NCT04338815

Exoskeleton Variability Optimization

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

• Status: Terminated
• Phase: N/A
• Study type: Interventional
• Enrollment: 9 (actual)
• Sponsor: University of Nebraska · Academic / Other
• Sex: All
• Age: 19 Years – 85 Years
• Healthy volunteers: Accepted

Summary

Exoskeletons, wearable devices that assist with walking, can improve mobility in clinical populations. With exoskeletons, it is crucial to optimize the assistance profile. Recent studies describe algorithms (i.e., human-in-the-loop) to optimize the assistance profile with real-time metabolic measurements. The needed duration of current human-in-the-loop (HITL) algorithms range from 20 minutes to 1 hour which is longer than the average duration that most patients with peripheral artery disease (PAD) can walk. Because of this limited walking duration, it is often not possible for patients with PAD to reach steady-state metabolic cost, which makes these measurements are not useful for optimizing exoskeletons. In this study, investigators intend to develop and evaluate HITL optimization methods for exoskeletons and use the information to design and evaluate a portable hip exoskeleton. Shorter and more clinically feasible HITL optimization strategies based on experiments in healthy adults might allow utilizing these optimization strategies to become available for patient populations such as patients with PAD.

Detailed description

Exoskeletons, wearable devices that assist with walking, can improve mobility in clinical populations. With exoskeletons, it is crucial to optimize the assistance profile. Recent studies describe algorithms (i.e., human-in-the-loop) to optimize the assistance profile with real-time metabolic measurements. The needed duration of current human-in-the-loop (HITL) algorithms range from 20 minutes to 1 hour which is longer than the average duration that most patients with peripheral artery disease (PAD) can walk. Because of this limited walking duration, it is often not possible for patients with PAD to reach steady-state metabolic cost, which makes these measurements are not useful for optimizing exoskeletons. Shorter and more clinically feasible HITL optimization strategies based on experiments in healthy adults might allow utilizing these optimization strategies to become available for patient populations such as patients with PAD. 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-in-the-loop algorithm) and a post-test at the end of optimization session to compare different conditions. The outcomes will be evaluated by surface electromyography, exoskeleton sensors, ground reaction force, walking speed, indirect calorimetry, and motion capture (Vicon).

Conditions

• Peripheral Arterial Disease

Interventions

Type	Name	Description
OTHER	Exoskeleton Optimization	Participants will walk 10-minute trials while an optimization algorithm changes the assistance profile of the exoskeleton.
OTHER	Endurance Evaluation	Participants will walk 2 trials at a speed of 1 meter per second until the participant indicates claudication or a maximum duration of 6 minutes, which ever comes first.

Timeline

• Start date: 2022-01-31
• Primary completion: 2025-03-28
• Completion: 2025-03-28
• First posted: 2020-04-08
• Last updated: 2025-06-19
• Results posted: 2025-06-19

Locations

1 site across 1 country: United States