Selective characteristic for needle electrode arrays for functional electrical stimulation

Selective characteristic for functional electrical stimulation is very important for restoring lost motor or sensory functions. The stimulation should broadly generate action potentials with a stimulating electrode and simultaneously blocks unnecessary stimulation with given grounded ones. 1-, 2-, 3-, and 5-needle electrode arrays were designed and simulated with finite element software, respectively. Animal experiments were carried out and the validity of the numerical results is demonstrated. Activating function were computed in the aforementioned four cases. The results show that the array with only one grounded electrode provides the best selective activation in the four cases.