Brain-State Dependent Stimulation boosts functional recovery following stroke

This is the peer reviewed version of the following article: “Brain-State Dependent Stimulation boosts functional recovery following stroke”, which has been published in final form at http://dx.doi.org/10.1002/ana.25375. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived.Objective Adjuvant protocols devised to enhance motor recovery in subacute stroke patients have failed to show benefits with respect to classic therapeutic interventions. Here we evaluate the efficacy of a novel brain-state dependent intervention based on known mechanisms of memory and learning, that is integrated as part of the weekly rehabilitation program in subacute stroke patients. Methods Twenty-four hospitalized subacute stroke patients were randomly assigned to two intervention groups; 1. The associative group received thirty pairings of a peripheral electrical nerve stimulus (ES) such that the generated afferent volley arrived precisely during the most active phase of the motor cortex as patients attempted to perform a movement; 2. In the control group the ES intensity was too low to generate a stimulation of the nerve. Functional (including the lower extremity Fugl-Meyer assessment (LE-FM; primary outcome measure)) and neurophysiological (changes in motor evoked potentials (MEPs)) assessments were performed prior to and following the intervention period. Results The associative group significantly improved functional recovery with respect to the control group (median (interquartile range) LE-FM improvement: 6.5 (3.5-8.25) and 3 (0.75-3), respectively; p=0.029). Significant increases in MEP amplitude were seen following all sessions in the associative group only (p’s≤0.006). Interpretation This is the first evidence of a clinical effect of a neuromodulatory intervention in the subacute phase of stroke. This was evident with relatively few repetitions in comparison to available techniques, making it a clinically-viable approach. The results indicate the potential of the proposed neuromodulation system in daily clinical routine for stroke rehabilitation. This article is protected by copyright. All rights reserved.Kong Christian den Tiendes Fond (39/2016

Eyes-free tongue gesture and tongue joystick control of a five DOF upper-limb exoskeleton for severely disabled individuals

Spinal cord injury can leave the affected individual severely disabled with a low level of independence and quality of life. Assistive upper-limb exoskeletons are one of the solutions that can enable an individual with tetraplegia (paralysis in both arms and legs) to perform simple activities of daily living by mobilizing the arm. Providing an efficient user interface that can provide full continuous control of such a device—safely and intuitively—with multiple degrees of freedom (DOFs) still remains a challenge. In this study, a control interface for an assistive upper-limb exoskeleton with five DOFs based on an intraoral tongue-computer interface (ITCI) for individuals with tetraplegia was proposed. Furthermore, we evaluated eyes-free use of the ITCI for the first time and compared two tongue-operated control methods, one based on tongue gestures and the other based on dynamic virtual buttons and a joystick-like control. Ten able-bodied participants tongue controlled the exoskeleton for a drinking task with and without visual feedback on a screen in three experimental sessions. As a baseline, the participants performed the drinking task with a standard gamepad. The results showed that it was possible to control the exoskeleton with the tongue even without visual feedback and to perform the drinking task at 65.1% of the speed of the gamepad. In a clinical case study, an individual with tetraplegia further succeeded to fully control the exoskeleton and perform the drinking task only 5.6% slower than the able-bodied group. This study demonstrated the first single-modal control interface that can enable individuals with complete tetraplegia to fully and continuously control a five-DOF upper limb exoskeleton and perform a drinking task after only 2 h of training. The interface was used both with and without visual feedback

User Based Development and Test of the EXOTIC Exoskeleton:Empowering Individuals with Tetraplegia Using a Compact, Versatile, 5-DoF Upper Limb Exoskeleton Controlled through Intelligent Semi-Automated Shared Tongue Control

This paper presents the EXOTIC- a novel assistive upper limb exoskeleton for individuals with complete functional tetraplegia that provides an unprecedented level of versatility and control. The current literature on exoskeletons mainly focuses on the basic technical aspects of exoskeleton design and control while the context in which these exoskeletons should function is less or not prioritized even though it poses important technical requirements. We considered all sources of design requirements, from the basic technical functions to the real-world practical application. The EXOTIC features: (1) a compact, safe, wheelchair-mountable, easy to don and doff exoskeleton capable of facilitating multiple highly desired activities of daily living for individuals with tetraplegia; (2) a semi-automated computer vision guidance system that can be enabled by the user when relevant; (3) a tongue control interface allowing for full, volitional, and continuous control over all possible motions of the exoskeleton. The EXOTIC was tested on ten able-bodied individuals and three users with tetraplegia caused by spinal cord injury. During the tests the EXOTIC succeeded in fully assisting tasks such as drinking and picking up snacks, even for users with complete functional tetraplegia and the need for a ventilator. The users confirmed the usability of the EXOTIC