Patent ID: 6921419

Claim:
An externally-powered prosthesis mechanism usable with persons with amputations at or proximal to the level of the metacarpophalangeal joint, as well as persons with high-level amputations, said prosthesis mechanism comprising: a grasping mechanism including at least one mechanically operable finger member and at least one mechanically operable thumb member kinematically linked to said finger member such that said grasping mechanism is disposed in respective opened and closed configurations when said finger member is respectively moved away from and toward said thumb member; and a drive system extending tangentially with respect to said grasping mechanism, said drive system including a motor operatively connected to drive at least one planetary gear stage, said planetary gear stage being operatively connected to drive said grasping mechanism to said opened configuration when said motor is driven in a first direction and further drive said grasping mechanism to said closed configuration when said motor is driven in a second opposite direction, wherein said planetary gear stage includes at least one input and at least one output planetary gear stage, said motor is operatively connected to drive said input planetary gear stage, said input planetary gear stage is operatively connected to drive said output planetary gear stage, said output planetary gear stage being operatively connected to drive said grasping mechanism to said opened configuration when said motor is driven in said first direction and further drive said grasping mechanism to said closed configuration when said motor is driven in said second opposite direction, and wherein said motor includes a drive shaft, said input planetary gear stage and said drive shaft include a generally common central axis, such that said externally-powered prosthesis mechanism is usable with persons with amputations at or proximal to the level of the metacarpophalangeal joint, as well as persons with high-level amputations.