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

Abstract

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.

Tongue control of a five-DOF upper-limb exoskeleton rehabilitates drinking and eating for individuals with severe disabilities

“…The EXOTIC Exo (Fig. 2) consisted of four actuated joints on the right arm namely shoulder flexion/extension, shoulder external/ internal rotation, elbow flexion/extension, wrist supination/pronation (Thøgersen et al, 2020(Thøgersen et al, , 2022. A CarbonHand (BioServo, Sweden) exoskeleton closed the hand for grasping objects, and a passive elastic mechanism opened the hand (Thøgersen et al, 2020).…”

“…We used MoveIt (Coleman et al, 2014) and jog_control (Tajima et al, 2020) ROS packages for inverse kinematics and trajectory planning, resulting in velocity control in a Cartesian frame. More details of the low-level control are described in another paper (Thøgersen et al, 2022).…”

Frame-Based Slip Detection for an Underactuated Robotic Gripper for Assistance of Users with Disabilities

“…This necessitated stabilizing the frames relative to the end effector movements, which could potentially have influenced the results. However, the fact that our algorithm performed well on artificially stabilized image data suggests that potential applications with a stationary or non-endeffector-attached camera, like the EXOTIC Exoskeleton [22], are feasible. The EXOTIC Exoskeleton is a 5-DoF upper limb exoskeleton, controlled by a tongue-computer interface, where the camera is located on the user's shoulder, rather than the end effector or wrist.…”

Emotional design of medical devices: exoskeletons and post-stroke recovery devices

“…al, 2020). The project built on user requirements (Thøgersen, M. B. et. al, 2022) and users' perception of exoskeletons by Kobbelgaard, F., et al, (2021).…”