Fig. 7

Application of closed-loop (CL)-SCS in freely behaving animals. A An example of open-loop (OL)-SCS vs. CL-SCS in a freely behaving SNI SCS-ON animal. B The frequency distribution of the measured evoked compound action potential (ECAP) amplitude and delivered current during 30 min of CL-SCS in an SNI SCS-ON animal (animal number two (#2)). The target amplitude was set at 0.1495 mV for this animal. The mean measured ECAP amplitude value was 0.1500 ± 0.0001 mV. Values followed a normal distribution around the target value (left panel). The current varied between 0.029 mA and 0.049 mA (right panel). The dash-dotted lines represent the motor threshold (MT; 0.6507 mV, 0.060 mA) and the dotted line represents the extrapolated ECAP threshold (ECAPT; 0.014 mA). C Frequency distributions of the difference between measured and target ECAP amplitude for each sham SCS-ON and SNI SCS-ON animal. D Frequency distributions of the difference between measured current and ECAPT for each sham SCS-ON and SNI SCS-ON animal. Current and amplitude values three standard deviations above or below the mean were considered outliers and were excluded from the analysis. SNI: spared nerve injury