An implantable apparatus for controlling fluid flow within a host body includes
a constricting member for allowing fluid flow within a body canal when in an open
position, and for reducing fluid flow within a body canal when in an closed position.
Remote telemetry can be used to operate the constricting member from a position
outside the body. The constricting member can include a piston having at least
two protrusions for contacting the vessel surface of the body canal. A fluid-operated
member can receive fluid to reduce fluid flow within the body canal and expel fluid
to allow fluid flow within the body canal. An actuating member is provided for
operating the fluid-operated member between the open and closed positions. The
actuating member has structure for flowing fluid into and out of the fluid-operated
member. A control device is provided for operating the actuating member. An implantable
drive mechanism for a constricting member or other medical device includes a sealed
housing for implantation in a patient body, a drive magnet positioned within the
housing, an actuator for moving the drive magnet, and a magnetically susceptible
drive member positioned outside the housing such that movement of the drive magnet
within the housing will move the drive member outside of the housing.