Myoelectric Channel Configurations for Below Elbow Amputation

Recruiting at 1 trial location

Overseen By Craig Kelly

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Liberating Technologies, Inc.

Disqualifiers: Cognitive impairment, Significant new injury

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 5

Duration: 5 weeks

32 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine how different configurations of myoelectric (muscle signal) sensors affect the use of prosthetic arms for individuals who have lost a limb below the elbow. The study will test various numbers and placements of these sensors to identify which configurations improve task performance. Suitable participants should have lost a limb below the elbow, have prior experience with a myoelectric prosthetic, and be capable of using a prosthetic with various hand and wrist functions. As an unphased trial, this study provides participants the opportunity to contribute to innovative research that could enhance prosthetic technology for future users.

Do I need to stop my current medications for this trial?

The trial information does not specify whether you need to stop taking your current medications. It is best to discuss this with the trial coordinators or your doctor.

What prior data suggests that these myoelectric channel configurations are safe for individuals with transradial limb loss?

In a previous study, researchers found that using more myoelectric channels can improve control in prosthetic limbs without causing harm. Specifically, increasing the number of EMG (electromyography, which measures muscle signals) channels did not lead to any reported negative effects on the limb. This is encouraging for those considering joining a trial that uses these channels.

For the different socket setups being tested in this trial—whether with 4, 8, or up to 16 channels—no evidence of harm has been found from using these configurations. The focus is on identifying the best setup for control and performance. The trial explores different numbers of channels and their placement to determine what works best for users.

Although this trial is not officially a safety study, previous research suggests the myoelectric channel setups being tested are safe and well-tolerated. For potential participants, this means the technology has been used before without causing problems. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the different myoelectric channel configurations for below elbow amputation because they offer new ways to enhance prosthetic control. Unlike traditional prosthetics that primarily use a limited number of electrodes to capture muscle signals, these experimental sockets explore using up to 16 channels, both targeted and untargeted, to capture more detailed muscle activity. Specifically, the use of targeted channels, as in the 8-channel targeted configuration, allows for more precise identification of muscle signals, potentially improving the functionality and user experience of the prosthetic. By evaluating different channel configurations, this approach could lead to more intuitive and responsive prosthetics, offering amputees better control and comfort.

What evidence suggests that these myoelectric channel configurations are effective for improving prosthesis function in individuals with transradial limb loss?

Research has shown that using more myoelectric channels can improve control of prosthetic limbs. In this trial, participants will experience different conditions to test various channel configurations. For example, using 8 or more channels, as tested in Conditions B, C, and D, can enhance the natural and precise movement of a prosthesis. This improvement may help users perform better on tasks like the Box and Blocks test, which assesses hand coordination. Additionally, placing electrodes in specific spots based on clinical advice, as in Condition D, can enhance signal detection accuracy. Early findings suggest that more channels, especially when well-positioned, lead to better performance and greater user satisfaction. ^{2 4 6 7 8}

Who Is on the Research Team?

Todd Farrell, PhD

Principal Investigator

Liberating Technologies, Inc.

Are You a Good Fit for This Trial?

This trial is for individuals aged 18 or older who have lost an arm below the elbow, either from birth or due to injury. Participants must be able to attend multiple lab sessions and commit to playing virtual games regularly with a special cuff.

Inclusion Criteria

I can use a prosthetic arm with a rotating wrist and moving hand.

I am missing one arm at the forearm level.

My prosthetic socket fits well, with a comfort score of 6 or above.

Exclusion Criteria

Significant new injury that would prevent use of a prosthesis

I understand and can follow the study's requirements.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo randomized crossover study with different EMG channel conditions and complete functional outcome measures

5 weeks

5 visits (in-person)

At-home Practice

Participants practice pattern recognition control using the Coapt Cuff and virtual games

1-2 weeks between visits

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Experimental socket with 4 untargeted channels active
• Experimental socket with 8 targeted channels active
• Experimental socket with 8 untargeted channels active
• Experimental socket with up to 16 untargeted channels active

Trial Overview The study tests different prosthetic sockets with varying numbers of myoelectric channels (4, 8, up to 16) that detect muscle signals in the residual limb. It also compares targeted vs. untargeted sensor placement on prosthesis control through tasks like the Box and Blocks test.

How Is the Trial Designed?

Group I: Condition C: Up to 16 untargeted channels Experimental Treatment 1 Intervention

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.

Group II: Condition B: 8 untargeted channels Experimental Treatment 1 Intervention

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.

Group III: Condition A: 4 untargeted channels Experimental Treatment 1 Intervention

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.

Group IV: At-home Pattern Recognition Practice Experimental Treatment 1 Intervention

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.

Group V: Condition D: 8 targeted channels Active Control 1 Intervention

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.

Who Is Running the Clinical Trial?

Liberating Technologies, Inc.

Lead Sponsor

Trials

13

Recruited

100+

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12370269/

Evidence-Generated Sockets for Transtibial Prosthetic ... In total, 6 EG sockets were rated as more comfortable than the CAD/CAM control, by between 2.0 and 3.5 points; 4 EG sockets demonstrated lower ...

2. ctv.veeva.com ctv.veeva.com/study/effects-of-myoelectric-channel-count-and-targeting-for-upper-limb-prosthetic-control

Effects of Myoelectric Channel Count and Targeting for Upper ... The specific aims of this study are: To evaluate the effect of changing untargeted myoelectric channel count on the functional performance of ...

3. centerwatch.com centerwatch.com/clinical-trials/listings/location/united-states/MA/Holliston

Holliston, Massachusetts Clinical Research Trials Untargeted sites, for the second socket, will ideally be located by creating a band of electrode pairs at the largest muscular circumference distal to the elbow ...

4. oandplibrary.org oandplibrary.org/al/pdf/1964_02_004.pdf

The Munster-Type Below-Elbow Socket, an Evaluation The sample in this study consisted of eight adult below-elbow amputee subjects (includ- ing one bilateral amputee) whose stumps were relatively short—from 3-1/4 ...

5. clinicaltrials.gov clinicaltrials.gov/study/NCT04725461

NCT04725461 | Low Cost Socket for Lower Limb Amputees Unilateral transtibial amputees having had their amputation at least 6 months prior, so that they have a relatively stable conical residual limb shape and can ...

6. withpower.com withpower.com/trial/phase-amputation-traumatic-arm-forearm-between-elbow-and-wrist-6-2025-292bb

Myoelectric Channel Configurations for Below Elbow ... This N/A medical study run by Liberating Technologies, Inc. is evaluating whether Experimental socket with 4 untargeted channels active, Experimental socket ...

7. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/4000912/

Experimental fittings of sockets for below-knee amputees ... The experiments showed that it is possible to successfully design a socket using a computer based socket model. Variability of results, however indicates ...

8. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9397974/

The Impact of Limited Prosthetic Socket Documentation In this article, the concerns, issues and consequences arising from lack of upper and lower limb socket documentation are discussed from a researcher ...