Table 1.
Motor unit, EMG signal, and noise properties for the sleeve and HDEMG patch arrays
| Task | Number of Identified Motor Units, # |
Pulse-to-Noise Ratio (Means ± SD) |
MUAP Amplitude, μVPP (Means ± SD) |
Baseline Voltage, μVRMS (Means ± SD) |
||||
|---|---|---|---|---|---|---|---|---|
| Sleeve Array | HDEMG Patch | Sleeve Array | HDEMG Patch | Sleeve Array | HDEMG Patch | Sleeve Array | HDEMG Patch | |
| Thumb flex/ext | 1 | 4 | 45.3 ± 0 | 45.3 ± 6.9 | 417.7 ± 0 | 231.6 ± 128.6 | 46.6 ± 15.9 | 8.8 ± 3.6 |
| Index flex/ext | 5 | 2 | 34.6 ± 5.4 | 49.7 ± 3.3 | 473.0 ± 57.4 | 146.1 ± 90.2 | 43.7 ± 14.4 | 9.9 ± 4.7 |
| Middle flex/ext | 3 | 3 | 31.6 ± 4.4 | 42.6 ± 13.3 | 455.4 ± 124.5 | 108.0 ± 91.7 | 43.2 ± 14.2 | 9.7 ± 4.3 |
| Ring flex/ext | 3 | 5 | 44.2 ± 8.6 | 34.8 ± 9.6 | 439.1 ± 27.5 | 145.5 ± 80.2 | 46.9 ± 15.8 | 10.1 ± 4.6 |
| Pinky flex/ext | 3 | 3 | 27.9 ± 7.0 | 46.8 ± 16.6 | 438.4 ± 24.6 | 123.9 ± 75.9 | 47.1 ± 16.2 | 7.1 ±2.8 |
| Wrist flex/ext | 7 | 6 | 30.8 ± 2.4 | 37.8 ± 14.4 | 476.4 ± 86.1 | 191.2 ± 104.0 | 50.6 ± 14.8 | 12.0 ± 4.9 |
| Forearm pro/sup | 4 | 3 | 33.6 ± 6.6 | 42.9 ± 10.8 | 569.4 ± 61.7 | 239.1 ± 111.0 | 55.6 ± 28.5 | 15.7 ± 7.3 |
| Elbow flex/ext | 5 | Not tested | 33.6 ± 3.9 | Not tested | 522.6 ± 33.6 | Not tested | 47.1 ± 14.5 | Not tested |
| Avg. | 3.9 ± 1.8 | 3.7 ± 1.4 | 35.2 ± 4.8 | 42.8 ± 10.7 | 474.0 ± 51.9 | 169.3 ± 97.4 | 47.6 ± 16.8 | 10.5 ± 4.6 |
The total number of motor units identified during each task are reported when the sleeve array (150 electrodes) and the high-density electromyography (HDEMG) patch (one 64-channel array on dorsal aspect) were used to record electromyogram (EMG). Only data from the HDEMG patch on the extensor side of the forearm is reported here. The pulse-to-noise ratio (PNR) is an estimate of the signal-to-noise ratio of the extracted motor units. The motor unit action potential (MUAP) amplitude for each unit is taken from the average of all waveforms associated with that unit detected during a particular task. The PNRs and MUAP amplitudes are reported as the mean and standard deviation across the motor units identified during each task. The baseline voltage was sampled during “rest” periods where the participant was instructed to relax his arm. The baseline voltage is reported as the mean and standard deviation of the root-mean-square (RMS) voltages taken across all electrodes in the sleeve array or patch. Boldface indicates the average value of each column.