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EMG-Based Hand-Wrist Control: Study B Mirrored (PSICON-B)

Primary Purpose

Amputation, Amputation; Traumatic, Hand, Amputation, Congenital

Status
Completed
Phase
Early Phase 1
Locations
United States
Study Type
Interventional
Intervention
PSICON Measurement Apparatus
Sponsored by
Liberating Technologies, Inc.
About
Eligibility
Locations
Arms
Outcomes
Full info

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

18 Years - undefined (Adult, Older Adult)All SexesAccepts Healthy Volunteers

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

Arm Type

Experimental

Experimental

Arm Label

Study B: Limb-Absent Subject

Study B: Able-bodied Subjects

Arm Description

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.

Outcomes

Primary Outcome Measures

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.

Secondary Outcome Measures

Full Information

First Posted
December 28, 2020
Last Updated
December 30, 2020
Sponsor
Liberating Technologies, Inc.
Collaborators
Worcester Polytechnic Institute, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
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1. Study Identification

Unique Protocol Identification Number
NCT04692571
Brief Title
EMG-Based Hand-Wrist Control: Study B Mirrored
Acronym
PSICON-B
Official Title
EMG-Based Hand-Wrist Control: Study B: Comparison of Contralateral (Mirrored) EMG-
Study Type
Interventional

2. Study Status

Record Verification Date
December 2020
Overall Recruitment Status
Completed
Study Start Date
June 29, 2017 (Actual)
Primary Completion Date
August 24, 2020 (Actual)
Study Completion Date
August 24, 2020 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Liberating Technologies, Inc.
Collaborators
Worcester Polytechnic Institute, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Product Manufactured in and Exported from the U.S.
No
Data Monitoring Committee
No

5. Study Description

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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Amputation, Amputation; Traumatic, Hand, Amputation, Congenital, Prosthesis User
Keywords
prosthesis, electromyography, EMG, sEMG, control, myo, regression, transradial, terminal device, electrodes

7. Study Design

Primary Purpose
Basic Science
Study Phase
Early Phase 1
Interventional Study Model
Sequential Assignment
Model Description
Transradial limb-absent vs able-bodied subjects tested in sequence.
Masking
None (Open Label)
Allocation
Non-Randomized
Enrollment
20 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Study B: Limb-Absent Subject
Arm Type
Experimental
Arm Description
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).
Arm Title
Study B: Able-bodied Subjects
Arm Type
Experimental
Arm Description
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.
Intervention Type
Device
Intervention Name(s)
PSICON Measurement Apparatus
Other Intervention Name(s)
load cell, electrode array
Intervention Description
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.
Primary Outcome Measure Information:
Title
EMG-Force Models
Description
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.
Time Frame
1 day visit

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
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
Facility Information:
Facility Name
Liberating Technologies, Inc
City
Holliston
State/Province
Massachusetts
ZIP/Postal Code
01746
Country
United States
Facility Name
Worcester Polytechnic Institute
City
Worcester
State/Province
Massachusetts
ZIP/Postal Code
01609
Country
United States

12. IPD Sharing Statement

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EMG-Based Hand-Wrist Control: Study B Mirrored

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