Multisensor piezoelectric polymer insole for pedobarography

Abstract Analysis of the pressure distribution under the foot in walking and standing patients (pedobarography) can be used to detect orthopaedic as well as neurological defects. Sensorized insoles are increasingly used, at least for research purposes, because of the inherent advantages they offer compared to the force platforms presently available. We have developed and evaluated a piezoelectric polymer insole for pedobarography, using a 200 μm thick polyvinylidene fluoride (PVDF) film which had been uniaxially stretched and poled in selected areas. Sixteen circular aluminium disks, 6 mm diameter each, deposited onto the film by vacuum evaporation, served as the electrodes for the pressure sensors and were located so as to optimize the response of the five metatarsal transducers, which are particularly critical for a correct gait analysis. The 16 sensors were disposed on the ideal loading surface, the response of which identified incorrect foot conformation on loading. Sixteen conductive tracks, one for ...