JPS6312633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a device for separating blood cell components and plasma components using a filtration device provided in a closed extracorporeal circulation circuit.

(Prior Art and its Problems) Plasma separation method has recently been known as a treatment method for renal failure, liver failure, autoimmune diseases, and the like.

This method generally involves continuously separating plasma components using a filtration membrane in a closed extracorporeal circulation circuit, and returning blood cell components to the body.

The filtration membranes used in these plasma separators have large pore sizes, and even a slight increase in pressure causes blood cell components to adhere to the membrane, reducing filtration efficiency.
It is known that hemolysis occurs because blood cells close to the membrane pore size forcefully try to pass through the membrane pores.

Therefore, in the plasma separation method, the transmembrane pressure difference (TMP) of the filtration membrane is constantly monitored and measured.
It is necessary to control the TMP so that it is maintained within the critical pressure range.

Measurements of TMP have been carried out using hemodialysis, but since the target substance used in the plasma separation method is different, the method of applying membrane pressure, the membrane pore size, the critical membrane pressure, etc. are also different, strict control is required. It cannot be directly applied to plasma separation methods that require

In addition, in plasma separators, if abnormal pressure were generated in the blood cell extraction circuit due to a problem such as a shunt, there was a risk that pressure exceeding the limit value would immediately occur in the filtration membrane.

The present invention was proposed as a result of studies in view of the current situation.

(Means for Solving the Problems) As shown in FIG. 1 corresponding to an embodiment, the present invention includes a filter 5 in a closed extracorporeal circulation circuit, and this filter 5 is used to collect blood cell components and plasma components. In the plasma separator for separating blood, a means P1 for detecting the differential pressure between the plasma inlet side and the blood outlet side of the filtration device 5 is provided, and the plasma outlet circuit 8 is controlled in conjunction with the differential pressure detecting means to adjust the set pressure or A pump M2 is provided which can adjust the flow rate so that the pressure is below a set pressure, and a pressure gauge P3 is provided on the blood cell derivation circuit side 17 to sense abnormal pressure within the closed extracorporeal circulation circuit.

(Effect) When separating plasma using a filter in a closed circuit,
The differential pressure detection means detects the transmembrane pressure difference from the difference between the pressure on the blood introduction side and the pressure on the plasma extraction side, and according to this information, the pump M2 of the plasma extraction circuit sets the pressure applied to the filtration membrane 2. The pressure is controlled so that the pressure is lower than the set pressure, and abnormal pressure is not applied to the membrane 2. In addition, the pressure gauge P3 at 17 in the blood cell evacuation circuit is used to monitor the pressure to prevent abnormal pressure from being applied to the filtration membrane 2 due to a problem with the shunt or the like on the patient's side.

(Embodiment) FIG. 1 shows an embodiment of the present invention. To explain the structure and operation thereof, first, blood is introduced from the patient through the blood introduction circuit 1 by the pump M1, and once the blood is introduced into the blood reservoir 4. to be stored. The subsequent filtration device 5 is partitioned by a filtration membrane such as a polyvinyl alcohol membrane, and the blood introduced from the blood reservoir 4 is connected to the positive pressure of the pump M1 on the blood introduction side and the plasma derivation circuit 8. The blood cells are separated into blood cell components and plasma components through the filtration membrane 2 by the negative pressure generated by the pump M2.

The plasma components separated here are collected in a drainage bag or the like, but the pore size of the filtration membrane of the filtration device 5 used in the plasma separation method is approximately 0.02 to 0.4μ, and is used in normal hemodialysis. Its pore size is larger than that of the membrane. Therefore, if the pore size approaches the size of blood cells and, for example, abnormal negative pressure is applied to the membrane 2 by pump M2, the blood cells will forcefully try to pass through the membrane pores, leading to the risk of hemolysis. There is.

Therefore, in the present invention, as a means for sensing the differential pressure between the blood inlet side and the plasma outlet side of the filter 5, for example, a differential pressure gauge P1 between the blood inlet side and the plasma outlet side as shown in FIG. 1 is provided. , by interlocking control with this differential pressure gauge P1, the pump M provided in the plasma derivation circuit
Differential pressure gauge P1 can be changed automatically by changing the rotation speed of P1 or turning the switch ON/OFF automatically.
The flow rate is adjusted so that the pressure is at or below the set pressure.

In the case of this embodiment, the differential pressure gauge P1 is configured to measure the differential pressure between the blood reservoir 4 disposed in front of the filtration device 5 and the plasma reservoir 7 disposed in front of the pump M2. preferably less than 100mmHg
The flow rate of the pump M2 is controlled at 15 to 20 mml/min so that the flow rate is 60 mmHg or less.

In FIG. 1, reference numeral 17 is a blood cell derivation circuit for returning blood cells to the patient. In the present embodiment shown in the figure, this blood cell derivation circuit 17 is equipped with a blood reservoir 14, and the upstream thereof is a blood cell derivation circuit 17. Replacement fluid introduction circuit 18
are set up in a branched manner. This replacement fluid introduction circuit 1
From 8, a replacement fluid such as albumin or HES contained in a replacement fluid container 16 is sent to the blood reservoir 14 by a pump M4.

In this embodiment, when introducing this replacement fluid, the replacement fluid introduction pump M4 is controlled according to the flow rate of the plasma derivation circuit 8. Specifically, the pump M2 may be controlled in direct conjunction with the pump M2, or if the pump M2 and another pump are controlled in conjunction with each other, the pump M2 may be indirectly controlled in conjunction with the pump M2 via the other pump. good.

Further, in this embodiment, a blood reservoir 14 is provided in the middle of the blood cell deriving circuit 17, and a pressure gauge P3 is provided in this blood reservoir 14.
In addition to monitoring the patient's condition (anemia, etc.) and problems with the shunt, it also monitors and prevents abnormal pressure from occurring in the filtration membrane 2 due to patient's arm movements.

FIG. 2 shows an embodiment in which the present invention is applied to a double filtration type plasma separation and exchange apparatus, in which a second filtration device 11 is incorporated into the embodiment of FIG.

In the same embodiment, the filter 5 in FIG.
The plasma component separated here is sent to the second filter 11 through the plasma derivation circuit 8.

The second filtration device 11 is internally partitioned with a filtration membrane 10 such as an ethylene vinyl alcohol membrane,
The plasma introduced into the second filter 11 is passed through the pump M2 and the pump M provided in the discharge circuit 12, which will be described later.
The positive pressure generated by the flow rate difference between the two substances is separated into a high molecular weight substance and a low molecular weight substance.

The separated high molecular weight substances are led out through the discharge circuit 12 and discharged into the storage container 13, but in this case, if the flow rates of pumps M2 and M3 become unbalanced, abnormal pressure will be generated in the second filtration device 11. As a result, stable filtration and separation effects cannot be obtained. Therefore, in this embodiment, the flow rate ratio of the pumps M2 and M3 is controlled in conjunction with each other to adjust the flow rate ratio between the amount of plasma introduced into the second filter 11 and the amount of high molecular weight substance discharged to a predetermined value. . For example, the flow rate of the pump M2 is 15
mml/min, the flow rate of pump M3 is automatically controlled to be 1/3 to 1/4 of that, that is, 3 to 5 mml/min.

In addition, P2 in the figure is a pressure gauge provided in the plasma reservoir 9, and if high pressure is applied to the second filtration device 11, there is a risk that the filtration membrane 10 etc. will be punctured.
It is monitored with this pressure gauge P2.

On the other hand, the low molecular weight substances separated by the second filter 11 are passed through the derivation circuit 15 to the blood reservoir 14.
After combining with the blood cell components sent from the first filter 5 through the derivation circuit 17, the blood cells are returned to the patient's body. In order to supplement the plasma components removed in the second filter 11, a replacement fluid such as albumin or HES is sent from the replacement fluid container 16 to the blood reservoir 14 through the introduction circuit 18.

In this embodiment, when introducing this replacement fluid, a pump M for introducing replacement fluid provided in the introduction circuit 18 is used.
4 and a pump M3 provided in the discharge circuit 12 for the high molecular weight substance are controlled in conjunction with each other, and indirectly controlled in conjunction with the pump M2. In this way, the flow rate can be adjusted so that the amount of high molecular weight substance drawn out and the amount of replacement fluid injected are equal. For example, as mentioned above, the flow rate of pump M3 is 3 to 5 mm.
In the case of 1/min, the pump M4 is also adjusted to have the same flow rate, so that just the right amount of replacement fluid is injected into the blood reservoir 14.

In the case of this embodiment, each of the above-mentioned pumps M2,
The interlocking control means for M3 and M4 may be electrical control, but two or three tubes constituting each circuit 8, 12, 13 may be appropriately combined and squeezed at the same time. As an example, as shown in FIG. 3, the tube 8a of the circuit 8 and the circuits 12 and 18
The inner diameter of the tubes 12a, 18a is changed, for example, the inner diameter of the tube 8a is 8 mm, the inner diameter of the tube 12a, 1
If the inner diameter of tube 8a is set to 4 mm and these tubes are simultaneously squeezed by the same drive roller 20, the flow rate can be adjusted according to the diameter of each tube.

What has been explained above is an example of the present invention, and the first
The filtration device 5 and the second filtration device 11 may be of a hollow fiber type or other types, and other devices may also be modified according to the spirit of the present invention.

(Effects) According to the present invention described above, when blood cell components and plasma components are separated by a filter provided in a closed extracorporeal circulation circuit, the differential pressure between the blood introduction side and the plasma outlet side of the filter is is detected and the flow rate of the pump on the plasma output side is adjusted by interlocking control with the differential pressure detection means, so the pressure applied to the filtration membrane can be detected from the relative pressure on the inlet side and outlet side. A well-balanced pressure control is possible at all times using the plasma outlet pump. Therefore, destruction of blood cells due to abnormal negative pressure or the like can be prevented.

Furthermore, the safety of the plasma separation device is improved by using a pressure gauge in the blood cell extraction circuit to prevent abnormal pressure from occurring in the membrane of the filtration device due to shunt trouble or other factors. Become.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing an embodiment of the present invention, and FIG. 3 is a schematic diagram showing another embodiment of the pump control means in the present invention. In the figure, 1 is a blood introduction circuit, 2 is a filtration membrane, 5 is a filtration device, 8 is a plasma derivation circuit, 17 is a blood cell derivation circuit,
18 is a replacement fluid introduction circuit, P1 is a differential pressure gauge, P3 is a pressure gauge, M2 is a blood extraction pump, and M4 is a replacement fluid introduction pump.

Claims (1)

[Claims] 1. In a plasma separation device that includes a filtration device in a closed extracorporeal circulation circuit and separates blood cell components and plasma components using the filtration device, means for detecting the differential pressure between the blood introduction side and the plasma outlet side of the filtration device. A pump is provided in the plasma derivation circuit that can adjust the flow rate to a set pressure or below the set pressure by interlocking control with the differential pressure detection means, and the blood cell derivation circuit side is provided with a pump capable of adjusting the flow rate to a set pressure or below the set pressure. A plasma separation device characterized by being equipped with a pressure gauge for sensing.