Tactile or thermal sensory substitution is applied to persons with sensory loss of
vision or hearing. It has been known that the blind has more sensitive tactile acuity
than the normal person. In this study, thermal acuity was assessed in groups of
control, blind and deaf to investigate a thermal display system for blind and deaf.
Thermal threshold on heat pain, warm, cool, and cold pain was measured by
home-made thermal stimulator in five fingers. Thermal acuity in control group did
not show any significant difference between male and female, and among five fingers.
Range of threshold of heat pain, warm, cool, and cold pain in five fingers was
43.2~44.9℃, 35.0~36.0℃, 23.1~23.8℃, 15.1~15.8℃, respectively, in control group,
43.0~43.7℃, 33.2~34.5℃, 22.5~23.9℃, 14.4~15.8℃, respectively, in blind group, and
42.5~43.2℃, 34.1~34.6℃, 22.0~23.6℃, 15.0~16.1℃, respectively, in deaf group.
Indifferent thermal zone was 23.8~35.0℃ in control group, 22.9~33.2℃ in blind
group, and 23.6~34.1℃ in deaf group, which did not show any significant difference
among three groups. These results suggest that thermal acuity does not show any
significant difference among control, blind, and deaf groups. Thermal display system
for blind and deaf should be considered the thermal threshold and indifferent thermal
zone.