Design and simulation of wheel-chaired elliptical stepping exercise for stroke rehabilitation

Stroke disease is one of the major killer diseases worldwide and most of the survivors will end with certain level of impairment. They commonly are wheelchair bounded and require scheduled rehabilitation exercise to regain their walking capability or mobility. This paper presents the design of elliptical stepping exercise ergometer for functional electrical stimulation (FES) assisted exercise. The concept of wheel-chaired cycling and elliptical stepping had been adapted in producing the ergometer design. The dynamic simulation has been performed on Visual Nastran 4D and Matlab Simulink to evaluate the performance of the exercise that includes the exercise ergometer, humanoid model and quadriceps muscle model. In the simulation work, the paretic leg (left side) is driven via FES-assisted while the non-paretic leg (right side) is driven via controlled knee joint torque. The result shows that the FES-assisted elliptical stepping exercises with voluntary non-paretic movement contribute better cadence speed control. Further improvement on the controller design is required to make sure suitable FES pattern can be delivered and better cadence speed control can be achieved in simulation environment as well as real implementation.