JPH06114102A - Blood dialysis and filtration device - Google Patents

Abstract

PURPOSE:To prevent the drastic change in the return flow rate at the time of an operation to draw moisture out of the blood and to force a dialyzate into the blood by providing a blood circuit and a dialyzate supply circuit with side circuits having pumps and constituting the pumps of the blood circuit and the dialyzate supply circuit in such a manner that these pumps are rotatable forward and backward. CONSTITUTION:The dialyzate supply circuit 5 provided with the dialyzate supply pump P5 and the dialyzate discharge circuit 6 provided with the dialyzate discharge pump P4 are connected. The dialyzate is supplied by the pump P5 to a dialyzer 4 and is discharged by the pump P4. The flow rates through the pumps P4, P5 are equaled to each other by discharging with pump P4. The dialyzate supply circuit 5 and the dialyzate discharge circuit 6 are provided with the dialyzate supply control pump P6 and the water removing pump P3. The pump P6 is so constituted that the pump is rotatable forward and backward. The part of the blood supply pump P1 of the first blood circuit 1 is provided with the forward and backward rotatable pump P2. The drastic change in the return blood flow rate at the time of forcing the dialyzate into the blood is averted by simultaneously and cooperatively operating these pumps in the same one direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention changes the pressure difference between the blood side and the dialysate side in a hemodialyzer alternately from positive to negative and from negative to positive to draw water from blood and dialysate. The present invention relates to an improvement of a hemodialysis filtration device that alternately pushes into blood.

[0002]

2. Description of the Related Art Blood purification using a dialyzer has been conventionally performed for the treatment of patients with renal failure. There are roughly two methods for this. One is a method called hemodialysis, in which blood and dialysate are brought into contact with each other through a semipermeable membrane, and waste products such as urea and uric acid in the blood are transferred to the dialysate by diffusion, and By making the pressure higher than that on the dialysate side, water in the blood is transferred to the dialysate. The other is a method called hemofiltration, which uses a semipermeable membrane having a slightly larger pore size than hemodialysis to remove low-molecular weight substances and medium-molecular weight substances in blood, which are then lost. This is a method of replenishing a liquid containing a useful component in order to replenish the useful component. In general, hemodialysis is widely used, but two methods are selectively used depending on the condition of the patient, such as performing hemofiltration for a patient to whom hemodialysis is difficult to apply. In the case of hemofiltration, it is necessary to replenish a large amount of a liquid containing useful components, but since this liquid is a sterile liquid containing predetermined components, the cost of hemofiltration is expensive. Further, in order to adjust the water content, it is necessary to make the replenishment amount of the liquid slightly smaller than the filtration amount, but since the adjustment requires a highly accurate control, the spread of hemofiltration is hindered. On the other hand, a method called hemodiafiltration that combines both hemodialysis and hemofiltration has been proposed. This method is disclosed in Japanese Examined Patent Publication No. Sho 58-1422.
As disclosed in Japanese Patent No. 3 or the like, the differential pressure between the blood side and the dialysate side in the dialyzer is alternately changed from positive to negative and from negative to positive, thereby changing the blood side to the dialysate side. This is a method of alternately extracting the water content and pushing the dialysate into the blood. According to this method, efficient blood purification can be performed without the need to replenish the liquid in the blood as in the case of hemofiltration. In the conventional hemodiafiltration method, the withdrawal of water from the blood and the pushing of the dialysate are alternately performed, and as a result, the flow rate of blood returned to the patient changes greatly periodically. However, such changes may adversely affect the patient. Therefore, a bag is provided to temporarily store blood by branching in the middle of the blood return circuit, and when pushing the dialysate, an amount of blood that is approximately equal to the pushing amount is stored in the bag from the blood return circuit and the amount of water from the blood is stored. A method has been proposed in which blood in the bag is returned to the circuit at the time of withdrawal so that the flow rate is always substantially constant.
However, this method has a problem in that a complicated control mechanism is required, a bag needs to be attached to the circuit, and the cost of the device and the blood circuit are significantly increased. Further, since complicated control is required, it is difficult to change the pushing flow rate of the dialysate according to the condition of the patient.

[0003]

[Purpose] A dialyzer having a semipermeable membrane built therein to purify blood by contacting blood and dialysate through the semipermeable membrane, and a first blood circuit for guiding blood taken out of a living body to the dialyzer. A second blood circuit for guiding the blood flowing out from the dialyzer to the living body, a dialysate supply circuit for guiding the dialysate to the dialyzer, and a dialysate discharge circuit for discharging the dialysate flowing out from the dialyzer. The pressure difference between the blood side and the dialysate side in the dialyzer is changed from positive to negative and from negative to positive alternately, and both operations of withdrawing water from the blood and pushing the dialysate into the blood are alternated. In the hemodiafiltration apparatus equipped with the means for performing, the return blood flow does not change significantly during both operations,
An object of the present invention is to provide a hemodiafiltration device which has a simple device and circuit and does not cause a large increase in cost.

[0004]

DISCLOSURE OF THE INVENTION In the present invention, a dialyzer for incorporating therein a semipermeable membrane and purifying blood by contacting blood and dialysate through the semipermeable membrane, and blood taken out from a living body A first blood circuit having a means for guiding the blood to the dialyzer, a second blood circuit having a means for guiding the blood flowing out of the dialyzer to the living body, and a dialysate supply circuit having a means for guiding the dialysate to the dialyzer. A dialysate discharge circuit having a means for discharging the dialysate flowing out of the dialyzer, wherein at least a first blood circuit and a dialysate supply circuit in each of the circuits include: A side circuit having a pump is provided in the pump installation portion of the circuit, and at least the pumps of the first blood circuit and the dialysate supply circuit are capable of rotating in the forward and reverse directions among the pumps provided in these side circuits. Characterize.

In the hemodiafiltration apparatus of the present invention, the dialyzer 4 basically has a dialysate supply circuit 5 having a dialysate supply pump P5 and a dialysate discharge circuit 6 having a dialysate discharge pump P4. Connected, the dialysate is supplied to the dialyzer 4 by the pump P5 and discharged by the pump P4,
Generally, the two pumps have the same flow rate. And
The dialysate supply circuit 5 and the dialysate discharge circuit 6 are further provided with a dialysate supply control pump P6 and a dewatering pump P3 in the former in order to supply the dialysate and remove water by controlling the flow rate with high accuracy. Has been.

According to the present invention, the pump P6 can be rotated in the forward and reverse directions, and the blood supply pump P of the first blood circuit 1 can be rotated.
Similarly, a pump P2 capable of rotating in the forward and reverse directions is provided in the portion 1
Furthermore, by simultaneously operating these in the same direction, the problem of the prior art that the return blood flow volume changes significantly when the dialysate is pushed in could be solved. Therefore, in the present invention, by adopting the above-mentioned means, it is not necessary to change the flow rate of the pump P1 in order to solve the problems of the conventional art (the flow rate of the pump P1 is constant. Not only can the apparatus itself be simplified, but the flow rates of the pumps P2 and P6 can be set in a wide range, and variations in the return blood flow can be eliminated more accurately and easily. The pumps P2 and P6 are controlled to work in the same direction, but in the "drawing process of water from blood", the pumps P2 and P6 are controlled.
Is performed in the direction A shown in FIG. 1, that is, in the forward rotation.
On the other hand, in the "step of pushing dialysate into blood",
The pumps P2 and P6 are operated in the B direction shown in FIG. 1, that is, in the reverse rotation. Further, it is preferable that the flow rates of the pumps P2 and P6 are the same, but it is not necessary that they are exactly the same.
For example, the flow rates of both pumps do not necessarily have to be the same as long as the return blood flow rate is within a permissible range. Further, the flow rate of the pump itself is not particularly limited as long as it is higher than the flow rate of the water removal pump P3. To control the pumps P2 and P6 in conjunction with each other as described above,
It is preferable to use a double pump in which P2 and P6 have a common motor, but this is preferable because the structure is simple and the control is easy. However, other suitable control means can be used.

An embodiment of the construction and operation of the hemodiafiltration apparatus of the present invention will be described in detail with reference to FIG. However, the hemodiafiltration apparatus of the present invention is not limited to the following embodiments. <Embodiment 1> In FIG. 1, 4 is a dialyzer as a blood purifying apparatus, which is composed of a box containing a film-shaped, tube-shaped or hollow fiber-shaped semipermeable membrane inside. The dialyzer 4 is provided with a first blood circuit 1 for guiding blood from the patient's body equipped with a blood delivery pump P1 and a second blood for returning the blood purified and taken out from the dialyzer 4 to the patient. The circuit 2 is connected and the blood taken from the patient is sent by the pump P1 through the first blood circuit 1 to the dialyzer 4 and back through the second blood circuit 2 back to the patient. The first blood circuit is provided with a pump P2 that can rotate in the normal and reverse directions.

Example 2 A dialysis operation was performed by the above dialysis device as follows. In the present example, the pressure difference between the blood side and the dialysate side in the dialyzer is changed from positive to negative and from negative to positive alternately to alternately draw water from the blood and push the dialysate into the blood. The operation is performed by alternately changing the difference between the inflow amount of dialysate per unit time into the dialyzer and the outflow amount per unit time from the dialyzer from negative to positive and then from positive to negative. . The process of drawing out water from the blood and the process of pushing in the dialysate are alternately switched every minute, and the treatment is performed for 4 hours. [Step of drawing water from blood] The pumps P2 and P6 are rotated in the A direction. The flow rate of each pump was as follows. Flow rate of pump P1 200 ml / min Flow rate of pump P2 50 ml / min Flow rate of pump P3 30 ml / min Flow rate of pump P4 500 ml / min Flow rate of pump P5 500 ml / min Flow rate of pump P6 50 ml / min Blood removal flow rate is P1 + P2 = 200 + 50 = 250 ml / min, return blood flow is P1 + P2-P3-P6 = 200 + 50-30-50 =
170 ml / min. [Step of pushing dialysate into blood] P2 and P6 are reversely rotated in the B direction. The example of the flow rate of each pump is as follows. P1 200 ml / min P2 80 ml / min (reverse) P3 30 ml / min P4 500 ml / min P5 500 ml / min P6 80 ml / min (reverse) Blood removal flow rate is P1-P2 = 200-80 = 120 ml / min, return blood The flow rate is P1-P2-P3 + P6 = 200-80-30 + 80 =
170 ml / min. From the above results, the return blood flow rate is 170 ml / min in both the water drawing step and the dialysate pushing step, which is completely unchanged. In the above embodiment, the flow rates of the pumps P4 and P5 are made equal, and the water is removed from the blood by the pump P3. However, the flow rate of the pump P4 is made larger than that of the pump P5 by the amount of water removal. By controlling, the pump P3 can be omitted. Further, in the case of FIG. 1, the sterilizing filter 10 is provided in the dialysate supply circuit immediately before the dialyzer, but this filter is not essential.
However, since the dialysate is not guaranteed to be sterile, it is preferable to provide a sterilization filter to prevent bacteria from entering the blood.

[0009]

[Effects of the Invention] When blood is treated using the hemodiafiltration apparatus of the present invention, the return blood flow rate during both operations of drawing water from the blood and pushing the dialysate into the blood can greatly change. It is excellent in terms of safety because it does not exist. And
The pushing flow rate of dialysate can be changed freely,
Can easily support a wide range of prescriptions. In addition, the device is inexpensive because it has a simple structure in which two pumps P2 and P6 are added to the existing hemodialysis device, and the blood circuit and dialysate circuit also require a complicated structure and special expensive parts. Since it does not, the running cost can be kept low.

[Brief description of drawings]

FIG. 1 is a system diagram of a hemodiafiltration device according to a first embodiment of the present invention.

[Explanation of symbols]

 1 1st blood circuit 2 2nd blood circuit 3 patient 4 dialyzer 5 dialysate supply circuit 6 dialysate discharge circuit 8 side circuit (dialysis solution supply circuit) 9 side circuit (dialysis solution discharge circuit) P1 pump P2 pump P3 Pump (water removal pump) P4 pump P5 pump P6 pump 10 bacteria removal filter 11 control device

Claims (4)

[Claims] 1. A dialyzer having a semipermeable membrane therein, for purifying blood by bringing blood and dialysate into contact with each other through the semipermeable membrane, and a blood pump for guiding blood taken out from a living body to the dialyzer. A first blood circuit having the same, a second blood circuit having means for guiding blood flowing out of the dialyzer to the living body, a dialysate supply circuit having a dialysate supply pump for guiding dialysate to the dialyzer, and a dialyzer A dialysate discharge circuit having a dialysate discharge circuit for discharging the dialysate that has flowed out, wherein a pump for the circuit is provided in at least a first blood circuit and a dialysate supply circuit in each circuit. Blood is characterized in that a side circuit having a pump is provided in the section, and at least the first blood circuit and the dialysate supply circuit of the pumps provided in these side circuits are pumps capable of forward and reverse rotation. Diafiltration equipment. 2. The forward and reverse rotatable pumps provided in the side circuits of the first blood circuit and the dialysate supply circuit can control the rotation directions in the same direction, and by the control. The hemodiafiltration apparatus according to claim 1, wherein the drawing of water from the blood and the pushing of the dialysate into the blood can be alternately performed. 3. The hemodiafiltration device according to claim 1, wherein the two pumps capable of rotating in the normal and reverse directions can be controlled in conjunction with each other so that their flow rates become equal. . 4. The two forward / reverse rotatable pumps,
The hemodiafiltration device according to claim 1, 2 or 3, which is a dual pump having a common motor.