A dual input device for self-assisted control of a virtual pendulum

We are proposing a new approach to rehabilitation robotics for people who have suffered neurological injuries resulting in impaired motor ability in the lower limbs. The central idea being developed in this research project is to design a teleoperated rehabilitation device that allows an incomplete spinal cord injured (SCI) patient to use their upper limbs, i.e. the intact portion of their neurological system, to direct the mechanical assistance of their lower limbs. This paper presents the design of a single axis dual interface apparatus and its connection to a computationally mediated virtual environment. A preliminary experiment was conducted wherein healthy subjects manipulate a virtual pendulum with their hand, feet, or both to track a pseudo-random signal. Results show that the combined efforts of the hand and feet demonstrate improved tracking performance. We now have an apparatus and associated task for which control sharing between the hand and feet yields benefit for healthy subjects. If further experiments with healthy subjects can demonstrate the benefit of a hand-assisted training phase for ultimate performance with feet alone, then we shall test the hypothesis that this hand-assisted phase can accelerate rehabilitation for neurologically injured patients.