Secondary analysis will assess noninferiority of the bolus to the basal infusion method on mean tolerance to cutaneous current across all time points measured, using a noninferiority delta of 10 mA as above. In this repeated measures setting, noninferiority will be assessed in the context of a linear mixed model adjusting for the within-subject correlation (using an auto-regressive correlation structure).16 If the time-by-group interaction is non-significant (P>0.20) we will assess noninferiority collapsing over time and constructing a 1-tailed t-test (using noninferiority delta of 10 mA) based on the model-based treatment effect for bolus versus basal infusion. In presence of a group-time interaction noninferiority will be assessed separately at each time point and a Holm-Bonferroni correction made for multiple comparisons to maintain the hypothesis-wise type I error at 0.025.