WO2004045678A1

WO2004045678A1 - Haemodialysis unit

Info

Publication number: WO2004045678A1
Application number: PCT/DE2003/003523
Authority: WO
Inventors: Roland Seifert
Original assignee: Mesys Gmbh
Priority date: 2002-11-20
Filing date: 2003-10-23
Publication date: 2004-06-03
Also published as: DE10254099B3; AU2003281964A1

Abstract

The invention relates to a haemodialysis unit with a dialyser (4), arranged between a dialysis fluid circulation and a blood circulation (3) and a sterile filter in the dialysis fluid circulation, whereby the sterile filter (6) is divided by a membrane (7) into a first chamber (8) and a second chamber (9). An inlet (10) to the first chamber (8) is connected to a dialysis fluid supply (1) and the second chamber (9) is connected to the dialyser (4). An outlet (15) from the first chamber (8) of the sterile filter (6) is connected by means of a non-return valve (16) to an outlet (17) for the dialysis fluid.

Description

hemodialysis

The invention relates to a hemodialysis machine with a dialyzer connected between a dialysis fluid path and a blood path and with a sterile filter in the dialysis fluid path, the sterile filter being divided by a membrane into a first chamber and a second chamber, and an inlet of the first chamber to a dialysis fluid. Supply line and the second chamber is connected to the dialyzer, and wherein a shut-off valve is provided in the dialysis fluid path between the second chamber of the sterile filter and the dialyzer.

Hemodialysis machines are used to remove metabolic products and, if necessary, water from a patient's blood, particularly in the case of renal failure of the patient. For this purpose, a dialyzer is used, which is divided into two chambers with a membrane. A dialysis fluid is passed on one side of the membrane and the patient's blood on the other side. The dialysis fluid absorbs the metabolic products that are to be removed from the blood through the pores of the membrane. With the help of a vacuum on the membrane, water can also be removed from the blood using ultrafiltration.

The dialysis fluid is made from fresh water and a self-sterile electrolyte concentrate. In order to guarantee an absolutely sterile dialysis fluid, the dialysis fluid path is in front of the dialyzer. Conventionally, a sterile filter is connected, which generally extends in a cylindrical shape and is divided into an inner first chamber and an outer second chamber by radially arranged membranes extending in the longitudinal direction. A connection is provided for each chamber at the two opposite ends of the sterile filter for each chamber. The two connections of the second chamber of the sterile filter are connected to the inlet of the dialyzer.

A hemodialysis machine is known from JP 56-158664, in which the outlet of the first chamber of the sterile filter is connected to a drain for the dialysis liquid via a servo valve and an optional throttle. With the help of a shut-off valve between the outlet of the second chamber and the dialyzer, the dialyzing process can be interrupted and the dialyzing liquid can be completely passed through the first chamber of the sterile filter by opening the servo valve. This flushes and cleans the sterile filter. If the outlet of the first chamber is closed during operation, particles and other substances can accumulate over time, in particular in the area of the closed end of the sterile filter, and clog the sterile filter. A disadvantage is that an unintentional opening of the servo valve during the treatment leads to a drop in pressure in the dialyzer.

EP 0 270 794 B1 describes a hemodialysis machine in which the outlet of the first chamber of the sterile filter is connected to the discharge line of the dialyzer with a bypass line and a bypass valve in the bypass line. Each time the hemodialysis machine is disinfected and rinsed, the dialyzer is disconnected with a shut-off valve and the bypass line is opened. Then the sterile filter is rinsed automatically. The object of the invention was to provide an improved hemodialysis machine with a safe and inexpensive way of rinsing the sterile filter.

The object is achieved by the generic hemodialysis machine according to the invention in that an outlet of the first chamber of the sterile filter is connected to a drain for the dialysis fluid with a check valve.

By using a check valve, the sterile filter is flushed only if the pressure for the check valve is sufficiently high. This is the case when the dialyzer is disconnected using shut-off valves and the dialysis fluid continues to be pumped through the sterile filter.

According to the invention, the control of the rinsing process is pressure-dependent and can be implemented safely and easily without further actuation elements.

The inlet of the first chamber of the sterile filter and the outlet of the first chamber are preferably arranged at a distance from one another such that the inlet is in the region of a first end of the sterile filter and the outlet is in the region of a second end of the sterile filter.

A shut-off valve is preferably provided in the dialysis fluid path between the second chamber of the sterile filter and the dialyzer and between the outlet of the dialyzer and a drain line for dialysis fluid. By closing the shut-off valves, the treatment process is ended and the dialysis fluid is then over the automatically opening check valve is led through the first chamber of the sterile filter into a drain. In this way, the sterile filter is rinsed automatically.

In an advantageous embodiment of the hemodialysis machine, a bypass line with a bypass valve is provided between the inlet of the first chamber of the sterile filter and the outlet line for the dialysis fluid. This means that the dialysis fluid can also be drained without passing through the sterile filter and flushing it. With the bypass line, the pressure conditions can also be set before the sterile filter. In contrast to this, conventional bypass lines are located behind the sterile filter, as seen in the flow direction of the dialysis liquid, that is to say at the outlet of the first chamber and not, as now proposed, at the inlet.

The invention is explained in more detail below with reference to the accompanying drawing. It shows:

Figure 1 - block diagram of a section of a hemodialysis device according to the invention with sterile filter and check valve.

FIG. 1 shows a section of a hemodialysis machine as a block diagram. The hemodialysis machine has a dialysis fluid circuit with a dialysis fluid supply line 1 and a drain line 2 for the dialysis fluid and a blood path 3. The dialysis fluid circuit and the blood path 3 are separated from one another by a dialyzer 4, which is separated by a membrane 5 in a known manner a first chamber for dialysis fluid and a second chamber for the blood flowing through a patient is divided.

In order to ensure that the dialysis fluid is sterile, a sterile filter 6 is connected into the dialysis fluid supply line 1 of the dialysis fluid path. The sterile filter 6 is divided by a membrane 7 into a first chamber 8 and a second chamber 9. The dialysis fluid supply line 1 is connected to an inlet 10 of the first chamber 8 of the sterile filter 6.

The second chamber 9 of the sterile filter each has an outlet 11, 12 at that end of the sterile filter 6, the outlets of the second chamber 9 of the sterile filter 6 being connected to the dialysing liquid inlet of the dialyzer 4 via a flow shut-off valve 13. The dialysis fluid outlet of the dialyzer 4 is connected to the drain line 2 for the dialysis fluid via a non-return valve 14. During the treatment of a patient, the flow shut-off valve 13 and the return shut-off valve 14 are open and the dialysis fluid flows through the dialysis fluid supply line 1, the sterile filter 6 and the dialyzer 4 and is disposed of via the drain line 2.

The first chamber 8 of the sterile filter 6 has an outlet 15 at the end opposite the inlet 10 of the first chamber 8, which outlet is usually closed during operation. Because of this dead end, particles and other substances, such as e.g. Pyrogens, accumulate from membrane 7 and block it.

According to the invention, the outlet 15 of the first chamber 8 is connected to an outlet 17 for the dialysis fluid via a check valve 16. The drain 17 can open into the drain pipe 2, for example.

In addition, the inlet 10 of the first chamber 8 of the sterile filter 6 is connected to the drain line 2 via a bypass line 18 and a bypass valve 19 connected to the bypass line 18, so that the sterile filter 6 and the dialyzer 4 can be short-circuited.

To vent and / or flush the sterile filter, the bypass valve 19, the flow shut-off valve 13 and the return shut-off valve 14 are closed at the same time. This leads to an increase in pressure in the dialysis fluid path, which is determined by the opening pressure of the check valve 16, provided that the dialysate flow rate is kept constant with the aid of a flow control. After the check valve 16 is opened, residual air from the dialysis fluid path and impurities enter the outlet 17.

The check valve 16 also has the advantage that an excessive system pressure is prevented in the event of a technical fault. In addition, the sterile filter 6 is protected against an impermissible pressure load. Furthermore, the check valve 16 prevents liquid from getting into the hydraulic system from the outlet 17.

The described venting or rinsing process is automatically carried out cyclically during the treatment. In the disinfection of the hemodialysis machine, the sterile filter 6 can also be vented and flushed by cyclically closing the bypass valve 19 and the flow and return valves 13, 14.

In the event of defective dialysate, the dialysate flow can be led directly from the inlet 10 of the sterile filter 6 into the outlet line 2 by opening the bypass valve 19 via the bypass line 18, without this flowing into the sterile filter 6 and the safety-critical branch of the dialysis fluid between the second chamber 9 of the sterile filter 6 and the dialyzer 4.

Claims

Expectations

1 . Hemodialysis machine with a dialyzer (4) connected between a dialysis fluid path and a blood path (3) and with a sterile filter (6) in the dialysis fluid path, the sterile filter

(6) is divided by a membrane (7) into a first chamber (8) and a second chamber (9), and an inlet (10) of the first chamber (8) to a dialysis fluid supply line (1) and the second chamber (9) is connected to the dialyzer (4), and a shut-off valve (13) is provided in the dialyzing liquid path between the second chamber (9) of the sterile filter (6) and the dialyzer (4), characterized in that a Outlet (15) of the first chamber (8) of the sterile filter (6) with a check valve (16) is connected to an outlet (17) for the dialysis fluid.

2. Hemodialysis machine according to claim 1, characterized in that the inlet (10) of the first chamber (8) of the sterile filter (6) in the region of a first end of the sterile filter (6) and the outlet (15) of the first chamber (8) in Area of a second end of the sterile filter (6) is arranged.

3. Hemodialysis machine according to claim 1 or 2, characterized in that a shut-off valve (14) is provided between the outlet of the dialyzer (4) and an outlet line (2) for dialysis fluid.

Hemodialysis machine according to one of the preceding claims, characterized in that the inlet (10) of the first chamber (8) of the sterile filter (6) with a bypass line (18) and with a by- pass valve (19) in the bypass line (18) can be connected to the drain line (2) for the dialysis fluid.