Robotic psychophysics system for assessment, diagnosis and rehabilitation of the neurological causes of falls in the elderly

Falls are the leading causes of unintentional injuries in the elderly and thus a pose a major hazard to our ageing society. We present the FOHEPO (FOot HEight POsitioning) system to measure, diagnose and eventually rehabilitate ageing-related neurological causes of falls. We hypothesise that both perceptual and motor variability is likely to increase with age and may lead to imprecise perception and movements causing trip overs, the major triggers of falls. Our robotic experimental system automatically measures and tracks different sources of noise in the nervous system: visual perception noise of obstacle height, proprioceptive noise of localising raising one´s foot to a desired height, noise in the visual feedback of the foot movements. We developed age-appropriate psychophysical measurement protocols shorter than standard protocols for perceptual and motor accuracy. These quantify individual subjects perceptual and movement accuracy thresholds through their psychometric curves. Therefore, these platform measurements will enable us to estimate fall probabilities quantitatively, i.e. the chance that a foot will clip an obstacle because subjects did not add a sufficient safety factor when clearing it. Potentially, we can use our FOHEPO system in a game-ified setting to rehabilitate elderly users to move with larger safety factors so as to reduce their risks of trip-over.