Projects: Electrotactile display of computer graphics for blind (ET Haptic)

Research in this effort has shown that:

• Controlled, localized touch sensations can be induced via electrical stimulation on the fingertips.
  
• Subjects can identify simple geometric patterns via haptic exploration of a matrix of small electrodes embedded in a flat plate.
• Sensory adaptation on the fingertips is somewhat less than that on the abdomen, particularly if the fingertips are allowed to move over the surface of the electrode array.
• It is possible to identify small spatial patterns presented at the level of sensory threshold, whereas good pattern identification performance requires stimuli presented at 1.5 times threshold. 
• A contrast (ratio of pattern intensity to background intensity) of at least 2 is required for good performance in identification of small spatial patterns.
• The timing of pulses and bursts in the stimulation waveform affects the pattern identification performance. In general, more pulses per second yield better performance.
• Subjects are able to estimate the correlation of tactile scatterplots presented on the fingertips.

Photos of 576-pixel (24x24) display

Final report for both project segments, 12/1/92–5/31/97, 9/30/98–9/30/04  (MS Word file, 2.4MB)  (PDF file, 0.8 MB)
This report includes a complete list of all publications resulting from the research.

Supported by the National Eye Institute grant R01-EY10019, Kurt Kaczmarek, Principal Investigator.
Project periods: 12/1/1992–5/31/1997, 9/30/1998–9/30/2004