JPH09239024A - Blood purifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blood purifying device where an operation is easily executed and also the safety of a patient is secured by automatically measuring and controlling filtration liquid, dialysis liquid and substitution liquid in the device. SOLUTION: A dialysis liquid supply route and a filtration liquid discharging route or a dialysis liquid and dialysis liquid discharging route and a replenish liquid route are respectively provided with a liquid supply pump, a valve, a storage container and weight meters 103 measuring weight and the weight change of the storage container is fed-back so that the flow rate of the liquid supply pump is controlled. Then, when the weight of the storage container becomes a fixed value, the flow rate of the liquid supply pump is controlled and also the valve is opened so as to replenish fresh dialysis liquid and replenish liquid and to abolish filtration liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood purification device, particularly a continuous slow hemofiltration method in the emergency / intensive care area for renal diseases with severe circulatory complications, multiple organ failure, etc. The present invention relates to a device suitable for continuous hemofiltration and dialysis (hereinafter simply referred to as “CHDF”).

[0002]

2. Description of the Related Art In recent years, a CHF or CHDF blood purification method has been effective in treating renal diseases having multiple cardiovascular complications and multiple organ failure. CHF is a method in which blood is allowed to flow through a blood purifier containing a semipermeable membrane, the fluid filtered through the membrane is discharged, and replacement fluid is replenished into the body continuously and slowly. In addition, CHDF is a substance in which a dialysate is flowed to the filtrate side in addition to CHF so that a dialysis effect can be obtained in order to improve the ability of CHF to remove small molecules. These treatments include a blood pump that circulates blood through the blood purifier, a filtrate pump that discharges filtrate from the blood purifier, a replacement fluid pump that replenishes the patient with replacement fluid, and a dialysate that supplies dialysate to the blood purifier. The flow rate of the pump (only in the case of CHDF) is set, and the change amount of the body fluid (dialysis fluid amount + replacement fluid amount-filtrate amount) is managed so that the target amount is achieved.

[0003]

In order to maintain sterility, a so-called tubing pump is used for discharging the filtrate and injecting the replacement liquid, in which the tube is pressure-closed and the solution is fed while being squeezed. However, it is difficult to maintain a constant flow rate of the tubing pump because the physical properties of the tube change due to fatigue and temperature, and an error of 5 to 10% cannot be avoided with respect to changes in conditions within the normal usage range. In order to strictly control the amount of change in body fluid, it is necessary to frequently measure and adjust the flow rate of each pump. This operation is complicated, and there is a problem that the patient is constantly monitored from the viewpoint that it is likely to cause an erroneous operation. On the other hand, as shown in FIG. 2, a method of automatically adjusting each pump while measuring the injection amount of the replacement liquid and the discharge amount of the filtered liquid by a weight scale has been devised. When the filtrate is discarded, the treatment has to be stopped once, which requires a complicated procedure. In addition, there are cases in which replenishment and disposal operations are mistakenly performed during treatment, resulting in a large error. in addition,
In order to reduce the frequency of replenishment and disposal operations, widening the measurement range of the weighing scale so that a large amount of replacement liquid or filtrate can be suspended at one time will deteriorate the measurement accuracy and increase the disturbance due to vibration etc. , Will cause an error. The present invention has been made to solve the above-mentioned problems of the prior art, and automatically measures the flow rates of the filtrate, the dialysate, and the replacement fluid of the blood purification device during the treatment of renal diseases and multiple organ failure. It is an object of the present invention to provide a device capable of facilitating the operation and ensuring the safety of the patient by controlling the operation.

[0004]

A blood circulation path for introducing blood of a patient into a blood purifier containing a semipermeable membrane and returning it to the patient again, and a replacement fluid for supplying a replacement fluid to the patient via the blood circulation path. And a dialysate supply passage for supplying dialysate to the blood circulation passage, the replacement fluid passage, and the blood purifier, and the blood purification passage, and a filtrate discharge passage for discharging blood filtrate from the blood purifier. In a blood purification device for performing hemofiltration, hemodialysis or hemodiafiltration, which comprises a filtrate / dialysate discharge passage for discharging blood filtrate and used dialysate from a blood vessel, the dialysate supply passage and the filtrate discharge passage Alternatively, by providing a liquid feed pump, a valve, a storage container, and a weight scale for measuring the weight of the storage container in the filtrate / dialysate discharge passage and the replacement fluid passage, respectively, and by feeding back the change in weight of the storage container, While controlling the flow rate of the liquid delivery pump, When the weight of the container reaches a constant value, the flow rate of the liquid feed pump is controlled, and when the weight of the storage container reaches a constant value, the valve is opened to replenish the fresh dialysate and replacement fluid, and A blood purification device characterized in that the filtrate is discarded.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a flow chart showing the configuration when CHDF is implemented in the device of the present invention. Blood taken from the patient by the blood pump 4 passes through the blood sampling line 17, is introduced into the blood purifier 16 containing the filtration membrane M, and forms a blood circulation path so as to return to the patient again from the blood returning line 18. . A replacement fluid line 24 is connected to the blood return line 18 so that the replacement fluid can be injected into the patient by the replacement fluid pump 7. On the other hand, the blood component filtered by the filter membrane M of the blood purifier 16 is discharged by the filtrate pump 6 provided in the filtrate line 20. Further, the dialysate pump 5 supplies the dialysate from the dialysate supply line 19 to the blood purifier 16, and the dialysate pump 6 discharges the dialysate together with the filtrate. Here, the flow rate of the replacement fluid pump is Q _C (ml / h), the flow rate of the filtrate pump is Q _F (ml / h), and the flow rate of the dialysate pump is Q
_{Assuming D} (ml / h), the change in the body fluid volume of the patient dV (m
1 / h) is represented by dV = Q _D + Q _C −Q _F. Usually, patients often have decreased urine output due to decreased renal function and become overhydrated, so that dV is set to a negative value to remove water (hereinafter simply referred to as “water removal”). The amount of change in total body fluid during treatment is called water removal amount and is managed. The amount of water removed must be controlled accurately, but due to the long treatment time, a slight error in Q _D , Q _C , and Q _F causes a large amount of water removed error. For example, Q _D = 500 ml /
h, Q _C = 400 ml / h, Q _F = 1,000 ml / h
If treated for 20 hours, the amount of water removed is 2,000m
However, if each pump has an error of ± 5%, the water removal error is (± 25 ± 20 ± 50) × 20 = ±
It will be 1,900 ml, and will have an error of approximately ± 100% with respect to the desired amount of water removed. Therefore, in the device of the present invention, the precision of the amount of water removed is improved by measuring Q _D , Q _C , and Q _F and performing feedback control of each pump.

First, the control of the dialysate flow rate Q _D will be described. The dialysate stored in the dialysate reservoir 14 is sent to the measuring bag 11 by dropping the valve 8 provided in the dialysate replenishing line 21. The weighing scale 1 measures the weight of the weighing bag 11 and sends data to the control device 25.
The control device 25 detects that the weight of the weighing bag 11 exceeds a certain value, closes the valve 8, and
Stop the flow of dialysate to the cell and set this state as the initial state.
The dialysate pump 5 starts to send the dialysate to the blood purifier 16 by driving the motor at a rotation speed according to a preset flow rate. The controller 25 constantly monitors the data of the weighing scale 1 and calculates the actual flow rate of the dialysate from the weight change per unit time. If there is a difference between this actual flow rate and the set flow rate, the number of rotations of the motor is changed. Automatically adjust and control so that the set flow rate and the actual flow rate are equal. When the amount of dialysate remaining in the measuring bag 11 is reduced and the weight falls below a certain value, the control device 25 opens the valve 8 again and the measuring bag 1
Fill 1 with dialysate and return to the initial state. While the valve 8 is open, the dialysate pump 5 retains the immediately preceding rotation speed, but the control starts again when the dialysate pump 5 returns to the initial state. By repeating the above, the dialysate flow rate can be accurately maintained at the set flow rate. Although the dialysate pump is not controlled while the valve 8 is open, it is much shorter than the control time, and the flow rate characteristic of the pump does not change abruptly, so it does not cause a large error.

The replacement fluid flow rate Q _C is controlled similarly to the dialysate flow rate Q _D. That is, the replacement liquid stored in the replacement liquid storage portion 15 is sent to the measuring bag 13 by a drop by opening the valve 10 provided in the replacement liquid replenishing line 22. The weighing scale 3 measures the weight of the weighing bag 13 and sends data to the control device 25. The control device 25 detects that the weight of the weighing bag 13 exceeds a certain value and closes the valve 10,
The flow of the replacement liquid to the measuring bag 13 is stopped, and this state is set as the initial state. The replacement fluid pump 7 starts to inject the replacement solution into the patient through the replacement fluid line 24 and the blood return line 18 by driving the motor at a rotation speed according to a preset flow rate. The control device 25 constantly monitors the data of the weighing scale 3,
The actual flow rate of the replacement liquid is calculated from the weight change per unit time, but if there is a difference between this actual flow rate and the set flow rate, the motor speed is automatically adjusted so that the set flow rate and the actual flow rate become equal. To control. Eventually, when the amount of the replacement liquid remaining in the measuring bag 13 decreases and the weight falls below a certain value, the control device 25 opens the valve 10 again to fill the measuring bag 13 with the replacement liquid and restore the initial state. While the valve 10 is open, the replacement fluid pump 7 retains the rotation speed immediately before, but the control is started again when it returns to the initial state.

The filtrate flow rate Q _F is as follows:
Is controlled by The filtrate pump 6 starts to send the filtrate to the measuring bag 12 by driving the motor at a rotation speed according to a preset flow rate. At this time, the valve 9 is closed, and the weight change of the weighing bag 12 detected by the weight scale 2 becomes the actual flow rate of the filtrate. The rotation speed of the motor is controlled so that this actual flow rate becomes equal to the set flow rate. Eventually, if the weighing bag 12 is full and the weight exceeds a certain value, the valve 9 is opened to remove the filtrate in the weighing bag 12 from the waste liquid line 2
Discard from 3. At this time, the filtrate pump 6 holds the immediately preceding rotation speed, but when the weight of the measuring bag 12 falls below a certain value and the disposal of the filtrate is completed, the valve 9 is closed and the same rotation speed control is started again. With the above, each pump can maintain a high flow rate accuracy, and as a result, an error in the amount of water removed can be controlled to be small. Further, according to the present embodiment, the replacement liquid and the dialysate supplement and the discard of the filtrate do not directly affect the weight measurement, and thus can be arbitrarily performed without stopping the treatment. Furthermore, the measuring range of each weighing scale is well within the range of the capacity of each weighing bag, and the measuring accuracy can be kept high and the disturbance is reduced.

[0009]

As described above, according to the present invention, the dialysate flow rate, the replacement fluid flow rate, and the filtrate flow rate can be automatically controlled with high accuracy, and frequent measurement and adjustment work by staff is not required. Treatment can be performed while safely managing the body fluid volume of the patient.

[Brief description of drawings]

FIG. 1 is a flowchart showing the configuration of an embodiment of the device of the present invention.

FIG. 2 is a flowchart showing the configuration of an example of a conventional device.

[Explanation of symbols]

 1, 2, 3 Weight scale 4 Blood pump 5 Dialysis fluid pump 6 Filtration fluid pump 7 Replacement fluid pump 8, 9, 10 Valves 11, 12, 13 Measuring bag 14 Dialysis fluid storage portion 15 Replacement fluid storage portion 16 Blood purification device 17 Blood sampling Line 18 Blood return line 19 Dialysate supply line 20 Filtrate line 21 Dialysate replenishment line 22 Replacement fluid replenishment line 23 Waste fluid line 24 Replacement fluid line 25 Controller 26 Filtrate reservoir

Claims (1)

[Claims] 1. A blood circulation path for introducing blood of a patient into a blood purifier containing a semipermeable membrane and returning it to the patient again, and a replacement fluid path for supplying a replacement fluid to the patient via the blood circulation path, Blood filtration from a filtrate discharge passage for discharging blood filtrate from the blood purifier, or from the blood circulation passage, the replacement fluid passage, and a dialysate supply passage for supplying dialysate to the blood purifier and the blood purifier. In a blood purification apparatus for performing hemofiltration, hemodialysis or hemodiafiltration, which comprises a filtrate and a dialysate discharge path for discharging a liquid and a used dialysate, the dialysate supply path and the filtrate discharge path or the filtration The liquid / dialysate discharge passage and the replacement fluid passage are provided with a liquid feed pump, a valve, a storage container, and a weighing scale for measuring the weight of the storage container, and a feed bag is provided to measure the weight change of the storage container. The flow rate is controlled and the weight of the storage container is When the weight of the reservoir reaches a constant value, the valve is opened to control the flow rate of the liquid delivery pump when the value reaches a constant value, and the fresh dialysate and replacement fluid are replenished and the filtrate is discarded. A blood purification device characterized by performing.