JPS6127062B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hypertype blood purification system using a molecular membrane. In the present invention, blood filtration refers to operations that involve separating all or most of cellular components such as red blood cells, white blood cells, and platelets from blood, as well as operations that include separating all or part of protein components such as globumin and albumin. say.

In recent years, various blood purification methods have been implemented to remove and treat toxic substances present in the blood of patients suffering from renal failure, liver failure, etc. Among these blood purification methods, body fluids containing toxic substances are overseparated from blood using a body fluid separation membrane with a pore size of 0.002 to 2μ,
Toxic substances in the blood are removed by discarding the separated fluid and mixing other body fluids that do not contain toxic substances or artificial body fluids (hereinafter referred to as replacement fluids) with the obtained blood. (post-dilution method) or a method in which blood pre-diluted with a replacement fluid is filtered through a membrane (pre-dilution method). The above method requires that the blood flow rate entering the diaphragm and the purified blood flow rate after the obtained blood and replacement fluid are remixed are substantially equal or maintained at a predetermined flow rate ratio. If this flow rate ratio deviates or fluctuates significantly, the patient's circulating blood volume increases or decreases too much, which increases the burden on the circulatory system, resulting in a very alarming situation.

Therefore, it is necessary to maintain the amount of fluid separated from blood and the amount of replacement fluid added to the obtained blood equal to each other or at a predetermined ratio. For this reason, in conventional systems, a method has been adopted in which a liquid separated from blood is measured, and an amount of replacement fluid corresponding to the separated amount is mixed with the blood by adjusting a pump or a pot. However, this method has many problems, such as large fluctuations in circulating blood volume and the need to separate small amounts, making the operation extremely complicated and reducing reliability.

In view of the above points, it is an object of the present invention to provide a highly reliable hypertype blood purification system that can maintain the amount of circulating blood at a predetermined flow rate and is automatically and continuously operated.

The present invention provides hypertype blood purification in which blood taken out from a living body is supplied to a blood vessel via a blood pump, filtered, and the obtained blood is supplied to a mixer where it is mixed with replacement fluid and then returned to the body. In the system,
A measuring container is attached to each of the overline of the overflow device and the supply line of the replacement fluid, a valve is connected to the liquid outlet of the measuring container, and upper and lower liquid level detectors are installed at two locations above and below the measuring container. When each valve is closed, set the liquid level operating time between the upper and lower liquid level detectors to be the same, and if there is a difference in the liquid level operating time of the two measuring containers, This is an overtype blood purification system characterized in that it is configured to automatically perform an operation to adjust the liquid extraction pressure to bring it closer to a predetermined flow rate ratio.

Next, an embodiment of the hypertype blood processing system of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a negative pressure system, in which blood taken from a living body is sent to the filter 1 by a metering pump 12, separated by a membrane, and then
The liquid containing toxic substances in the blood is measured in a liquid measuring container 3 provided in the overline, and then stored in a liquid bottle 11. On the other hand, the obtained blood (excess blood) is mixed with a replacement fluid in a mixer 10, heated to body temperature in a blood warmer 16, and then returned to the patient's vein in fixed amounts. The replacement fluid is sent from the replacement fluid tank 15 to the replacement fluid measuring container 2 by the metering pump 4 installed in the replacement fluid line, and then sent to the mixer 10 using the head difference.
guided by.

The liquid measuring container 3 and the replacement liquid measuring container 2 may be of any shape as long as they are airtight containers. Among them, a cylindrical container with a length that is longer than the distance between the maximum liquid level detectors will cause the distance between the detectors to change even if the relative position of the measuring container and the liquid level detector shifts slightly. It is preferably used because it does not. When a phototube is used as a liquid level detector, the light emitting and receiving surface of the measuring container is preferably perpendicular to the optical axis and has a flat surface, and a cylindrical type is usually used. However, as long as the liquid level can be captured reliably, a cylindrical one may be used.

The material of the measuring container needs to be a hard transparent container because of the conditions such as that the internal volume of the container is constant and that a photoelectric liquid level detector can be used.
Furthermore, since the replacement fluid that has passed through the replacement fluid measuring container is returned to the human body, it must be harmless and free from problems such as eluates. Materials that meet these conditions include hard vinyl chloride, polycarbonate, poly(4-methylpentene), and polymethyl methacrylate.

As the liquid level detector of the measuring container, a known detector such as a magnetic float type or an electrode type can be used, but the measuring container is disposable and contact between the liquid level detector and the liquid or replacement liquid should be avoided. Therefore, a phototube type is preferably used. A transparent phototube type liquid level detector is preferably used from the viewpoint of reliable operation. Further, it is preferable that the light emitter and receiver be integrated so that the optical axes of the light emitter and receiver do not shift. It is desirable for the phototube amplifier to use a modulation method that is less susceptible to the effects of external light and fluorescent lights.

The flow path shutoff valves 8 and 7 connected to the liquid outlets of the liquid and replacement liquid measuring containers 3 and 2 are valves for measuring the flow rate of each liquid. In consideration of waste, it is preferable to use a pinch-tock type in which the flow path is supported by pressure from the outside. When the valves 8 and 7 attached to the outlets of the measuring containers 3 and 2 for the liquid and replacement fluid are open, each liquid passes through the measuring containers 3 and 2 and flows into the liquid bottle 11 and the mixer 10, respectively. . When the metering start signal is issued by the controller 9, the valves 8 and 7 close simultaneously, and then the liquid and replacement fluid begin to accumulate in the respective metering containers 3 and 2. The liquid accumulates in the measuring containers 3 and 2, and the liquid level in the containers rises, causing the lower liquid level detector 6 to rise.
b, 5b, a signal is sent to the controller 9. Subsequently, the liquid level rises and the upper liquid level detector 6
When it passes through a and 5a, the detector is activated and a signal is sent to the controller 9. At the same time as receiving the signal from the upper liquid level detector, the controller 9 issues a signal to open the valves 8 and 7, and the valves 8 and 7 open. At the same time as the valves 8 and 7 open, the liquid in the container escapes to the outlet and the liquid level in the container begins to drop. The liquid level in the measuring containers 3, 2 decreases, and the liquid level is detected by the lower liquid level detector 6b,
5b, the controller 9 issues a metering start signal again, the valves 8 and 7 close, and the same liquid storage operation as described above is repeated.

In the flow rate ratio control, for example, the inner area of each measuring container 3, 2 is kept constant, and the capacity ratio from the lower liquid level detectors 6b, 5b to the upper liquid level detectors 6a, 5a is made the same as the desired flow rate ratio. When the desired flow rate ratio is achieved, the lower liquid level detector in each metering vessel is activated and
The time it takes for the upper liquid level detector to operate is equal for both, and if there is a lot of replacement fluid, the operation time of the replacement fluid measuring container will be shorter than that of the fluid measuring container, and conversely, if there is less replacement fluid, the operating time will be longer. The operating time difference is calculated by the controller 9, and a control setting signal is sent to the pressure control valve 14 so that the difference is always zero, thereby controlling the flow rate ratio. Measurement of the flow rate ratio is performed by sampling. It goes without saying that this sampling period can be determined as appropriate. If the sampling period is shortened, it is possible to control the flow rate ratio with sufficient accuracy from the viewpoint of controllability of the entire system.

The total amount of liquid can be determined with high accuracy by correcting the number of sampling times and the ratio of container measuring time to draining time.

Setting and changing the flow rate ratio can be done by fixing the lower and upper liquid level detectors of the liquid measuring container and the lower liquid level detector of the replacement liquid measuring container and changing the position of the upper liquid level detector of the auxiliary measuring container. be exposed.

The liquid discharged from the liquid measuring container 3 is stored in a liquid bottle 11. As the liquid bottle 11, a glass bottle with good sealability is preferably used. The liquid bottle is maintained at negative pressure by a vacuum pump 13. This negative pressure allows blood to be filtered through the membrane through the ultraviolet action of the pressure gradient. The negative pressure in the liquid bottle is controlled by a pressure control valve 14. The pressure control valve is preferably provided on the bypass of the vacuum pump 13 from the viewpoint of pressure stability. On the other hand, the replacement fluid discharged from the replacement fluid measuring container 2 is led to the mixer 10, mixed with blood, and then returned to the patient's vein.

FIG. 2 shows another embodiment (positive pressure type system) of the device of the present invention, in which the replacement fluid tank 15 is placed at a high position and a flow rate adjustment valve 18 is installed in place of the metering pump 4 shown in FIG. It is set up. Further, a negative pressure pump 17 is provided in the overflow line between the overflow vessel 1 and the liquid measuring container 3 instead of the liquid bottle shown in FIG. The liquid flow rate of the negative pressure pump 17 can be controlled by a controller 9.

As described above, the blood purification system of the present invention can not only accurately add replacement fluid to the obtained blood (excess blood) in an amount equal to that of the body fluid that has passed, but also adjust the amount of fluid and replacement fluid supplied at any set ratio. It is also possible to automatically control the Therefore, it is an easy-to-use system that does not require the trouble of changing complicated ratio settings during clinical practice.

[Brief explanation of the drawing]

The drawings show one embodiment of the device of the present invention; FIG. 1 is an example of a negative pressure system, and FIG. 2 is an example of a positive pressure system. 1... Container, 2, 3... Measuring container, 5, 6...
...Liquid level detector, 7, 8...Valve, 9...Controller.

Claims (1)

[Claims] 1. Blood taken out from the living body via the blood pump 12 is supplied to the strainer 1 and filtered, and the obtained blood is supplied to the mixer 10 and mixed with replacement fluid,
In the hypertype blood purification system for returning to the living body, measuring containers 3 and 2 are attached to the overline and replacement fluid supply line of the diaphragm 1, respectively, valves 8 and 7 are connected to the liquid outlet of the measuring container, and When the valves 8 and 7 of the upper and lower liquid level detectors 6a, 6b, 5a, and 5b attached to the upper and lower parts of the measuring container are closed, the liquid level movement between the upper and lower liquid level detectors is detected. The time is set to be the same, and if there is a difference in the liquid level operation time of the two measuring containers, the liquid take-out pressure is automatically adjusted to bring it closer to the predetermined flow rate ratio. A hypertype blood purification system characterized by the following configurations.