James H. Lipsey

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We present a novel hybrid knee prosthesis that uses a motor, transmission and control system only for active dynamics tasks, while relying on a spring/damper system for passive dynamics activities. Active dynamics tasks require higher torque, lower speed, and occur less frequently than passive dynamic activities. By designing the actuation system around(More)
A case of palatodigital syndrome is added to the eight cases in the literature. The accessory phalanx between the index metacarpal and proximal phalanx produces a significant deformity of extreme radial deviation with mild supination. This deformity was treated by rotation and stabilization of the accessory bone. Follow-up at 1 year shows correction of the(More)
Harmonic and cycloid drives are both compact, high ratio transmissions appropriate for use in anthropomorphic robots, although cycloid drives are rarely used in the field. This paper describes the design parameters for cycloid drives and shows the results of six cycloid models designed to match corresponding harmonic drives. Cycloid drive models were(More)
Body-powered prostheses use a cable-operated system to generate forces and move prosthetic joints. However, this control system can only generate forces in one direction, so current body-powered prehensor designs allow the user either to voluntarily open or voluntarily close the tongs. Both voluntary opening (VO) and voluntary closing (VC) modes of(More)
A piezoelectric (PZT) stack-based actuator was developed to provide a means of actuation with dynamic characteristics appropriate for small-scale manipulation. In particular, the design incorporates a highly nonlinear, large-ratio transmission that provides approximately two orders of magnitude motion amplijication from the PZT stack. In addition to motion(More)
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