Powered Prosthesis for Amputation

Overseen By Robert D Gregg, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Michigan

Disqualifiers: Pregnancy, Neuromuscular disorders, Cognitive deficits, others

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

Approved in 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

40 Participants Needed

Trial Summary

What is the purpose of this trial?

The overall goal of this project is to model human joint biomechanics over continuously-varying locomotion to enable adaptive control of powered above-knee prostheses. The central hypothesis of this project is that variable joint impedance can be parameterized by a continuous model based on measurable quantities called phase and task variables. This project will use machine learning to identify variable impedance functions from able-bodied data including joint perturbation responses across the phase/task space to bias the solution toward biological values.

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 might be best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment Powered Prosthesis for Amputation?

Research shows that powered prostheses, which mimic the natural movements of the knee, ankle, and toe, can improve walking and stair climbing for individuals with above-knee amputations. These devices help restore natural leg movements and reduce the effort needed to walk, potentially enhancing mobility and quality of life. ^{1 2 3 4 5}

Is the powered prosthesis generally safe for humans?

Research suggests that powered prostheses can provide safe and efficient movement for individuals with above-knee amputations, although some designs may require users to adjust their movements to avoid falls. Safety can depend on the specific technology and design of the prosthesis. ^{1 6 7 8 9}

How is the powered prosthesis treatment different from other treatments for amputation?

The powered prosthesis is unique because it uses motors to mimic the natural movements of the knee, ankle, and toe, providing more controlled and natural walking and sitting experiences compared to passive prostheses. It also features a lightweight design with a longer battery life, allowing for extended use without frequent charging, which is not possible with other powered or microprocessor-controlled prostheses. ^{1 4 6 10 11}

Research Team

Robert D Gregg, PhD

Principal Investigator

University of Michigan

Eligibility Criteria

This trial is for adults aged 18-65 who are able-bodied, and those with above-knee amputations aged 18-70 who can walk without assistance. Participants must not be pregnant, have significant disorders that affect movement, or cognitive deficits. Amputees must weigh under 250 lbs and meet certain mobility classifications.

Inclusion Criteria

I have been walking on my own for over two months after losing a leg above the knee.

I am an amputee who can walk with my prosthesis without needing another device.

Exclusion Criteria

An excessively long residual limb length, and/or a non-removable cosmetic cover determined by the prosthetist performing the evaluations for subjects with amputation

Co-morbidity that interferes with the study (e.g., pace maker placement, severe ischemia, cardiac disease, etc.) for subjects with amputation

Adults unable to consent for subjects with amputation

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Initial Testing

Able-bodied subjects are recruited for initial testing of various prosthesis controllers

4 weeks

Multiple visits (in-person)

Validation

Amputee subjects validate the prosthesis controllers and participate in endurance and symmetry studies

8 weeks

Multiple visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

• Powered Prosthesis

Trial Overview The study tests a powered prosthesis designed to adapt to varying activities using machine learning based on human joint biomechanics. It aims to improve the control of prosthetic legs by modeling variable joint impedance through measurable quantities in different locomotion tasks.

Participant Groups

Group I: Prosthesis Experimental Treatment 1 Intervention

Participants in this arm of the study will perform various tasks while wearing the powered prosthesis

Powered Prosthesis is already approved in United States, European Union for the following indications:

Approved in United States as Powered Prosthetic Limbs for:

• Above-knee amputations
• Mobility assistance

Approved in European Union as Robotic Prosthetic Legs for:

• Lower limb amputations
• Rehabilitation

Who Is Running the Clinical Trial?

University of Michigan

Lead Sponsor

Trials

1,891

Recruited

6,458,000+

Findings from Research

A case study demonstrated that lightweight powered knee and ankle prostheses can effectively restore natural leg movements for individuals with bilateral above-knee amputations, allowing them to walk and climb stairs with improved gait patterns.

The powered prostheses were able to replicate essential biomechanical functions, such as ankle push-off during walking and knee power generation during stair ascent, which are crucial for enhancing mobility and quality of life.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Powered knee and ankle prostheses enable natural ambulation on level ground and stairs for individuals with bilateral above-knee amputation: a case study. Hood, S., Creveling, S., Gabert, L., et al.[2023]

Early rehabilitation measures, including the provision of a prosthesis, are crucial for aged individuals following above-knee amputation to prevent physical and mental decline, as energy consumption for walking with a prosthesis is significantly higher than for non-amputated individuals.

A comprehensive approach to rehabilitation is necessary, considering not just the physical aspects of recovery but also the individual's social environment and personal needs, ensuring that both prosthetic and wheelchair management are tailored to the patient's unique circumstances.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Prosthetic and wheelchair management of elderly patients following above the knee amputation--a decision at the acute hospital]. Dorian, R.[2022]

The use of an active powered microprocessor-controlled prosthetic knee (A-MPK) resulted in greater knee range of motion and reduced hip torque during walking compared to a passive microprocessor-controlled prosthetic knee (P-MPK) in four transfemoral amputees, suggesting improved gait mechanics.

A follow-up case study indicated that using the A-MPK for four weeks increased the amputee's confidence and highlighted the importance of adaptation time for optimizing the benefits of the A-MPK.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Assessment of transfemoral amputees using a passive microprocessor-controlled knee versus an active powered microprocessor-controlled knee for level walking. Creylman, V., Knippels, I., Janssen, P., et al.[2018]

The new robotic leg prosthesis effectively mimics the biomechanics of a biological leg while matching the weight, size, and battery life of traditional prostheses, making it more practical for daily use.

Preclinical tests with three individuals showed that this prosthesis allows for natural walking movements and includes a passive mode for unlimited walking on level ground without needing to recharge, which is a significant advancement over existing powered prosthetics.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A lightweight robotic leg prosthesis replicating the biomechanics of the knee, ankle, and toe joint. Tran, M., Gabert, L., Hood, S., et al.[2023]

In a study involving 41 individuals with above-knee amputations, those with higher functional mobility levels showed significant improvements in performance speed when using microprocessor-controlled prosthetic knee joints compared to mechanically controlled ones.

The results indicate that while there is considerable variability in functional performance among MFCL-2 amputees, many can benefit from the advanced technology of microprocessor-controlled knees for daily activities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Functional added value of microprocessor-controlled knee joints in daily life performance of Medicare Functional Classification Level-2 amputees. Theeven, P., Hemmen, B., Rings, F., et al.[2014]

The study demonstrated that a powered knee-ankle prosthesis significantly improved weight-bearing symmetry by 42.1% during sit-down movements compared to passive prostheses, indicating enhanced stability for above-knee amputees.

Despite the improvement in weight-bearing symmetry, there was no significant reduction in muscle effort from the intact quadricep muscle, suggesting that while powered prosthetics improve balance, they may not lessen the physical demands on the user's intact limb.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Can a powered knee-ankle prosthesis improve weight-bearing symmetry during stand-to-sit transitions in individuals with above-knee amputations? Hunt, GR., Hood, S., Gabert, L., et al.[2023]

Powered exoskeletons, like the ReWalk™, Indego™, and Ekso™, have been approved as medical devices to help individuals with gait disabilities walk upright, but the understanding of their risks and safety is still developing.

There is a significant need for standardized regulations and awareness of potential risks associated with powered exoskeletons to ensure safe and effective use, as current criteria for their use and reported adverse events vary widely.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Risk management and regulations for lower limb medical exoskeletons: a review. He, Y., Eguren, D., Luu, TP., et al.[2020]

The study of two transfemoral amputees showed that powered knee-ankle prostheses (PKA) can enable walking patterns that closely resemble normal gait, improving mobility and reducing asymmetry in mechanical loading and muscle activation.

Compared to advanced microprocessor-controlled knee prostheses (MPK), the PKA allowed for a greater range of walking speeds and cadence, suggesting enhanced safety and adaptability in various environments for users.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of Powered Knee-Ankle Prosthesis on Low Back Muscle Mechanics in Transfemoral Amputees: A Case Series. Jayaraman, C., Hoppe-Ludwig, S., Deems-Dluhy, S., et al.[2020]

In a study involving six unilateral transfemoral amputees, the Rheo Knee XC showed advantages in walking with small steps due to its 'default swing' concept, which provided a consistent swing phase release.

However, the C-Leg demonstrated better safety and load-bearing capacity during activities like walking down stairs and slopes, while the Rheo Knee XC required more compensatory movements, potentially increasing the risk of falls in certain situations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparative biomechanical evaluation of two technologically different microprocessor-controlled prosthetic knee joints in safety-relevant daily-life situations. Bellmann, M., Köhler, TM., Schmalz, T.[2019]

Current lower limb prostheses lack the ability to replicate the energy distribution and function of natural musculature, which is crucial for effective movement.

The proposed above-knee prosthesis incorporates a self-energized mechanism that captures and stores energy from passive movements at the knee and ankle, enabling active plantar-flexion and improving locomotion efficiency.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Active plantar-flexion above-knee prosthesis: concept and preliminary design. Rigas, C.[2017]

The review highlights the ongoing advancements in transfemoral prosthesis design, focusing on mechanical performance and the integration of modern technologies like sensors and software to enhance functionality and user experience.

Future research aims to create more cost-effective and safer prosthetic components that better restore the capabilities of amputees, addressing both technical and social challenges in prosthetic development.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An insight into Transfemoral Prostheses: Materials, modelling, simulation, fabrication, testing, clinical evaluation and performance perspectives. Amudhan, K., Vasanthanathan, A., Anish Jafrin Thilak, J.[2022]

References

1. England pubmed.ncbi.nlm.nih.gov

Powered knee and ankle prostheses enable natural ambulation on level ground and stairs for individuals with bilateral above-knee amputation: a case study. [2023]

2. Germany pubmed.ncbi.nlm.nih.gov

[Prosthetic and wheelchair management of elderly patients following above the knee amputation--a decision at the acute hospital]. [2022]

3. England pubmed.ncbi.nlm.nih.gov

Assessment of transfemoral amputees using a passive microprocessor-controlled knee versus an active powered microprocessor-controlled knee for level walking. [2018]

4. United States pubmed.ncbi.nlm.nih.gov

A lightweight robotic leg prosthesis replicating the biomechanics of the knee, ankle, and toe joint. [2023]

5. Sweden pubmed.ncbi.nlm.nih.gov

Functional added value of microprocessor-controlled knee joints in daily life performance of Medicare Functional Classification Level-2 amputees. [2014]

6. England pubmed.ncbi.nlm.nih.gov

Can a powered knee-ankle prosthesis improve weight-bearing symmetry during stand-to-sit transitions in individuals with above-knee amputations? [2023]

7. New Zealand pubmed.ncbi.nlm.nih.gov

Risk management and regulations for lower limb medical exoskeletons: a review. [2020]

8. Switzerland pubmed.ncbi.nlm.nih.gov

Impact of Powered Knee-Ankle Prosthesis on Low Back Muscle Mechanics in Transfemoral Amputees: A Case Series. [2020]

9. Germany pubmed.ncbi.nlm.nih.gov

Comparative biomechanical evaluation of two technologically different microprocessor-controlled prosthetic knee joints in safety-relevant daily-life situations. [2019]

10. France pubmed.ncbi.nlm.nih.gov

Active plantar-flexion above-knee prosthesis: concept and preliminary design. [2017]

11. England pubmed.ncbi.nlm.nih.gov

An insight into Transfemoral Prostheses: Materials, modelling, simulation, fabrication, testing, clinical evaluation and performance perspectives. [2022]