Exoskeletal meal assistance system (EMAS III) for progressive muscle dystrophy patient

This paper proposes an exoskeleton that supports activities of an upper extremity including a wrist joint so that a patient with muscle weakness could work on a table or a desk with his/her hand in a daily activity. The exoskeleton compensates gravity of the upper limb using two counterweights in order to reduce loads of a shoulder joint and an elbow joint. The exoskeleton also supports a wrist joint against its own gravity by interlocking with elbow joint angle so that a user could carry an object on his/her palm by keeping it horizontal. An orientation of a grasping object is partially constrained by a hand frame of the exoskeleton for object stable improvement. Through some experiments, the gravity compensations of upper limb´s joints are confirmed based on bioelectric potentials of muscles when subjects drink water from an aluminum can.