A new approach to body balance analysis based on the eight-phase posturographic signal decomposition. (August 2022)

• Record Type: Journal Article
• Authors: Michalak, Krzysztof Piotr; Przekoracka, Katarzyna
• Is Part Of: Biomedical signal processing and control. Volume 77(2022)
• Publication Date: 2022-08
• Subjects: Balance control -- Posturography -- Postural control -- Single inverted pendulum model -- Center of pressure -- Center of mass; CoP Center of Pressure on the posturographic platform -- CoM Center of Mass of the body -- xCoP the path of the CoP signal -- xCoM the path of the CoM signal estimated from xCoP using digital fitler -- xCoPM the signal calculated as: xCoP - xCoM -- vCoP/ vCoM / vCoPM signals representing the momentary velocities of xCoP, xCoM and xCoPM respectively -- aCoP/ aCoM / aCoPM signals representing the momentary accelerations of xCoP, xCoM and xCoPM respectively -- TB Turning Back of xCoM path (vCoM=0), TBF - forwards, TBB - backwards -- ZC Zero Crossing, the points when xCoP and xCoM paths cross each other (aCoM=0, xCoPM=0), ZCF – forwards, ZFB – backwards -- IE Impulse Extremum, the points when the distance between xCoP and xCoM reaches maximum or minimum (vCoPM=0), IEF – forwards, IEB – backwards -- Imax Impulse Maximum, distance between xCoP and xCoM reaches maximum, ImaxF - forwards, ImaxB - backwards -- Imin Impulse Minimum, distance between xCoP and xCoM reaches minimum, IminF - forwards, IminB - backwards; Signal processing -- Periodicals; Biomedical engineering -- Periodicals; Signal Processing, Computer-Assisted -- Periodicals; Image Processing, Computer-Assisted -- Periodicals; Biomedical Engineering -- Periodicals; 610.28
• DOI: 10.1016/j.bspc.2022.103807
• Languages: English
• ISSNs: 1746-8094

Abstract

Graphical abstract: Highlights: Decomposition of the posturographic signals into 8 phases is proposed. Phase and Phase Transition parameters are analyzed. 55 new parameters show improved discrimination power between open and closed eyes. New method presents an enormous diagnostic potential for the healthcare sector. Abstract: Static posturography possesses a significant, although undiscovered to date, diagnostic potential hidden in the subtle oscillations which represent individual muscle contractions regulating body balance when standing still. This paper presents the principles of a new approach to posturographic signal analysis. First, the Center of Mass path (xCoM ) is estimated from Center of Pressure (xCoP ) signal using digital filtering. The difference xCoPM = xCoP − xCoM approximately corresponds to the corrective muscle impulses. Then, the velocities and accelerations of xCoM and xCoPM paths (vCoM, aCoM, vCoPM, aCoPM ) are calculated. Next, 8 phases of body balance regulation are defined based on the combination of instantaneous signs of vCoM, aCoM and vCoPM . Finally, 16 phase transitions are defined which represent different special instants of body balance regulation. They may be divided into 3 main types: Zero Crossing (ZC), Turning Back (TB) and Impulse Extremum (IE). They can be subsequently divided into Forward and Backward subtypes. Based on the presented decomposition 822 new parameters have been analyzed. The exemplary analysis including 23 young healthy subjects (eyes open vs. eyes closed condition) indicated that a number of new parameters showed a higher discrimination power than the standard parameters analyzed to date. Advanced big data methods, such as neural networks or decision trees, should be applied in the future to the extracted parameters in order to evaluate the possible diagnostic potential of the new method of analysis.