EMG-Based Hand-Wrist Control: Study B Mirrored

NCT04692571 | Completed Early Phase 1

• 3 other identifiers: 124039IRB-17-1555R42HD076519-03
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 2

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

Conditions

Amputation; Amputation; Traumatic, Hand; Amputation, Congenital; Prosthesis User

Keywords

prosthesis; electromyography; EMG; sEMG; control; myo; regression; transradial; terminal device; electrodes

Outcome Measures

Primary Outcomes (1)

• EMG-Force Models

  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.

  1 day visit

Study Arms (2)

Study B: Limb-Absent Subject

EXPERIMENTAL

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).

Device: PSICON Measurement Apparatus

Study B: Able-bodied Subjects

EXPERIMENTAL

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.

Device: PSICON Measurement Apparatus

Interventions

PSICON Measurement Apparatus DEVICE

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.

Also known as: load cell, electrode array

Study B: Able-bodied Subjects; Study B: Limb-Absent Subject

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Limb-absent subjects: unilateral trans-radial limb absence or amputation
• Be capable of completing the requested contractions on the affected dominant side

You may not qualify if:

• 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

Sponsors & Collaborators

• Liberating Technologies, Inc.: lead
• Worcester Polytechnic Institute: collaborator
• Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD): collaborator

Study Sites (2)

Liberating Technologies, Inc

Holliston, Massachusetts, 01746, United States

Location

Worcester Polytechnic Institute

Worcester, Massachusetts, 01609, United States

Location

MeSH Terms

Conditions

Amputation, Congenital

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Transradial limb-absent vs able-bodied subjects tested in sequence.

Study Record Dates

• First Submitted: December 28, 2020
• First Posted: January 5, 2021
• Study Start: June 29, 2017
• Primary Completion: August 24, 2020
• Study Completion: August 24, 2020
• Last Updated: January 5, 2021

Record last verified: 2020-12

Locations

US (2)