Desenvolvimento e avaliação de uma interface para controle de cadeira de rodas motorizada por meio de movimentos da cabeça

Abstract

There are many challenges faced by people with disabilities, especially when it comes to mobility, where being able to travel independently require overcoming obstacles along the way. A device for transportation widely used is the electric-powered wheelchair (EPW). Instead of requiring physical effort from the user, it demands the ability to control a joystick to indicate the desired direction. However, not every person with disability is able to use a joystick due to limitations in the upper limbs. In this context, researchers have developed alternative methods for controlling a wheelchair. For example, using hand or head movements, electromyographic signals (from muscle contractions), electroencephalographic signals (brain activity), voice commands, among others. However, users with severe motor disabilities are still find difficulties while using a EPW, making training an indispensable step. The goal of this work is to develop an alternative control from head movements recorded by an accelerometer, for individuals with lower and upper limb impairment. Its goal is to provide a low-cost, reduced size solution, integrable with different devices (computer, EPW), easy to learn and with plug-and-play capacities, dispensing technical knowledge from the user. As strategy for assessment of developed tool, Virtual Reality (VR) technology was used for training, allowing the user to learn in a comfortable, safe and controlled environment. The interface for the alternative control was integrated with a specific VR simulator that provides training for EPW. The assessment step was executed in AACD (Associação de Assistência à Criança Deficiente, portuguese for Association for Assistance to Disabled Children) in the city of Uberlândia, with the participation of four volunteers with quadriplegia resulted from spinal cord injury, with total paralysis of the lower limbs and partial paralysis of the upper limbs. The assessment was divided into two parts: (1) analysis of user performance navigating a virtual wheelchair while using the proposed control interface and, (2) the user's perspective according to the usability of the control modality developed. The results obtained were shown to be satisfactory, according the functional and usability expectations. Furthermore, the observations made during data collection allowed to suggest improvements to be addressed in future works.