Georgia Center for Medical Robotics Seminar Series

Gregory Sawicki, Ph.D.
Associate Professor
School of Mechanical Engineering and School of Biological Sciences
Georgia Tech

"Ankle Exoskeletons to Restore Mobility Post-stroke"

The goal of the Human Physiology of Wearable Robotics (PoWeR) Laboratory is to discover and exploit key principles of locomotion neuromechanics in order to build wearable devices that can augment intact and/or restore impaired human locomotion. The primary performance goal of such devices is to reduce metabolic energy consumption of the user.

Our design approach is motivated by two key mechanisms observed in human gait that are crucial to efficient movement. The first is optimally timed, impulsive ankle joint ‘push-off’ for propelling the body forward. The second is the effective cycling of mechanical energy from the body’s center of mass to elastic tissues (i.e., tendon and aponeurosis) and back.

In this talk I will highlight our work over the last ~5 years to understand how changes in neuromechanics -- from limbs to joints – may underpin elevated energetic cost of walking due to unilateral hemiparesis following stroke. Then I will detail our (mostly failed) efforts to improve human ’gas-mileage’ post-stroke using myoelectrically controlled powered ankle exoskeletons at both fixed and increasing walking speeds.

I will conclude with some thoughts on the major gaps in knowledge that may be preventing successful application of robots to restore mobility following neurological injury; suggest what we might try next; and motivate the need for more formal collaboration between scientists studying the neuroscience of motor (re)learning and rehabilitation engineers seeking to develop wearable robots that can restore movement post-stroke.