JPH0337951B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a body fluid purification device using hemodiafiltration (HDF), and in particular, in dialysis and purification operations of body fluids such as blood, dialysate is transferred from the dialysate side to the body fluid side. By repeatedly pushing water in and pulling water from the body fluid side to the dialysate side, it is highly efficient and has both hemofiltration (HF) and hemodialysis (HD) effects. The present invention relates to a body fluid purification device that enables easy-to-operate dialysis and eliminates the need for a replacement fluid introduction mechanism, which is essential in conventional HF devices.

(Prior Art) In recent years, so-called artificial kidneys, which are devices that dialyze and purify body fluids such as blood or its components, have come into widespread use in the treatment and life support of patients with renal failure. Such a device uses a clarifier (dialyzer) containing a semipermeable membrane such as a film, tube, or hollow fiber cellulose membrane, such as a cuprammonium rayon membrane, in a box, thereby allowing, for example, In the case of HD operation, by bringing blood and other body fluids into contact with dialysate through the semipermeable membrane, urea, uric acid, water, etc. accumulated in the patient's body fluids are dialyzed and removed, resulting in a state close to normal. The body fluid has a solute concentration and is returned to the patient's body. During HF operation, the semipermeable membrane draws out a solution containing mainly unnecessary medium and low molecular weight substances from the blood. While removing it, the blood will be refilled with a solution containing the necessary substances and returned to the body.

(Problem to be solved) However, in view of the HD and HF removal functions, there is a desire for a device (HDF device) that can perform both functions at the same time.
The reality is that a practically satisfactory device that can perform both functions with high efficiency in the same device and is easy to operate has not yet been developed.

Moreover, when performing HF operation, it is necessary to control at least one of the substituting liquid introduction mechanism that returns the substituting liquid containing necessary substances into the body, the injection rate of the substituting liquid, or the filtration rate of the solution containing unnecessary substances from the body fluid side. A mechanism must be used and controlled so that the amount and rate of fluid loss during HF operation is as planned. but,
The mechanism is extremely complex and highly precise.
The drawback was that it required a complicated operation. In addition, problems such as the need for the replacement liquid itself, its transportation, and storage, as well as the need for a special mechanism,
This makes it an expensive and complex process.

Therefore, it enables highly efficient dialysis and filtration,
The development of a diafiltration device that is easy to operate and inexpensive is highly desirable.

(Solution Means) Here, the present invention has been made against the background of the above, and its gist is to house a semipermeable membrane and to allow body fluids such as blood to flow through the semipermeable membrane. A dialyzer that purifies body fluids by contacting the dialysate through a membrane, a dialysate supply channel for supplying the dialysate to the dialyzer, and a dialysate drain for discharging the dialysate from the dialyzer. It is provided on the dialysate discharge flow path, the supply flow path, and the discharge flow path, and simultaneously adjusts both the inlet flow rate in the dialysate supply flow path and the outlet flow rate in the discharge flow path, and adjusts the difference between them from inside the body. In a body fluid purification device using hemodiafiltration (HDF), which includes a dialysate inflow and outflow adjustment mechanism that equalizes the amount of water removed, the inflow and outflow amounts of the dialysate supply channel or discharge channel A container for accommodating the dialysate taken out from the flow path section between the adjustment mechanism and the dialyzer is provided, and the dialysate flowing through the flow path section is provided on a connecting flow path connecting the container and the flow path section. A single pump capable of forward and reverse rotation is provided which can alternately perform an operation of taking out the dialysate into the container and pushing the dialysate from the container into the flow path portion, and a pump that can be rotated in forward and reverse directions. Therefore, a control device is provided for switching control so that the amount of the dialysate taken out into the container and the amount pushed in from the container are equal, and the control device controls the forward and reverse rotation. Possible forward and reverse rotation of the pump may be controlled to increase or decrease the amount of dialysate supplied to the dialyzer through the supply channel or the amount of dialysate discharged from the dialyzer to the discharge channel. That's what I did.

(Operation/Effect) That is, according to the present invention, the amount of dialysate supplied to the dialyzer through the supply channel or the dialyzer is increased by the forward and reverse rotation of one pump capable of forward and reverse rotation. The amount of dialysate discharged from the dialyzer into the discharge channel is increased or decreased, thereby increasing or decreasing the difference between the amount of dialysate flowing into the dialyzer and the amount of dialysing fluid flowing out from the dialyzer (per unit time). It became possible to repeatedly change the value from positive to negative and from negative to positive.

In other words, when the inflow of dialysate into this dialyzer is larger than its outflow, the fluid pressure of dialysate in the dialyzer increases, and the pressure on the body fluid side that comes in contact with it through the semipermeable membrane increases. When the dialysate pressure becomes higher than the body fluid side, a pushing action (displacement) of the dialysate towards the body fluid side occurs.Conversely, if the inflow volume is made smaller than the outflow volume, the pressure of the dialysate drops to the body fluid side. This is where the ultrafiltration effect occurs, which forces dialysate into the body fluid through the semipermeable membrane inside the dialyzer, and repeatedly pulls water out of the body fluid. It is possible to do it.

In the above, when water is transferred from the body fluid side to the dialysate side, solutes (waste products) consisting of small and medium molecules are also transferred at the same time, and the required amount of waste products is removed. On the other hand, in order to compensate for the lack of water in the body fluids that occurs at this time, the above difference (amount of dialysate flowing into the dialyzer per unit time - amount of dialysate flowing out from the dialyzer per unit time) is corrected. Then, the dialysate containing the necessary substances is automatically forced into the body fluid as a replacement fluid through the semipermeable membrane. At this time, the amount of dialysate taken out of the system from the dialysate flow path by the operation of one pump is equal to the amount of fluid pushed into the dialysate flow path from outside the system, so it is drawn out from the body. The difference between the amount of fluid and the amount of fluid pushed into the body is equal to the amount of water drawn out of the body from the body fluid, which is determined by the dialysate inflow and outflow adjustment mechanism. Therefore, by alternately repeating the water pulling and pushing operations, the same device can perform both conventional HF operation and HD operation.

Therefore, the operation of the body fluid purification device using hemodiafiltration (HDF) according to the present invention is extremely easy, and there is no need to separately provide a special sterile replacement fluid and replacement fluid introduction mechanism.
That troublesome operation can be completely omitted,
The device can be made smaller and simpler, and its cost can be significantly reduced.

(Example) Hereinafter, the present invention will be described in further detail based on an example shown in the drawings.

First, the drawing is a system diagram showing a specific example of the body fluid purification device according to the present invention. In this figure, reference numeral 1 denotes a dialyzer as a blood purification device, which is composed of a box housing a semipermeable membrane in the form of a film, a tube, or a hollow fiber. A blood supply channel 2 for guiding blood from the patient's body is connected to the dialyzer 1,
The blood purified in the dialyzer 1 is returned to the patient's body through the blood delivery channel 3.

Further, a dialysate supply channel 4 is connected to the dialyzer 1 for guiding the dialysate from a storage tank (not shown) into the dialyzer 1, and furthermore, a semipermeable membrane is connected to the dialyzer 1. A dialysate discharge channel 5 is provided for discharging the dialysate that has come into contact with the blood through the semipermeable membrane, or for discharging unnecessary or harmful substances taken out from the blood by the filtration action of the semipermeable membrane. It is provided.

Further, on the flow paths of the dialysate supply flow path 4 and the dialysate discharge flow path 5, a known dialysate inflow and outflow adjustment mechanism 6 is provided to adjust the supply and discharge amounts of dialysate. The mechanism 6 adjusts the amount of dialysate discharged from the dialyzer 1 through the mechanism 6 and the flow rate of the dialysate supplied to the dialyzer 1, and the difference therebetween becomes the amount of water removed from the body. As such, it is set. The dialysate inflow and discharge adjustment mechanism 6 is a well-known device attached to a dialysis machine, and is basically an inflow pump mechanism disposed on the supply channel 4. and a discharge pump mechanism disposed on the discharge channel 5, and a control device for controlling these two pump mechanisms, such as the commercially available Ultrafiltration Controller (Toray: UFC).
) etc. can be used.

A connecting flow path 7 which is located on the dialysate discharge flow path 5 and is branched from a flow path between the dialyzer 1 and the adjustment mechanism 6 is connected to a tank 8 for accumulating the dialysate.
A pump 9 that is connected to the housing body and can be rotated in forward and reverse directions is provided on the connection flow path 7 between the discharge flow path 5 and the tank 8 . That is, pump 9
When rotating in the forward direction, the dialysate flowing through the discharge flow path 5 is taken out of the system and guided into the tank 8, and during reverse rotation, the dialysate in the tank 8 is pushed in from outside the system,
It is designed to lead to the discharge flow path 5.

Further, a control device 10 is provided between the tank 8 and the pump 9, and when the water level in the tank 8 rises due to forward rotation of the pump 9 and reaches a predetermined height,
The control device 10 causes the pump 9 to rotate in reverse, and when the water level in the tank 8 is lowered to a predetermined height due to the reverse rotation of the pump 9, the control device 10 causes the pump 9 to rotate in the reverse direction. 9 is returned to normal rotation again, and the water level is raised again.

Furthermore, a pressure sensor 11 is provided in the discharge passage 5, and the discharge amount of the pump 9 during forward rotation is controlled by a control device 12 so that the pressure in the discharge passage 5 does not fall below a pressure safety range. It is controlled accordingly. Similarly, the discharge amount of the pump 9 during reverse rotation is:
The pressure in the discharge passage 5 is controlled by the control device 12 so that it does not exceed the pressure safety limit.

Therefore, when purifying blood using a device with such a configuration, the inflow and outflow amount adjustment mechanism 6
The dialysate flow rate in the supply flow path 4 and the discharge flow path 5 is controlled by the dialyzer 1, and the dialysate is maintained at a constant flow rate and flows steadily in the dialyzer 1, that is, the inflow and discharge amount adjustment mechanism 6 is maintained. Therefore, in a state where the difference between the amount of dialysate discharged from the discharge channel 5 and the amount of dialysate supplied through the supply channel 4 is adjusted to be the amount of water removed from the body, the pump 9 is controlled by the controller. 10
The flow path 7 is rotated periodically in forward and reverse directions by
This allows the same amount of dialysate to be alternately moved between the discharge channel 5 and the tank 8.

Therefore, when the dialysate flowing through the discharge channel 5 is taken out into the tank 8, even though the amount of dialysate supplied to the dialyzer 1 remains unchanged, the amount of dialysate discharged from the dialyzer 1 is increases by the amount of discharge from the pump 9, the dialysate circuit pressure becomes more negative, the pressure on the dialysate side becomes lower than the pressure on the blood side, and the semipermeable membrane inside the dialyzer 1 is As a result, an amount of water in the blood is drawn out to the dialysate side in an amount corresponding to the discharge amount of the pump 9.

On the other hand, when the dialysate in the tank 8 is pushed into the discharge channel 5, the amount of dialysate discharged from the dialyzer 1 is increased even though the amount of dialysate supplied to the dialyzer 1 remains unchanged. is reduced by the discharge amount of the pump 9, and the dialysate circuit pressure becomes positive pressure, and the pressure on the dialysate side becomes higher than the pressure on the blood side. Therefore, the semipermeable membrane inside the dialyzer 1 This results in the dialysate being forced into the blood through the dialysis fluid. Moreover, the amount of dialysate to be pushed in is the same as the amount of water drawn by the pump 9.

Therefore, by alternately rotating the pump 9 in forward and reverse directions, water is drawn out and dialysed fluid is alternately pushed between the blood side and the dialysate side within the dialyzer 1 via the semipermeable membrane. Therefore, the lack of water in the blood caused by the transfer of water from the blood side to the dialysate side is then replenished by the transfer of an equal amount of dialysate to the blood side. A special replacement liquid or replacement liquid introduction mechanism is no longer required.

In other words, in conventional hemofiltration (HF) operation, a large amount of water is only drawn out through a semipermeable membrane in the purifier (corresponding to dialyzer 1), so some of that water is In order to replenish the solutes (necessary solutes are also replenished at the same time), a replacement fluid is prepared separately, and this is returned to the blood by a separate introduction mechanism. Because the dialysate is forced into the blood side as a replacement fluid by the reverse rotation of the dialyzer, there is no need to separately prepare such a replacement fluid or provide a mechanism for introducing it.
At this time, the control device 12 rotates the pump 9 in forward and reverse directions so that the negative and positive dialysate pressures in the dialyzer 1 do not damage the durability of the semipermeable membrane in the dialyzer 1. This means that the discharge amount is controlled.

In this way, such a device can effectively, safely, and accurately replace body fluids while performing dialysis (hemodialysis, HD) operations, and can reduce the amount of filtration and injection of replacement fluid used in the past. By using a single pump that can be rotated in forward and reverse directions, the entire device can be simplified, made more compact, and lower in cost, without requiring any complicated equipment to control the amount or special replacement liquid. Of course, the method itself called hemodiafiltration (HDF) could be made safe and low-cost.

Although the embodiments of the present invention have been described above, the present invention is not limited only to these embodiments or by the description of the embodiments, and as long as it does not depart from the spirit of the present invention. , various changes and improvements can be made based on the knowledge of those skilled in the art.

For example, in the above example, the pump 9 is provided for the dialysate discharge channel 5 from the dialyzer 1, but it is provided for the dialysate supply channel 4 to the dialyzer 1. It is also possible. However, considering the problem of contamination of liquid such as dialysate that is pumped in by the pump 9, it goes without saying that it is desirable to provide the discharge channel 5.

Further, in the above example, the dialysate taken out from the discharge channel 5 by the pump 9 is stored in the tank 8, and the control device 10 is operated by detecting the water level in the tank 8. However, of course, instead of such a configuration, a bag is used as a container for the dialysate, which is obvious to those skilled in the art, and its weight changes (changes depending on the amount of dialysate).
There is no problem in detecting this and operating the control device 10, or even mechanically controlling the forward and reverse rotation of the pump 9 using a timer or the like.

In this way, the present invention enables accurate, safe, and easy control of body fluid replacement, dialysis, etc. by appropriately controlling a single pump that can be rotated in forward and reverse directions. Moreover, it does not require the use of complicated auxiliary devices such as conventional replacement fluid introduction mechanisms and special replacement fluid for intravenous drips.
The major feature of this device is that it enables blood purification operation using an extremely simple mechanism, making the device smaller, more compact, and lower in cost.

[Brief explanation of the drawing]

The drawing is a system diagram showing one embodiment of the body fluid purification device of the present invention. 1: dialyzer, 4: supply channel, 5: discharge channel,
6: Inflow and outflow amount adjustment mechanism, 7: Connection channel,
8: Tank, 9: Pump, 10, 12: Control device.

Claims (1)

[Scope of Claims] 1. A dialyzer that contains a semipermeable membrane and purifies body fluids such as blood by bringing the body fluids, such as blood, into contact with the dialysate through the semipermeable membrane; A dialysate supply channel for supplying dialysate to the dialyzer, a dialysate discharge channel for discharging the dialysate from the dialyzer, and a dialysate supply channel provided on the supply channel and the discharge channel, and supplying the dialysate. Hemodiafiltration (HDF) includes a dialysate inflow and outflow adjustment mechanism that simultaneously adjusts both the inlet flow rate in the flow path and the outlet flow rate in the discharge flow path, and makes the difference equal to the amount of water removed from the body. ) A body fluid purification device according to the present invention includes a container for accommodating dialysate taken out from a flow path portion of the dialysate supply flow path or discharge flow path between the inflow and outflow amount adjustment mechanism and the dialyzer. A connection flow path connecting the container and the flow path section is provided with an operation for taking out the dialysate flowing through the flow path section into the container and an operation for pushing the dialysate from the container into the flow path section. A single pump capable of rotating in forward and reverse directions is provided, and the amount of dialysate taken out of the dialysate into the container and the amount of pumped in from the container are controlled by the operation of the pump. A control device is provided to control switching so that the amount of water is equal, and the control device controls forward and reverse rotation of the pump capable of forward and reverse rotation, so that the amount of water supplied to the dialyzer through the supply channel is controlled by the control device. 1. An apparatus characterized in that the amount of dialysate used or the amount of dialysate discharged from the dialyzer into the discharge channel can be increased or decreased.