Amputation, Amputation, Congenital, Amputation; Traumatic, Hand, Prosthesis User
Conditions
Keywords
prosthesis, electromyography, EMG, sEMG, control, myo, regression, transradial, terminal device, electrodes
Brief summary
Study assessing four-channel prosthesis controller, that compares contralateral (mirrored) EMG-force training to ipsilateral EMG-target training with both limb-absent and able-bodied subjects
Detailed description
System identification models relating forearm electromyogram (EMG) signals to phantom wrist radial-ulnar deviation force, pronation-supination moment and/or hand open-close force (EMG-force) are hampered by lack of supervised force/moment output signals in limb-absent subjects. In able-bodied and unilateral transradial limb-absent subjects, we studied three alternative supervised output sources in one degree of freedom (DoF) and 2-DoF target tracking tasks: (1) bilateral tracking with force feedback from the contralateral side (non-dominant for able-bodied/ sound for limb-absent subjects) with the contralateral force as the output, (2) bilateral tracking with force feedback from the contralateral side with the target as the output, and (3) dominant/limb-absent side unilateral target tracking without feedback and the target used as the output.
Interventions
DEVICEPSICON Measurement Apparatus
Test apparatus acquires 16 sEMG channels, measure four DoFs of force/moment at the hand-wrist \[hand open-close (Opn-Cls); wrist extension-flexion (Ext-Flx), radial-ulnar deviation (Rad-Uln) and pronation-supination (Pro-Sup)\]. sEMG system used 16 custom encased bipolar electrodes. A commercial LTI EMG amplifier (BE328) conditioned each EMG signal before A/D conversion on a PC. A thermoplastic hand cuff secured the wrist to a six-axis load cell (AMTI, model MC3A-100) for force/moment measurement. A separate hand-grasp one-axis load cell (Omega Engineering Inc., model LCR-150) was Velcro-secured between the fingers and the thumb, to measure power grip forces. The PC acquired and stored the sEMG and load cell data, and commanded a triangular screen target. The subject controlled a second triangular cursor. Left-right movement of the cursor was controlled by wrist Ext-Flx, up-down movement by Rad-Uln deviation, cursor rotation by Pro-Sup and cursor size by hand Opn-Cls forces.
Sponsors
Worcester Polytechnic Institute
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Liberating Technologies, Inc.
Study design
Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Transradial limb-absent vs able-bodied subjects tested in sequence.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| EMG-Force Models | 1 day visit | Electromyogram waveform measurements (signal amplitude, frequency) will be related to force measurements (magnitude and moment) as related to the target tracking tasks. These signal-force data will be use to generate the models. The specific outcome for each subject will be the RMS error measured in the tracking tasks as the difference between the generated control signal from the user versus the prompted target signal, as measured by an EMG array. |
Countries
United States
Outcome results
None listed