Novel wearable armband helps users of prosthetic hands to ‘get a grip’
Typing on a keyboard, pressing buttons on a remote control or braiding a child’s hair has remained elusive for prosthetic hand users. With current myoelectric prosthetic hands, users can only control one grasp function at a time even though modern artificial hands are mechanically capable of individual control of all five digits.
A first-of-its-kind study using haptic/touch sensation feedback, electromyogram (EMG) control and an innovative wearable soft robotic armband could just be a game changer for users of prosthetic hands who have long awaited advances in dexterity. Findings from the study could catalyze a paradigm shift in the way current and future artificial hands are controlled by limb-absent people.
Researchers from Florida Atlantic University’s College of Engineering and Computer Science in collaboration with FAU’s Charles E. Schmidt College of Science investigated whether people could precisely control the grip forces applied to two different objects grasped simultaneously with a dexterous artificial hand.
For the study, they also explored the role that visual feedback played in this complex multitasking model by systematically blocking visual and haptic feedback in the experimental design. In addition, they studied the potential for time saving in a simultaneous object transportation experiment compared to a one-at-a-time approach. To accomplish these tasks, they designed a novel multichannel wearable soft robotic armband to convey artificial sensations of touch to the robotic hand users.
Results, published in Scientific Reports, showed that multiple channels of haptic feedback enabled subjects to successfully grasp and transport two objects simultaneously with the dexterous artificial hand without breaking or dropping them, even when their vision of both objects was obstructed.
In addition, the simultaneous control approach improved the time required to transport and deliver both objects compared to a one-at-a-time approach commonly used in prior studies. Of note for clinical translation, researchers did not find significant differences between the limb-absent subject and the other subjects for the key performance metrics in the tasks. Importantly, subjects qualitatively rated haptic feedback as considerably more important than visual feedback even when vision was available, because there was often little to no visually perceptible warning before grasped objects were broken or dropped. More