This paper discusses a project based on a contact sensor attached to a headset that is connected to a circuit. The circuit is triggered by the sensors to control the wheelchair’s motors. Results occurring from the contact between the cheek and the sensor, due to the tongue movement,apply order to the motors to work allowing the person to move right, left, forward and even to stop according to his needs.This development was accomplished to make patients feel more satisfied because it is a safe and easy technology that doesn’t need any complicated programs to realize and perform the movements.

This system has used array of Hall Effect magnetic sensors which are mounted on mouthpiece along with the small permanent magnet placed on the tongue. These Hall Effect sensors are used to measure the magnetic field generated by the small permanent magnet. The sensed signals are transmitted via wireless link which is processed by microcontroller to control the movement of wheelchair. In early days many assistive technologies have been designed every design had some demerits. This paper gives an efficient, ease of access, low cost solution for all the demerits encountered in previous designs.

PROPOSED SYSTEM DESIGN

In the Tongue motion controlled system, the motion of the tongue is traced by an array of Hall-effect magnetic sensors, which measure the magnetic field generated by a small permanent magnet that is contained within a nonmagnetic fixture and pierced on the tongue. The magnetic sensors are mounted on a dental retainer and attached on the outside of the teeth to measure the magnetic field from different angles and provide continuous real-time analog outputs. Figure 5 shows the Tongue Drive system block diagram with two major units: one inside the mouth, the mouthpiece, and the other outside, a portable body worn controller. Small batteries such as hearing aid button-sized cells are intended to power the mouthpiece for extended durations up to a month. The power management circuitry scans through the sensors and turns them on one at a time to save power. The time division multiplexed (TDM) analog outputs are then digitized, modulated, and transmitted to the external controller unit across a wireless link.

CONCLUSION

A tongue operated magnetic sensor based wireless assistive technology has been developed for people with severe disabilities to lead a self-supportive independent life by enabling them to control their environment using their tongue. This technology works by tracking the movements of a permanent magnet, secured on the tongue, utilizing an array of linear Hall-effect sensors. The sensor outputs are a function of the position-dependent magnetic field generated by the permanent magnet. This allows a small array of sensors to capture a large number of tongue movements. Thus, providing quicker, smoother, and more convenient proportional control compared to many existing assistive technologies. Other advantages of the Tongue Drive system are being unobtrusive, low cost, minimally invasive, flexible, and easy to operate.