Design, Characterization, andImpedance Limits ofaHandRobot

Previous workhasexpanded theplanar MIT- MANUS toinclude ananti-gravity robotforshoulder-and- elbowandwrist robot. Inthispaperwepresent the"missing link": ahandmodule. We will discuss indetail thedesign and characterization ofthis module. Itconsists ofasingle degree of freedom mechanism inanovelstatorless configuration, which enablesrehabilitation ofgrasping. The systemusesthe kinematic configuration ofadouble crankandslider wherethe membersarelinked tostator androtor; afreebasemotor, i.e., amotorhaving tworotors thatarefreetorotate instead ofa fixedstator and a single rotatable rotor. A cylindrical structure, madeofsixpanels anddriven bytherelative rotation oftherotors, isabletoincrease itsradius linearly, movingor guiding thehandofthepatients during grasping. Thismodule completes ourdevelopment ofrobots fortheupper-extremity affording forthefirst timea whole-armrehabilitation experience. I.INTRODUCTION S troke istheleading cause ofpermanent impairment and disability (1), andthere hasbeenarenewed effort to improve motorrecovery after stroke. To increase the effectiveness ofrobotic therapy we mustdevelop new whole-aim therapy approaches that integrate robotic therapy withclinical practice andenhance thecarry-over ofrobot trained movements during functional tasks. We expect that a treatment protocol, properly targeted toemphasize a sequence andtiming ofsensory andmotorstimuli similar to those naturally occurring indaily life tasks, could facilitate carry-over oftheobserved gains inmotorabilities, thereby conferring greater improvements infunctional recovery. A