The research team, Gil Weinberg, Minoru Shinohara, Chris Fink, and Levent Degertekin, have been working with amputee Jason Barnes, a musician, to develop a prosthetic hand based on Open Bionics’ open source design that can move each finger individually. Instead of electromyogram (EMG), they used Ultrasound to detect muscle movements which allowed them to create prosthetic that could move each finger individually.

Source: http://www.news.gatech.edu/2017/12/11/force-strong-amputee-controls-individual-prosthetic-fingers