Towards a Platform for Robot-Assisted Minimally-Supervised Therapy of Hand Function: Design and Pilot Usability Evaluation

Abstract

BackgroundRobot-assisted therapy can increase therapy dose after stroke, which is often considered insufficient in clinical practice and after discharge, especially with respect to hand function. Thus far, there has been a focus on rather complex systems that require therapist supervision. To better exploit the potential of robot-assisted therapy, we propose a platform designed for minimal therapist supervision, and present the preliminary evaluation of its immediate usability, one of the main and frequently neglected challenges for real-world application. Such an approach could help increase therapy dose by allowing the training of multiple patients in parallel by a single therapist, as well as independent training in the clinic or at home.MethodsWe implemented design changes on a hand rehabilitation robot, considering aspects relevant to enabling minimally-supervised therapy, such as new physical/graphical user interfaces and two functional therapy exercises to train hand motor coordination, somatosensation and memory. Ten participants with chronic stroke assessed the usability of the platform and reported the perceived workload during a single therapy session with minimal supervision. The ability to independently use the platform was evaluated with a checklist.ResultsParticipants were able to independently perform the therapy session after a short familiarization period, requiring assistance in only 13.46 (7.69–19.23)% of the tasks. They assigned good-to-excellent scores on the System Usability Scale to the user-interface and the exercises [85.00 (75.63–86.88) and 73.75 (63.13–83.75) out of 100, respectively]. Nine participants stated that they would use the platform frequently. Perceived workloads lay within desired workload bands. Object grasping with simultaneous control of forearm pronosupination and stiffness discrimination were identified as the most difficult tasks.DiscussionOur findings demonstrate that a robot-assisted therapy device can be rendered safely and intuitively usable upon first exposure with minimal supervision through compliance with usability and perceived workload requirements. The preliminary usability evaluation identified usability challenges that should be solved to allow real-world minimally-supervised use. Such a platform could complement conventional therapy, allowing to provide increased dose with the available resources, and establish a continuum of care that progressively increases therapy lead of the patient from the clinic to the home.

Design, characterization and preliminary usability testing of a portable robot for unsupervised therapy of hand function

“…Our approach was to develop HandyBot as a portable and more easily scalable haptic device that could offer the same type of sensorimotor therapy as the HK and the RHK, with the longterm objective of independent training in the home environment. To ensure the compatibility with therapy exercises previously clinically validated (Metzger et al, 2014b;Ranzani et al, 2019;Ranzani et al, 2021) and guarantee training conditions similar to the interaction with real objects, the same movements (i.e., grasping and forearm pronosupination) should be trained through an end-effector approach. Moreover, given its relevance in ADL tasks (Nelson et al, 1994;Reissner et al, 2019) and its important synergies with grasping functions (Pezent et al, 2017), it was decided to add a third degree of freedom (DOF) to train wrist flexion-extension (FE).…”

“…It includes two sections, one for the user and one for the therapist to customize the therapy parameters, for example, before the first therapy session. For more details, please refer to (Ranzani et al, 2021).…”

“…As a result, only few robotic devices for upper limb rehabilitation have been proposed and tested for use in different environments (e.g., home (Lemmens et al, 2014;Sivan et al, 2014;Wolf et al, 2015;Hyakutake et al, 2019;McCabe et al, 2019)), often without an indepth evaluation of their technical performance. Furthermore, little is known about their usability, which should be assessed already in early development stages to optimize the device design based on the user needs (Meyer et al, 2021), as well as increase acceptance and user compliance to a therapy plan (Lee et al, 2005;Lu et al, 2011;Just et al, 2018;Meyer et al, 2019;Ranzani et al, 2021).…”

“…The tasks can be reproduced with high haptic accuracy through active instrumented pads that get in touch with the fingers, and are visualized in virtual reality through a computer screen. This robot-assisted therapy approach already proved their efficacy in terms of motor impairment reduction in supervised clinical settings (Lambercy et al, 2011;Ranzani et al, 2020) and was recently redesigned to allow to perform unsupervised therapy in controlled clinical settings (Ranzani et al, 2019;Ranzani et al, 2021;Devittori et al, 2022). However, the essential step necessary for using this technology outside of the controlled settings of the clinic could not yet be achieved due to the device size, cost and technology complexity.…”

User-centered design and spatially-distributed sequential electrical stimulation in cycling for individuals with paraplegia

“…To assess the resulting improvements in our system, we used the System Usability Scale (SUS), the most widely used standardized questionnaire for the assessment of perceived usability [ 7 ]. In the context of assistive devices, the SUS has been widely used as an evaluation tool for telerehabilitation systems [ 8 ] and robot-assisted devices [ 9 ].…”