Biologically Inspired Modelling for the Control of Upper Limb Movements: From Concept Studies to Future Applications

Modelling is continuously being deployed to gain knowledge on the mechanisms of motor control. Computational models, simulating the behaviour of complex systems, have often been used in combination with soft computing strategies, thus shifting the rationale of modelling from the description of a behaviour to the understanding of the mechanisms behind it. In this context, computational models are preferred to deterministic schemes because they deal better with complex systems. The literature offers some striking examples of biologically inspired modelling, which perform better than traditional approaches when dealing with both learning and adaptivity mechanisms. Can these theoretical studies be transferred into an application framework? That is, can biologically inspired models be used to implement rehabilitative devices? Some evidences, even if preliminary, are presented here, and support an affirmative answer to the previous question, thus opening new perspectives

A hierarchical sensorimotor control framework for human-in-the-loop robotic hands.

Human manual dexterity relies critically on touch. Robotic and prosthetic hands are much less dexterous and make little use of the many tactile sensors available. We propose a framework modeled on the hierarchical sensorimotor controllers of the nervous system to link sensing to action in human-in-the-loop, haptically enabled, artificial hands

Exploring the bases for a mixed reality stroke rehabilitation system, Part II: Design of Interactive Feedback for upper limb rehabilitation

abstract: Background Few existing interactive rehabilitation systems can effectively communicate multiple aspects of movement performance simultaneously, in a manner that appropriately adapts across various training scenarios. In order to address the need for such systems within stroke rehabilitation training, a unified approach for designing interactive systems for upper limb rehabilitation of stroke survivors has been developed and applied for the implementation of an Adaptive Mixed Reality Rehabilitation (AMRR) System. Results The AMRR system provides computational evaluation and multimedia feedback for the upper limb rehabilitation of stroke survivors. A participant's movements are tracked by motion capture technology and evaluated by computational means. The resulting data are used to generate interactive media-based feedback that communicates to the participant detailed, intuitive evaluations of his performance. This article describes how the AMRR system's interactive feedback is designed to address specific movement challenges faced by stroke survivors. Multimedia examples are provided to illustrate each feedback component. Supportive data are provided for three participants of varying impairment levels to demonstrate the system's ability to train both targeted and integrated aspects of movement. Conclusions The AMRR system supports training of multiple movement aspects together or in isolation, within adaptable sequences, through cohesive feedback that is based on formalized compositional design principles. From preliminary analysis of the data, we infer that the system's ability to train multiple foci together or in isolation in adaptable sequences, utilizing appropriately designed feedback, can lead to functional improvement. The evaluation and feedback frameworks established within the AMRR system will be applied to the development of a novel home-based system to provide an engaging yet low-cost extension of training for longer periods of time.The electronic version of this article is the complete one and can be found online at: https://jneuroengrehab.biomedcentral.com/articles/10.1186/1743-0003-8-5

The Impact of Augmented Information on Visuo-Motor Adaptation in Younger and Older Adults

BACKGROUND: Adjustment to a visuo-motor rotation is known to be affected by ageing. According to previous studies, the age-related differences primarily pertain to the use of strategic corrections and the generation of explicit knowledge on which strategic corrections are based, whereas the acquisition of an (implicit) internal model of the novel visuo-motor transformation is unaffected. The present study aimed to assess the impact of augmented information on the age-related variation of visuo-motor adjustments. METHODOLOGY/PRINCIPAL FINDINGS: Participants performed aiming movements controlling a cursor on a computer screen. Visual feedback of direction of cursor motion was rotated 75 degrees relative to the direction of hand motion. Participants had to adjust to this rotation in the presence and absence of an additional hand-movement target that explicitly depicted the input-output relations of the visuo-motor transformation. An extensive set of tests was employed in order to disentangle the contributions of different processes to visuo-motor adjustment. Results show that the augmented information failed to affect the age-related variations of explicit knowledge, adaptive shifts, and aftereffects in a substantial way, whereas it clearly affected initial direction errors during practice and proprioceptive realignment. CONCLUSIONS: Contrary to expectations, older participants apparently made no use of the augmented information, whereas younger participants used the additional movement target to reduce initial direction errors early during practice. However, after a first block of trials errors increased, indicating a neglect of the augmented information, and only slowly declined thereafter. A hypothetical dual-task account of these findings is discussed. The use of the augmented information also led to a selective impairment of proprioceptive realignment in the younger group. The mere finding of proprioceptive realignment in adaptation to a visuo-motor rotation in a computer-controlled setup is noteworthy since visual and proprioceptive information pertain to different objects

I-BaR: Integrated Balance Rehabilitation Framework

Neurological diseases are observed in approximately one billion people worldwide. A further increase is foreseen at the global level as a result of population growth and aging. Individuals with neurological disorders often experience cognitive, motor, sensory, and lower extremity dysfunctions. Thus, the possibility of falling and balance problems arise due to the postural control deficiencies that occur as a result of the deterioration in the integration of multi-sensory information. We propose a novel rehabilitation framework, Integrated Balance Rehabilitation (I-BaR), to improve the effectiveness of the rehabilitation with objective assessment, individualized therapy, convenience with different disability levels and adoption of an assist-as-needed paradigm and, with an integrated rehabilitation process as a whole, i.e., ankle-foot preparation, balance, and stepping phases, respectively. Integrated Balance Rehabilitation allows patients to improve their balance ability by providing multi-modal feedback: visual via utilization of Virtual Reality; vestibular via anteroposterior and mediolateral perturbations with the robotic platform; proprioceptive via haptic feedback.Comment: 37 pages, 2 figures, journal pape

Evaluating Embodiment in Musical Instrument Modification and Augmentation

This PhD seeks to identify key aspects that optimise the learning process of new musical interfaces by professional musicians. Modifying or extending an existing musical instrument can impact players' skills. Fluency of execution or pitch accuracy can deteriorate due to demands on the performer's attention from the unfamiliarity of the instrument. As a result, players may require additional training on a modified instrument before they regain their fluency. The problem is that performers, especially professional players who have already invested many years in the unmodified musical instrument, might prefer to start from a high level. Thus, designing a new instrument that builds upon existing skills can be appealing. However, which design strategies might support such a goal? Which aspects of the original design should be preserved? How can we assess whether the resulting modified instrument allows the performer to retain their skills? This research presents four studies that tackle these questions. Results from the first two studies suggest that the design strategy should focus on participants’ sensorimotor imagery rather than the instrument's auditory feedback. During these studies, participants were still able to retain their fluency and pitch accuracy even in the presence of disrupting or irrelevant auditory feedback. Two additional studies propose quantitative methods to evaluate skill retention in instrument modification. This research can advise designers on whether they are on the right track in crafting an interface that builds upon existing skills. This challenge may apply to augmented instruments, the modification of existing musical instruments, or new digital instruments

Exploring the bases for a mixed reality stroke rehabilitation system, Part I: A unified approach for representing action, quantitative evaluation, and interactive feedback

<p>Abstract</p> <p>Background</p> <p>Although principles based in motor learning, rehabilitation, and human-computer interfaces can guide the design of effective interactive systems for rehabilitation, a unified approach that connects these key principles into an integrated design, and can form a methodology that can be generalized to interactive stroke rehabilitation, is presently unavailable.</p> <p>Results</p> <p>This paper integrates phenomenological approaches to interaction and embodied knowledge with rehabilitation practices and theories to achieve the basis for a methodology that can support effective adaptive, interactive rehabilitation. Our resulting methodology provides guidelines for the development of an action representation, quantification of action, and the design of interactive feedback. As Part I of a two-part series, this paper presents key principles of the unified approach. Part II then describes the application of this approach within the implementation of the Adaptive Mixed Reality Rehabilitation (AMRR) system for stroke rehabilitation.</p> <p>Conclusions</p> <p>The accompanying principles for composing novel mixed reality environments for stroke rehabilitation can advance the design and implementation of effective mixed reality systems for the clinical setting, and ultimately be adapted for home-based application. They furthermore can be applied to other rehabilitation needs beyond stroke.</p

The Influence of Real-Time Visual Feedback Training on Vocal Control

Trained singers have better vocal control when compared to singers without vocal training. The development of precise vocal control, like any motor skill, requires practice with some form of feedback, such as auditory feedback. In addition to auditory feedback, singing training programs use online visual feedback to improve performance accuracy. The purpose of this thesis is to investigate the recent body of literature concerning the cognitive processing of vocal control, and apply this knowledge practically to develop an effective real-time visual feedback training program that enhances vocal control. In the first of two studies, non-singers and singers were randomly assigned to one of two training conditions: one condition with visual feedback of vocal performance, and the other condition with no feedback. Changes in vocal control as a function of training condition were assessed by comparing measures of pitch accuracy, vocal variability, and responses to sudden frequency-altered perturbations in participants’ pitch feedback, before and after training. In the second study, training sessions were doubled and tested with another group of non-singers, with results from this second study compared to the first study. Overall, there was no effect of real-time visual feedback training or length of training on measures of vocal control. These findings may contribute to a better understanding of vocal control, and assist in improving singing training programs