Quantifying sway through surface deflection patterns: a novel approach using distributive tactile sensing

This paper describes an experiment that extends the distributive sensing approach to identify the three-dimensional location of an object in constant motion. Distributive sensing has previously been successful in the identification of size and location of statically placed objects. Here, a novel system is developed to measure balance or sway in patients. The experimental set-up consisted of a pendulum structure positioned on a supported steel plate. Three low-cost deflection sensors were positioned under the plate with the resulting signals used as inputs to a neural network implemented on a field-programmable gate array. The results show that the embedded system can accurately track the pendulum position in real time with a mean tracking error of around 6 per cent in all three dimensions. This evidence indicates that the technique is sufficiently sensitive and could be implemented in a pragmatic configuration for discriminating between balance and sway.