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Step Prediction During Perturbed Standing Using Center Of Pressure Measurements
Rehabilitation Engineering Laboratory, Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario, Canada
Rehabilitation Engineering Laboratory, Lyndhurst Centre, Toronto Rehabilitation, 520 Sutherland Drive, Toronto, Ontario, Canada
* Author to whom correspondence should be addressed.
Received: 23 February 2007; Accepted: 13 April 2007 / Published: 18 April 2007
Abstract: The development of a sensor that can measure balance during quiet standing and predict stepping response in the event of perturbation has many clinically relevant applica- tions, including closed-loop control of a neuroprothesis for standing. This study investigated the feasibility of an algorithm that can predict in real-time when an able-bodied individual who is quietly standing will have to make a step to compensate for an external perturbation. Anterior and posterior perturbations were performed on 16 able-bodied subjects using a pul- ley system with a dropped weight. A linear relationship was found between the peak center of pressure (COP) velocity and the peak COP displacement caused by the perturbation. This result suggests that one can predict when a person will have to make a step based on COP velocity measurements alone. Another important feature of this finding is that the peak COP velocity occurs considerably before the peak COP displacement. As a result, one can predict if a subject will have to make a step in response to a perturbation sufficiently ahead of the time when the subject is actually forced to make the step. The proposed instability detection algorithm will be implemented in a sensor system using insole sheets in shoes with minitur- ized pressure sensors by which the COPv can be continuously measured. The sensor system will be integrated in a closed-loop feedback system with a neuroprosthesis for standing in the near future.
Keywords: Posture; Balance Control; Center of Pressure; Neuroprosthesis; Functional Elec- trical Stimulation; Functional Neuromuscular Stimulation
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MDPI and ACS Style
Tortolero, X.; Masani, K.; Popovic, M.R. Step Prediction During Perturbed Standing Using Center Of Pressure Measurements. Sensors 2007, 7, 459-472.
Tortolero X, Masani K, Popovic MR. Step Prediction During Perturbed Standing Using Center Of Pressure Measurements. Sensors. 2007; 7(4):459-472.
Tortolero, Xavier; Masani, Kei; Popovic, Milos R. 2007. "Step Prediction During Perturbed Standing Using Center Of Pressure Measurements." Sensors 7, no. 4: 459-472.