Implantable patient-activated fluid delivery device and outlet valve therefor

Claim 1

An implantable patient-activated device for dispensing metered amounts of fluid to such a patient, comprising a casing formed of soft, deformable polymeric material having a top wall and a bottom wall defining a fluid reservoir with an outlet port; pumping means within said casing including a compressible pump housing having a pumping chamber; first passage-providing means defining an inlet passage extending between said reservoir and said chamber; inlet valve means restricting flow through said inlet passage from said chamber to said reservoir; second passage providing means defining an outlet passage extending between said chamber and said outlet port; outlet valve means along said outlet passage for controlling flow therethrough; said outlet valve means including an annular valve seat of elastomeric material providing a valve opening and a cup-shaped valve member formed of elastomeric material having an outer surface normally sealingly engaging said valve seat; said top wall of said casing having a target zone operatively connected to said pump housing and deformable by finger pressure to compass said pump housing; said valve seat and valve member being deformable together, when said target zone is depressed to compass said pump housing and displace fluid from said chamber, until said seat reaches a limit of deformation and said valve member breaks away from said seat to allow fluid to surge through said outlet passage, said breakway and surge providing tactile feedback to signal a user applying finger pressure to said target zone that a metered amount of fluid has been discharged from said device; said body portion of said valve member including a base having a truncated stem portion; said truncated stem portion having an outer surface sealingly engageable with said deformable annular valve seat.