Alternative design of inductive pointing device for oral interface for computers and wheelchairs.

An inductive pointing device was designed and implemented successfully in a tongue controlled oral interface. Sensors were manufactured as an assembly of multilayer coils in the printed circuit board technology on two pads. The sensor pads were encapsulated together with electronics and battery in a mouthpiece, placed in the upper palate of the oral cavity. The PCB technology allowed surface activation of one or more sensors by gliding over the surface of the coils assembly of a small cylindrical unit attached to the tongue. The model consisted of 8 sensors and allowed real time proportional control of both speed and direction similar to a joystick. However, the size of the oral cavity, the number and geometry of the coil loops and characteristics of the activation unit impose limits in designing the sensors and call for an alternative layout design. Two alternative sensor designs are proposed in this paper, aiming to reduce the size of the sensor pad by one third, extending the target group, including children, and increasing the easiness of wear of the oral interface.