System and method for pumping intravenous fluid
AssigneeCarefusion Corporation
InventorRobert Siefert
Life of this patent
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Abstract
An intravenous fluid pump (IV) contains a disposable part including a fluid chamber having a resilient top membrane and a non-disposable part including a piston abutting a resilient membrane and a vacuum chamber fitted on top of the resilient top membrane. An external pump is used to create vacuum in the vacuum chamber, resulting in the resilient top membrane being held taut. The flow rate through the pump is relatively independent of changes in the pressure of IV fluid on the upstream and the downstream due to changes in the relative elevation of the fluid reservoir and the patient with respect to the fluid pump.
Claims9
A method of delivering fluid from a reservoir to a patient-side instrument, the method comprising the steps of:
- providing a fluid chamber with a pumping membrane that is flexible but not stretchable, the fluid chamber having an opening for allowing fluid in and out of the fluid chamber;
- providing a vacuum chamber formed between the pumping membrane of the fluid chamber and a sealing membrane;
- providing a piston touching the pumping membrane;
- removing at least some air from the vacuum chamber so that the pressure in the vacuum chamber is less than the pressure in the fluid chamber;
- and
- pumping fluid through the fluid chamber by alternating between:
- moving the piston outwards to allow fluid to enter the fluid chamber without stretching the pumping membrane;
- and
- pushing the piston inwards to expel fluid from the fluid chamber without stretching the pumping membrane.
A method of delivering intravenous fluid, the method comprising the steps of:
- removing air through an opening from a vacuum chamber that is formed between a pumping membrane that is flexible but not stretchable and forms a side of a fluid chamber of a disposable delivery element and a sealing membrane that is part of a non-disposable casing that is configured to form a seal with the pumping membrane;
- displacing the pumping membrane so as to decrease a volume of the fluid chamber without stretching the pumping membrane;
- and
- displacing the pumping membrane so as to increase the volume of the fluid chamber without stretching the pumping membrane.
Dependencies are inferred from the claim text.