9511731 Kazerooni The overall objective of this research project is to design and construct electromagnetic actuators which behave as Hill's model of human muscle predicts. The researchers hypothesize that, to restore function properly to motor- impaired humans, the electromagnetic actuators of powered orthotic and prosthetic devices should exhibit behavior similar to that of human muscles. With the use of emulation computer software, the investigators will emulate Hill's model in several experimental orthotic devices available to them to determine how the use of such actuators will improve the restoration function in motor-impaired humans. Following the use of the emulation software, design principles will be derived for an electromagnetic actuator that inherently behaves as Hill's model predicts. The technology to be developed from successful results of the research can be used by a person with mild movement disorders, such as a mid-level quadriplegic. It is expected that atrophy and deformity will be minimized and limb function will improve with the development of an intelligent orthosis that allows the patient's arm to maneuver in all possible directions. This intelligent orthosis should become a natural complement of the patient's arm. ***