Stroke is the leading cause of long-term disability worldwide. However, despite extensive rehabilitation efforts, marked physical inactivity remains emblematic of individuals in the chronic phase of stroke recovery and contributes to poor health and quality of life. For poststroke rehabilitation to be better positioned to enable more physical activity, factors such as insufficient training dosage and poor ecological validity, which limit the effectiveness of clinic-based gait training, must be overcome. Community-based rehabilitation approaches can overcome these limitations; however, the amount of walking practice that they are able to leverage is inherently limited by the reduced walking capacity typical after stroke. Indeed, recent work has shown that despite producing some improvement in poststroke walking activity, individuals still remain largely sedentary after community-based walking programs. A critical need thus exists for rehabilitation technologies that bridge the gap between the clinic and the real world and facilitate the massed walking practice in salient contexts that is necessary to induce experience-dependent neuroplasticity. In response to this need, we are developing lightweight and unobtrusive soft wearable robots (exosuits) suitable for community-based rehabilitation after stroke. Exosuits use innovative force-transmitting, conformal textiles that anchor to the body and proximally-mounted, lightweight, cable-based actuation systems to generate assistive joint forces. Adaptive control algorithms that use signals from the minimum number of sensors direct the timing of assistance. These innovative wearable robots have the potential to increase an individual's capacity for community ambulation. Indeed, we have demonstrated through preliminary treadmill-based studies that an ankle-assisting exosuit produces paretic limb functional restoration in a manner that induces gait symmetry, reduces the energy cost of walking, and increases walking stability. In contrast to the rigid exoskeletons that have dominated the last half century, exosuits provide partial assistance through a lightweight platform (<3kg overall, including motors and batteries) that requires low power (<100W), can be used unilaterally, and does not impose an unnatural gait on the wearer. The exosuit technology is ideally suited to assisting the impaired gait of individuals poststroke who have residual walking capacity. This technology development-focused project seeks to build gait-restorative exosuits made of modular components that can be easily assembled to serve the heterogeneous needs of individuals poststroke. This project will optimize existing ankle, knee, and hip modules that have undergone >1000 hours of testing on >130 healthy and impaired subjects for use by persons poststroke in clinical- and community- settings. This work will be completed by a multidisciplinary team of engineers, clinicians, and researchers. Qualitative and quantitative data gathered from patients and other stakeholders will inform all development.

Public Health Relevance

Stroke is the leading cause of long-term disability worldwide. However, despite extensive rehabilitation efforts, marked physical inactivity remains emblematic of individuals in the chronic phase of stroke recovery and contributes to poor health and quality of life. For poststroke rehabilitation to be better positioned to enable more physical activity, factors such as insufficient training dosage and poor ecological validity, which limit the effectiveness of clinic-based gait training, must be overcome. In response to this need, we are developing a modular exosuit platform that can assist any combination of the paretic ankle, knee, and hip to increase an individual's walking capacity in the clinic or community through the unique use of force-transmitting, conformal textiles that anchor to the body, proximally-mounted cable-based actuation systems, wearable sensors, and adaptive control algorithms.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
1R01HD088619-01A1
Application #
9260493
Study Section
Musculoskeletal Rehabilitation Sciences Study Section (MRS)
Program Officer
Quatrano, Louis A
Project Start
2016-09-22
Project End
2021-05-31
Budget Start
2016-09-22
Budget End
2017-05-31
Support Year
1
Fiscal Year
2016
Total Cost
$707,284
Indirect Cost
$250,543
Name
Harvard Medical School
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115