Passive wireless tags for tongue controlled assistive technology interfaces

Low Cost Magnetic Field Control for Disabled People

Our research presents a cost-effective navigation system for electric wheelchairs that utilizes the tongue as a human-machine interface (HMI) for disabled individuals. The user controls the movement of the wheelchair by wearing a small neodymium magnet on their tongue, which is held in place by a suction pad. The system uses low-cost electronics and sensors, including two electronic compasses, to detect the position of the magnet in the mouth. One compass estimates the magnet's position while the other is used as a reference to compensate for static magnetic fields. A microcontroller processes the data using a computational algorithm that takes the mathematical formulations of the magnetic fields as input in real time. The system has been tested using real data to control an electric wheelchair, and it has been shown that a trained user can effectively use tongue movements as an interface for the wheelchair or a computer.

Palatal Electrotactile Display Outperforms Visual Display in Tongue Motor learning

Incomplete tongue motor control is a common yet challenging issue among individuals with neurotraumas and neurological disorders. In development of the training protocols, multiple sensory modalities including visual, auditory, and tactile feedback have been employed. However, the effectiveness of each sensory modality in tongue motor learning is still in question. The object of this study was to test the effectiveness of visual and electrotactile assistance on tongue motor learning, respectively. Eight healthy subjects performed the tongue pointing task, in which they were visually instructed to touch the target on the palate by their tongue tip as accurately as possible. Each subject wore a custom-made dental retainer with 12 electrodes distributed over the palatal area. For visual training, 3×4 LED array on the computer screen, corresponding to the electrode layout, was turned on with different colors according to the tongue contact. For electrotactile training, electrical stimulation was applied to the tongue with frequencies depending on the distance between the tongue contact and the target, along with a small protrusion on the retainer as an indicator of the target. One baseline session, one training session, and three post-training sessions were conducted over four-day duration. Experimental result showed that the error was decreased after both visual and electrotactile trainings, from 3.56±0.11 (Mean±STE) to 1.27±0.16, and from 3.97±0.11 to 0.53±0.19, respectively. The result also showed that electrotactile training leads to stronger retention than visual training, as the improvement was retained as 62.68±1.81% after electrotactile training and 36.59±2.24% after visual training, at 3-day post training.

Design and evaluation of an alternative wheelchair control system for dexterity disabilities

This work details the design and development of a novel 3D printed, modular alternative wheelchair control system for powered wheelchair users afflicted with dexterity inhibiting disorders, which mechanically interfaces directly with the installed standard joystick. The proposed joystick manipulator utilises an accelerometer for gesture control input processed by the Arduino microprocessor and a mechanical control interface, which sits over a standard installed two-axis proportional joystick, the preferential control system for most powered chair manufacturers. When fitted, this allows powered electric wheelchair users with limited dexterity, independent to navigate their wheelchair unassisted. The mechanical system has been selected so that the joystick manipulator is as universal as possible and can be installed to almost any powered wheelchair that uses a two-axis joystick. The design process and key aspects of the operation of the joystick manipulator are presented as well as field testing on a wheelchair conducted. The test results show that the proposed joystick manipulator is a successful system that can be universally fitted to most powered chairs and offers potentially greater independence for the powered wheelchair user.