Spatiotemporal Identification of Moving Patterns on a Fingertip-based
Electro-Tactile Display Array
Abstract
An electro-tactile display can be used to stimulate sensations in the
skin. The ultimate achievement in this area is to open a new information
communication channel using this sensory substitution system. One of the
requirement of such communication channel is to deliver meaningful
commands to the user. The sensations should be distinctive enough to be
readily understandable for the operator.
This study is perusing the feasibility of generating identifiable moving
patterns in the electro-tactile display. Then, the degree of
identification performed by the users will be
validated.
An electro-tactile display is built using an
array of sixteen contacts to form a moving pattern by delivering
electrical signal to the fingertip skin.
This signal can have varying voltages, frequencies or duty cycles to
form the most comfortable sensation.
Moving patterns can be generated by individually or collectively
toggling the electrical contacts on the electro-tactile display. This
will achieve a stimulation of a moving pattern. In this regard, a moving
pattern can be compared to a set of frame-by-frame pictures that
construct a movie. Similarly, by toggling the contacts in a specific
order, a moving pattern can be achieved.
In this study,
eight subjects participated. A questionnaire was used to assess the
sensation of the corresponding movement.
The results of these reports were analyzed and a conclusion regarding
the identification of the direction of the movement was drawn. It became
clear that the direction of the movement had a significant impact on the
recognition of the patterns.
Furthermore, an analysis
of the detection threshold (DT) voltage and current mapping was
performed to evaluate the effect of the internal structure of the skin
for each user on the assessment performance.
Based on the mapping results, it became clear that the DT voltage is
vastly different for each contact and the resulting spatial map is also
unique to each user.