Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03924765 |
| Other study ID # |
H19179 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
July 24, 2019 |
| Est. completion date |
November 19, 2020 |
Study information
| Verified date |
October 2021 |
| Source |
Georgia Institute of Technology |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The increased metabolic and biomechanical demands of ambulation limit community mobility in
persons with lower limb disability due to neurological damage. There is a critical need for
improving the locomotion capabilities of individuals with stroke to increase their community
mobility, independence, and health. Robotic exoskeletons have the potential to assist these
individuals by increasing community mobility to improve quality of life. While these devices
have incredible potential, current technology does not support dynamic movements common with
locomotion such as transitioning between different gaits and supporting a wide variety of
walking speeds. One significant challenge in achieving community ambulation with exoskeletons
is providing an adaptive control system to accomplish a wide variety of locomotor tasks. Many
exoskeletons today are developed without a detailed understanding of the effect of the device
on the human musculoskeletal system. This research is interested in studying the question of
how the control system affects stroke biomechanics including kinematic, kinetics and muscle
activation patterns. By optimizing exoskeleton controllers based on human biomechanics and
adapting control based on task, the biggest benefit to patient populations will be achieved
to help advance the state-of-the-art with assistive hip exoskeletons.
Description:
One significant challenge in achieving community ambulation with exoskeletons is providing an
adaptive control system to accomplish a wide variety of locomotor tasks. Many exoskeletons
today are developed without a detailed understanding of the effect of the device on the human
musculoskeletal system. The study is interested in exploring the question of how the control
system affects human biomechanics including kinematic, kinetics and muscle activation
patterns. By optimizing exoskeleton controllers based on human biomechanics and adapting
control based on task, this work will be able to provide the biggest benefit to patients and
advance the state-of-the-art with assistive hip exoskeletons. A large patient population that
could benefit from lower limb assistive technology are stroke survivors, which is the
specific population this proposal targets. One common characteristic of stroke survivors who
regain their ability to walk is that the hip muscles are overtaxed due to distal weakness.
The investigators propose to use a powered hip exoskeleton to augment their proximal
musculature, which needs to produce significant power output in most locomotion activities
such as standing up, walking, and going up stairs or slopes. Another biomechanical aspect of
stroke survivors is an asymmetric gait in terms of kinematics, kinetics and muscle
activations. The research will examine what kind of exoskeleton assistance is most beneficial
to stroke survivors for enhancing community ambulation. The hypothesis is that since the gait
is asymmetric, the controller will need to be asymmetric to provide optimal assistance to aid
in mobility. The long-term research goal is to create powered assistive exoskeletons devices
that are of great value to individuals with serious lower limb disabilities by improving
clinical outcomes such as walking speed and community ambulation ability. The overall
objective of the proposed project is to study the biomechanical effects of using a hip
exoskeleton with adaptive controllers for assisting stroke survivors with lower limb deficits
to improve their community ambulation capabilities. The central hypothesis overarching both
aims is that exoskeleton control that adapts to environmental terrain will improve mobility
metrics for human exoskeleton users on community ambulation tasks. The rationale is that
since human biomechanics change based on task, exoskeleton controllers likewise need to
optimize their assistance levels to match what the human is doing. The team has previously
designed and extensively tested an autonomous hip exoskeleton in able-bodied subjects on a
treadmill and plan to follow this up with a separate study on able bodied subjects during
overground locomotion of walking, stairs, and ramps. The aim of this study is to translate an
autonomous robotic hip exoskeleton to provide adaptive assistance in community ambulation for
stroke survivors with mobility impairment. The team will analyze the biomechanical effects
and clinical benefits with using an autonomous hip exoskeleton for a walking impaired user
(due to stroke). The primary hypothesis for this aim is that stroke survivors will increase
their mobility in community ambulation tasks using the adaptive control framework. A
sub-hypothesis is that stroke survivors who present with unilateral impairment will have
superior biomechanical and clinical outcomes using a controller with asymmetric assistance.
The investigators expect a controller that provides a greater assistance to the impaired side
to improve overall symmetry and help the stroke survivor maintain a more efficient gait
pattern to help improve walking speed (primary outcome measure). The expected outcome of
these aims will be an increased understanding of the biomechanical and clinical effects in
applying hip assistance with a robotic exoskeleton in community ambulation tasks such as
overground walking, ramps and stairs. This work will serve as a foundational start for a
broader planned study of optimizing controllers to improve biomechanics in the walking
impaired using powered hip autonomous exoskeletons. This aim will have a positive impact by
helping to inform the design and control of future exoskeleton for assisting individuals with
lower limb disabilities, with specific insight in stroke survivors with mobility impairment.
