Prosthetic Limb Pump for Amputees

(HIPPI Trial)

Overseen By Matthew J Major, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: VA Office of Research and Development

Must not be taking: Balance medications

Disqualifiers: Poor prosthetic fit, others

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

Compensation: Varies

Number of Visits: 1

Duration: 3 hours

20 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new pump design for prosthetic limbs to improve mobility and limb health for amputees. The pump creates a vacuum between the prosthetic socket and the limb, potentially offering advantages over other attachment methods like straps or suction. Participants will test the pump's functionality while walking in a lab setting. It suits individuals who have used a vacuum-assisted prosthesis for at least six months and can walk for 10 minutes without a cane or walker. As an unphased trial, this study allows participants to contribute to innovative advancements in prosthetic technology.

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

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are taking medicine that affects walking or balance.

What prior data suggests that this pump prototype is safe for amputees?

Research has shown that pumps used in prosthetics, like the one being tested, are generally safe. Previous studies found that these pumps can enhance the fit and function of a prosthetic limb, aiding in walking and everyday activities. By creating a vacuum, these pumps secure the prosthetic limb in place.

Regarding safety, evidence suggests that participants typically tolerate these pumps well, with no major reports of harm or serious side effects. Some users might experience minor issues, but these are often manageable. Overall, this pump design aims to improve comfort and movement for prosthesis users. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the Prosthetic Limb Pump for amputees because it offers a novel mechanical approach to managing the fit and comfort of prosthetic limbs. Unlike traditional prosthetics, which often rely on static sockets and liners, this new pump system actively adjusts to changes in limb volume throughout the day. The "Unlocked" version allows for natural compression, potentially improving limb comfort and reducing skin irritation. Meanwhile, the "Locked" version provides a stable fit by preventing compression, which might enhance stability during movement. This dynamic adjustment capability could lead to a more comfortable and personalized prosthetic fit, addressing a key challenge faced by many amputees.

What evidence suggests that this pump prototype is effective for improving limb health and mobility in amputees?

Research shows that vacuum-assisted suspension (VAS) for prosthetic limbs offers advantages over other attachment methods like suction or pin-locking liners. Studies have found that VAS helps maintain the health of the remaining limb by reducing swelling and skin problems. This setup can also ease walking for users. In this trial, participants will test a new pump design in two configurations: the "Unlocked" arm, where the prototype mechanical system compresses normally, and the "Locked" arm, where the system remains locked from compressing. Early results suggest that the new pump design might enhance these benefits by providing better support and comfort. This could lead to a more comfortable and functional experience for prosthetic limb users. ^{1 2 6 7 8}

Who Is on the Research Team?

Matthew J. Major, PhD

Principal Investigator

Jesse Brown VA Medical Center, Chicago, IL

Are You a Good Fit for This Trial?

This trial is for individuals who have had an amputation and are already using a prosthesis with vacuum-assisted suspension. Participants should be able to walk without assistance for at least 10 minutes, have good limb health, and have been using their current prosthesis for six months or more. Those with poor prosthetic fit, reduced limb sensation, or conditions affecting walking or balance cannot join.

Inclusion Criteria

My amputated limb is healthy.

I can stand and walk for 10 minutes without help or feeling overly tired.

I can walk with minimal assistance.

Exclusion Criteria

I don't have conditions affecting my walking or balance, except for amputation.

Poor prosthetic fit or poor residual limb sensation

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants test the new pump design in a laboratory setting during a single 3-hour visit

3 hours

1 visit (in-person)

Follow-up

Participants are monitored for immediate outcomes such as socket comfort and mobility capability

Immediate

What Are the Treatments Tested in This Trial?

Interventions

• Pump prototype

Trial Overview The study is testing a new pump prototype designed to improve the suspension of prosthetic limbs by creating a vacuum between the socket and the limb. The goal is to enhance mobility and limb health. Participants will use this pump in laboratory settings while walking to assess its performance.

How Is the Trial Designed?

Group I: Unlocked Experimental Treatment 1 Intervention

The prototype mechanical system is free to compress normally

Group II: Locked Experimental Treatment 1 Intervention

The prototype mechanical system is locked from compressing

Who Is Running the Clinical Trial?

VA Office of Research and Development

Lead Sponsor

Trials

1,691

Recruited

3,759,000+

Published Research Related to This Trial

In a study involving 8 men with transtibial amputation, using a heavier prosthetic mass (up to 100% of the intact limb's mass) did not significantly increase oxygen consumption or gait efficiency during walking at various speeds.

However, as the prosthetic mass increased, the relative exercise intensity increased and stride frequency decreased, indicating that while energy costs remained stable, the effort required to walk may have changed with heavier prosthetics.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of added prosthetic mass on physiologic responses and stride frequency during multiple speeds of walking in persons with transtibial amputation. Lin-Chan, SJ., Nielsen, DH., Yack, HJ., et al.[2019]

A structured protocol for testing lower limb prostheses emphasizes safety, requiring users to meet specific graded safety levels before progressing to more challenging environments.

This approach aims to reduce the risk of falls and injuries, thereby enhancing user confidence and overall experience with active prosthetic legs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Design of a stepwise safety protocol for lower limb prosthetic risk management in a clinical investigation. Thesleff, A., Ahkami, B., Anderson, J., et al.[2022]

The study developed a new method for configuring powered knee and ankle prostheses that significantly reduces the time needed to set them up for different walking modes, cutting the initial accommodation period by 56% to under 5 hours.

By using modified intrinsic control strategies, only 17% of the configuration parameters needed adjustment for novice users, making it easier for amputees to transition to using these advanced prosthetic devices.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Configuring a powered knee and ankle prosthesis for transfemoral amputees within five specific ambulation modes. Simon, AM., Ingraham, KA., Fey, NP., et al.[2022]

A new prosthetic system for above-knee amputees allows users to control knee resistance using EMG signals from their thigh muscles, enabling a more natural and variable gait compared to traditional prostheses.

This EMG-controlled hydraulic prosthesis offers advantages such as improved stability on uneven terrain and the ability for the user to rise on the prosthesis, although further development is needed to enhance its weight, size, and appearance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A voluntarily controlled electrohydraulic above-knee prosthesis. Dyck, WR., Onyshko, S., Hobson, DA., et al.[2013]

A pilot study involving five male amputees demonstrated that measuring limb temperature outside of a laboratory setting is feasible, with significant temperature increases observed during real-life activities compared to controlled lab conditions.

The study found that limb temperatures were significantly higher in out-of-lab settings (by 1.9°C), highlighting the need for further research on thermal discomfort in prosthesis wearers to develop effective preventive measures against skin conditions and improve quality of life.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A pilot study towards long-term thermal comfort research for lower-limb prosthesis wearers. Williams, RJ., Takashima, A., Ogata, T., et al.[2019]

The study investigated how errors in recognizing locomotion modes affect the control of powered prosthetic legs and the stability of users' gait, involving five able-bodied subjects and two above-knee amputees.

Not all recognition errors disrupt gait stability; the impact depends on the timing of the error during the gait phase and the mechanical changes in the prosthesis, leading to the identification of 'critical errors' that could improve the design of safer and more reliable prosthetic devices.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of locomotion mode recognition errors on volitional control of powered above-knee prostheses. Zhang, F., Liu, M., Huang, H.[2015]

Recent advancements in lower-limb prostheses have significantly improved their design and functionality, yet they still do not match the capabilities of natural limbs, highlighting ongoing deficiencies.

The article outlines specific areas for improvement in prosthetic technology and suggests research opportunities to develop next-generation prostheses that are neurally integrated and more functional for users.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Toward the development of user-centered neurointegrated lower limb prostheses. Barberi, F., Anselmino, E., Mazzoni, A., et al.[2023]

Only 36% of geriatric vascular amputees in the community were successfully fitted with prosthetics, highlighting a significant gap compared to the 74% success rate in specialized Amputee Clinics.

Factors such as increased age, cerebrovascular disease, dementia, and higher amputation levels (above knee) were strong predictors of failure to achieve a successful prosthetic fit, suggesting that careful patient selection and counseling are crucial for improving outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Rehabilitation of the geriatric vascular amputee patient: a population-based study. Fletcher, DD., Andrews, KL., Butters, MA., et al.[2022]

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]

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]

A new biarticular prosthesis (BP) designed for lower-limb amputees successfully mimicked the function of the gastrocnemius muscle, generating forces similar to those produced by the natural muscle during walking.

The BP demonstrated low power consumption (averaging 5.15 W) while effectively transferring energy between the ankle and knee joints, suggesting it could lead to lightweight and efficient prosthetic designs in the future.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Design and Development of a Quasi-Passive Transtibial Biarticular Prosthesis to Replicate Gastrocnemius Function in Walking. Willson, AM., Richburg, CA., Czerniecki, J., et al.[2021]

The lift-lock principle shows promise in enhancing the functionality of above-elbow body-powered prostheses, based on preliminary results from one amputee and prior laboratory trials.

Further extensive evaluations are needed to fully assess the effectiveness and benefits of the lift-lock mechanism in prosthetic applications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The lift lock: a device to increase the lifting ability of dual-control prostheses. Carlson, LE., Childress, DS.[2013]

The paper presents a new biomechanical method for assessing the functional status of lower extremity amputee systems, which can improve rehabilitation practices.

This method was specifically applied to evaluate both axillary crutches for unilateral lower extremity amputees and PTB prostheses for below-knee amputees, highlighting its practical relevance in everyday rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Analysis and evaluation of functional status of lower extremity amputee-appliance systems: an integrated approach. Ganguli, S.[2009]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9835280/

Testing and evaluation of lower limb prosthesis prototypes ... This review aims at identifying participant characteristics, research protocols, reference values, aims, and corresponding outcome measures used ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4940611/

Evaluation of a Prototype Hybrid Vacuum Pump to Provide ... Evidence of the suggested benefits of VAS over suspension techniques such as suction and pin-locking liners have been described as: reducing residual limb ...

3. clinicaltrials.gov clinicaltrials.gov/study/NCT06937242

Effects of Microprocessor-controlled Prosthetic Knees on ... The goal of this study is to find out if using microprocessor-controlled prosthetic knees (MPKs), prosthetic knees with a built-in computer, improves health ...

4. effectivehealthcare.ahrq.gov effectivehealthcare.ahrq.gov/sites/default/files/related_files/cer-213-lower-limb-protheses-evidence-summary.pdf

Effective Health Care Program - Lower Limb Prostheses In adults who use a lower limb prosthesis, how do ambulatory, functional, and patient-centered outcomes with different prosthetic components vary.

5. tandfonline.com tandfonline.com/doi/full/10.1080/19498241.2024.2420595

ADJUSTABLE-VOLUME PROSTHETIC INTERFACES The purpose of this article is to identify, critically appraise, synthesize, and to perform a meta-analysis of the available evidence pertaining to adjustable- ...

6. tandfonline.com tandfonline.com/doi/full/10.1080/09638288.2021.1989504

The effect of microprocessor controlled exo-prosthetic ... The meta-analysis provided clear insights that the use of MPKs in limited community ambulators led to a reduction in falls, fear of falling, an improvement in ...

7. researchgate.net researchgate.net/publication/383722688_Prosthetics_for_Lower_Limb_Amputees_A_Comprehensive_Review_of_Technologies_Applications_and_Future_Directions

Prosthetics for Lower Limb Amputees: A Comprehensive ... This review paper provides a comprehensive overview of these advancements and assesses their potential clinical impact.

8. journals.sagepub.com journals.sagepub.com/doi/10.1177/20556683241248584

Design and prototype validation of a laterally mounted ... Abstract. Prosthetic technology has advanced with the development of powered prostheses to enhance joint function and movement in the absence of native anatomy.