Design and Prototyping of a Haptic User Interface based on Head Movements for Patients with Cervical Spinal Cord Injury

Individuals with high levels of disability like patients with cervical spinal cord injury, are highly dependant on their relatives for daily life needs. Hence, this problem decreases the quality of life of this individuals and their relatives. New technologies such as robotics have the potential to help these kind of patients and give them some degree of independence. The first step in design and implementation of robots which have the capability of helping disabled people is to design a user interface that can receive user’s commands and transfer these commands into the robot environment. In this paper, a haptic user interface has been designed and implemented to serve patients with cervical spinal cord injury. In this user interface, user’s head angles have been extracted using a gyroscope sensor and then transferred into the computer simulation environment in which the robotic arm is graphically simulated and the user can control the arm using his/her head movements through a novel control pattern. A haptic unit has also designed and implemented to produce resistive torques against head movements to help user to physically sense the weight of gripped objects and the collision of the robotic arm with obstacles. The performance of haptic user interface evaluated using three sets of tests subject to two healthy individuals. Finally, obstacle collision detection tests was 100 percent successfully while heavy and light object recognition tests were 83 percent and heavy, medium and light object recognition tests were 72 percent successful.