Abstract: The present invention relates to a pumping device for delivering and metering fluids, in particular medical fluids such as dialysis fluids, with a piston unit having a driving device and a piston and with a membrane unit which has a membrane and a first chamber bordered by the membrane. The pumping device also has a hydraulic unit which has a space to accommodate a hydraulic fluid which is connected to the piston of the piston unit and to the first chamber of the membrane unit. The reliability of metering by such a pumping device is increased by providing a control unit for guaranteeing a predefinable metering rate and/or quantity and also providing a measuring device by means of which the axial position of the piston unit can be determined directly and which can be connected to the control unit.

Abstract: A blood treatment device, in particular a dialysis machine, which permits both single-needle and dual-needle operation. The device has a blood treatment unit, in particular a dialyzer that has an inlet connected to a feed line and an outlet connected to a return line. The feed line has two parallel line branches with a positive displacement pump being connected into the first and second line branches. To produce a fluid connection between the outlet of the dialyzer and one of the two pumps, a connection line is provided. For dual-needle operation, the feed and return lines are connected to an arterial and a venous needle. For single-needle operation, the feed and return lines are brought together and connected to a common needle. The connection line permits single-needle operation without great changes to the structure of the blood treatment device.

Abstract: The invention relates to a device for the treatment of a medical fluid, said device consisting of a permanently installed fluid treatment machine and a cassette with fluid-carrying channels as well as an elastic matt placed between these two items, with matt channels recessed in said elastic matt. The matt channels are provided with slits. Via the matt channels, an optimised vacuum distribution takes place and the slits serve the purpose of removing air between the cassette and the fluid treatment machine.

Abstract: A method for airtight joining of two membranes. An airtight and complete bonding of the two membranes is achieved by first producing a curvature in one of the membranes, then placing the convexly curved side of a membrane onto the membrane to be joined to it in an airtight manner, next joining the two membranes until the edge areas of the membranes are in contact, and finally applying a pressing force that seals the edge areas of the membranes in an airtight manner.

Abstract: A blood treatment device, in particular a dialysis machine, which permits both single-needle and dual-needle operation. The device has a blood treatment unit, in particular a dialyzer that has an inlet connected to a feed line and an outlet connected to a return line. The feed line has two parallel line branches with a positive displacement pump being connected into the first and second line branches. To produce a fluid connection between the outlet of the dialyzer and one of the two pumps, a connection line is provided. For dual-needle operation, the feed and return lines are connected to an arterial and a venous needle. For single-needle operation, the feed and return lines are brought together and connected to a common needle. The connection line permits single-needle operation without great changes to the structure of the blood treatment device.