The PneuHOPE Hand Exoskeleton: A Platform for Studying Brain Activation During Robot-Facilitated Hand Movement Using fMRI

Abstract

Upper motor neuron injuries such as traumatic brain injury and stroke can cause hemiparesis and subsequent hand impairment. Repeated hand movements in physical therapy are shown to maintain flexibility and potentially facilitate regaining functionality. To further understand the impact of hand exoskeletons on motor impairment and recovery, we aim to study brain activation during rehabilitation and assistive hand exoskeleton use. Functional magnetic resonance imaging (fMRI) can be used to measure brain activation with high spatial resolution, but devices used within a magnetic resonance imaging (MRI) machine must be designed within several constraints. We present the design of a pneumatic hand orthosis with powered extension—the PneuHOPE Hand—a wearable MRI conditional research platform to enable the studying of brain activation in the presence of hand spasticity. To demonstrate its use as an MRI compatible platform, we conducted MRI conditionality testing. Additionally, we collected brain activation data from two healthy control subject’s using fMRI to show that the exoskeleton can be comfortably worn in the MRI scanner and that appropriate brain activation data can be collected during use. The results indicate the PneuHOPE Hand platform can be safely used for neuroimaging studies in the MRI with < 12% reduction in SNR for T1 images, < 32% reduction for T2, and no visible paramagnetic artifacts.