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Exoskeleton Variability Optimization

Primary Purpose

Peripheral Arterial Disease

Status

Recruiting

Phase

Not Applicable

Locations

United States

Study Type

Interventional

Intervention

Exoskeleton optimization

Endurance evaluation

About this trial

This is an interventional basic science trial for Peripheral Arterial Disease focused on measuring Exoskeleton

Eligibility Criteria

19 Years - 85 Years (Adult, Older Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

Ability to provide written consent
Chronic claudication history
Ankle-brachial index < 0.90 at rest
Stable blood pressure, lipides, and diabetes for > 6 weeks
Ability to walk on a treadmill for multiple five-minute spans.
Ability to fit in exoskeleton: waist circumference 78 to 92 centimeters, thigh circumference 48 to 60 centimeters, minimal thigh length 28 centimeters.

Exclusion Criteria:

Rest pain or tissue loss due to peripheral artery disease (Fontaine stage III and IV).
Foot ulceration.
Acute lower extremity event secondary to thromboembolic disease or acute trauma
Walking capacity limited by diseases which are unrelated to peripheral artery disease such as:

Neurological disorders, musculoskeletal disorders (arthritis, scoliosis, stroke, spinal injury, etc.), a history of ankle instability, knee injury, diagnosed joint laxity, lower limb injury, surgery within the past 12 months, joint replacement, pulmonary disease or breathing disorders, cardiovascular disease, or vestibular disorder. This will be determined by verbal questioning from research personnel by verbally asking about conditions limiting their walking, whether subjects are taking medications for those conditions, and physicians' recommendations about limiting activity.

Acute injury or pain in their lower extremity or current illness.
Inability to follow visual cues due to blindness.
Inability to follow auditory cues due to deafness.
Women who are currently pregnant are excluded for safety reasons.

Sites / Locations

University of Nebraska OmahaRecruiting

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Arm Label

Optimal assistance pattern

Effects on endurance

Arm Description

An optimization algorithm will change the assistance pattern on the hip exoskeleton during walking sessions and the optimal assistance pattern will be determined when gait variability is minimized.

Determine effects on endurance of participants using ground reaction force (Bertec treadmill), walking speed (Bertec treadmill), indirect calorimetry (Cosmed), and motion capture (Vicon).

Outcomes

Primary Outcome Measures

Time to convergence

We will determine when the estimated optimal exoskeleton settings vary less than 10%

Peak extension timing

Timing of peak extension moment of exoskeleton (% stride cycle)

Peak flexion timing

Timing of peak flexion moment of exoskeleton (% stride cycle)

Largest lyapunov exponent

Largest lyapunov exponent of lower limb kinematics

Secondary Outcome Measures

Full Information

NCT ID

NCT04338815

First Posted

April 3, 2020

Last Updated

September 29, 2023

Sponsor

University of Nebraska

1. Study Identification

Unique Protocol Identification Number

NCT04338815

Brief Title

Exoskeleton Variability Optimization

Official Title

Exoskeleton Variability Optimization for Reducing Gait Variability for Patients With Peripheral Artery Disease

Study Type

Interventional

2. Study Status

Record Verification Date

September 2023

Overall Recruitment Status

Recruiting

Study Start Date

January 31, 2022 (Actual)

Primary Completion Date

September 1, 2024 (Anticipated)

Study Completion Date

September 1, 2024 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title

Sponsor

Name of the Sponsor

University of Nebraska

4. Oversight

Studies a U.S. FDA-regulated Drug Product

Studies a U.S. FDA-regulated Device Product

Data Monitoring Committee

Yes

5. Study Description

Brief Summary

The investigators will evaluate a potentially faster and more clinically feasible method to optimize exoskeletons in pilot tests in healthy in preparation for patients with peripheral artery disease.

Detailed Description

This study will test different methods for optimizing exoskeletons. It will consist of an habituation session to the hip exoskeleton, an optimization session to find the optimal actuation settings using an algorithm that converges toward the optimum based on real-time measurements (human-inthe-loop algorithm) and a post-test at the end of optimization session to compare different conditions. The outcomes will be evaluated by surface electromyography (Delsys), exoskeleton sensors (Futek), ground reaction force (Bertec treadmill), walking speed (Bertec treadmill), indirect calorimetry (Cosmed), and motion capture (Vicon).

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study

Peripheral Arterial Disease

Keywords

Exoskeleton

7. Study Design

Primary Purpose

Basic Science

Study Phase

Not Applicable

Interventional Study Model

Parallel Assignment

Masking

None (Open Label)

Allocation

Non-Randomized

Enrollment

22 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title

Optimal assistance pattern

Arm Type

Experimental

Arm Description

An optimization algorithm will change the assistance pattern on the hip exoskeleton during walking sessions and the optimal assistance pattern will be determined when gait variability is minimized.

Arm Title

Effects on endurance

Arm Type

Experimental

Arm Description

Determine effects on endurance of participants using ground reaction force (Bertec treadmill), walking speed (Bertec treadmill), indirect calorimetry (Cosmed), and motion capture (Vicon).

Intervention Type

Other

Intervention Name(s)

Exoskeleton optimization

Intervention Description

Participants will walk 10 times of 1 minute duration while an optimization algorithm changes the assistance profile of an exoskeleton.

Intervention Type

Other

Intervention Name(s)

Endurance evaluation

Intervention Description

Participants will walk 2 times at a speed of 1 meter per second until the participant indicates claudication or a maximum duration of 6 minutes.

Primary Outcome Measure Information:

Title

Time to convergence

Description

We will determine when the estimated optimal exoskeleton settings vary less than 10%

Time Frame

10 minutes

Title

Peak extension timing

Description

Timing of peak extension moment of exoskeleton (% stride cycle)

Time Frame

20 seconds

Title

Peak flexion timing

Description

Timing of peak flexion moment of exoskeleton (% stride cycle)

Time Frame

20 seconds

Title

Largest lyapunov exponent

Description

Largest lyapunov exponent of lower limb kinematics

Time Frame

20 seconds

10. Eligibility

Sex

All

Minimum Age & Unit of Time

19 Years

Maximum Age & Unit of Time

85 Years

Accepts Healthy Volunteers

Eligibility Criteria

Inclusion Criteria: Ability to provide written consent Chronic claudication history Ankle-brachial index < 0.90 at rest Stable blood pressure, lipides, and diabetes for > 6 weeks Ability to walk on a treadmill for multiple five-minute spans. Ability to fit in exoskeleton: waist circumference 78 to 92 centimeters, thigh circumference 48 to 60 centimeters, minimal thigh length 28 centimeters. Exclusion Criteria: Rest pain or tissue loss due to peripheral artery disease (Fontaine stage III and IV). Foot ulceration. Acute lower extremity event secondary to thromboembolic disease or acute trauma Walking capacity limited by diseases which are unrelated to peripheral artery disease such as: Neurological disorders, musculoskeletal disorders (arthritis, scoliosis, stroke, spinal injury, etc.), a history of ankle instability, knee injury, diagnosed joint laxity, lower limb injury, surgery within the past 12 months, joint replacement, pulmonary disease or breathing disorders, cardiovascular disease, or vestibular disorder. This will be determined by verbal questioning from research personnel by verbally asking about conditions limiting their walking, whether subjects are taking medications for those conditions, and physicians' recommendations about limiting activity. Acute injury or pain in their lower extremity or current illness. Inability to follow visual cues due to blindness. Inability to follow auditory cues due to deafness. Women who are currently pregnant are excluded for safety reasons.

Central Contact Person:

First Name & Middle Initial & Last Name or Official Title & Degree

Philippe Malcolm, PhD

Phone

617-487-1148

pmalcolm@unomaha.edu

Overall Study Officials:

First Name & Middle Initial & Last Name & Degree

Philippe Malcolm

Organizational Affiliation

University of Nebraska

Official's Role

Principal Investigator

Facility Information:

Facility Name

University of Nebraska Omaha

City

Omaha

State/Province

Nebraska

ZIP/Postal Code

68182

Country

United States

Individual Site Status

Recruiting

Facility Contact:

First Name & Middle Initial & Last Name & Degree

Philippe Malcolm, PhD

Phone

402-554-4182

pmalcolm@unomaha.edu

First Name & Middle Initial & Last Name & Degree

Philippe Malcolm, PhD

12. IPD Sharing Statement

Plan to Share IPD

Learn more about this trial

Exoskeleton Variability Optimization

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