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An Automatically Adjusting Prosthetic Socket for People With Transtibial Amputation

An Automatically-adjusting Prosthetic Socket for People With Transtibial Amputation

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05124652
Enrollment
100
Registered
2021-11-18
Start date
2021-10-18
Completion date
2027-06-01
Last updated
2026-05-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Diurnal Residual Limb Fluid Volume Fluctuation, Lower Limb Amputation Below Knee (Injury)

Keywords

amputee, prosthetic

Brief summary

People with leg amputations often experience daily changes in the size (volume) of their residual limb. These daily changes can cause a prosthesis to fit poorly. They can also cause limb problems like pain or skin breakdown. Prosthetic socket systems that accommodate limb volume changes can help address these issues, but they require users to make adjustments throughout the day. The aim of this research is to create a system that will automatically adjust the fit of the socket and create a well-fitting prosthesis for people with leg amputations who experience volume fluctuations when using their prosthesis.

Detailed description

he goal of this research is to determine if an automatic-adjusting prosthetic socket produces better participant outcomes than a manually-adjusting socket or a standard of care control in people with trans-tibial limb amputation. Prosthesis users will wear each socket configuration for 2 weeks. Endpoints will include self-reported comfort, convenience, and fatigue; residual limb health; wear time; activities time; and variability in socket fit. Each condition will be tested separately in a cross-over study design, including a 2-week washout period between the conditions. This aim will use a crossover randomized trial to evaluate the importance of the socket condition The three test conditions will be (1) an automatic-adjusting socket; and (2) a manual-adjusting socket; and (3) a standard of care (adjust socks) control in which socket adjustment is locked. Participants will test each of these three conditions in a random order. There will be a 2-week washout period between test conditions. Participation will begin with an initial sessions where the researchers will evaluate inclusion criteria, collect demographic information, conduct a brief bioimpedance test and thermal imaging test, scan the participant's existing socket and instrument the participant's traditional socket with a monitor to collect activity data for 2 weeks while the investigational prosthesis is fabricated. When the investigational prosthesis is prepared, participants will return to the lab. Self-report questionnaires will be completed, and residual limb health assessed. The participant will be trained on how to operate the socket. The socket will be set to the first condition (order of conditions randomly selected). After using the socket for 3 to 5 days, the researchers will go to the participant's location for a check-in visit. The participant will have an opportunity to ask questions and discuss any issues they are having with the socket. The researchers will make sure the socket is functioning properly. After 2 weeks total, participants will return to the lab and complete self-report questionnaires and have their residual limb health assessed. They will participate in an interview about their experience wearing the socket. After a 2-week washout period, they will conduct the same procedure wearing another socket condition. After another 2-week washout period, they will conduct the same procedure wearing the remaining socket condition.

Interventions

DEVICEAuto Adjusting Prosthesis

Participants will test the auto adjusting prosthesis. The prosthesis will be able to move up to 3 panels built into the socket walls to expand or tighten the socket's fit. The auto adjustments will take place during periods of sitting, standing, or walking. Manual adjustments will also be possible either via the researcher controlling the prosthesis or via the key fob developed in the first aim.

Sponsors

University of Washington
Lead SponsorOTHER
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
CollaboratorNIH

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE

Intervention model description

All aims will be conducted as randomized control trials and test various developments to the auto adjusting system, with each previous aim informing the next.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* 18 years or older * Unilateral or bilateral trans-tibial amputation at least 12 months prior * Have a limb of length 9 cm or greater * Are capable of at least 5 minutes of continuous walking * Are capable of at least 1 hour of intermittent walking * Regularly use a definitive prosthesis with a pin-lock suspension system and no or few pads * Have adequate sensation to verbalize a socket that is too large or too small to be tolerated * Do not regularly use assistive devices (e.g., cane, walker) for ambulation * Do not have open wounds on their residual limb at the time of enrollment

Design outcomes

Primary

MeasureTime frameDescription
Socket Comfort Scorethrough study completion, an average of 1 yearParticipants in Aim 2 and Aim 3 will test various configurations of the auto adjustment algorithm. Socket comfort score will be asked at various time points during testing, and overall changes in this metric will be calculated from the start and end of session.
Integral Absolute Error of Control Systemthrough study completion, an average of 1 yearCalculated error will be measured through each test session, both in and out of lab.

Secondary

MeasureTime frameDescription
Percent change in Limb Fluid Volumethrough study completion, an average of 1 yearParticipant's limb fluid volume will be measured during the structured in-lab protocol (Aim 2), and changes will be compared against an initial reference point of activity during which no interventions will take place.
Residual limb healthBaseline and through study completion, an average of 1 yearData collected using a standard skin assessment protocol and an IR imaging camera will be used. For IR data, thermal recovery time will be calculated and a difference map of TRT between the beginning and end test condition created
Prosthesis wear timeUp to 12 weeksSocket fit sensor data will be used
Time of activitiesUp to 12 weeksDurations of walking, standing, sitting, sitting partially doffed, and doffed will be calculated for each day, using socket fit sensor and pin sensor data
Variability in socket fitUp to 12 weeksThis will be calculated from socket sensor SFM data

Countries

United States

Contacts

CONTACTKatheryn Allen, CPO
kate@allyn.org206-390-0228
CONTACTTessa S Viljamaa
tessasv@uw.edu
PRINCIPAL_INVESTIGATORJoan E Sanders, PhD

University of Washington

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 8, 2026