JP3277569B2 - Hemodiafiltration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extracting water from blood and dialysate in a hemodialyzer by changing the pressure difference between the blood side and the dialysate side alternately from positive to negative and from negative to positive. The present invention relates to an improvement of a hemodiafiltration apparatus which alternately pushes blood into blood.

[0002]

2. Description of the Related Art For the treatment of patients with renal insufficiency, blood purification using a dialyzer has been conventionally performed. 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 semi-permeable membrane, and waste substances such as urea and uric acid in blood are transferred to the dialysate by diffusion, and the blood side. By making the pressure higher than the dialysate side, the water in the blood is transferred to the dialysate. The other is a method called hemofiltration, which uses a semi-permeable membrane with a slightly larger pore size than hemodialysis to remove low- and medium-molecular-weight substances in blood by filtration, and is lost by that. 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 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 a useful component, but since this liquid is a sterile liquid containing a predetermined component, the cost of hemofiltration is high. In addition, the amount of replenishment of the liquid needs to be slightly smaller than the amount of filtration for the purpose of controlling the water content. However, the control requires highly precise control, which hinders the spread of blood filtration. On the other hand, a method called hemodiafiltration (hemodiafiltration) that combines both hemodialysis and hemofiltration has been proposed. This method is disclosed in JP-B-58-1422.
As disclosed in Japanese Unexamined Patent Publication No. 3 (1993) -2003, by changing the differential pressure between the blood side and the dialysate side in the dialyzer alternately from positive to negative and from negative to positive, from the blood side to the dialysate side. This method alternately draws out water and pushes dialysate into blood. According to this method, efficient blood purification can be performed without requiring replenishment of blood into the blood as in the case of hemofiltration. In the conventional hemodiafiltration method, as a result of alternately extracting water from the blood and pushing in the dialysate, the flow rate of blood returned to the patient periodically changes significantly. However, such a change may adversely affect the patient. Therefore, a bag is provided for temporarily storing blood by branching in the middle of the blood return circuit, and when the dialysate is pushed in, an amount of blood substantially equal to the pushed amount is stored in the bag from the blood return circuit, and water from the blood is removed. A method has been proposed in which the 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 requires a complicated control mechanism, requires a bag to be attached to the circuit, and has a problem that the cost of the apparatus and the blood circuit is significantly increased. Further, since complicated control is required, it is difficult to change the flow rate of the dialysate in accordance with the condition of the patient.

[0003]

A dialyzer having a semi-permeable membrane therein for purifying blood by contacting blood and dialysate through the semi-permeable membrane, and a first blood circuit for guiding blood taken from a living body to the dialyzer. A second blood circuit that guides blood flowing out of the dialyzer to a living body, a dialysate supply circuit that guides dialysate to the dialyzer, and a dialysate discharge circuit that discharges dialysate flowing out of the dialyzer. In the dialyzer, the pressure difference between the blood side and the dialysate side 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. In the hemodiafiltration device equipped with means to perform in, the blood return flow rate does not significantly change during both operations,
It is an object of the present invention to provide a hemodiafiltration apparatus which has a simple apparatus and circuit and does not cause a significant increase in cost.

[0004]

According to the present invention, there is provided a dialyzer having a semi-permeable membrane therein for purifying blood by bringing blood and dialysate into contact with each other through the semi-permeable membrane; A first blood circuit having a means for guiding dialysis fluid to the dialyzer, a second blood circuit having means for guiding blood flowing out of the dialyzer to a living body, and a dialysis fluid supply circuit having means for guiding dialysate to the dialyzer. A hemodiafiltration device comprising a dialysate discharge circuit having a means for discharging dialysate flowing out of the dialyzer, wherein at least a first blood circuit and a dialysate supply circuit in each of the circuits are provided with: A side circuit having a pump is provided in a pump installation portion of the circuit, and in the pumps provided in these side circuits, at least the first blood circuit and the dialysate supply circuit pump are capable of rotating forward and reverse. Features.

In the hemodiafiltration apparatus of the present invention, the dialyzer 4 basically includes a dialysate supply circuit 5 having a dialysate supply pump P5 and a dialysate discharge circuit 6 having a dialysate discharge pump P4. Connected, dialysate is supplied to dialyzer 4 by pump P5 and drained by pump P4;
Generally, the flow rates of the two pumps are made equal. And
The dialysate supply circuit 5 and the dialysate discharge circuit 6 are further provided with a dialysate supply control pump P6 and a water removal pump P3 in the former in order to supply and remove the dialysate with precise control of the flow rate. Have been.

According to the present invention, the pump P6 can be rotated forward and reverse, and the blood supply pump P of the first blood circuit 1 can be rotated.
A pump P2 which can be rotated forward and backward in the same manner as in part 1 is provided.
Furthermore, by simultaneously operating them in the same direction, it was possible to solve the problem of the prior art that the blood return flow rate greatly changes when the dialysate is pushed. Therefore, in the present invention, it is not necessary to change the flow rate of the pump P1 in order to solve the problems of the prior art by adopting the above means (the flow rate of the pump P1 is constant). Not only), the apparatus itself can be simplified, but also the flow rates of the pump P2 and the pump P6 can be set in a wide range, and the variation in the blood return flow rate can be more accurately and easily eliminated. The pumps P2 and P6 are controlled in conjunction with each other in the same direction, but in the "step of extracting water from blood", the pumps P2 and P6 are controlled.
Is performed in the direction A shown in FIG. 1, that is, in the normal rotation.
On the other hand, in the "step of pushing dialysate into blood",
The pumps P2 and P6 are operated in the direction B shown in FIG. 1, that is, in the reverse rotation. The flow rates of the pumps P2 and P6 are preferably the same, but need not be exactly the same.
For example, the flow rates of both pumps do not necessarily have to be the same as long as the variation in the blood return flow rate is within an allowable range. Further, the flow rate of the pump itself is not particularly limited as long as it is larger than the flow rate of the water removal pump P3. The interlocking control of the pumps P2 and P6 as described above
It is preferable to use a dual pump having a common motor for P2 and P6 because the structure is simple and the control is easy. However, it is possible to adopt another suitable control means.

Next, an embodiment of the structure 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, reference numeral 4 denotes a dialyzer as a blood purification apparatus, which is constituted by a box in which a film, tube or hollow fiber semi-permeable membrane is housed. The dialyzer 4 includes a first blood circuit 1 provided with a blood delivery pump P1 for guiding blood from the body of the patient, and a second blood circuit for returning blood purified and extracted from the dialyzer 4 to the patient. The circuit 2 is connected, and blood drawn from the patient is pumped by the pump P1 through the first blood circuit 1 to the dialyzer 4 and returned to the patient again through the second blood circuit 2. Further, the first blood circuit is provided with a pump P2 that can rotate forward and backward.

Example 2 A dialysis operation was performed by the dialysis apparatus as follows. In the present embodiment, 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. This is performed by alternately changing the difference between the inflow amount of dialysate into the dialyzer per unit time and the outflow amount per unit time from the dialyzer from negative to positive, and then from positive to negative. . The process of extracting water from the blood and the process of pushing the dialysate are alternately switched every minute to perform a process for 4 hours. [Step of extracting water from blood] The pumps P2 and P6 are rotated in the A direction. The flow rate of each pump was as follows. The flow rate of the pump P1 200 ml / min. The flow rate of the pump P2 50 ml / min. The flow rate of the pump P3 30 ml / min. The flow rate of the pump P4 500 ml / min. The flow rate of the pump P5 500 ml / min. The flow rate of the pump P6 50 ml / min. 200 + 50 = 250 ml / min, blood return flow rate is P1 + P2-P3-P6 = 200 + 50-30-50 =
170 ml / min. [Step of forcing dialysate into blood] P2 and P6 are reversely rotated in the B direction. The example of the flow rate of each pump was 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) The blood removal flow rate is P1-P2 = 200-80 = 120 ml / min, blood return The flow rate is P1-P2-P3 + P6 = 200-80-30 + 80 =
170 ml / min. From the above results, the blood return flow rate is 170 ml / min in the water withdrawing step and the dialysate pushing step, which is not changed at all. 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 set to be larger than that of the pump P5 by the amount of water removal. By controlling, the pump P3 can be omitted. In FIG. 1, the sterilization filter 10 is provided in the dialysate supply circuit immediately before the dialyzer, but this filter is not essential.
However, since the sterility of the dialysate is not guaranteed, it is preferable to provide a sterilization filter to prevent bacteria from entering the blood.

[0009]

According to the present invention, when blood is processed using the hemodiafiltration apparatus of the present invention, the flow rate of blood returned during both the operation of extracting water from the blood and the operation of pushing the dialysate into the blood is greatly changed. No, it is excellent in terms of safety. And
The pushing flow rate of dialysate can be changed freely,
Can easily handle a wide range of prescriptions. Further, the device is inexpensive because it has a simple configuration in which only two pumps P2 and P6 are added to an existing hemodialysis device, and the blood circuit and dialysate circuit also require a complicated configuration and special expensive parts. , The running cost can be kept low.

[Brief description of the drawings]

FIG. 1 is a system diagram of a hemodiafiltration apparatus according to Embodiment 1 of the present invention.

[Explanation of symbols]

 1 first blood circuit 2 second blood circuit 3 patient 4 dialyzer 5 dialysate supply circuit 6 dialysate discharge circuit 8 side circuit (dialysate supply circuit) 9 side circuit (dialysate discharge circuit) P1 pump P2 pump P3 Pump (Water removal pump) P4 Pump P5 Pump P6 Pump 10 Disinfection filter 11 Controller

Claims (4)

(57) [Claims] 1. A dialyzer having a semi-permeable membrane therein for purifying blood by bringing blood and dialysate into contact with each other through the semi-permeable membrane, and a blood pump for guiding blood taken out of a living body to the dialyzer. A first blood circuit, a second blood circuit having means for guiding blood flowing out of the dialyzer to a living body, a dialysate supply circuit having a dialysate supply pump for guiding dialysate to the dialyzer, A hemodiafiltration apparatus having a dialysate discharge circuit having a dialysate discharge pump for discharging the dialysate flowing out, wherein a pump is installed in at least a first blood circuit and a dialysate supply circuit in each of the circuits. Blood circuits, wherein at least the first blood circuit and the dialysate supply circuit among the pumps provided in these side circuits are forward / reverse rotatable pumps. Diafiltration equipment. 2. A forward / reverse rotatable pump provided in a side circuit of the first blood circuit and the dialysate supply circuit can control the rotation direction in conjunction with the same direction, and the control enables 2. The hemodiafiltration apparatus according to claim 1, wherein the extraction of water from the blood and the pushing of the dialysate into the blood can be performed alternately. 3. The hemodiafiltration apparatus according to claim 1, wherein the two forward and reverse rotatable pumps can be controlled in conjunction so that their flow rates are equal. . 4. The two forward / reverse rotatable pumps,
4. The hemodiafiltration apparatus according to claim 1, wherein the apparatus is a dual pump using a common motor.