Abstract: Hand movement assistance apparatus of both the active and passive types and usable for movement stabilization by either a normal human subject seeking to perform a task of great precision or a neurologically impaired human subject having Parkinson's disease or similar dysfunction. Both the active and passive apparatus provide a glove-like receptacle for the subject's hand; the passive system applies closed-loop feedback system generated forces to the glove and the active system provides a hand guidance track arrangement for the subject's hand. Three axis stabilization forces and rotationally oriented forces are alternatively provided by the active system, along with responses particularly adopted to the Parkinson's tremor frequency.

Abstract: Mechanical impedance determining apparatus for the control stick of an aircraft, an aircraft simulator, or non-aircraft apparatus such as a video game. Impedance determination is accomplished by a feedback path connected from output to input of the control stick with feedback transfer function coefficients determined by operator election in order to achieve positive, negative, or zero mechanical impedance at the control stick. Electrical network and computer realization of the feedback signal transfer function are contemplated using s plane pole descriptions of overall stick and feedback path characterizing transfer functions.