Implantable patient-activated fluid delivery device

Abstract

An implantable fluid delivery device for dispensing metered aliquots of liquid medication upon finger-pressure activation of the device by a patient. The device includes a soft, deformable needle-piercable casing having a fluid reservoir in which is located a relatively-rigid, apertured support plate that divides the reservoir into upper and lower chambers. A compressible, positive displacement pump chamber or housing is mounted upon the plate within the upper chamber and includes passages communicating with both the lower chamber and an outlet port. Force applied to a central target zone of the top wall causes compression of the pump housing and delivery through the outlet port of an amount of fluid equal to the displacement of the pump housing. The same target zone of the top wall serves as a self-sealing injection site for replenishing the fluid supply of the reservoir. A rigid, protective needle guard is disposed within the upper chamber above the pump housing to shield that housing against contact by an injection needle when the fluid supply is being replenished. The rigid plate that supports the pump housing also distributes applied pumping forces and provides a platform for supporting other elements of the device, including a fluid filter and surge protector located in the lower chamber of the reservoir at the inlet to the pump housing.