Recruiting

Hip Exoskeleton

Sponsor:

North Carolina State University

Code:

NCT05447884

Conditions

Stroke

Eligibility Criteria

Sex: All

Age: 18 - 64

Healthy Volunteers: Accepted

Interventions

A zero impedance mode, controlling a wearable bilateral hip exoskeleton

A personalized optimal assistance mode, controlling a wearable bilateral hip exoskeleton

A free walking mode, without wearing a wearable bilateral hip exoskeleton

Study Details

Brief summary:

Robotic lower limb exoskeletons aim to improve or augment limb functions. Automatic modulation of robotic assistance is very important because it can increase the assistive outcomes and guarantee safety when using exoskeletons.

However, this automatic assistance adjustment is challenging due to person-to-person and day-to-day variations, as well as the time-varying complex human-machine-interaction forces. In recent years, human-in-the-loop optimization methods have been investigated to reduce participants' metabolic costs by providing personalized assistance from robotic exoskeletons. However, metabolic cost measure is noisy and the experimental protocol is usually relatively long. In addition, the influence of exoskeleton control on this human state in terms of energetic cost is unclear and indirect. More importantly, the optimization by reducing metabolic cost is found to affect human gait patterns and cause undesired outcomes. In this study, new evaluation measures other than metabolic cost will be investigated to optimize the assistance from a powered hip exoskeleton based on a reinforcement learning method. It is hypothesized that the new reinforcement learning-based optimal control approach will produce personalized torque assistance, reduce human volitional effort, and improve balance and other performance during walking tasks. Both participants without and with neurological disorders will be included in this study.

Conditions

Stroke

Study ID

NCT05447884

Start date

Jun 1, 2022

Status verified date

Dec, 2023

Completion date

Dec 31, 2025

Anticipated

Primary completion date

Dec 31, 2024

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 64

Healthy Volunteers: Accepted

Inclusion Criteria for non-neurologically affected populations:

  • Between 18 and 64 years old
  • Live in the United States
  • Able to understand study requirements and sign an informed consent
  • Have full range of motion in your hip joint
  • Able to walk normally without any assistance.

Exclusion Criteria for non-neurologically affected populations:

  • Cannot follow instructions or provide feedback due to cognitive or language limitations
  • Suffered from a stroke that affects balance or walking
  • Use an electronically controlled medical device, such as a pacemaker, implanted defibrillator, or drug pump
  • Pregnancy
  • Experience numbness, tingling, muscle weakness, pain, or paralysis in any part of your body
  • Cannot walk or balance without help from a person or a tool, such as a walker or cane
  • Limited movement in your hip or ankle
  • You have any skin-related allergies or irritation to adhesives
  • Have blood circulation, heart, metabolic, or cognitive disorders, including but not limited to: Peripheral vascular disease, Pitting edema, Heart disease, Diabetes (uncontrolled), Seizures, and Cognitive diagnoses that affect their ability to process information.

Inclusion Criteria for subjects who suffered a stroke:

  • Between 18 and 64 years old
  • Live in the United States
  • Able to understand study requirements and sign an informed consent
  • Have weakness on one side of their body due to a stroke within the past 6 months
  • Have the doctor confirm that the subjects had a stroke within the past 6 months
  • Can walk without any assistance for at least 6 minutes and 1000 feet (a little less than a quarter-mile)
  • Can walk at a speed of 1 mile per hour
  • Have normal or corrected-to-normal vision and hearing
  • Capable of safely stepping on stairs without an Ankle-Foot Orthosis but may use canes as needed

Exclusion Criteria for subjects who suffered a stroke:

  • Cannot follow instructions or provide feedback due to cognitive, spatial awareness, and/or language limitations
  • Are pregnant
  • Cannot walk without an ankle-foot brace or a therapist's assistance
  • Cannot walk or balance without the help of a tool, such as a walker or cane
  • Have vision, balance, or reaching issues unrelated to stroke
  • Use an electronically controlled medical device, such as a pacemaker, implanted defibrillator, or drug pump
  • Have numbness, tingling, muscle weakness, or pain in any part of your body
  • Have any skin related allergies or irritation to adhesives
  • Have blood circulation, heart, metabolic, or cognitive disorders, including but not limited to: Peripheral vascular disease, Pitting edema, Heart disease, Diabetes (uncontrolled), and Seizures.

Study Design

Enrollment

100 participants

Anticipated

Allocation

Non randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Group A - Participants without neurological disorders

Individuals without any neurological disorders will be recruited (Group A). Usually, participants from this group are able to walk normally on different terrains and at multiple typical walking speeds.

experimental: Group B - Participants with paretic stroke

Individuals with paretic stroke will be recruited (Group S). Usually, participants from this group have limited hip joint motion of range, weakened hip joint flexion or extension, or both flexion and extension functionalities, but they can also walk independently.

Interventions

A zero impedance mode, controlling a wearable bilateral hip exoskeleton

The bilateral hip exoskeleton has two degrees of freedom to enable the hip joint extension and flexion movement on both left and right sides. The zero impedance mode will not provide any assistance or resistance to the hip joints.

A personalized optimal assistance mode, controlling a wearable bilateral hip exoskeleton

The personalized optimal assistance mode includes both individualized hip flexion and hip extension assistance, which is determined by using the reinforcement learning-based automatic control parameters tuning during walking tasks. Therefore, the personalized optimal assistance will be able to improve the walking gait performance and reduce the energetic consumption.

A free walking mode, without wearing a wearable bilateral hip exoskeleton

The free walking mode will not include the usage of the wearable bilateral hip exoskeleton, and the human walking subjects will conduct pure natural walking tasks.

Primary outcome measure

  • Human lower limb joints angular position [ Time Frame: Through study completion, an average of 55 months. ]
  • Human lower limb joints angular velocity [ Time Frame: Through study completion, an average of 55 months. ]

Central Contacts and Locations

Central contacts

Qiang Zhang, Ph.D.

412-628-4758qzhang25@ncsu.edu

Laura Rohrbaugh

919-513-3840lasmith6@ncsu.edu

Locations

North Carolina State University

Recruiting

Raleigh, North Carolina, United States, 27695

Contacts

Helen Huang, Ph.D.

919-515-5218hhuang11@ncsu.edu

Laura Rohrbaugh

919-513-3840lasmith6@ncsu.edu

Principal Investigator:

Helen Huang, Ph.D.

More Information

Sponsor

North Carolina State University

Last update posted

Dec 20, 2023

Last verified

Dec, 2023

Keywords

  • Hip exoskeleton
  • Assistance personalization
  • Walking balance
  • Walking energetics
  • Reinforcement learning
  • Adaptive optimal control
  • Learning-based control
  • Gait analysis
  • Human-in-the-loop optimization
  • Human-robot-interaction

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by North Carolina State University on 2023-12-20.