Explore Electrotactile Parametric Properties Using an Electrical Stimulation System

Influenced by multiple factors, to understand electrotactile properties is challenging but significant in comparing individual differences, parameters control and coding, and model studies. However, the inadequacy of measurement systems and methods limits the application and development of electrotactile feedback. This study focuses on the exploration of parametric properties using an electrical stimulation system (ESS) via innovative measurement methods and electrotactile control. A 6-channel portable stimulator and a graphical user interface (GUI) with interactive algorithms have been designed. Modified staircase method, bisection and parametric-random algorithms are developed for the psychophysical measurement of detection thresholds (DT), pain threshold (PT), just-noticeable difference (JND), parameter-intensity properties (PIP) and sensitivity index (SI). The system performance is verified by conducting four sub-experiments on eight subjects. Bisection algorithm is proved to be more robust (p < 0.05). JND measurement based on bisection algorithm achieves 50% efficiency improvement over traditional methods. The individual differences and sensitivities are quantified by SI. The JND and PIP measurement results indicate the potential for iso-resolution and iso-intensity control in information coding as well as parameter-intensity modelling. The results of this paper could provide a basis for tactile information encoding as well as an experimental platform for investigating perception mechanism.