Tactile sensibility through tactile display: Effect of the array density and clinical use

Sensing in humans is carried out in different modalities, among them, the touch is essential in every-day life allowing most of all the manual activities. Less known is the fundamental role in the screening of some neurological diseases. In fact it is possible, trough the assessment of the level of tactile perception, to evaluate during clinical/medical diagnosis the nervous system health state. It is therefore fundamental to determine valid measurement procedures aiming to this task. The analysis has started with the investigation of tactile frequency sensibility, on healthy subjects, who examined tactile stimuli with devices called arrays. Arrays are formed by passive pins, which follow the shape of the stimuli. There were different arrays depending on the number of pins on them. The only task of subjects was to recognize the higher between couples of stimuli (one grating) with different frequency. The aim of these tests is that of creating a diagnostic scale for tactile neurodegenerative syndromes and diseases. Results show a significant role of pins density with a performance that falls when pins distance is higher than 1 mm. Preliminary clinical tests on 3 patients with tunnel carpal syndrome suggest positive development for use as a diagnostic tool.