Fig. 4
Block thresholds current (left) and power (right) across all nerves, frequencies, and cuff types. A and C Raw block thresholds and polynomial fits to block thresholds as a function of frequency for each cuff type. Shaded areas show the 95% confidence interval of the fits. See Additional file 1: Table S2 for polynomial coefficients. For visualization, data points are offset on the frequency axis by + 0.25 kHz (tripolar) and − 0.25 kHz (monopolar). B and D Block thresholds of all measurements (within-nerve replicates averaged as described in Methods) after removing categorical frequency effect (i.e., after dividing thresholds by corresponding cn coefficients in Eq. 4). Significant differences from bipolar thresholds are denoted by ‘*’. Interaction effects between the tripolar cuff and frequencies greater than 14 kHz are illustrated by plotting the measurements for the tripolar > 14 kHz separately from ≤ 14 kHz. No nerve underwent testing with multiple cuffs