Smart Wheelchair Controls System Using Intelligent Algorithm and Biosensor Signal
Authors: Plaza Mauricio , Bernal Fredy , Chacon Yeison Fernel 
Published: May 2020

Introduction

Quadriplegia caused by spinal cord injury can occur in people of any age range and can be caused by any etiology (traumatic or no traumatic) and directly affects both motor and sensory neurological functions. The aim of this research project is developing a control device for an electric wheelchair for mobility of people with spinal cord injury) in closed or controlled environments, with quadriplegia (very limited mobility or complete immobility of upper and lower limbs. Specifically, the system takes the head position data (head tracking) of the user supplied by a webcam and through an application developed on a Raspberry PI3 single board computer finally, the system generates the movement of the wheelchair depending on the position and movement of the user's head through an electromechanical system with servomotors using intelligent algorithm. The system was tested on 10 immobilized people with upper and lower limbs obtaining a learning response between 1 and 5 minutes, the device is fully portable and adaptable to any electric wheelchair with joystick control. The developed device worked successfully and was compared with other head control devices for electric wheelchairs in the current market, it is, economical and versatile non-invasive system as a solution for mobility autonomy for people with quadriplegia.

Keywords: Quadriplegia, Spinal Cord Injurie, Head tracking, Raspberry PI3, Joystick, Servomotors, intelligent algorithm

Method

During the research process, the importance of the assistive devices has been evidenced as a fundamental component of the rehabilitation, autonomy and improvement of the quality of life. More than 90% of people with spinal cord injuries require some type of wheelchair. These chairs should be appropriate for the needs and limitations of patients and to navigate properly in their environment. Other possible needs for assistive technology are home modifications for home control and communication systems for people with quadriplegia.

For the development of the prototype, a Raspberry PI3 with 7-inch LCD touch screen was used. The necessary peripherals for the correct operation are connect at development card for the operation of the electric wheelchair control, using algorithms that ensure the correct operation of the device in adverse conditions for the user. In the final phase of development, a user interface was programmed in Python. The software is user friendly and intuitive for quadriplegic users. The system sends the control signal to the motors according to the instructions indicated by the user. The algorithm process the instruction and signal to guarantees the integrity of the user in advance condition.

Results and Conclusions

Control system for translation devices using cephalic tracking used for mobility of people in tetraplegia or quadriplegia condition is an option for self-mobility and given to the user autonomy and better quality of life in closed or controlled spaces.
The tests carried out during the current research resulted in a low rate crash on the way obstacles and low deviation from the original trajectory, less than 7% for a user learning time between 1 and 6 minutes.
The proposed system differ from the other cephalic tracking developments reviewed in the state of the art, with effective autonomy by the use of control algorithms

References

Wolters Kluwer "ISCOS - Textbook on comprehensive management of spinal cord injuries ". Harvinder Singh Chhabra. New Delhi, India. ISBN: 9351294404. 2005.
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