EMG-Based Hand-Wrist Control: Study B Mirrored (PSICON-B)
Amputation, Amputation; Traumatic, Hand, Amputation, Congenital
About this trial
This is an interventional basic science trial for Amputation focused on measuring prosthesis, electromyography, EMG, sEMG, control, myo, regression, transradial, terminal device, electrodes
Eligibility Criteria
Inclusion Criteria:
- Limb-absent subjects: unilateral trans-radial limb absence or amputation
- Be capable of completing the requested contractions on the affected dominant side
Exclusion Criteria:
- Past injuries to the upper limbs that would limit their ability to complete the requested contractions
- Scars that would impede the use of surface electrodes
Sites / Locations
- Liberating Technologies, Inc
- Worcester Polytechnic Institute
Arms of the Study
Arm 1
Arm 2
Experimental
Experimental
Study B: Limb-Absent Subject
Study B: Able-bodied Subjects
Ten unilateral transradial limb-absent subjects will each participate in one, half-day experimental session. Subjects will be seated and prepared in test apparatus seat (16 electrodes on the affected side, hand-wrist on the able side secured to load cells). Subjects will complete the 1-DoF and 2-DoF "dynamic" (force-varying) contractions (40-s duration, 0.75 Hz bandlimited, uniform random target). With 2 DoF contraction trials, hand Opn-Cls will always be one of the dimensions. The subject will then be released from the cuff and their able side not further involved in the experiment. The force feedback triangle cursor on the computer screen will be deleted such that only the target remains. Subjects will then repeat 1-DoF and 2-DoF trials in which the affected side attempts to produce hand-wrist effort that mimic movement of the target (with no feedback provided).
Ten able-bodied subjects, the electrodes will be mounted on the dominant arm for the EMG-force and EMG-target tracking trials. In addition, the non-dominant arm will also be constrained and measured in a second load cell. This load cell will not be used for feedback during the experiment, but will compare (RMS error, off-line) the dominant vs. non-dominant forces. For EMG-target tracking, the dominant hand will remain in the wrist cuff (to prevent flailing during contractions), with the screen feedback disabled. These subjects will repeat the trials with the electrodes moved to the non-dominant side. EMG-force tracking will be repeated using mirrored contractions. The three training methods (EMG-force ipsilateral, EMG-force contralateral mirrored, EMG-target on the dominant side) will be contrasted to help understand the source of errors when training with limb-absent subjects.