Pump arrangement for medical purposes
First Claim
1. In an apparatus for pumping liquids for medical purposes, in particular blood fluid or infusion fluid, including at least one pump housing 12 having a cavity which is divided by an impermeable diaphragm into a working chamber (16) and a drive chamber (18), said working chamber being provided with at least one opening (2) for the supply and discharge of the fluid to be conveyed, and said drive chamber being adapted to be subjected to a gas as a pumping fluid and coupled via a conduit (50) of a limited pumping volume, the improvement comprising:
- a valve means (56) connected to said drive chamber (18) for pressure compensation upon stroke change of the pumping means (46); and
a control means (70) connected to said valve means (56) and means responsive to the pumping means for controlling opening said valve means before each said stroke change and closing said valve means (56) after pressure equalization with ambient pressure.
1 Assignment
0 Petitions
Accused Products
Abstract
Pump arrangement (10) for medical purposes, in particular blood or infusion pump, comprising a pump housing (12) having two pump chambers (16, 18), of which the work chamber (16) is subjected to the liquid to be pumped while the drive chamber (18) is connected via a connecting conduit to a pneumatic pump (14) of restricted pumping volume.
This connecting conduit (50) comprises a valve (56) which is opened at the respective changeover point (top and bottom dead-center) of the pump (14) to set the entire pump arrangement (16) to atmospheric pressure.
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Citations
19 Claims
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1. In an apparatus for pumping liquids for medical purposes, in particular blood fluid or infusion fluid, including at least one pump housing 12 having a cavity which is divided by an impermeable diaphragm into a working chamber (16) and a drive chamber (18), said working chamber being provided with at least one opening (2) for the supply and discharge of the fluid to be conveyed, and said drive chamber being adapted to be subjected to a gas as a pumping fluid and coupled via a conduit (50) of a limited pumping volume, the improvement comprising:
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a valve means (56) connected to said drive chamber (18) for pressure compensation upon stroke change of the pumping means (46); and a control means (70) connected to said valve means (56) and means responsive to the pumping means for controlling opening said valve means before each said stroke change and closing said valve means (56) after pressure equalization with ambient pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification