Employing electrical field sensing for detecting static thumb position using the Finger-Joint Gesture Keypad input paradigm

A wearable ubiquitous fragmentised mobile terminal concept, the Finger-Joint Gesture Keypad paradigm (FJGK), utilising the 12 finger phalanges as telephone keypad keys and the thumb as operator, was implemented in a prototype. Isolated digit-gesture recognition of the static thumb position of the 12-character telephone keypad vocabulary (1-9, *, 0 and #) entered 50 times without replacement by a single user was recorded using electric field sensing. A simple threshold-based algorithm for classifying the various channel-input readings was used. Mean detection rate was 78% for a 4-channel electrode configuration where the electrodes were placed next to each other in one plane. Character detection rates varied between 18-100%. Detection rates were lowest for digit 5 (18%), 2 (50%) and 6 (66%). In a context where portability issues are at stake, the FJGK ubiquitous terminal concept may provide a viable alternative.