Sensory Feedback Stimulation for Amputees

Overseen By Aarika Sheehan, PT, DPT

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Louis Stokes VA Medical Center

Disqualifiers: Uncontrolled diabetes, Vascular disease, Infections, others

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

Compensation: Varies

Number of Visits: 1

15 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores a new method to help individuals who have lost a lower limb feel sensations in their missing limb again. It uses tiny electrical currents sent to the remaining nerves through implanted electrodes (multi-contact electrode implant) and may also aid in controlling a robotic prosthetic leg. This trial could suit someone who has had a stable leg amputation for over three months and is interested in using a prosthetic leg for walking or standing. As an unphased trial, this study offers participants a unique opportunity to contribute to groundbreaking research in prosthetic technology.

Will I have to stop taking my current medications?

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

What prior data suggests that this technique is safe for amputees?

Research has shown that multi-contact cuff electrodes used in people with amputations are stable and well-tolerated. One study demonstrated that these electrodes functioned consistently over time without causing unexpected problems or discomfort. Other studies have examined similar nerve implants and found them safe and effective for providing sensory feedback, which restores the feeling in the missing limb.

This treatment sends small electrical currents through the implanted electrodes to the remaining nerves. It mimics the natural signals sent to the brain, helping to create a sense of the missing limb. An optional part of the treatment involves placing electrodes in the muscles to help control a robotic leg.

Research supports that these electrode implants are generally safe for use in humans, with no major adverse events reported. This indicates they have been tested and found largely free of serious side effects. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about sensory feedback stimulation for amputees because it offers a unique approach to enhancing prosthetic limbs. Unlike current options, which mainly focus on improving the mechanical aspects of prosthetics, this treatment uses multi-contact electrode implants to deliver electrical signals directly to the nerves in the residual limb. This can potentially restore a sense of touch and improve control over the prosthetic, making it feel more like a natural limb. Additionally, the use of recording electrodes within muscles helps develop a controller for a robotic myoelectric prosthesis, paving the way for more intuitive and responsive artificial limbs.

What evidence suggests that this sensory feedback stimulation is effective for amputees?

Research has shown that special implants with multiple contact points can greatly improve the lives of people who have lost a leg. In this trial, participants will receive multi-contact stimulating nerve cuff electrodes. Studies have found that these electrodes restore natural feeling by sending tiny electrical signals to the remaining nerves, helping the brain receive signals similar to those before the amputation. Additionally, this technology might reduce phantom limb pain, a common issue for amputees. Early evidence also suggests it can aid in controlling robotic limbs, making movement feel more natural. Overall, this approach appears promising for enhancing both sensation and movement for amputees. ^{2 4 6 7 8}

Who Is on the Research Team?

Ronald Triolo, PhD

Principal Investigator

Louis Stokes VA Medical Center

Are You a Good Fit for This Trial?

This trial is for adults over 18 with lower limb amputations who may use prostheses for standing or walking. They must have good nerve function in the remaining limb, stable health, and no severe skin issues. Excluded are those with chronic infections, obesity (BMI > 35), uncontrolled diabetes, balance disorders, significant mental health issues, or a need for MRI during the study.

Inclusion Criteria

My leg nerves respond well to standard tests.

I have had a stable leg amputation above or below the knee for over 3 months.

Exclusion Criteria

I experience significant pain in the part of my body where I had an amputation.

I have arthritis near where my implant is located.

I am not a good candidate for surgery.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Surgical Implantation

Electrodes are surgically implanted on nerves and muscles of the residual limb

1-2 weeks

1 visit (in-person)

Experimental Testing

Participants receive electrical stimulation and engage in functional tasks with the sensory neuroprosthesis

9 months

Regular visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the experimental testing

3 months

What Are the Treatments Tested in This Trial?

Interventions

• Multi contact electrode implant

Trial Overview

The trial tests if stimulating nerves through implanted electrodes can restore sensation to amputees' missing limbs. It also explores whether recording electrodes in muscles can help control a robotic prosthetic leg intuitively.

How Is the Trial Designed?

Group I: Stimulating nerve electrodes & intramuscular recording electrodes Experimental Treatment 1 Intervention

Fifteen subjects with lower limb amputation will have multi-contact stimulating nerve cuff electrodes implanted around the nerves in their residual limb. These electrodes will be connected to temporary percutaneous leads. During experimental testing, a small amount of electrical current will be delivered to the nerves through multi-contact nerve cuff electrodes. Participants also have the option to have recording electrodes implanted within muscles in their lower limb(s). These muscles are associated with prosthetic movement, and recordings from these muscles will be used to develop a controller for a robotic myoelectric prosthesis.

Who Is Running the Clinical Trial?

Louis Stokes VA Medical Center

Lead Sponsor

Trials

21

Recruited

4,100+

United States Department of Defense

Collaborator

Trials

940

Recruited

339,000+

Case Western Reserve University

Collaborator

Trials

314

Recruited

236,000+

Published Research Related to This Trial

Implanted peripheral nerve interfaces provided stable and natural touch sensations in two human subjects with upper limb amputation for over 1 year, demonstrating the potential for long-term sensory restoration.

Electrical stimulation of peripheral nerve cuff electrodes allowed subjects to experience various tactile perceptions, such as tapping and vibration, which improved their ability to control prosthetic grasping strength and manipulate delicate objects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A neural interface provides long-term stable natural touch perception. Tan, DW., Schiefer, MA., Keith, MW., et al.[2022]

The study involved two transfemoral amputees using a neuroprosthetic device that provided sensory feedback through intraneural stimulation, leading to increased walking speed and confidence while reducing mental and physical fatigue.

Participants also experienced a decrease in phantom limb pain when receiving neural sensory feedback, suggesting that restoring sensory information could significantly improve the quality of life for above-knee amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Sensory feedback restoration in leg amputees improves walking speed, metabolic cost and phantom pain. Petrini, FM., Bumbasirevic, M., Valle, G., et al.[2022]

A new leg neuroprosthesis developed for transfemoral amputees successfully provided real-time sensory feedback through nerve stimulation, leading to improved mobility and fall prevention during active tasks.

The study demonstrated that this sensory feedback increased the embodiment of the prosthesis and reduced cognitive effort during tasks, suggesting that integrating sensory feedback can significantly enhance the quality of life for amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Enhancing functional abilities and cognitive integration of the lower limb prosthesis. Petrini, FM., Valle, G., Bumbasirevic, M., et al.[2020]

Vibrotactile stimulation on the upper leg was well perceived by ten healthy subjects, indicating its potential for providing feedback in prosthetic applications.

The study explored various aspects of vibrotactile feedback, including perception at different frequencies and locations, but further research is needed to assess its effectiveness specifically for trans-femoral prostheses.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Vibrotactile stimulation of the upper leg: effects of location, stimulation method and habituation. Wentink, EC., Mulder, A., Rietman, JS., et al.[2020]

A new sensory feedback system using transcutaneous electrical nerve stimulation (TENS) has been developed to help amputees perceive touch through their prosthetic hands, addressing a major challenge in prosthetic technology.

Preliminary tests with amputee subjects showed that they could distinguish different levels of pressure applied to the prosthetic fingers, indicating that this system effectively restores tactile sensation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A sensory feedback system for prosthetic hand based on evoked tactile sensation. Liu, XX., Chai, GH., Qu, HE., et al.[2020]

The study successfully applied the Rubber Hand Illusion concept to the lower limb, showing that 19 healthy participants could perceive ownership of a rubber foot when receiving synchronized vibrotactile stimulation on both their biological foot and the rubber foot.

The illusion of body ownership was enhanced with matched stimulation but could still be achieved with mismatched stimulation, suggesting potential for developing sensory feedback devices for amputees to improve their experience with prosthetics.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The rubber foot illusion. Crea, S., D'Alonzo, M., Vitiello, N., et al.[2022]

A novel tactile feedback system for prosthetic hands was developed, integrating a flexible sensing array with 16 sensors and a matrix of 24 stimulation pads, allowing users to receive detailed touch feedback.

In tests with six able-bodied subjects, the system achieved high recognition rates for static patterns (91% for low resolution) and dynamic movements (94% for sliding touch), indicating its potential to enhance the user experience and control of bionic limbs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Embedded Electrotactile Feedback System for Hand Prostheses Using Matrix Electrode and Electronic Skin. Abbass, Y., Saleh, M., Dosen, S., et al.[2022]

A non-invasive method using transcutaneous electrical nerve stimulation (TENS) successfully induced sensations in the phantom hands of amputees, providing sensory feedback that corresponds to the innervation regions of the median and ulnar nerves.

This sensory feedback allowed amputees to perform complex tasks with their prostheses, such as applying varying levels of force, suggesting that TENS could be a practical alternative to surgical interventions for restoring sensory feedback.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A somatotopic bidirectional hand prosthesis with transcutaneous electrical nerve stimulation based sensory feedback. D'Anna, E., Petrini, FM., Artoni, F., et al.[2019]

Current prosthetic devices lack the ability to provide natural sensory feedback, which leads to unnatural movements and difficulties in controlling the prosthetic, potentially causing health issues for users.

There is a significant clinical need for devices that can restore sensory feedback by mimicking the complex signals from skin, muscles, and joints, and various neurotechnological approaches are being explored to achieve this for amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Sensory feedback for limb prostheses in amputees. Raspopovic, S., Valle, G., Petrini, FM.[2023]

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