Surface electromyography signals - finger_position
Six subjects, healthy able-bodied (three men, three women) aged 20-24 participated in the study and were instructed to grasp five spheres randomly. The spheres are made of expanded polystyrene (negligible weight) with different diameters. Volunteers are seated comfortably and perform the requested fastening of a sphere D_i (i = 1, ..., 3). Electrodes are placed on five muscles of volunteers known as superficial muscles: flexor carpi radialis, flexor carpi ulnaris, flexor pollicis longus, flexor digitorum profundus, and extensor digitorum. The results of experiments are shown as F1, F2, and F3 for females and M1, M2 and M3, for males. This is research in progress where we are developing a new approach to distinguish finger positions with very low mechanical fluctuations. The study uses electromyographic data, which is recorded while the hand of subjects is constricted to grasp a set of spheres with a small variation in diameter. The experiment is organized in batches; each subject performed a batch, which is established as the grasps of three spheres randomly with a span of six seconds between each grasp. A relaxing period of twenty seconds between batches is introduced to avoid muscular fatigue. Subjects are prompted to perform six batch repetitions. In order to synchronize the task of grasping and the recording of signals, subjects are trained to introduce a short contraction at the beginning and at the ending of grasping each sphere which is triggered by an auditory cue. Data was obtained with Trigno Wireless System (Delsys).