AmputationNCT02355912
Adaptive Recalibration of Prosthetic Leg Neural Control System
A study testing Powered knee and ankle prosthesis in people with Amputation, run by Shirley Ryan AbilityLab at 1 site in United States.
Trial summary
The purpose of this study is for transfemoral amputees to walk with an experimental robotic prosthesis. Electric signals will be measured from their muscles and used to help control an artificial leg. Read more about this study
- Who is it for?
- Ages 18 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Amputation
- What is being tested?
- Powered knee and ankle prosthesis
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 22 participants
- Where
- 1 siteUnited States
- Study dates
- Jan 2015to Jan 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Lower Limb Amputees
- K2/K3/K4 ambulators
- no injury on either lower extremity
Who cannot join
- Over 250lbs body weight
- Inactive, physically unfit
- cognitive deficits or visual impairment that would impair their ability to give informed consent or to follow simple instructions during the experiments
- Pregnant women
- co-morbidity that interferes with the study (e.g. stroke, pace maker placement, severe ischemia cardiac disease, etc.)
- Able-bodied Subjects:
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- inactive, physically unfit
- over 250 lbs body weight
- cognitive deficits or visual impairment that would impair their ability to give informed consent or impair their ability to follow simple instructions during the experiments
- Pregnant women (status determined by self-reporting)
- co-morbidity that interferes with the study (e.g. stroke, pace maker placement, severe ischemia cardiac disease, etc.)
Trial locations and contacts
1 site in 1 country.
United States1 site
Rehabilitation Institute of Chicago
Chicago, Illinois, 60611
About this study
The purpose of this study is for transfemoral amputees to walk with an experimental robotic prosthesis. Electric signals will be measured from their muscles and used to help control an artificial leg. The investigators will record from sensors placed on a prosthesis and electric signals measured from muscles in the participants leg to see if the investigators can develop better computer programs to help predict subject actions and prostheses function.
Read the detailed description
The investigators propose to use a powered knee-ankle prosthesis that is not yet commercially available. The hierarchical control framework the investigators are developing will be equally applicable to any prosthetic leg that needs to be transitioned between ambulation modes, including microprocessor-controlled passive devices.
The overall objective is to develop and evaluate an adaptive framework for controlling lower limb prostheses that compensates for changes in EMG signals. When a participant walks on a lower limb prosthesis, the output of the high-level controller (or ambulation mode predictor) directly influences patterns generated by the participant. After the participant has completed the subsequent stride, a gait pattern estimator (GPE), will provide a label of what the participant actually did. This may differ from the ambulation mode predictor output if there was a misclassification. The label will then be used to update the ambulation mode predictor algorithm such that future steps are predicted with higher accuracies. Finally, the resulting system will be transferred to an embedded system and tested in real-time with transfemoral amputees and compared to a non-adaptive system.
- Conditions
- Amputation
- Being tested
- Powered knee and ankle prosthesis
- Keywords
- Transfemoral
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Powered knee and ankle prosthesisDevice
A powered knee and ankle prosthesis developed by Vanderbilt University.
| Study group | Role | What they receive |
|---|---|---|
| Evaluate a real-time adaptive neural control system | Experimental | The prosthesis will be tuned, for each subject: level-ground walking, walking up and down slopes and walking up and down stairs. We anticipate that participants will visit the laboratory approximately 6-9 times over 2 months (2-3 visits for socket duplications and modifications, 2-3 visits for control system tuning, and an additional 2-3 visits for practice using the tuned system). By the end of these visits, the goal is to have a properly fitting socket and for the subjects to ambulate proficiently with the powered prosthesis. After tuning, the subjects will complete 20 ambulation circuits (level ground walking, walking up and down slopes, up and down stairs). This will provide training data for our pattern recognition control systems. Receives: Device: Powered knee and ankle prosthesis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Decreased error rates for pattern recognition system used to predict ambulation modes
Pattern recognition algorithms have been used to allow seamless and automatic transitioning between ambulation modes. Classification errors result in the prosthesis predicting the wrong ambulation mode. A decrease in errors results in improved mode prediction by the prosthesis. EMG from the participant and mechanical sensor data from the prosthesis are processed with the use of a phase-based-dependent pattern recognition classification method. The data collection will yield three groups of 10 real-time trials. The investigators primary analysis will be a repeated measures ANOVA with a planned contrast between the groups. The investigators will also complete a secondary analysis using the data collected while the participants ambulated outside of the laboratory. The total number of misclassifications will be computed. This will allow the investigator to evaluate the rate at which the overall classification system adapted.
Measured: Assessed at approximately 2 months and 6 months after enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Feb 2015 (estimated)
- Study startJan 2015
- Primary completionJan 2020
- Study completionJan 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AmputationStudies of the same condition, open and under way.
- More trials run by Shirley Ryan AbilityLabThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 22 participants (actual)
Sponsor and investigators
- Lead sponsor
- Shirley Ryan AbilityLab
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Levi Hargrove, Shirley Ryan AbilityLab
- Investigators
- Levi Hargrove, PhD, Principal investigator, Shirley Ryan AbilityLab
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02355912
- Sponsor's protocol ID
- STU00101767
- Status last verified
- Oct 2020
- First submitted
- 16 Jan 2015
- Last updated
- 28 Oct 2020
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Oct 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Adaptive Recalibration of Prosthetic Leg Neural Control System
- ClinicalTrials.gov ID
- NCT02355912
- Acronym / sponsor ID
- STU00101767
- Conditions
- Amputation
- Keywords
- Transfemoral
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 22 participants (actual)
- Lead sponsor
- Shirley Ryan AbilityLabUniversity, hospital or other
- Study start
- Jan 2015
- Primary completion
- Jan 2020 (actual)
- Study completion
- Jan 2020 (actual)
- First posted
- 4 Feb 2015 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is for transfemoral amputees to walk with an experimental robotic prosthesis. Electric signals will be measured from their muscles and used to help control an artificial leg. The investigators will record from sensors placed on a prosthesis and electric signals measured from muscles in the participants leg to see if the investigators can develop better computer programs to help predict subject actions and prostheses function.
Detailed description
The investigators propose to use a powered knee-ankle prosthesis that is not yet commercially available. The hierarchical control framework the investigators are developing will be equally applicable to any prosthetic leg that needs to be transitioned between ambulation modes, including microprocessor-controlled passive devices.
The overall objective is to develop and evaluate an adaptive framework for controlling lower limb prostheses that compensates for changes in EMG signals. When a participant walks on a lower limb prosthesis, the output of the high-level controller (or ambulation mode predictor) directly influences patterns generated by the participant. After the participant has completed the subsequent stride, a gait pattern estimator (GPE), will provide a label of what the participant actually did. This may differ from the ambulation mode predictor output if there was a misclassification. The label will then be used to update the ambulation mode predictor algorithm such that future steps are predicted with higher accuracies. Finally, the resulting system will be transferred to an embedded system and tested in real-time with transfemoral amputees and compared to a non-adaptive system.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Evaluate a real-time adaptive neural control system | Experimental | Device: Powered knee and ankle prosthesisThe prosthesis will be tuned, for each subject: level-ground walking, walking up and down slopes and walking up and down stairs. We anticipate that participants will visit the laboratory approximately 6-9 times over 2 months (2-3 visits for socket duplications and modifications, 2-3 visits for control system tuning, and an additional 2-3 visits for practice using the tuned system). By the end of these visits, the goal is to have a properly fitting socket and for the subjects to ambulate proficiently with the powered prosthesis. After tuning, the subjects will complete 20 ambulation circuits (level ground walking, walking up and down slopes, up and down stairs). This will provide training data for our pattern recognition control systems. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Lower Limb Amputees
- K2/K3/K4 ambulators
- no injury on either lower extremity
Key exclusion criteria (11 listed)
- Over 250lbs body weight
- Inactive, physically unfit
- cognitive deficits or visual impairment that would impair their ability to give informed consent or to follow simple instructions during the experiments
- Pregnant women
- co-morbidity that interferes with the study (e.g. stroke, pace maker placement, severe ischemia cardiac disease, etc.)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Powered knee and ankle prosthesisA powered knee and ankle prosthesis developed by Vanderbilt University. | Device | Evaluate a real-time adaptive neural control system |
Primary outcome
Decreased error rates for pattern recognition system used to predict ambulation modes
Time frame: Assessed at approximately 2 months and 6 months after enrollment
Pattern recognition algorithms have been used to allow seamless and automatic transitioning between ambulation modes. Classification errors result in the prosthesis predicting the wrong ambulation mode. A decrease in errors results in improved mode prediction by the prosthesis. EMG from the participant and mechanical sensor data from the prosthesis are processed with the use of a phase-based-dependent pattern recognition classification method. The data collection will yield three groups of 10 real-time trials. The investigators primary analysis will be a repeated measures ANOVA with a planned contrast between the groups. The investigators will also complete a secondary analysis using the data collected while the participants ambulated outside of the laboratory. The total number of misclassifications will be computed. This will allow the investigator to evaluate the rate at which the overall classification system adapted.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Oct 2020.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Levi Hargrove, PhD principal investigator
Shirley Ryan AbilityLab
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Powered knee and ankle prosthesis in people with Amputation, run by Shirley Ryan AbilityLab at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Oct 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Decreased error rates for pattern recognition system used to predict ambulation modes (time frame: Assessed at approximately 2 months and 6 months after enrollment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Oct 2020.