JPH025091B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a diafiltration device that can perform dialysis and filtration simultaneously.

BACKGROUND OF THE INVENTION In recent years, so-called artificial kidneys, devices that purify blood through dialysis, have come into widespread use in the treatment and life support of patients with renal failure. Generally, this device includes a dialyzer in which a semipermeable membrane is housed in a box, a blood flow path that guides blood taken out of the body to the dialyzer, and also guides blood flowing out of the dialyzer back into the body. The dialysate is configured to include a pump that circulates blood in the flow path, and a dialysate flow means that supplies dialysate to the dialyzer and discharges dialysate that flows out of the dialyzer, and that the dialysate flows within the dialyzer. Blood is brought into contact with a dialysate via a semipermeable membrane, and the blood is purified by the dialysis action of the semipermeable membrane.

By the way, the present inventors have developed a dialysis filtration device that can perform such dialysis and filtration to draw out water from the blood at the same time, and does not require a replacement fluid introduction mechanism. . This device is disclosed in Japanese Patent Publications No. 58-14223 and No. 56-33107, so a detailed explanation will be omitted, but the general idea is that it measures the amount of dialysate flowing into the dialyzer per unit time. By alternating the difference between the flow rate from the dialyzer and the flow rate from positive to negative and then from negative to positive, the pressure of the dialysate inside the dialyzer is changed to push the dialysate into the blood. This method alternately draws water from the blood. When the water is drawn out, harmful substances contained in the blood are simultaneously drawn out and the blood is purified, while dialysate containing the necessary substances to be replenished into the body is pumped in, and the drawn out water is removed. A fixed amount is returned to the body.

Problems: However, in such a device, water is drawn out and dialysate is pushed in alternately, so the flow rate of blood returned to the body changes drastically periodically, and as a result, the second The linear velocity of the blood flow returned to the blood vessel from the outlet of the flow path increases significantly periodically,
Subsequent studies revealed that there is a possibility that it may have an adverse effect on blood vessels. In such a device, a part of the blood flow path is branched off for dogs, and a blood tank such as a blood bag is provided in the branch flow path. If water is drawn into the blood tank, and conversely, when water is drawn from the blood, the blood in the blood tank is supplied into the blood flow path, the amount of blood returned to the body will be almost constant, and the above-mentioned Although this problem is solved, the disadvantage is that the control of the device becomes complicated and the cost of the device increases significantly. This is because blood tanks such as blood bags must be completely sterilized, and when supplying blood from the blood tank to the blood flow path, care must be taken to ensure that air does not enter the blood flow path. This is because the equipment must be installed in duplicate or triple.

Means for Solving the Problems The present invention has been made to solve these problems, and its gist is (a)
A dialyzer that includes a semipermeable membrane housed in a case, and purifies blood by bringing the blood being circulated into contact with a dialysate through the semipermeable membrane;
(b) a blood flow path comprising a first flow path for guiding blood taken out of the body to the dialyzer and a second flow path for guiding blood flowing out from the dialyzer into the body; A dialysis device comprising: a pump provided to circulate blood in the blood flow path; and (d) a supply flow path for supplying dialysate to the dialyzer and a discharge flow path for discharging dialysate flowing out from the dialyzer. (e) a dialysate flow path provided on the dialysate flow path to change at least one of the amount of dialysate flowing into the dialyzer and the amount of dialysing fluid flowing out from the dialyzer per unit time; , by changing the difference between them alternately from positive to negative and from negative to positive, the dialysate pressure in the dialyzer is changed to force the dialysate into the blood and to remove water from the blood. and (f) controlling the operation of a pump provided in the first flow path to stop or reverse the pump, and controlling the operation of the dialysate in the dialyzer by the dialysate pressure changing means. blood flow control means configured to stop the flow of blood from the first flow path to the dialyzer or to cause the blood to flow back from the dialyzer to the first flow path when the dialyzer is pushed into the blood. A diafiltration apparatus is characterized in that it has.

Operation and Effects of the Invention In the diafiltration apparatus of the present invention, when the dialysate is forced into the blood and the blood flow in the blood flow path is about to increase, the blood flow control means is activated and the first flow path is increased. The pump is stopped or reversed, thereby suppressing a sudden increase in the linear velocity of the blood flow returned to the body from the outlet of the second flow path. This is because when the pump in the first flow path is stopped, the amount of blood equivalent to the pump's discharge volume is no longer returned to the body, and only the amount of blood equivalent to the amount of dialysate pushed into the blood is returned to the body. This is because it will be returned to on the other hand,
When the pump in the first flow path is reversed, the blood in the dialyzer is also returned to the body through the first flow path, so the amount of blood returned to the body through the second flow path is the amount of dialysate pumped. It becomes even less than that. And by this,
This suppresses a sudden increase in the linear velocity of the blood flow returned into the body from the outlet of the second flow path.

Further, in the present invention, if a part of the blood returned into the body from the second flow path is configured to be returned into the body through the first flow path, the blood will be returned to the body separately. Therefore, a sudden increase in the linear velocity of the blood flow returned into the body from the outlet of the second flow path is suppressed, thereby avoiding adverse effects on blood vessels.

Moreover, in the present invention, a blood bag or other device that draws out blood in the blood flow path in synchronization with the pushing of dialysate or supplies the drawn blood into the blood flow path in synchronization with the withdrawal of water. Since no expensive accessory equipment is required, the cost of the equipment is also reduced.

As can be understood from the above explanation, in the diafiltration device according to the present invention, changes in the flow rate of blood returned to the body are not eliminated, but the linear velocity of blood flow is adjusted to an extent that does not adversely affect blood vessels. This suppresses changes in That is, changes in blood flow still exist. This change in blood flow is advantageous for diafiltration. This is because when the blood volume in the body increases, peripheral blood vessels, which are normally constricted to maintain blood pressure, expand, increasing microcirculation and promoting the transfer of harmful substances from outside the blood vessels into the blood vessels. In order to
This is because the amount of harmful substances removed per unit time increases accordingly, increasing the diafiltration efficiency.

Embodiment Next, an embodiment of the present invention will be described in detail based on FIG. In the figure, 10 is a blood flow path through which blood taken out from the body flows, including a first flow path 14 that leads the blood taken out from the body to the dialyzer 12, and a first flow path 14 that leads the blood that has flowed out from the dialyzer 12 back into the body. It is composed of a second flow path 16. A rotary pump 18 is provided in the first flow path 14,
Blood flowing in from the blood inflow section 36 flows into the blood flow path 10.
The inside is sent out by the operation of this pump 18,
The blood flows through the same flow path 10, and furthermore, the blood outflow part 3
7, it is now being returned to the body.

The dialyzer 12 is composed of a box housing a hollow fibrous semipermeable membrane therein, and purifies the blood by bringing the blood into contact with the dialysate via the semipermeable membrane. . And this dialyzer 1
2 includes a dialysate supply channel 20 for introducing the dialysate to the dialyzer 12, and a dialysate supply flow path 20 for guiding the dialysate to the dialyzer 12, and a dialysate supply channel 20 for guiding the dialysate to flow out from the dialyzer 12 after being brought into contact with blood through a semipermeable membrane in the dialyzer 12. A dialysate discharge channel 22 is connected to the dialysate discharge channel 22 for discharging or discharging water taken out together with harmful substances from the blood by the filtration action of the semipermeable membrane. The dialysate supply channel 20 and the dialysate discharge channel 22 are provided with pumps 24 and 26, and the operation of these pumps 24 and 26 causes the dialysate to flow from the dialysate supply channel 20 to the dialyzer 12. Furthermore, the dialysate is discharged from the dialysate discharge channel 22 to the outside of the system. In other words, in this example,
The dialysate supply channel 20, the dialysate discharge channel 22, and the pumps 24 and 26 constitute a dialysate flow means.

The pump 26 used has a larger discharge amount than the pump 24. That is, the dialysate pressure in the dialyzer 12 is made to be lower than the blood pressure due to the difference in the discharge amount of these pumps 26 and 24, and the water in the blood is dialyzed due to the difference in fluid pressure. It is designed to be drawn out to the liquid side. The difference in discharge amount between the pumps 26 and 24 is determined in accordance with a predetermined amount of water to be drawn out.

A dialysate tank 30 is connected to the dialysate supply channel 20 via a branch channel 28 , and a rotary pump 32 is provided in the branch channel 28 to supply dialyzer 12 through the dialysate supply channel 20 . A part of the dialysate introduced into the dialysate is taken out to the dialysate tank 30, or the dialysate in this tank 30 is connected to the dialysate supply channel 2.
It is now sent out to 0. That is, the dialysate tank 30, the branch flow path 28, and the rotary pump 32 constitute a dialysate pressure changing means that increases or decreases the amount of dialysate supplied to the dialyzer 12 to change the dialysate pressure within the dialyzer 12. That's what I'm doing.

The operation of the rotary pump 32 on this branch flow path 28 and the rotary pump 18 on the first flow path 14 is controlled by a control device 34, respectively. That is, when the rotary pump 32 on the branch flow path 28 operates in the direction of supplying the dialysate in the dialysate tank 30 to the dialysate supply flow path 20, the control device 34 operates the rotary pump 18 on the first flow path 14. It is configured to stop the flow of blood in the blood flow path 10.

In such a device, the dialysate supply channel 20
When the pumps 24 and 26 on the dialysate discharge flow path 22 are activated and the rotary pump 18 of the first flow path 14 is rotated in the forward direction, the blood and dialysate in the blood flow path 10 are caused to flow. They are brought into contact with each other via a semipermeable membrane within the dialyzer 12. Harmful substances in the blood are then removed to the dialysate side by the dialysis action of this semipermeable membrane, thereby purifying the blood.

In this state, when the rotary pump 32 on the branch flow path 28 is operated, the amount of dialysate supplied into the dialyzer 12 through the dialysate supply flow path 20 is increased or decreased, and the amount of dialysate in the dialyzer 12 is increased or decreased. The dialysate pressure is increased and decreased alternately from positive to negative and then from negative to positive. For example, when the dialysate in the dialysate supply channel 20 is drawn out to the dialysate tank 30 side and the amount of dialysate supplied to the dialyzer 12 decreases, the dialyzer 12
The dialysate pressure inside the body decreases to the negative side, and based on the pressure difference between the decreased dialysate pressure and the pressure on the blood side, water in the blood is removed along with harmful substances by the filtration action of the semipermeable membrane. The blood is drawn out to the dialysate side, where the blood is purified in addition to the dialysis action.

On the other hand, the rotary pump 28 on the branch flow path 28 is rotated in the opposite direction to the above direction, and the dialysate in the dialysate tank 30 is supplied into the dialysate supply flow path 20, thereby dialysis When the amount supplied to the dialyzer 12 per unit time is greater than the amount outflowed from the dialyzer 12, the pressure of the dialysate becomes greater than the pressure of the blood, and the necessary substances to be replenished into the body are The containing dialysate is forced through the semi-permeable membrane into the blood.

By the way, when the dialysate is forced into the blood in this way, the amount of blood returned to the body through the second flow path 16 increases rapidly. This is because not only the blood pumped out by the rotary pump 18 on the first flow path 14, but also the dialysate pushed into the blood based on the pressure difference within the dialyzer 12 is returned to the body as a blood stream. Because it will be. Then, when the amount of blood returned to the body through the second flow path 16 increases, the outflow port 3 of the second flow path 16 increases.
Although the linear velocity of the blood flow at 7 increases and causes vascular damage as described above, this is effectively avoided in the device of the above embodiment. That is, when the rotary pump 32 on the branch flow path 28 reverses and the dialysate begins to be pushed into the blood, the controller 34 stops the rotary pump 18 on the first flow path 14,
It stops the blood from flowing. Therefore, the amount of blood returned to the body is only the amount based on the pushing of the dialysate, and the amount of blood returned to the body is limited to the amount based on the pushing of the dialysate.
7, a rapid increase in the linear velocity of blood returned to the body is suppressed.

In this way, in the device of this embodiment, although a sudden increase in blood flow at the outlet 37 of the second flow path 16 is suppressed, when pushing the dialysate,
Even when the rotary pump 18 is stopped, the linear velocity of the blood flow at the outlet 37 is still increasing. This is because the amount of blood returned into the body based on pumping of the dialysate is usually greater than the amount of blood returned into the body based on the pumping of the rotary pump 18. This temporary increase in the amount of blood returned to the body is advantageous for blood purification by diafiltration. However, if the amount of blood in the body increases,
This is because the amount of harmful substances that migrate from the outside of the blood vessel into the inside of the blood vessel per unit time in the reticular blood vessels increases, and the blood purification efficiency also increases accordingly.

In the above embodiment, when the rotary pump 32 on the branch flow path 28 is reversed, that is, when the dialysate is pushed into the blood, the control device 34
is configured to stop the rotary pump 18 on the first flow path 14, but in contrast to such embodiments, the controller 34 reverses the rotary pump 18 as dialysate is forced into the blood. It is also possible to configure it as follows. In this case, the blood in the blood flow path 10 flows between the second flow path 16 and the first flow path 1.
Since the second flow path 16 is returned to the body through the two flow paths 4 and 4, an increase in the linear velocity of the blood flow at the outlet 37 of the second flow path 16 is more effectively suppressed.

The present invention can also be implemented in other embodiments as shown in FIG. In the embodiment shown in FIG. 2, a second flow path 1 is provided in the blood flow path 10.
6 and a portion of the first flow path 14 near the blood inflow portion 36 is provided with a return path 38, and an electromagnetic valve 4 for opening and closing the return path 38 is provided on the return path 38.
0 is set. The electromagnetic valve 40 is normally in a closed state, but the rotary pump 3 on the branch flow path 28
2 is rotated in the direction of supplying dialysate to the dialyzer 12, ie when the dialysate is forced into the blood, it is switched into the open state by the control device 34. Note that, at this time, the rotary pump 18 on the first flow path 14 is stopped by the control device 34. In this embodiment, other parts are the same as those in the previous embodiment, so only the reference numerals are shown and detailed explanations are omitted.

In such devices, once the dialysate begins to be forced into the blood, the controller 34 controls the first flow path 1.
Since the rotary pump 18 on the blood flow path 10 is stopped and the electromagnetic valve 40 is opened almost at the same time, the blood in the blood flow path 10 is transferred to the body through two flow paths, the second flow path 16 and the return path 38. will be returned to. This suppresses a sudden increase in the linear velocity of the blood flow at the outlet 37 of the second flow path 16. In this embodiment, blood is returned into the body through two channels, the inlet of the first channel 14 and the outlet 37 of the second channel 16. This is similar to the case where the rotary pump 18 is reversed, but this embodiment has the advantage that the blood purification efficiency can be further increased than when the rotary pump 18 is reversed. This is because, when the rotary pump 18 is reversed, the dialysate pushed into the blood in the dialyzer 12 is caused to flow back on the first flow path 14 toward the blood inflow section 36, and then water is removed from the blood. Rotary pump 1 when withdrawing
8 is rotated in the forward direction, the dialysate that has flowed into the first flow path 14 passes through the dialyzer 12 again, and the blood is not purified very much until the dialysate passes through the dialyzer 12. However, this is not the case in the apparatus of this embodiment. In the device of this embodiment, the amount of dialysate that exists in the first flow path 14 when pushing the dialysate is small (the amount of dialysate that exists in the range from the blood inflow part 36 to the connection part to the first flow path 14 of the return path 38) is small. Therefore, when the pump 18 is rotated in the forward direction, the amount of dialysate flowing through the first flow path 14 is also extremely small.

Although two or three embodiments of the present invention have been described in detail above, the present invention can also be implemented in embodiments different from these.

For example, the dialysate pressure changing means can be configured in various ways other than those exemplified in the above embodiments, such as those disclosed in the above-mentioned publications, and may also be configured in various other ways. The device can be configured in other ways as well. For example, by detecting the difference between the dialysate pressure and the blood pressure, the rotary pump 3 on the branch channel 28
2. It may be configured to control the rotary pump 18, electromagnetic control valve 40, etc. on the first flow path 14.

In addition, the present invention can be implemented with various modifications based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a diafiltration device that is an embodiment of the present invention, and FIG. 2 is a system diagram of a diafiltration device that is another embodiment of the invention. 10: blood flow path, 12: dialyzer, 14: first flow path, 16: second flow path, 18: rotary pump, 20:
Dialysate supply channel, 22: Dialysate discharge channel, 24,
26: Pump, 28: Branch flow path, 30: Dialysate tank, 32: Rotary pump, 34: Control device, 3
6: Blood inflow section, 38: Return path, 40: Solenoid valve.

Claims (1)

[Scope of Claims] 1. A dialyzer that includes a semi-permeable membrane housed in a box and purifies blood by bringing the circulating blood into contact with a dialysate through the semi-permeable membrane; a blood flow path including a first flow path for guiding blood taken out into the dialyzer to the dialyzer and a second flow path for guiding blood flowing out from the dialyzer into the body; a dialysate flow path having a supply flow path for supplying dialysate to the dialyzer and a discharge flow path for discharging dialysate flowing out from the dialyzer; is provided on the flow path to change at least one of the inflow amount of dialysate into the dialyzer and the outflow amount from the dialyzer per unit time, and to change the difference from positive to negative or from negative to negative. dialysate pressure changing means for changing the dialysate pressure in the dialyzer by alternately changing it to a more positive value, pushing the dialysate into the blood and drawing out water from the blood; and the first flow path. controlling the operation of a pump installed in the pump, stopping or reversing the pump;
When the dialysate is pushed into the blood in the dialyzer by the dialysate pressure changing means, the flow of blood from the first flow path to the dialyzer is stopped, or the blood from the dialyzer to the first flow path is stopped. 1. A diafiltration device comprising: blood flow rate control means configured to cause reverse flow of the dialysis filtration device.