JPH0576594A - Device and method for switching blood flow direction to blood dialyzer - Google Patents

Abstract

PURPOSE:To decrease the blood clotting in a dialyzer by intermittently inverting the blood flow in the dialyzer. CONSTITUTION:The blood led out of the patient's artery A by a blood pump 1 is admitted into an artery inlet A1 of a blood direction changeover means 2, is emitted from an outlet B1 and is admitted from the inlet D1 of the dialyzer 3 into the dialyzer 3. The blood is emitted from the outlet D2, is admitted from B2 of a blood flow passage switching means 2, is emitted from a vein outlet V1 and returns to the patient's vein V. The dialyzate flows through a dialyzate flow direction changeover means F1 from an inflow port E-IN, is admitted into the dialyzer from its E1 and flows in the direction reverse from the flow direction of the blood therein. The dialyzate is emitted from a dialyzate outlet E2, flows through a dialyzate flow direction switching means F2 and is discharged from a dialyzate discharge port E-OUT. The respective switching means are so switched that the flows of the blood and the dialyzate are reversed in the respective directions. The above-mentioned operations are intermittently repeated.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to medical care, and more particularly to hemodialysis. In particular, it relates to an apparatus and method for injecting blood and dialysate into a hemodialyzer.

[0002]

2. Description of the Related Art Hollow fiber hemodialyzer
When hemodialysis is carried out using, the flow of blood and the flow of dialysate flowing through the dialyzer are fixed from the start to the end of dialysis. Normally, the blood inlet (arterial header) to the dialyzer is marked with red, and the blood outlet (venous header) is marked with blue. On the other hand, although the color inlet / outlet of the dialysate is not particularly marked, it is common to flow the dialysate in the opposite direction (counterflow) to the blood in order to improve the dialysis efficiency.

At the start of hemodialysis, the arterial and venous circuits of the blood circuit are connected to the arterial and venous blood ports of the dialyzer, and the dialysate supply and discharge hoses are connected to the dialysate inlet and outlet of the dialyzer. As described above, the blood circuit and dialysate hose once connected cannot be removed during dialysis or from the dialyzer. In particular, it is impossible to attach or detach the blood circuit and the dialyzer during dialysis.

The blood inlet and the outlet (header) of the hollow fiber dialyzer are the places where blood coagulation occurs most easily. This is because at the blood inlet, blood flows from the narrow inlet of the blood inlet into the header of a large space, the flow of blood suddenly becomes gentle and stagnation occurs, and at the outlet, the large space still remains. Because it causes stagnation in the blood flow.

Conventionally, various solutions have been proposed to prevent blood coagulation at the header portion. Patent No. 126783
No. 3, JP-B-62-54510 and Practical-use Sho-63-100051 are all proposals to improve the shape of the header part, but in actual dialysis, the blood flow rate is 100 to 300 ml per minute and the range of use is wide, and The problem of blood coagulation in the header part has not been solved by improving the shape of the header part because there are individual differences in the stickiness and the viscosity changes with time during dialysis.

Further, regarding the reuse of the dialyzer, the dialyzer is removed from the circuit and washed by a special device.

[0007]

[Problems to be Solved by the Invention] Blood tends to coagulate when it touches a foreign substance outside the body. In particular, coagulation occurs when there is a place where the blood flow becomes slow or stagnant in the extracorporeal circulation. When performing hemodialysis with a hollow fiber dialyzer, the blood injection port header portion D- of the dialyzer 3 shown in FIG.
1 and blood outlet side D-2 portion are apt to cause blood coagulation. In the injection-side header D-1, the blood flows from the narrow injection port with an inner diameter of 3 to 4 mm into a wide space with an inner diameter of 20 to 60 mm, and the flow suddenly becomes slow. Although it flows into a hollow fiber with a thickness of about a micron, the flow near the periphery of the header is liable to stagnant, and solidification begins in a ring shape from the portion near the circumference and gradually grows toward the center. Blood does not flow in the hollow fiber whose inlet is blocked by the blood coagulation layer, so that blood inside is coagulated. On the other hand, also at the outlet side header portion D-2, the flow becomes slower than at the inlet side, but solidification tends to occur at the circumferential portion.

When the flow pattern of blood changes little, blood clots rapidly at the stagnation site. Japanese Patent Application No. 2-213702, which prevents blood coagulation by changing the speed of flow and intermittently changing the pattern, has already been proposed.

In the process for reusing the dialyzer, the dialyzer is removed from the circuit, so that miscellaneous bacteria enter the dialyzer unless it is handled very carefully. Moreover, it poses a risk to healthcare workers for the transmission of pathogenic bacteria.

[0010]

SUMMARY OF THE INVENTION An apparatus and method for redirecting blood to a hemodialyzer according to the present invention further develops the prior proposals to provide a fundamental change in the pattern of blood flow to the dialyzer. The blood coagulation is suppressed by intermittently switching the flow direction of the blood flowing to the dialyzer during dialysis and causing the blood to flow in the opposite direction. Fibrin and platelets, which are coagulation components of blood, start to adhere to the periphery of the header portion and the surface of the hollow fiber, and coagulation expands with the adhered matter as the nucleus, but the blood flow direction of the present invention is reversed intermittently. By doing so, there is an effect that the adhered matter that has already started to adhere is peeled off, and there is a much larger coagulation preventing effect than a change in the blood flow pattern that simply changes the blood velocity.

The invention of claim 2 is the invention of the method of the above apparatus. Furthermore, the invention of claim 3 is, in addition to the invention of claim 1, provided with filters near the outlet of the blood circuit and near the inlet of the dialysate inflow circuit, respectively, to prevent the inflow of thrombus into the body and to prevent bacteria. This is a device designed to prevent the inflow of dialysate into the dialysate. Finally, the invention of claim 4 is an apparatus in which the flow direction of the dialysate can be switched by the switching means so as to always be opposite to the blood flow direction in the dialyzer.

The specific construction of the blood flow direction switching device and method for the hemodialyzer according to the present invention will be described in detail below. First, the constitution of the invention of claim 1 of the blood flow direction switching device to the hemodialyzer according to the present invention will be described. First, in a dialysis machine, there is a dialyzer. Next is the blood circuit. This is what connects to the dialyzer. Then, there is a blood flow direction switching means. This is provided in the blood circuit and switches the direction of blood flow in the dialyzer. In addition, there are control means. This allows the blood flow direction switching means to perform intermittent switching control. Finally, there is the dialysate circuit. This delivers fresh dialysate to the dialyzer described above.

Next, the constitution of the invention of claim 2 of the blood flow direction switching device and method for the hemodialyzer according to the present invention will be explained. The present invention is a method of intermittently switching the direction of blood flow in a dialyzer by a blood flow circuit switch provided in a blood circuit connected to a dialyzer.

The blood flow direction switching device and method for a hemodialyzer according to the present invention will be described below. Since the present invention is the same as the structure of claim 1 except for the following points, the entire description of the structure of the invention of claim 1 is incorporated herein, and the following description is added thereto. That is, a dialysate circuit for sending fresh dialysate to the dialyzer, a filter for preventing thrombus inflow provided near the outlet of the blood circuit, that is, a portion where dialyzed blood returns to the body, and the dialysate described above. There is a sterilization or pyrogen filter installed near the entrance of the circuit.

Finally, the constitution of the invention of claim 4 of the apparatus and method for switching the blood flow direction to the hemodialyzer according to the present invention will be described. Since the present invention is the same as the structure of claim 1 except for the following points, the entire description of the structure of the invention of claim 1 is incorporated herein, and the following description is added thereto. That is, by providing a dialysate flow path switching device (such as a three-way valve) on the supply line (inlet) and discharge line (outlet) of the dialysate circuit, the supply and discharge of the dialysate to and from the dialyzer are always performed. This is a device that is switched in the direction opposite to the flow direction. This is a device for controlling the blood flow path and dialysate flow path switching means as described above by a control means such as electrical and switching the respective flow directions at appropriate intervals.

[0016]

The apparatus and method for changing the direction of blood flow to the hemodialyzer according to the present invention has the following effects because it is configured as described above. First, a blood flow path switching device is provided between the blood pump and the dialyzer of the arterial blood circuit connected to the dialyzer from the patient's artery to connect the blood circuit. Next, the blood circuit that connects the dialyzer and the patient is also connected so that the blood circuit on the venous side also passes through the blood flow path switch on the way. Blood enters the blood flow path switch from the blood pump. The inlet of the artery and the outlet of the vein returning to the patient are fixed, but the delivery to and from the dialyzer is an internally switchable device. The direction of the blood flowing in the dialyzer is switched by intermittently switching this by the control means.

Next, the operation of the invention of claim 2 will be described. First, according to the present invention, in the dialysate device, the direction of blood flow in the dialyzer is intermittently switched by the blood flow circuit switch provided in the blood circuit coupled to the dialyzer. Therefore, since the blood inlet and the outlet of the dialyzer are always inverted, blood coagulation is less likely to occur, or even if blood coagulation occurs, it is discharged by reversing the blood flow.

The operation of the blood flow direction switching device and method for the hemodialyzer according to the present invention will be described. Since the present invention is the same as the operation of claim 1 except for the following points, the entire description of the configuration of the invention of claim 1 is incorporated herein, and the following description is added thereto. That is, the dialysate circuit described above delivers fresh dialysate to the dialyzer. Next, a filter for preventing the inflow of thrombus, which is provided near the outlet of the above blood circuit, that is, where dialyzed blood returns to the body, prevents the return of the blood clot to the body, and the inlet of the above dialysate circuit. Prevent bacteria from entering the dialyzer with bacteria elimination or pyrogen filter provided nearby.

Finally, the operation of the blood flow direction switching device and method for a hemodialyzer according to the present invention will be described. Since the present invention is the same as the operation of claim 1 other than the following points, the entire description of the operation of the invention of claim 1 is incorporated herein, and the following description is added thereto. That is, by providing a dialysate flow path switching device (such as a three-way valve) on the supply line (inlet) and discharge line (outlet) of the dialysate circuit, the supply and discharge of the dialysate to and from the dialyzer are always performed. Switch in the opposite direction of flow. The blood flow path and dialysate flow path switching device as described above are controlled by electrical or other control means to switch the respective flow directions at appropriate intervals.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus and method for switching a blood flow direction to a hemodialyzer according to the present invention will be described below in detail with reference to the accompanying drawings by using an embodiment of each invention. FIG. 1 is a schematic view of a hemodialysis apparatus equipped with the blood flow path switch and the dialysate flow path switch of the present invention. FIG. 2 shows a diagram in which the blood flow path and the dialysate flow path shown in FIG. 1 are switched.

First, an embodiment of the invention of claim 1 of the blood flow direction switching device to the hemodialyzer according to the present invention will be described.
First, in a dialysis machine, there is a blood circuit 10 having a blood pump 1 and a blood flow direction switching means 2. This is what connects to the dialyzer. The blood flow direction switching means 2 switches the blood flow direction in the dialyzer. Furthermore, there is a control means 4. This causes the blood flow direction switching means 2 to perform intermittent switching control. Finally, dialysate circuit 2
There is 0. This sends fresh dialysate to the dialyzer 3 described above.

Next, an embodiment of the invention of the method of claim 2 will be described. This embodiment is a method of intermittently switching the direction of blood flow in the dialyzer 3 to the blood circuit 10 connected to the dialyzer 3 in the dialysate device.

An embodiment of the invention of claim 3 will be described. Since this embodiment is the same as the embodiment of claim 1 described above except the following points, the entire text of the description of the embodiment of the invention of claim 1 is incorporated herein by reference, and the following description is omitted here. Add to. That is, there is a sterilizing filter 6 or a pyrogen filter provided near the inlet of the dialysate circuit 20 for sending fresh dialysate to the dialyzer 3. Then, there is a filter 5 for preventing the inflow of thrombus, which is provided near the outlet of the blood circuit 10 described above, that is, near the place where dialyzed blood returns to the body.

Finally, an embodiment of the invention of claim 4 of the apparatus and method for changing the direction of blood flow to the hemodialyzer according to the present invention will be described. Since the present invention is the same as the embodiment of claim 1 described above except for the following points, the entire text of the description of the embodiment of the invention of claim 1 is incorporated herein, and the following description is added thereto. To do. That is, by providing dialysate flow path switching devices (three-way valves, etc.) F1 and F2 on the supply line (inlet) and discharge line (outlet) of the dialysate circuit 20, the supply and discharge of dialysate to the dialyzer 3 is performed. Is a device which is always switched in the direction opposite to the blood flow direction in the dialyzer 3. The blood flow direction switching means 2 and the dialysate flow direction switching means F1 and F2 as described above are controlled by the control means 4 such as electrical, and the respective flow directions are switched at appropriate intervals. In this embodiment, the embodiment of claim 3 may be used instead of the embodiment of claim 1 described above.

To describe the operation of the above embodiment, first, the blood drawn from the patient's artery A by the blood pump 1 enters the arterial inlet A1 of the blood flow direction switching device 2 and the outlet B1.
Go out and enter the dialyzer 3 from the entrance D1 of the dialyzer 3. Then, it exits from the outlet D2 and enters B-2 of the blood flow path switching device 2, exits from the vein outlet V1 and returns to the vein V of the patient. At this time, the dialysate enters from the inlet E-IN through the dialysate flow direction switching means F1 and enters the dialyzer E1 and flows in the direction opposite to the blood there. Then, it is discharged from the dialysate outlet E2, and is discharged from the dialysate outlet E-OUT via the dialysate flow direction switching means F2. Therefore, in this case, the lines L1 and L2 do not flow.

FIG. 2 shows a state in which the blood flow and the dialysate flow in FIG. 1 are in opposite directions. At this time, the dialysate passes through the line L1 from the dialysate flow direction switching means F1,
It enters from E2, exits from E2, and is discharged via the line L2 and the dialysate flow direction switching means F2. The flow direction of blood and dialysate is set to be switched at the same time, and the switching interval can be set freely.

[0027]

The blood flow direction switching device and method for a hemodialyzer according to the present invention have the following great effects because of the above-mentioned effects. That is, first, blood coagulation in the dialyzer during hemodialysis could be significantly suppressed. Next, it is easier to return blood at the end of dialysis. Furthermore, it brings great benefits to the reuse of the dialyzer.

[Brief description of drawings]

FIG. 1 is a schematic view of a hemodialysis apparatus equipped with a blood flow path switcher and a dialysate flow path switcher of the present invention.

FIG. 2 shows a diagram in which the blood channel and the dialysate channel shown in FIG. 1 are switched.

FIG. 3 is a side sectional view showing an embodiment of a dialyzer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 blood pump 2 blood flow direction switching device 3 dialyzer 4 control means 10 blood circuit 20 dialysate circuit F1, F2 dialysate flow direction switching means

Claims (4)

[Claims] 1. A dialyzer, a dialyzer, a blood circuit coupled to the dialyzer, a blood flow direction switching means for switching the direction of blood flow in the dialyzer, which is provided in the blood circuit, and the blood flow. A blood flow direction switching device for a hemodialyzer, comprising: a control means for causing the direction switching means to perform intermittent switching control; and a dialysate circuit for sending fresh dialysate to the dialyzer. 2. A dialyzer, wherein blood flow direction switching means is provided in a blood circuit connected to the dialyzer, and the direction of blood flow in the dialyzer is intermittently switched.
A method for switching the direction of blood flow to a hemodialyzer, characterized by comprising: 3. A dialyzer, a dialyzer, a blood circuit coupled to the dialyzer, a blood flow direction switching means for switching the direction of blood flow in the dialyzer, which is provided in the blood circuit, and the blood flow. Control means for causing the direction switching means to perform intermittent switching control, dialysate circuit for sending fresh dialysate to the dialyzer, thrombus inflow provided near the outlet of the blood circuit, that is, the place where dialyzed blood returns to the body A blood flow direction switching device to a hemodialyzer, comprising a filter for prevention, and a sterilizing or pyrogen filter provided near the inlet of the dialysate circuit. 4. A dialysis machine, a dialyzer, a blood circuit coupled to the dialyzer, a blood flow direction switching means provided in the blood circuit for switching the direction of blood flow in the dialyzer, and the dialyzer. A dialysate circuit for sending fresh dialysate to the dialyzer, and a dialysate flow direction switching means provided in a part of the dialysate circuit for reversing the flow direction of the dialysate in the dialyzer to the blood flow direction. A blood flow direction switching device for a hemodialyzer, comprising: the dialysate flow direction switching means and a control means for causing the blood flow direction switching means to perform intermittent switching control.