Portable system for human stability assessment based on head movement analysis

A portable system for human stability assessment based on head movement analysis, recorded by micro machined accelerometers, was developed. This work is based on a procedure known as stimulus - response technique. A visual stimuli was provoked to the participant subjects, the output is a 3D set of signals corresponding to the head movements. The similar behavior of the recorded signals to those corresponding to an under damped second order control system let us to make this proposal. Digital signal processing was applied in order to obtain the roots of the characteristic equation and in this way to apply stability criteria from control theory criteria. This is a novel, safe and simple in situ method for stability assessment.