Sensors 2007, 7(4), 459-472; doi:10.3390/s7040459

Step Prediction During Perturbed Standing Using Center Of Pressure Measurements

1 Rehabilitation Engineering Laboratory, Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario, Canada 2 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
(This article belongs to the Special Issue Physiological Sensing)
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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.

AMA Style

Tortolero X, Masani K, Popovic MR. Step Prediction During Perturbed Standing Using Center Of Pressure Measurements. Sensors. 2007; 7(4):459-472.

Chicago/Turabian Style

Tortolero, Xavier; Masani, Kei; Popovic, Milos R. 2007. "Step Prediction During Perturbed Standing Using Center Of Pressure Measurements." Sensors 7, no. 4: 459-472.

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