High accuracy disposable cassette infusion pump
First Claim
1. A pump for supplying a controlled quantity of liquid comprising:
- cassette means for defining a liquid path, the cassette means including an inlet region for receiving the liquid, an outlet region for discharging the liquid, and a pressurization region for forcing the liquid from the outlet region;
flexible membrane means disposed over the cassette means to enclose the liquid path;
controllable piston means disposed to move the flexible membrane means to pressurize the liquid in the pressurization region, thus forcing liquid from the outlet region;
inlet valve means disposed in proximity to the flexible membrane means and the inlet region for controlling liquid flow through the inlet region, the inlet valve means capable of operating independently of the controllable piston means;
outlet valve means disposed in proximity to the flexible membrane means and the outlet region for maintaining the outlet region closed except when liquid is being forced from the outlet region;
a second outlet region for discharging any gas in the cassette means, the second outlet region being disposed in the liquid path before the outlet region; and
additional outlet valve means disposed in proximity to the second outlet region for controlling gas flow through the second outlet region.
1 Assignment
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Accused Products
Abstract
An infusion pump for delivery of drugs to a patient includes a unit in which the pump mechanism is situated and a cassette through which the drugs to be delivered to the patient are pumped. The cassette includes a path for the fluid to flow from a drug vial to an outlet port. Disposed along the path are recesses for an inlet valve, a pressurization region, and an outlet valve. The cassette is sealed by an elastomeric layer to maintain the drugs to be delivered in a contaminant-free condition. The pump includes an inlet valve which has a contour matching the recess of the inlet port, and an outlet valve matching the recess of the outlet port. By biasing the inlet and outlet valves against the recesses, a pumping chamber is created. A piston in the unit pressurizes the pumping chamber to open the outlet valve and permit fluid to escape. By appropriate timing of the operation of the inlet valve and the piston, a continuous stream of fluid is delivered by the pump to the patient.
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Citations
15 Claims
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1. A pump for supplying a controlled quantity of liquid comprising:
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cassette means for defining a liquid path, the cassette means including an inlet region for receiving the liquid, an outlet region for discharging the liquid, and a pressurization region for forcing the liquid from the outlet region; flexible membrane means disposed over the cassette means to enclose the liquid path; controllable piston means disposed to move the flexible membrane means to pressurize the liquid in the pressurization region, thus forcing liquid from the outlet region; inlet valve means disposed in proximity to the flexible membrane means and the inlet region for controlling liquid flow through the inlet region, the inlet valve means capable of operating independently of the controllable piston means; outlet valve means disposed in proximity to the flexible membrane means and the outlet region for maintaining the outlet region closed except when liquid is being forced from the outlet region; a second outlet region for discharging any gas in the cassette means, the second outlet region being disposed in the liquid path before the outlet region; and additional outlet valve means disposed in proximity to the second outlet region for controlling gas flow through the second outlet region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification