Assessing the DSR Ankle

November 20, 2023 updated by: Synchro Motion LLC

Assessment of a Microprocessor Ankle for Low Mobility Individuals

This research is being done to conduct a preliminary investigation into a new prosthetic microprocessor controlled (MPC) ankle, called the Damping, Stiffness, and Repositioning (DSR) ankle. The DSR ankle is a new design to support a person while they walk on both even and uneven ground, as well as with bending the ankle for safe foot clearance while a person takes a step. In particular, in this study we are interested in seeing how this type of new device may benefit people who are rated as a K2-level ambulator.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Synchro Motion, LLC developed a novel MPC ankle. Because of its unique actuation scheme, the prosthesis can behave as: (1) a lockable conformal damper, (2) a variable set-point spring, and (3) an actively repositionable joint.

The investigators therefore refer to the device as the damping, stiffness, and repositioning (DSR) ankle. The DSR ankle is small, lightweight, quiet, and runs for multiple days on a single charge. No other commercially available prosthesis combines this set of features. It will be shown in preliminary work that the features of the DSR ankle can increase toe clearance in swing, reduce the time-to-foot-flat after heel strike, and improve weight bearing symmetry when standing on slopes for K3 Individuals with Lower Limb Amputation (ILLAs). These biomechanical functions have all been linked to improved safety and stability, which leads the investigators to hypothesize that the DSR ankle may provide benefits to K2 ILLAs as well.

The main purpose of this research is to determine the ways in which the DSR ankle may be adapted to provide benefits specifically to ILLAs who use their prosthesis at the K2 level. For purposes of the Phase I work, the development and assessment will be performed exclusively with K2 ILLAs in order to provide an opportunity to implement any necessary refinements to the DSR ankle to ensure optimal K2 performance. The remainder of the research is to quantify the effectiveness of the DSR ankle as compared to a predicate non-MPC ankle in improving performance for K2 ILLAs.

Study Type

Interventional

Enrollment (Estimated)

5

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Illinois
      • Chicago, Illinois, United States, 60611-4805
        • Recruiting
        • Shirley Ryan AbilityLab
        • Principal Investigator:
          • Arun Jayaraman, PhD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Adults aged 18-89 years
  2. Patients who have a unilateral transtibial amputation who are able to use a prosthesis and who currently use a passive, non-MPC prosthesis
  3. K2 level ambulators

Exclusion Criteria:

  1. Pregnant women
  2. Children (<18 years old)
  3. Prisoners or institutionalized individuals
  4. Individuals who have the inability to give informed consent
  5. Participants unable to walk for 2 minutes without an assistive device
  6. Participants with complicating health conditions that interfere with the study
  7. Inability to read and understand the English language. As this is a pilot study with a small sample size, it is prohibitive to translate Study documents to other languages as recruitment will be from a sample of convenience.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: DSR Ankle
The DSR Ankle is a novel microprocessor-controlled ankle prosthesis that is able to provide enhanced mobility and stability to individuals with lower limb amputation. It interfaces to the user by attaching to their socket via an industry-standard pyramid connector.
Device: DSR Ankle
This is the experimental ankle component used in the overall prosthetic intervention.
Other Names:
  • The Damping, Stiffness and Repositioning Ankle
Active Comparator: Predicate Ankle
The predicate ankle is the user's prescribed prosthesis worn for the activities of daily living.
Device: Predicate Ankle
This is the participant's prescribed ankle/foot complex used in the overall prosthetic intervention.
Other Names:
  • Daily Use Ankle

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Minimum Foot Clearance
Time Frame: after up to 3 weeks of training
Minimum foot clearance is the shortest distance between the foot and the ground during swing, and it occurs approximately halfway through the swing phase of gait.
after up to 3 weeks of training
Time to Foot Flat
Time Frame: after up to 3 weeks of training
Time to foot flat is the duration of time between initial contact at heel strike and the full contact of the sole of the foot on the ground in stance.
after up to 3 weeks of training
Maximum Lyapunov Exponent
Time Frame: after up to 3 weeks of training
The maximum Lyapunov exponent is a measure of dynamic gait stability that uses nonlinear time series analysis.
after up to 3 weeks of training
Weight Bearing Symmetry
Time Frame: after up to 3 weeks of training
Weight bearing symmetry is a measure of standing stability represented by the ratio of left to right side weight bearing.
after up to 3 weeks of training
Center of Pressure RMS Velocity
Time Frame: after up to 3 weeks of training
Center of pressure RMS velocity is measured by calculating the velocity of the COP from force plate data while standing.
after up to 3 weeks of training

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Orthotics Prosthetics User Survey (OPUS)
Time Frame: after up to 3 weeks of training
The OPUS is a self-report questionnaire consisting of 5 modules. It can be used for prosthetic and orthotic programs for quality assessment, to maintain awareness of improvement in activities, to evaluate changes in patient's functional status and quality of life, and to assess satisfaction with devices and services.
after up to 3 weeks of training
Numerical Pain Rating Scale (NPRS)
Time Frame: after up to 3 weeks of training
The NPRS is a segmented numeric version of the visual analog scale (VAS) in which a respondent selects a whole number (0-10 integers) that best reflects the intensity of his/her pain.
after up to 3 weeks of training
Borg Rating Scale (RPE)
Time Frame: after up to 3 weeks of training
The RPE is a tool for measuring an individual's effort and exertion, breathlessness and fatigue during physical work.
after up to 3 weeks of training
Modified Falls Efficacy Scale (mFES)
Time Frame: after up to 3 weeks of training
The mFES indicates the level of perceived confidence an individual has about carrying out everyday activities without falling. The modified version includes outdoor activities.
after up to 3 weeks of training
10 Meter Walk Test (10 MWT)
Time Frame: after up to 3 weeks of training
The 10 MWT assesses walking speed in meters per second over a distance of 10 meters.
after up to 3 weeks of training
Six Minute Walk Test (6 MWT)
Time Frame: after up to 3 weeks of training
The 6 MWT assesses walking distance in meters over a period of 6 minutes.
after up to 3 weeks of training
Berg Balance Test (BBS)
Time Frame: after up to 3 weeks of training
The BBS is used to objectively determine a patient's ability to safely balance during a series of predetermined tasks. It is a 14 item list with each item consisting of a five-point ordinal scale ranging from 0 to 4, with 0 indicating the lowest level of function and 4 the highest level of function and takes approximately 20 minutes to complete.
after up to 3 weeks of training
Functional Gait Assessment (FGA)
Time Frame: after up to 3 weeks of training
The FGA is used to assess postural stability during walking and assesses an individual's ability to perform multiple motor tasks while walking.
after up to 3 weeks of training
Hill Assessment Index (HAI)
Time Frame: after up to 3 weeks of training
The HAI is scored on an ordinal scale from 0 to 11 and measures the patient's ability to navigate sloped terrain.
after up to 3 weeks of training
Timed Up and Go (TUG)
Time Frame: after up to 3 weeks of training
The TUG assesses mobility, balance, walking ability, and fall risk in older adults.
after up to 3 weeks of training

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Synchro Motion LLC

Collaborators

Shirley Ryan AbilityLab

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 15, 2023

Primary Completion (Estimated)

July 15, 2024

Study Completion (Estimated)

July 31, 2024

Study Registration Dates

First Submitted

July 3, 2023

First Submitted That Met QC Criteria

July 18, 2023

First Posted (Actual)

July 21, 2023

Study Record Updates

Last Update Posted (Actual)

November 22, 2023

Last Update Submitted That Met QC Criteria

November 20, 2023

Last Verified

November 1, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • STU00217993

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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