The H2 robotic exoskeleton for gait rehabilitation after stroke: early findings from a clinical study

Abstract

BackgroundStroke significantly affects thousands of individuals annually, leading to considerable physical impairment and functional disability. Gait is one of the most important activities of daily living affected in stroke survivors. Recent technological developments in powered robotics exoskeletons can create powerful adjunctive tools for rehabilitation and potentially accelerate functional recovery. Here, we present the development and evaluation of a novel lower limb robotic exoskeleton, namely H2 (Technaid S.L., Spain), for gait rehabilitation in stroke survivors.MethodsH2 has six actuated joints and is designed to allow intensive overground gait training. An assistive gait control algorithm was developed to create a force field along a desired trajectory, only applying torque when patients deviate from the prescribed movement pattern. The device was evaluated in 3 hemiparetic stroke patients across 4 weeks of training per individual (approximately 12 sessions). The study was approved by the Institutional Review Board at the University of Houston. The main objective of this initial pre-clinical study was to evaluate the safety and usability of the exoskeleton. A Likert scale was used to measure patient’s perception about the easy of use of the device.ResultsThree stroke patients completed the study. The training was well tolerated and no adverse events occurred. Early findings demonstrate that H2 appears to be safe and easy to use in the participants of this study. The overground training environment employed as a means to enhance active patient engagement proved to be challenging and exciting for patients. These results are promising and encourage future rehabilitation training with a larger cohort of patients.ConclusionsThe developed exoskeleton enables longitudinal overground training of walking in hemiparetic patients after stroke. The system is robust and safe when applied to assist a stroke patient performing an overground walking task. Such device opens the opportunity to study means to optimize a rehabilitation treatment that can be customized for individuals.Trial registration: This study was registered at ClinicalTrials.gov (https://clinicaltrials.gov/show/NCT02114450).

Brain–machine interfaces for controlling lower-limb powered robotic systems

“…Falls, skin damage, and bone fracture are among the foreseeable risks of using exoskeletons, requiring continued vigilance from researchers. Several pilot studies have concluded that it is feasible and safe for the clinical population to use exoskeletons (Kolakowsky-Hayner 2013, Bortole et al 2015, Yang et al 2015. However, their conclusions were reached because no injuries were reported in these studies, which generally consist of a limited number of subjects and sessions.…”

Robust Real-Time Musculoskeletal Modeling Driven by Electromyograms

“…the need for recording from large sets of muscles. Applications will also include the interfacing of our proposed framework with wearable assistive technologies for restoring (robotic exoskeletons) [51] or replacing (artificial limbs) [30] lost motor capacity. In this context, previously proposed offline neuromusculoskeletal modeling formulations demonstrated to successfully capture patient-specific musculoskeletal function in conditions including cerebral palsy [52], stroke [14] or quadriceps weakness [30].…”

Design and evaluation of a new exoskeleton for gait rehabilitation

“…Another research theme from this subject area is the development and evaluation of a new leg robotic exoskeleton, called H2, intended for gait rehabilitation of the stroke survivors (Bortole et al, 2015). In order to guide the development of lower limb exoskeletons, some studies (Kao et al, 2010) had, as purpose, the understanding of how humans adapt to powered assistance.…”