Fig. 3

Representative trial to illustrate prosthesis control. The plot shows the traces for flexor (blue) and extensor EMG (purple), grasping force (red), prosthesis aperture (yellow), and EMG feedback level (dotted black line). The thresholds defining the levels are indicated as continuous thin black lines. The touch onset and opening command (trigger) are represented by the vertical red lines. The feedback signal (dotted black line) was conveyed to the participants online using vibration patterns defined in Fig. 2A.