Patent ID: 6770067
Filing Date: 2004-08-03
Classification: A61M

Abstract:
A drive mechanism for delivery of infusion medium comprising:an inlet for receiving infusion medium; an outlet for discharging infusion medium; a channel through which infusion medium is communicated between the inlet and the outlet; a piston moveable between an quiescent position and a forward position to drive infusion medium from the piston channel toward the outlet; a valve member facing a first end of the channel, the valve member being moveable between closed and open positions to open and close the first end of the channel in conjunction with movement of the piston between quiescent and forward positions; and a valve seat located adjacent the end of the channel that faces the valve member for contacting the valve member when the valve member is in closed position; the valve member including at least one generally rigid stop surface for contacting the valve seat upon the valve member being in a closed position, the valve member further including a generally compliant portion extending toward the valve seat, beyond the generally rigid stop surface for contacting the valve seat when the valve member is in a closed position, wherein the generally compliant portion includes at least one annular projection, and wherein the stop surface surrounds the generally compliant portion.