Non-Rectangular Neurostimulation Waveforms Elicit Varied Sensation Quality and Perceptive Fields on the Hand

Abstract

Abstract Electrical stimulation of the nerves is known to elicit distinct sensations perceived in distal parts of the body. The stimulation is typically modulated in current with charge balance rectangular shape that, although they are easily generated by the stimulators available on the market, they are not able to cover the entire range of somatosensory experiences required in daily life. In this regard, we have investigated the effect of electrical neurostimulation with four non-rectangular waveforms in an experiment involving 11 healthy able-bodied subjects. Weiss curves were estimated for different subjects, showing different charges required to elicit a sensation based on the shape. The localization and dimensions of the sensations reported in the hand also differed between waveforms showing larger areas for non-rectangular waveforms. Finally, the possibility of distinguishing different charge- and amplitude-matched stimuli was demonstrated through a two-alternative-forced-choice (2AFC) task, showing the ability of participants to successfully distinguish between waveforms. This study shows that by using different waveforms to stimulate nerves, it is possible to affect not only the required charge to elicit sensations, but also the quality of sensation and its dimension, in terms of area and location.