INTRAVENOUS LIQUID PUMPING SYSTEM AND METHOD

摘要

TO ALL WHOM IT MAY CONCERN: BE IT KNOWN that I, INGEMAR H. LUNDQUIST, a citizen of the United States of America, residing in the city of Oakland, County of Alameda, State of California, have invented certain new and useful improvements in INTRAVENOUS LIQUID PUMPING SYSTEM AND METHOD of which the following is the specification. Intravenous Fluid Pumping System having a controller and a pump controlled by the controller. The controller has a sealed chamber with a flexible membrane covering a portion thereof. An incompressible fluid is disposed in the chamber. A piston member is movable in the chamber causing extension and retraction of the membrane as the piston is moved in and out relative to the chamber. A motor is provided for reciprocating the piston. The pump has a pump body with a pumping chamber therein with one portion of the pump body being covered by a flexible membrane in contact with flexible membrane carried by the sealed chamber of the controller. The pump has an inlet adapter connected to the source of fluid. The pump also has an outlet adapted connected to the patient. Inlet and outlet valves are provided in the pump body whereby when the controller is operated to flex the membrane of the sealed chamber of the controller, the diaphragm of the pump is operated to cause movement of the valve members to cause fluid to pass from the source through the pump and to the patient under the control of the pump. The controller is also provided with an alarm system whereby positive and negative pressure conditions in the pumping chamber can be sensed. In the method a piston-like member is used to positively cause displacement of a liquid within a sealed chamber to cause movement of a flexible membrane forming a portion of the sealed chamber. The movement of the flexible membrane causes simultaneous movement of another flexible membrane in intimate contact with the firstnamed flexible membrane. The movement of the second flexible membrane is used to create a pumping action in a pump having a pumping chamber in which the last-named flexible membrane forms a part of the pumping chamber.