Development of a Tongue-Operated Switch Array as an Alternative Input Device

This article presents a tongue-operated switch array (TOSA) that provides not only an alternate input for a computer or operative system, but also an approach for silent and hands-free communication among humans or between human and machine. A TOSA has been designed and fabricated using printed circuit board technology and a membrane-switching mechanism and is integrated with a dental palate mold made from a silicone impression material. The TOSA has 5 switches (4 switches are laid out in cardinal directions and a fifth switch is located in the center). Human participant experiments have been conducted to evaluate and improve device performance. The characteristics of tactile sensation and mobility of the tongue are used to quantify the performance and optimize the geometric design of the TOSA. The results from controlled studies using repeated measures with 4 participants revealed a maximum average accuracy of 91% with SD = 5 in a switch depression task and a maximum repetition rate of 2.47 depressions/sec (SD = .21). These results indicate that operation on all switches is highly accurate and fast enough for use as an alternate input device.