Dispersion and accuracy of simulated phosphene positioning using tactile board.

The evaluation of phosphene is one of the most important things after the electrode array's implantation. Some experiments have been used to study the basic rules on people using their tactile perception in describing the characteristics of simulated phosphenes, such as the dispersion, accuracy, and response time. In order to describe the simulated phosphenes more systematically and scientifically, an improved phosphene-positioning method using tactile board was designed in this study. Using tactile board to guide the tactile perception, the dispersion was limited to less than 6 mm, while the largest mean error was 8.1 mm, which was nearly equal to the minimal resolution of tactile board (8 mm). The response time greatly increased because of the standard processes in using tactile board. Moreover, the long-term experiment to repeat the procedure could improve and sustain the subjects' performance in good results.