JPH01303156A - Dialysis device - Google Patents

Abstract

PURPOSE:To attain a target dewatering rate regardless of ultrafiltration power by passing a prescribed flow rate of a dialysis liquid to an inlet side dialysis liquid circuit at the time of dialysis and controlling a dewatering control pump in such a manner that the difference between the flow rate at which the liquid flows in the inlet side dialysis liquid circuit and the flow rate at which the liquid flows in the outlet side dialysis liquid circuit attains the target dewatering rate. CONSTITUTION:The zero outputs Z11 and Z01 of an inlet side flow meter 8 and an outlet side flow meter 9 are measured while a valve V4 is held closed. The dialysis liquid of a specified flow rate QD1 is allowed to flow from a constant flow rate valve 10 by opening the valve V4 and the span point output points S11 and S01 of the inlet side flow meter 8 and the outlet side flow meter 9 of this time are measured. A constant flow rate pump P3 is operated in the state of allowing the dialysis liquid of the specified flow rate QD1 to flow from the constant flow rate valve 10 to allow the specified flow rate of the dialysis liquid to flow from the upper stream side of the outlet side flow meter 9 as shown by an arrow, by which the sensitivity of the flow meter is calibrated. The dialysis device which can attain the target dewatering rate by controlling the dewatering pump regardless of the ultrafiltration power is thereby realized with the extremely simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a dialysis device in which the amount of water removed (ultrafiltration) can be directly controlled by a water removal pump regardless of the ultrafiltration capacity.

<Conventional technology> Conventionally, in a dialysis machine, an inner chamber and an outer chamber are separated by a tube-shaped membrane, and blood and dialysate flow through these in opposite directions.
A dialyzer is used to dialyze and remove water from the blood. In order to perform the desired water removal, the pressure on the blood circuit side and the pressure on the dialysate circuit side are measured by sandwiching the membrane of the dialyzer, and the difference between these pressures, the ultrafiltration pressure 1'MP, is set for ultrafiltration. For example, a positive pressure pump provided on the dialysate circuit side is controlled so as to maintain the same pressure.

The ultrafiltration capacity tJ F RP of the dialyzer decreases over time, and if the set overpressure remains constant, desired water removal cannot be performed. Conventionally, errors caused by a decrease in ultrafiltration capacity UFRP have been corrected by a method as shown in Japanese Patent Application Laid-Open No. 59-2749. In this conventional example, a device for measuring the ultrafiltration capacity UFRP of the dialyzer is provided, the ultrafiltration capacity is measured at predetermined intervals during artificial dialysis, and the desired water removal can be performed based on the measurement results. A new set ultrafiltration pressure is calculated again, and the positive pressure pump is controlled so that the ultrafiltration pressure TMP becomes the set ultrafiltration pressure.

However, such a device requires a means to measure ultrafiltration capacity, making the configuration complicated, and also requires artificial dialysis (
Because it is necessary to measure the ultrafiltration capacity many times during the process (e.g., at 30-minute intervals) (time required: approximately 5 hours), dialysis may not be possible during that time, and errors may occur in the ultrafiltration capacity of UFRP. There is.

On the other hand, Japanese Patent Publication No. 56-82, for example, proposes a method in which the dialysate circuit including the dial-alive is closed and water is removed from the closed circuit using a water removal pump. In this known example, two or more dialysate containers are provided which are divided into two chambers by a displaceable partition, one chamber of one dialysate container is communicated with the dialysate inlet of the dialyzer, and the dialysate inlet of the dialyzer is communicated with the dialysate inlet of the dialyzer. A closed dialysate circuit is formed by communicating a dialysate outlet of the dialyzer with the dialysate chamber, and dialysate is supplied from the one chamber to the dialysate inlet, and used dialysate is transferred from the dialysate outlet to the dialysate inlet. The water flows out into the other chamber according to the displacement of the partition wall, and is removed by a water removal pump installed in the middle of this closed circuit.
The same operation is repeated by switching to the other dialysate container.

In the case of such a device, there is an advantage that the water removal pump can perform the desired water removal regardless of the decrease in the ultrafiltration ability of the dialyzer. However, a large number of valves are required to switch the flow paths, and in addition to the water removal pump, a pump means must be provided to send a fixed volume of dialysate to the dialyzer, making the mechanism complicated. was there.

<Problem to be Solved by the Invention> The technical problem to be solved by the present invention is to realize a dialysis machine with an extremely simple configuration that can control a water removal pump and achieve a target water removal amount regardless of ultrafiltration capacity. It's about doing.

Means for Solving the Problems> The device of the present invention has a configuration including a dialyzer through which blood and dialysate flow through a dialysis membrane, an inlet-side dialysate circuit connected to the dialysate-side inlet of the dialyzer, and an outlet-side dialysate circuit connected to the dialysate-side outlet of the dialyzer; a bypass circuit that bypasses the dialyzer and allows dialysate to flow from the inlet-side dialysate circuit to the outlet-side dialysate circuit; an inlet flow rate detection means provided in the inlet dialysate circuit on the upstream side; an outlet flow rate detection unit provided in the outlet dialysate circuit downstream from the bypass circuit; and an outlet dialysate circuit in the outlet dialysate circuit. a water removal control pump provided in the dialyzer, a valve for switching the flow path between the flow path a and a flow path bypassing the dialyzer, and a constant flow rate of driftwood flowing through the dialyzer from the upstream side of the outlet side flow rate detection means. a constant flow supply means for supplying a constant flow rate to the dialysate circuit on the outlet side, and during calibration, the flow path is switched to bypass the dialyzer, and with the constant flow supply means stopped, a constant flow rate of dialysis is supplied from the constant flow valve. The liquid is flowed, and the correlation between these flow rate detection means is determined based on the outputs of the inlet side flow rate detection means and the outlet side flow rate detection means, and the constant flow supply means is operated to supply a specified flow rate to the outlet side flow rate detection means. The sensitivity of the detection means is determined, and during dialysis, a target water removal amount is set based on the correlation and the sensitivity, the constant flow supply means is stopped, and the output of the outlet (l'lI flow rate detection means is equal to the target water removal amount). The reason is that the water removal control pump is controlled so that the water removal control pump is controlled.

<Operation> The above technical means operates as follows. That is, during dialysis,
The water removal control pump causes a predetermined flow rate of dialysate to flow through the inlet dialysate circuit, and controls the water removal control pump so that the difference between the flow rate through the inlet dialysate circuit and the flow rate through the outlet dialysate circuit becomes a target water removal amount. Water is removed by controlling the

In order to perform such control, during calibration, the inlet-side flow rate detection means and the outlet-side flow rate detection means are determined to have a zero characteristic when no dialysate is flowing, and a span characteristic when a predetermined flow rate of dialysate is flowing. are measured, and from these measurement results, the flow characteristics of the inlet side flow rate detection means and the outlet side flow rate detection means and the correlation thereof are determined. Furthermore, for example, a constant dialysate is caused to flow from the upstream side of the outlet side flow rate detection means using the constant flow rate pump, and the flow rate characteristic (sensitivity) per unit flow rate of the outlet side flow rate detection means is measured.

Based on the flow rate characteristics derived from these measurement results, the output when the target water removal amount is added to the dialysate at the standard flow rate is determined, and during dialysis, the output of the outlet side flow rate detection means is adjusted to this value. Water removal is performed by controlling the water removal control pump.

<Example> The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a patient, and 2 is a dialyzer schematically shown. and the dialysate is flowing in the opposite direction. 3 is a blood circuit between the patient 1 and the blood full inlet 2b+ of the dialyzer 2, 4 is a blood circuit between the blood side outlet 2b2 of the dialyzer 2 and the patient 1, and 5 is an inlet on the dialysate side of the dialyzer 2. An inlet side dialysate circuit is connected to 2CI, and 6 is an outlet side dialysate circuit connected to an outlet 2C2 of the dialyzer 2 on the dialysate side.

7 is a bypass circuit that connects the inlet dialysate circuit 5 and the outlet dialysate circuit 6; 8 is an inlet flow meter provided in the inlet dialysate circuit 5 upstream from the bypass circuit 7; and 9 is a bypass circuit 7. This is an outlet flow meter provided in the outlet dialysate circuit 6 located further downstream.

As these flowmeters, for example, differential pressure flowmeters or electromagnetic flowmeters are used. 10 is a constant flow valve that allows a constant flow of dialysate to flow into the inlet side dialysate circuit 5. 11 is exit Ill! This is a circuit that connects the upstream side and downstream side of the I flowmeter 9.

Pl is a blood pump that sends blood from the patient 1 to the dialyzer 2, and P2 is a water removal control pump provided in the dialysate circuit 6 on the outlet side, for example, a gear pump is used. P3 is a constant flow pump provided in the circuit 11, such as a tubing pump or a plunger pump. ■,
is a valve provided in the inlet side dialysate circuit 5 between the bypass circuit 7 and the dialyzer 2, V2 is a valve provided in the outlet side dialysate circuit 6 between the dialyzer 2 and the bypass circuit 7, and v3 is the bypass a valve provided in circuit 8;
V4 is a valve provided in the inlet dialysate circuit 5 upstream of the constant flow valve 10.

CNT is a control unit which includes a multiplexer 12 for switching the detection signal from the flowmeter 8.9, an A/D converter 13, and a CNT.
It includes a PU 14, a water removal amount setting device 15, a drive circuit 16, etc.

With this configuration, valve #3 is opened and valves V, , V2 are opened.
is closed and the constant flow pump P3 is stopped, the characteristics of the inlet side flowmeter 8 and the outlet side flowmeter 9 and their correlation are determined. FIG. 2 is an explanatory diagram for explaining this operation. First, with valve v4 closed, the zero point outputs ZI+ and ZO+ of the inlet flow meter 8 and the outlet flow meter 9
is measured. Next, the valve 4 is opened and the dialysate is flowed at a constant flow rate Qo+ from the constant flow valve 10. At that time, the span point outputs SIt and So of the inlet flow meter 8 and the outlet flow meter 9 are
, is measured. From these measurement results, the flow rate/output characteristics (dotted line) of the inlet side flow meter 8 and the flow rate/output characteristics (solid line) of the outlet side flow meter 9 are determined, and based on these, the output SI of the inlet side flow meter 8 and the outlet side The relationship So = K (S - (Z) - (1)) is established between the output So of the flowmeter 9 and the output So of the flow meter 9.

However, α”ZX+ zo+ = (SI + ZI + )/(So
lZo+).

Next, the constant flow pump P3 is operated with the dialysate at a constant flow rate Qo+ flowing from the constant flow valve 10, and the dialysate at a specified flow rate is flowed from the upstream side of the outlet flowmeter 9 as shown by the arrow. Calibrate the sensitivity of the meter.

FIG. 3 is an explanatory diagram illustrating this sensitivity calibration.

Before the constant flow pump P3 operates, the reference flow rate of Qo+ is flowing, and the output of the flow meter 9 is Sol. In this state, drive the constant flow pump P3 to obtain the specified flow rate ΔQl:l
Flowing, an output of SO2 is obtained. Exit l from here
The sensitivity AS per unit flow rate of the 111 flowmeter 9 is determined by AS"'(SO2Sol>/ΔQo-(2).

If the target water removal amount is UFs, the corresponding output deviation △S is △5=UFs X ((So 2 So + )/△
Qo 1... (3) Find it.

During dialysis, the constant flow pump P3 is stopped, and the valve V.

V2. V is opened, valve 3 is closed, and a constant flow rate of dialysate is allowed to flow through the dialyzer 2 from the constant flow valve 10.

Based on the output of the inlet side flow meter 8, use equation (1) to calculate the output 1 for the reference flow rate flowing at that time! ! ! The reference output 301 of the flowmeter 9 is determined. Next, the blood pump P1 is rotated, and the output of the outlet side flow meter 9 is So or So = So I + △S
・Water removal control pump P2 so that (4>
If this is controlled, water removal of the target water removal amount UFs is performed.

In the case of the apparatus according to the embodiment of the present invention shown in FIG.
A constant flow pump P is used as a means for supplying a specified flow rate to the outlet side flow meter 9. This part combines a pump Pd and a flow meter 17 as shown in FIG. A configuration may be adopted in which a specified flow rate is supplied.

Further, in the case of the apparatus according to the embodiment of the present invention shown in FIG. 1, the circuit 11 is connected to the upstream and downstream sides of the outlet flow meter 9 to circulate the dialysate, but the invention is not limited to this. As shown in FIG. 1, a branch circuit 18 may be provided to supply fluid from the upstream side of the constant flow valve 10 to the outlet flow meter.

<Effects of the Invention> According to the present invention, a dialysis apparatus capable of achieving a target amount of water removal by controlling a water removal pump regardless of ultrafiltration capacity can be realized with an extremely simple configuration. Furthermore, since the correlation and sensitivity of the two flowmeters are measured and control is performed based on the measurement results, extremely accurate water removal amount control can be performed. Furthermore, the flowmeter can be calibrated before treatment without reducing the dialysis efficiency.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the apparatus according to the embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams for explaining the present invention in detail, and FIGS. 4 and 5 are the apparatus according to the embodiment of the present invention shown in FIG. It is a block diagram which shows the other specific example of the constant flow supply means in. DESCRIPTION OF SYMBOLS 1... Patient, 2... Dialyzer, 3, 4... Blood circuit, 5... Inlet D III dialysate circuit, 6... Outlet side dialysate circuit, 7... Bypass circuit, 8 ... Inlet side flow meter, 9... Outlet side flow meter, 10... Constant flow valve, 17... Flow meter, 18... Branch circuit, Pl...
Blood pump, P2...Water removal control pump, P3...Constant flow pump, P4...Pump, CNT...Control Department agent Patent attorney Nobuo Ozawa Help ゛゛'-7゛Figure 2 B QD Figure 4 Figure 5

Claims (1)

[Claims] A dialyzer through which blood and dialysate flow across a dialysis membrane, an inlet-side dialysate circuit connected to the dialysate-side inlet of the dialyzer, and an outlet-side dialysate circuit connected to the dialysate-side outlet of the dialyzer. a bypass circuit that bypasses the dialyzer and allows dialysate to flow from the inlet dialysate circuit to the outlet dialysate circuit; and an inlet side provided in the inlet dialysate circuit upstream of the bypass circuit. a flow rate detection means, an outlet flow rate detection means provided in the outlet side dialysate circuit downstream of the bypass circuit, a water removal control pump provided in the outlet side dialysate circuit, and a flow rate flowing through the dialyzer. a valve for switching a flow path between a channel and a flow path bypassing the dialyzer, and a constant flow supply means for flowing a constant flow rate of fluid from an upstream side of the outlet flow rate detection means to the outlet dialysate circuit, During calibration,
switching the flow path to bypass the dialyzer;
Flowing dialysate at a predetermined flow rate with the constant flow rate supply means stopped, determining the correlation between these flow rate detection means based on the outputs of the inlet side flow rate detection means and the outlet side flow rate detection means, and activating the constant flow rate supply means. Then, a specified flow rate is supplied to the outlet side flow rate detection means, and the sensitivity of this flow rate detection means is determined. During dialysis, a target water removal amount is set based on the correlation and the sensitivity, and the constant flow rate supply means is stopped. A dialysis apparatus characterized in that the water removal control pump is controlled so that the output of the outlet side flow rate detection means becomes the target water removal amount.