| 摘要 |
A piston-type drive mechanism in combination with a positive pressure reservoir for delivery of infusion medium. A coil (38) capable of being electrically activated to provide an electromagnetic field. The coil (38) surrounds a piston channel (35, 36) extending in an axial direction. The piston channel (35, 36) provides a passage for communication of infusion medium from the positive pressure reservoir (13) to an outlet chamber (64). A piston (44) is located within the piston channel (35, 36) and is moveable axially within the channel to a forward position. The piston (44) is moved toward a retracted position, when the coil (38) is not energized. As the piston (44) is moved to its forward position, pressure moves a valve member (66) into an open position. When the valve member (66) is in the open position, medium from the piston chamber (65) is discharged into the outlet chamber (64). An outlet is provided in flow communication with the outlet chamber (64), for discharging infusion medium from the outlet chamber (64). |
