Summary of chronic stimulation cohort.

Stimulation mode was monopolar. Stimulation was delivered using biphasic charge balanced rectangular current pulses (phase width: 400 µs; interphase gap: 20 µs). The maximum current denotes the stimulation level at the culmination of the ramp-up period (refer Figure 1). Charge density per phase was calculated by using the stimulation phase width of 400 µs per phase and the geometric electrode surface area of 0.2827 mm2. Electrode utilisation, expressed as “X|Y|Z” denotes the number of electrodes that were stimulated maximally during the stimulation period (X); the number of electrodes that were partially stimulated, either at lower levels or for an incomplete subset of the stimulation duration (Y); and the number of unstimulated controls on the array (Z). The lead system was damaged during subject 505’s implantation; therefore it was only stimulated for 18 days (asterisk) before being disconnected from the stimulator.