Nataraj R.,Case Western Reserve University |
Audu M.L.,Case Western Reserve University |
Triolo R.J.,Case Western Reserve University |
Triolo R.J.,Cleveland Louis Stokes Veterans Affairs Medical Center
IEEE Transactions on Biomedical Engineering | Year: 2013
This study investigated the use of center of mass (COM) acceleration feedback for improving performance of a functional neuromuscular stimulation control system to restore standing function to a subject with complete, thoracic-level spinal cord injury. The approach for linearly relating changes in muscle stimulation to changes in COM acceleration was verified experimentally and subsequently produced data to create an input-output map driven by sensor feedback. The feedback gains were systematically tuned to reduce upper extremity (UE) loads applied to an instrumented support device while resisting external postural disturbances. Total body COM acceleration was accurately estimated (>89% variance explained) using 3-D outputs of two accelerometers mounted on the pelvis and torso. Compared to constant muscle stimulation employed clinically, feedback control of stimulation reduced UE loading by 33%. COM acceleration feedback is advantageous in constructing a standing neuroprosthesis since it provides the basis for a comprehensive control synergy about a global, dynamic variable and requires minimal instrumentation. Future work should include tuning and testing the feedback control system during functional reaching activity that is more indicative of activities of daily living. © 1964-2012 IEEE.
Lowell D.L.,Cleveland Louis Stokes Veterans Affairs Medical Center |
Roberts J.,Cleveland Louis Stokes Veterans Affairs Medical Center |
Gogate P.,Cleveland Louis Stokes Veterans Affairs Medical Center |
Goodwin R.,Kent State University
Journal of Foot and Ankle Surgery | Year: 2014
Merkel cell carcinoma is a rare, aggressive, highly metastatic, often fatal, primary neuroendocrine tumor typically located on sun-exposed skin. It is frequently found in white males aged 60 to 70years. The somewhat typical benign clinical appearance of the lesion can result in a delayed diagnosis, leading to a less than optimal outcome. © 2014 American College of Foot and Ankle Surgeons.