Cassette
First Claim
1. A cassette for controlling fluid flow, the cassette comprising:
- a housing comprising a central chamber;
an inlet valve for hydraulically controlling pressurized fluid flow to the central chamber; and
an outlet valve for controlling fluid flow from the central chamber; and
a piston assembly for exerting pressure in the central chamber;
the piston assembly comprising a movable member, a covering for the moveable member; and
a flexible interface between the member and the housing for providing near frictionless movement of the member.
3 Assignments
0 Petitions
Accused Products
Abstract
A cassette for controlling fluid flow from a source to a sink, for example, a patient. The cassette comprises a housing, and a passive inlet valve for hydraulically controlling pressurized fluid flow from the inlet valve to a central chamber, and an actuatable outlet valve. The central chamber provides a fluid pathway between the inlet and outlet valves. The cassette further comprises a piston assembly for exerting pressure in the central chamber. The piston assembly comprises a movable member, a covering for the moveable member; and a flexible interface between the member and the housing for providing near frictionless movement between the member and the housing.
56 Citations
35 Claims
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1. A cassette for controlling fluid flow, the cassette comprising:
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a housing comprising a central chamber;
an inlet valve for hydraulically controlling pressurized fluid flow to the central chamber; and
an outlet valve for controlling fluid flow from the central chamber; and
a piston assembly for exerting pressure in the central chamber;
the piston assembly comprising a movable member, a covering for the moveable member; and
a flexible interface between the member and the housing for providing near frictionless movement of the member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. An inlet valve for use with a cassette of the type to be used with an infusion system, the inlet valve comprising:
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a stem;
an elastomeric dome; and
a geometrically preloaded valve element which strains the elastomeric dome;
wherein the inlet valve has an unbalanced surface area perpendicular to the axis of the valve. - View Dependent Claims (23, 24, 25)
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26. An outlet valve for use with a cassette of the type to be used with an infusion system, the outlet valve comprising:
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an outlet valve element;
a stem attached to the outlet valve element;
an elastomeric dome for biasing the outlet valve element to the closed position, wherein the cross-sectional area of the elastomeric dome is greater than the cross-sectional area of the outlet valve element; and
an actuator interface which opens the outlet valve. - View Dependent Claims (27, 28, 29, 30, 31)
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- 32. A check valve for use with a cassette of the type to be used with an infusion system, the check valve comprising a valve element, and an elastomeric wall, wherein the valve element is connected to the elastomeric wall, and wherein the check valve prevents upstream fluid flow by moving between an open and closed position in response to a pressure differential between the atmospheric pressure and pressure on the check valve.
Specification