Effects of Myoelectric Channel Count and Targeting for Upper Limb Prosthetic Control

NCT07011420 | Recruiting FDA Device

• 1 other identifier: 00171879
• Study Type: interventional
• Target: 32
• Locations: 1 country
• Sites: 2

Brief Summary

The goal of this clinical trial is to systematically evaluate whether or not two commonly held fundamental assumptions for pattern recognition control translates to functional performance when tested on individuals aged 18 years or older with upper limb absence at the transradial level while wearing a physical prosthesis. The specific aims of this study are:

• Attend up to 5 in-lab sessions that are expected to last 4 hours.
• Conduct site visits every 1-2 weeks to complete functional and self reported outcome measures with each condition.
• Play virtual games with the Coapt Cuff for 15 minutes a day, 3 days a week in between visits.

Conditions

Amputation; Amputation, Traumatic; Amputation, Congenital; Prosthesis User; Upper Limb Amputation Below Elbow (Injury); Amputation; Traumatic, Arm: Forearm, Between Elbow and Wrist

Keywords

amputee; upper limb amputee; transradial amputee; prosthetic arm; upper limb prosthesis user

Outcome Measures

Primary Outcomes (1)

• The Assessment of Capacity for Myoelectric Control (ACMC)

  The ACMC is a performance-based assessment where trained raters observe the user performing a task and rate their ability to control specific hand movements. These movements are rated on a 4-point scale, ranging from "not capable" to "spontaneously capable". 0 = Not capable. 1 = Sometimes capable, capacity not established. 2 = Capable on request. 3 = Spontaneously capable. The items comprising the ACMC describe different levels of difficulty of control of the myoelectric hand. The items are grouped into 4 categories: gripping, holding, releasing, and coordinating between hands. The task that will be done for our study is packing a suitcase for a weekend trip. A higher score corresponds with a greater ability to control a myoelectric hand. This assessment will be done for each condition, each of which will be tested in visits 2-5.

  4 hours

Study Arms (5)

Condition A: 4 untargeted channels

EXPERIMENTAL

The 4-channel untargeted condition (Condition A) will utilize every fourth channel, and their location will be targeted at positions that are 'on the 45s' when examining a cross section of the forearm with the elbow bent to 90 degrees and the thumb pointed up. This condition is conducted and completed during a site visit. Outcome measures will be conducted to assess functional outcomes and self-report measures.

Device: Experimental socket with 4 untargeted channels active

Condition B: 8 untargeted channels

EXPERIMENTAL

The 8-channel condition (Condition B) will use the same channels as the 4-channel condition but add the four channels that bisect the original four channels. This condition is conducted and completed during a site visit. Outcome measures will be conducted to assess functional outcomes and self-report measures.

Device: Experimental socket with 8 untargeted channels active

Condition C: Up to 16 untargeted channels

EXPERIMENTAL

The 16-channel untargeted condition (Condition C) will utilize all 16 electrodes. Due to different limb sizes a full singular ring of 16 channels may not be possible on all human subjects. In these situations, the clinicians fabricating will use their best clinical judgement in order to fit as many electrode channels as possible onto the arm. If there is no reasonable way to fit 16 channels within the socket, then the maximum possible number of channels will be placed in the socket and the "16-channel" condition will be completed with the maximum number of available channels. This condition is conducted and completed during a site visit. Outcome measures will be conducted to assess functional outcomes and self-report measures.

Device: Experimental socket with up to 16 untargeted channels active

Condition D: 8 targeted channels

ACTIVE COMPARATOR

This socket will use 8 targeted EMG channels identified and marked by the study prosthetist using Coapt's clinical instructions for identifying electrode sites. This condition is conducted and completed during a site visit. Outcome measures will be conducted to assess functional outcomes and self-report measures.

Device: Experimental socket with 8 targeted channels active

At-home Pattern Recognition Practice

OTHER

The subject will use a commercially available EMG Coapt Cuff to practice pattern recognition while at home between study visits. They will be asked to play virtual games with the Coapt Cuff for 15 minutes a day, 3 days a week in between visits. The time between visits will be based on scheduling availability of the participant and study team but is expected to be approximately 1-2 weeks.

Device: Coapt EMG Cuff

Interventions

Experimental socket with 4 untargeted channels active DEVICE

Participants will utilize the experimental socket made with untargeted EMG channels. Untargeted sites will ideally be located by creating a band of electrode pairs at the largest muscular circumference distal to the elbow. Only 4 channels will be active during this condition.

Condition A: 4 untargeted channels

Experimental socket with 8 untargeted channels active DEVICE

Participants will utilize the experimental socket made with untargeted EMG channels. Untargeted sites will ideally be located by creating a band of electrode pairs at the largest muscular circumference distal to the elbow. Only 8 channels will be active during this condition.

Condition B: 8 untargeted channels

Experimental socket with up to 16 untargeted channels active DEVICE

Participants will utilize the experimental socket made with untargeted EMG channels. Untargeted sites will ideally be located by creating a band of electrode pairs at the largest muscular circumference distal to the elbow. All16 channels (or the maximum number of channels based on limb size) will be active during this condition.

Condition C: Up to 16 untargeted channels

Experimental socket with 8 targeted channels active DEVICE

Participants will utilize the experimental socket made with targeted EMG channels. This socket will follow Coapt's clinical instructions for targeted site location to identify and mark locations for 8 targeted EMG channels.

Condition D: 8 targeted channels

Coapt EMG Cuff DEVICE

This device is the commercially available Coapt EMG Cuff. This armband cuff with electrodes can be strapped onto the user's arm to connect with the Coapt app and play virtual games with their EMG signals.

At-home Pattern Recognition Practice

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Unilateral transradial level limb absence
• Current or past user of myo-electric controlled prostheses
• Six months or more post-amputation
• Have adequate limb length such that a wrist rotation device can fit in the check socket
• Well-fitting socket as determined by a Socket-Comfort Score of 6 or above
• Capable of wearing and operating a prosthesis with a wrist rotator and multi-articulating hand
• Capable of understanding and following multi-step instructions and completing the tasks as described
• English speaking

You may not qualify if:

• Significant new injury that would prevent use of a prosthesis: The ability to consistently wear a prosthesis and perform activities of daily living and specific performance tasks is necessary to evaluate the relative benefits of the interventions.
• Cognitive impairment sufficient to adversely affect understanding of or compliance with study requirements, ability to communicate experiences, or ability to give informed consent: The ability to understand and comply with requirements of the study is essential for the study to generate useable, reliable data. The ability to obtain relevant user feedback through questionnaires and informal discussion adds significant value to this study.

Sponsors & Collaborators

• Liberating Technologies, Inc.: lead

Study Sites (2)

Shirley Ryan AbilityLab

Chicago, Illinois, 60611, United States

RECRUITING

Liberating Technologies, Inc.

Holliston, Massachusetts, 01746, United States

NOT YET RECRUITING

MeSH Terms

Conditions

Amputation, Traumatic; Amputation, Congenital; Wounds and Injuries

Study Officials

• Todd Farrell, PhD

  Liberating Technologies, Inc.

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Brianna Rozell

CONTACT

774-233-0876; brianna.rozell@liberatingtech.com

Craig Kelly

CONTACT

774.233.0878; craig.kelly@liberatingtech.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Researchers will perform a randomized crossover study to compare system configurations with different number of sensor channels and with various strategies for sensor placement on the limb. Participants will be assigned to a random test sequence that includes the following four different EMG channel conditions: Condition A: 4 untargeted channels Condition B: 8 untargeted channels Condition C: Up to 16 untargeted channels Condition D: 8 targeted channels Researchers will evaluate the effects of changing myoelectric channel counts on the functional prosthesis performance of individuals with transradial limb loss via functional outcome measures. Additionally, participants will be asked to play virtual games with the Coapt EMG Cuff for 15 minutes a day, 3 days a week between visits. This arm is meant for practicing pattern recognition control and will not be compared between the other conditions or reported on.

Study Record Dates

• First Submitted: May 15, 2025
• First Posted: June 8, 2025
• Study Start: October 1, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2026
• Last Updated: September 3, 2025

Record last verified: 2025-09

Locations

US (2)