In this paper, the effects of visual feedback and aging on postural sway systems and signals are investigated by analyzing the transient phase difference between "input" and "output" which correspond to center of pressure (COP) and center of mass (COM), respectively. In order to analyze the transient phase difference characteristics of COP and COM, a relatively new cross time-frequency analysis technique that provides time- and frequency-localized phase difference information is utilized. The feedback control process in the postural sway is interpreted in terms of a feedback compensator which is characterized in terms of a phase difference. Using the experimental results of the transient phase difference obtained from the cross time-frequency distribution, it is demonstrated that the postural control of young persons are more stable and rely more on visual sensory feedback to stabilize postural control compared to that of the elderly persons.
Bibliographical noteFunding Information:
He is currently the Texas Atomic Energy Research Foundation Professor in Engineering. His primary professional interests lie in the innovative application of digital higher order statistical signal processing in the analysis, interpretation, and modeling of random data characterizing nonlinear physical phenomena and systems; and the utilization of the wavelet transform and time-frequency analysis to detect and identify transient events in various physical systems.
All Science Journal Classification (ASJC) codes
- Biomedical Engineering