 is set to 50 kPa.
That is, the inlet pressure Pin of the first flow throttle means MV1 is, from the detected value of the pressure sensor PG3, the pressure loss due to the recovery valve V6 and the pressure loss due to the diaphragm in the second dialysis chamber 12 on the second dialysis chamber 12 side. The value is obtained by subtracting the pressure loss due to the supply valve V4, the pressure loss due to the first dialysate filter F1, the pressure loss due to the second dialysate filter F2, and the pressure loss due to the various components 21.
Since each of the above pressure losses can be calculated by a conventionally known calculation method as described above, if the detected value of the pressure sensor PG3 is known, the inlet pressure Pin of the first flow rate throttle means MV1 can be calculated by calculation. Can be done. In other words, if the detected value of the pressure sensor PG3 is a value such that the inlet pressure Pin of the first flow rate throttle means MV1 is 50 kPa, the pressure loss coefficient ζmv1 of the first flow rate throttle means MV1 has an optimum magnitude. It will be set.

After adjusting the pressure of the connection portion 22 to be equal to or higher than a predetermined value by the first flow flow throttle means MV1 in this way, the on-off valve V36b of the replacement fluid passage 5 is then opened to allow the dialysate chamber 11 or 12 to be opened. A part of the dialysate is circulated to the blood circuit 3 through the replacement fluid passage 5 at 100 ml / min as an example.
Even in this case, the inlet pressure Pin of the first flow rate throttle means MV1 and the second flow rate throttle means MV2 is controlled to 50 kPa. That is, when the replacement fluid passage 5 is opened and a flow rate of 100 ml / min flows there, the flow rate Qd on the dialysate supply passage 14 side becomes 600 ml / min. As a result, as can be understood from the equations (1) and (2), the pressure loss of each of the flow meter 23, the on-off valve V9b, etc. including the first flow rate throttle means MV1 is reduced, so that the first flow rate throttle means MV1 The inlet pressure Pin is smaller than 50 kPa.
Then, the control means controls the first flow rate throttle means MV1 so that the pressure loss coefficient ζmv1 of the flow rate throttle means MV1 becomes the optimum pressure loss coefficient, and maintains the inlet pressure Pin of the first flow rate throttle means MV1 at 50 kPa. ..
At this time, the method of obtaining the pressure loss coefficient ζmv1 when the flow rate Qd is 600 ml / min is the same as that when the flow rate Qd is 700 ml / min.

Next, under the conditions of the inlet pressure Pin = 50 kPa of the second flow rate throttle means MV2 and the flow rate Qs = 100 ml / min of the second flow rate throttle means MV2, the second flow rate throttle using the above equations (1) and (2). The pressure loss coefficient ζmv2 of the means MV2 is calculated. In this case, the pressure sensor PV provided in the vein side passage 8 can be used, and the pressure loss due to the on-off valve V36b and the second flow throttle means MV2 are used in the same manner as in the case of the first flow throttle means MV1 described above. The magnitude of the pressure loss coefficient ζmv2 is calculated so that the pressure including the pressure loss becomes 50 kPa, which is the inlet pressure Pin.
Then, when the magnitude of the pressure loss coefficient ζmv2 is calculated, the control means controls the second flow rate throttle means MV2 using the pressure loss coefficient ζmv2 as a parameter, whereby the flow rate by the second flow rate throttle means MV2 becomes 100 ml / min. Control to be. At this time, even if the pressure detected by the pressure sensor PV is different for each patient, the size of the pressure loss coefficient ζmv2 is selected to be optimum, so that the inlet pressure Pin is controlled to be 50 kPa. To.
The replacement fluid passage 5 may be connected to the upstream side of the dialyzer 2 of the blood circuit 3 (pre-dilution) or connected to the downstream side of the dialyzer 2 (post-dilution). Although selected, a common calculation method can be used in either case.

Further, the control means resets the pressure loss coefficient ζmv1 of the flow rate throttle means MV1 to the optimum pressure loss coefficient, and then confirms whether the dialysate having a predetermined flow rate Qs = 100 ml / min is flowing in the replenishment passage 5.
At this time, it is confirmed by the flow meter 23 whether or not the flow rate Qd on the dialysate supply passage 14 side is 600 ml / min. Since it is known that the total flow rate Qt is 700 ml / min, it can be confirmed that if the flow rate Qd on the dialysate supply passage 14 side is 600 ml / min, the flow rate Qs on the replacement fluid supply passage 5 side is 100 ml / min. ..
If it is detected that the flow rate Qs on the replacement fluid passage 5 side is not the target value, the control means controls the second flow rate throttle means MV2 from the difference between the detected value and the target value, and the second flow rate throttle means MV2 is used. Feedback control is performed so that the flow rate becomes the target value. After that, the control means monitors the flow rate Qs on the replacement fluid passage 5 side at an appropriate timing, and feedback-controls the second flow rate throttle means MV2 so that the flow rate Qs becomes a target value.
In this way, the control means controls the second flow rate throttle means MV2 to control the pressure of the connection portion 22 to be 50 kPa and to control the flow rate Qs on the replacement fluid passage 5 side to 100 ml / min. ..

As can be understood from the above description, in this embodiment, the pressure loss coefficients ζmv1 and ζmv2 are set so that the pressure of the connecting portion 22 in the dialysate supply passage 14 is maintained above the pressure of the blood circuit 3. Therefore, there is no possibility that the replenishment is not performed due to factors such as a small pressure difference between the connection portion 22 and the blood circuit 3 or an increase in the pressure on the blood circuit 3 side, so that the replenishment can be reliably performed. it can.

In the above embodiment, the case where the flow rate Qs on the replenishment passage 5 side is set to 100 ml / min has been described, but the value of this flow rate Qs can be any value, and the control means can be set to a large or small value of the flow rate Qs. Appropriate pressure loss coefficients ζmv1 and ζmv2 can be selected accordingly to control the flow rate limiting means MV1 and MV2, and the pressure of the connection portion 22 can be controlled to an appropriate pressure.
Further, in the above embodiment, the pressure sensor PG3 is provided to detect the completion of movement of the diaphragm in the dialysate chambers 11 and 12, and in this embodiment, it is manufactured by using this for pressure detection of the connection portion 22 as well. Although the cost is reduced, a dedicated pressure sensor may be provided for detecting the pressure of the connection portion 22.
Further, a flow meter may be added to the replacement fluid passage 5.

1 Hemodialysis device 2 Dialysis machine 3 Blood circuit 4 Dialysate circuit 5 Supplementary fluid passage 7 Arterial side passage 8 Venous side passage 14 Dialysate supply passage 15 Dialysate collection passage 22 Connection part 23 Flow meter MV1 1st flow throttle means MV2 2nd Flow throttle means

Claims (3)

A dialysate circuit consisting of a dialyzer for performing hemodialysis, a dialysate supply passage for supplying fresh dialysate to the dialyzer, and a dialysate recovery passage for collecting used dialysate that has passed through the dialyzer, and the dialysate. A blood circuit consisting of an arterial passage for supplying blood to the vessel and a venous passage for discharging blood from the dialyzer, a replenisher passage connecting the dialysate supply passage and the blood circuit, and the dialysate supply passage and the replenisher passage. A first flow throttle means for adjusting the flow rate of the dialysate supply passage and a control means for controlling the first flow throttle means, which are provided in the dialysate supply passage on the downstream side of the connection portion with the dialysate, are provided.
Blood is circulated through the dialyzer to purify the blood, and the pressure on the upstream side of the first flow drawing means is increased by the first flow drawing means to enter the dialysate into the blood circuit through the replacement fluid passage. In the fluid replacement device of the hemodialysis device that is designed to replenish the fluid
The replenishment passage is provided with a second flow rate throttle means for adjusting the flow rate of the replenishment passage, and the control means is provided with a replenishment flow rate setting means for inputting a target value of the flow rate of the replenisher flowing through the replenishment passage.
The control means controls the first flow rate throttle means so that the pressure at the connection portion becomes equal to or higher than a predetermined value, and controls the second flow rate throttle means so that the flow rate of the replacement fluid becomes a target value. A fluid replacement device for a hemodialysis machine. The replacement fluid device for a hemodialysis apparatus according to claim 1, wherein a flow meter for measuring the amount of dialysate flowing through the dialysate supply passage is provided in the dialysate supply passage on the downstream side of the connection portion. The control means is set to issue an alarm as an abnormality occurrence when the pressure upper limit value of the blood circuit is detected, and the predetermined value is set to a value larger than the pressure upper limit value. The fluid replacement device for the hemodialysis device according to claim 1 or 2.

Images