Somatosensory feedback improves operability of extra robotic thumb controlled by vestigial muscles

Human augmentation by wearable supernumerary robotic limbs: review and perspectives

“…Feedback. Tactile feedback through electrical stimulation to the opposite thumb [49,50,52], head mounted display to relay position information [50], vibrotactile feedback on the back of the hand wearing the device [51]. Soft-SixthFinger (2016), Hussain et al [53] Underactuated device with 1 DoA for the flexion of 7 joints, tendon driven, modular structure with rigid links and flexible joints.…”

“…Meraz et al [50] and Shikida et al [51] proposed the use of sEMG signals from posterior auricularis muscles to control an extra thumb. In particular, signals coming from the muscles behind both ears are used to control either the planar position of the fingertip [50] or the rotation of the base joint of the finger [51]. Posterior auricularis muscles are sometimes not easy to activate, but are suitable for the control of an extra limb because they are vestigial muscles without a predefined functionality.…”

“…In [49,52], tactile feedback through an electrical stimulation device worn on the opposite thumb was used to convey information about the force exerted at the tip of the robotic finger. In [50], a head mounted display was employed to relay information about the position of the thumb, whereas in [51] authors proposed to stimulate the back of the augmented hand with vibrotactile feedback according to the change of the base joint angle.…”

“…Control. Based on tracking data from the thumb of the opposite hand [49] or through EMG from auricularis muscles [50,51]. Feedback.…”

“…Meraz et al [50] and Shikida et al [51] proposed the use of sEMG signals from posterior auricularis muscles to control an extra thumb. In particular, signals coming from the muscles behind both ears are used to control either the planar position of the fingertip [50] or the rotation of the base joint of the finger [51].…”