Electrocutaneous display with receptor selective Stimulations

A tactile display of skin touch sensations to transcutaneous electric current stimulation is proposed. Since topdown design methods expressing various sensations (e.g., pressure sensation, vibration sensation, tactile sensation) expressed by language feedback have been used in many of the past skin touch sensation displays and since these sensations are the results of combining the activities of various kinds of sensory receptors, the displays thus designed have been limited in that they displayed only certain limited sensations. In contrast, the authors' device is based on stimulating sensory nerves differently by kind. It is considered that if stimulations can be performed to suit different kinds of sensory nerves, all sensations can be generated by combining them. These stimulations are called "tactile primary colors" from their similarity to the visual sense. Electrical stimulation from the skin surface is used as the stimulating means. Although the history of electrical stimulation itself is old, many studies regarding electrical stimulation have ended up generating ad hoc simple sensations without attempting to construct the above primary colors. In this paper, two methods for selectively stimulating the receptors are proposed. One is a method of changing the depth of stimulation by changing the weight of each electrode, using electrodes in an array form. The other is a method of selectively stimulating in the direction of a nerve axon by using an anodic electric current, in contrast to the cathodic current used in the transcutaneous electrical stimulation of the past methods. (C) 2002 Wiley Periodicals, Inc.