INFUSION DEVICE HAVING PISTON OPERATED DRIVING MECHANISM ANDPOSITIVE PRESSURE RESERVOIR

摘要

A piston-type drive mechanism in combination with a positive pressure reservoir for delivery of infusion medium. A coil capable of being electrically activated to provide an electromagnetic field. The coil surroun ds a piston channel extending in an axial direction. The piston channel provide s a passage for communication of infusion medium from the positive pressure reservoir to an outlet chamber. A piston is located within the piston channe l and is moveable axially within the channel to a forward position. The piston is moved toward a retracted position, when the coil is not energized. As the piston is moved to its forward position, pressure moves a valve member into an open position. When the valve member is in the open position, medium from th e piston chamber is discharged into the outlet chamber. An outlet is provided in flow communication with the outlet chamber, for discharging infusion medium from the outlet chamber.