Fig. 2: Data collection, image formation and augmentation.

a Ten passive reflective markers were positioned on the right arm of each participant. Four markers belonged to a upper arm cluster, two markers at the elbow on the styloid process of ulna and styloid process of radius, two markers at the wrist on the medial epicondyle and lateral epicondyle, and two at the hand on the head of the metacarpal bone of the middle finger and head of proximal phalanx of the middle finger. Data was collected with the bracelet at three distinct positions and 4 different rotations. b Raw A-mode multi-receive data from each circle of 16 transducers was collected and processed into a collection of 16 A-mode images per frame. c Examples of a non-augmented frame and the same frame augmented with the 6 proposed methods. From top to bottom and left to right, artificial clockwise rotation of channels, zeroing of random continuous amounts of A-mode data, zeroing of transmissions, zeroing of channel recordings, lateral right shift of shots, lateral shift to the left of shots.