Christopher F Holmes

US Patent:

20020004015, Jan 10, 2002

Filed:

Jul 6, 2001

Appl. No.:

09/900682

Inventors:

Jeffrey Carlisle - Rings Island MA, US
Peter Costa - Winthrop MA, US
Christopher Holmes - Harvard MA, US
John Kirkman - Kingston NH, US
John Thompson - San Clemente CA, US
Mark Semler - Bradford MA, US

International Classification:

F04B043/00

US Classification:

417/479000, 417/480000

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.