Voluntary control of wearable robotic exoskeletons by patients with paresis via neuromechanical modeling.

BACKGROUND: Research efforts in neurorehabilitation technologies have been directed towards creating robotic exoskeletons to restore motor function in impaired individuals. However, despite advances in mechatronics and bioelectrical signal processing, current robotic exoskeletons have had only modest clinical impact. A major limitation is the inability to enable exoskeleton voluntary control in neurologically impaired individuals. This hinders the possibility of optimally inducing the activity-driven neuroplastic changes that are required for recovery. METHODS: We have developed a patient-specific computational model of the human musculoskeletal system controlled via neural surrogates, i.e., electromyography-derived neural activations to muscles. The electromyography-driven musculoskeletal model was synthesized into a human-machine interface (HMI) that enabled poststroke and incomplete spinal cord injury patients to voluntarily control multiple joints in a multifunctional robotic exoskeleton in real time. RESULTS: We demonstrated patients' control accuracy across a wide range of lower-extremity motor tasks. Remarkably, an increased level of exoskeleton assistance always resulted in a reduction in both amplitude and variability in muscle activations as well as in the mechanical moments required to perform a motor task. Since small discrepancies in onset time between human limb movement and that of the parallel exoskeleton would potentially increase human neuromuscular effort, these results demonstrate that the developed HMI precisely synchronizes the device actuation with residual voluntary muscle contraction capacity in neurologically impaired patients. CONCLUSIONS: Continuous voluntary control of robotic exoskeletons (i.e. event-free and task-independent) has never been demonstrated before in populations with paretic and spastic-like muscle activity, such as those investigated in this study. Our proposed methodology may open new avenues for harnessing residual neuromuscular function in neurologically impaired individuals via symbiotic wearable robots.

Novel kinematic indices for quantifying upper limb ability and dexterity after cervical spinal cord injury.

Loss of motor function is a consequence after cervical spinal cord injury. Three-dimensional kinematic analysis equipments are used for quantifying human movements in clinical laboratories. These systems may provide objectivity to the patient assessments. Nowadays, the kinematic variables found in the literature have some deficiencies, and the efficient management of these data sets is a demand and a challenge in the clinical setting. The aim of the present paper is to propose a set of novel kinematic indices, as a combination of kinematic variables, for quantifying upper limb motor disorders in terms of characteristics in relation to ability and dexterity such as accuracy, efficiency, and coordination. These indices are defined for measuring patients' motor performance during the activity of daily living of drinking from a glass. This task is included within the upper limb rehabilitative process that patients receive. The main contribution of this research, with the aim of detecting upper limb impairments in patients, consists of the proposal of three kinematic indices from experimental data, whose results are dimensionless and relative to a pattern of healthy subjects. We hope that kinematic indices proposed are a step toward the standardization of the quantitative assessment of movement characteristics and functional impairments.

Efectividad de un programa de juego basado en realidad virtual para la mejora cognitiva en la esquizofrenia / Effectiveness of a programme based on a virtual reality game for cognitive enhancement in schizophrenia

Objetivo: Evaluar la efectividad de un programa de juego basado en la realidad virtual para la mejora de los dominios cognitivos en pacientes con esquizofrenia. Método: Ensayo clínico aleatorizado con 40 pacientes con esquizofrenia, 20 en el grupo experimental y 20 en el grupo control. El grupo experimental recibió 10 sesiones con Nintendo Wii® durante 5 semanas, 50 minutos/sesión, 2 días/semana, además del tratamiento convencional. El grupo control sólo recibió tratamiento convencional. Resultados: Se encontraron diferencias estadísticamente significativas de las puntuaciones T-Score entre la preevaluación y la postevaluación en el grupo experimental en cinco de los seis dominios cognitivos evaluados: velocidad de procesamiento (F=12,04, p=0,001), atención/vigilancia (F=12,75, p=0,001), memoria de trabajo (F=18,86, p <0,01), aprendizaje verbal (F=7,6, p=0,009), y razonamiento y resolución de problemas (F=11,08, p=0,002). Conclusiones: La participación en intervenciones de realidad virtual dirigidas al entrenamiento cognitivo ofrece un gran potencial de ganancias significativas en los diferentes dominios cognitivos evaluados en pacientes con esquizofrenia (AU)

Objective: To evaluate the effectiveness of a programme based on a virtual reality game to improve cognitive domains in patients with schizophrenia. Method: A randomized controlled trial was conducted in 40 patients with schizophrenia, 20 in the experimental group and 20 in the control group. The experimental group received 10 sessions with Nintendo Wii® for 5 weeks, 50minutes/session, 2 days/week in addition to conventional treatment. The control group received conventional treatment only. Results: Statistically significant differences in the T-Score were found in 5 of the 6 cognitive domains assessed: processing speed (F=12.04, p=0.001), attention/vigilance (F=12.75, p=0.001), working memory (F=18.86, p <0.01), verbal learning (F=7.6, p=0.009), visual learning (F=3.6, p=0.064), and reasoning and problem solving (F=11.08, p=0.002). Conclusions: Participation in virtual reality interventions aimed at cognitive training have great potential for significant gains in different cognitive domains assessed in patients with schizophrenia (AU)

Novel kinematic indices for quantifying movement agility and smoothness after cervical Spinal Cord Injury.

BACKGROUND: After cervical Spinal Cord Injury (SCI), upper limb movements made by patients have a lack of smoothness and a hand velocity profile characterized by a high number of velocity peaks. OBJECTIVE: The aim of the present paper is to propose three novel kinematic indices for quantifying movement agility and smoothness, and to analyze their discriminative capability between healthy and pathological people. METHODS: 18 people, healthy and two groups of patients with cervical SCI, participated in the study. Kinematic indices in relation to movement agility and smoothness were computed from hand trajectories and velocity profiles during the performance of the ADL of drinking from a glass. RESULTS: The proposed indices discriminated between healthy and SCI people. The results are greater in healthy than SCI people. Both smoothness indices detected significant differences between healthy and both SCI groups. Moreover, the Agility index showed capacity for discriminating between both patients groups. CONCLUSIONS: The main contribution of this research consists on the proposal of kinematic indices from experimental data, whose results are dimensionless and relative to a pattern of healthy subjects. We hope that kinematic indices proposed are a step toward the standardization of the quantitative assessment of movement characteristics and functional impairments.

[Effectiveness of a programme based on a virtual reality game for cognitive enhancement in schizophrenia]. / Efectividad de un programa de juego basado en realidad virtual para la mejora cognitiva en la esquizofrenia.

OBJECTIVE: To evaluate the effectiveness of a programme based on a virtual reality game to improve cognitive domains in patients with schizophrenia. METHOD: A randomized controlled trial was conducted in 40 patients with schizophrenia, 20 in the experimental group and 20 in the control group. The experimental group received 10 sessions with Nintendo Wii(®) for 5 weeks, 50 minutes/session, 2 days/week in addition to conventional treatment. The control group received conventional treatment only. RESULTS: Statistically significant differences in the T-Score were found in 5 of the 6 cognitive domains assessed: processing speed (F=12.04, p=0.001), attention/vigilance (F=12.75, p=0.001), working memory (F=18.86, p <0.01), verbal learning (F=7.6, p=0.009), visual learning (F=3.6, p=0.064), and reasoning and problem solving (F=11.08, p=0.002). CONCLUSIONS: Participation in virtual reality interventions aimed at cognitive training have great potential for significant gains in different cognitive domains assessed in patients with schizophrenia.

Upper limb rehabilitation after spinal cord injury: a treatment based on a data glove and an immersive virtual reality environment.

UNLABELLED: Purpose state: The aim of this preliminary study was to test a data glove, CyberTouch™, combined with a virtual reality (VR) environment, for using in therapeutic training of reaching movements after spinal cord injury (SCI). METHOD: Nine patients with thoracic SCI were selected to perform a pilot study by comparing two treatments: patients in the intervention group (IG) conducted a VR training based on the use of a data glove, CyberTouch™ for 2 weeks, while patients in the control group (CG) only underwent the traditional rehabilitation. Furthermore, two functional parameters were implemented in order to assess patient's performance of the sessions: normalized trajectory lengths and repeatability. RESULTS: Although no statistical significance was found, the data glove group seemed to obtain clinical changes in the muscle balance (MB) and functional parameters, and in the dexterity, coordination and fine grip tests. Moreover, every patient showed variations in at least one of the functional parameters, either along Y-axis trajectory or Z-axis trajectory. CONCLUSIONS: This study might be a step forward for the investigation of new uses of motion capture systems in neurorehabilitation, making it possible to train activities of daily living (ADLs) in motivational environments while measuring objectively the patient's functional evolution. Implications for Rehabilitation Key findings: A motion capture application based on a data glove is presented, for being used as a virtual reality tool for rehabilitation. This application has provided objective data about patient's functional performance. What the study has added: (1) This study allows to open new areas of research based on the use of different motion capture systems as rehabilitation tools, making it possible to train Activities of Daily Living in motivational environments. (2) Furthermore, this study could be a contribution for the development of clinical protocols to identify which types of patients will benefit most from the VR treatments, which interfaces are more suitable to be used in neurorehabilitation, and what types of virtual exercises will work best.

Quantitative assessment based on kinematic measures of functional impairments during upper extremity movements: A review.

BACKGROUND: Quantitative measures of human movement quality are important for discriminating healthy and pathological conditions and for expressing the outcomes and clinically important changes in subjects' functional state. However the most frequently used instruments for the upper extremity functional assessment are clinical scales, that previously have been standardized and validated, but have a high subjective component depending on the observer who scores the test. But they are not enough to assess motor strategies used during movements, and their use in combination with other more objective measures is necessary. The objective of the present review is to provide an overview on objective metrics found in literature with the aim of quantifying the upper extremity performance during functional tasks, regardless of the equipment or system used for registering kinematic data. METHODS: A search in Medline, Google Scholar and IEEE Xplore databases was performed following a combination of a series of keywords. The full scientific papers that fulfilled the inclusion criteria were included in the review. FINDINGS: A set of kinematic metrics was found in literature in relation to joint displacements, analysis of hand trajectories and velocity profiles. These metrics were classified into different categories according to the movement characteristic that was being measured. INTERPRETATION: These kinematic metrics provide the starting point for a proposed objective metrics for the functional assessment of the upper extremity in people with movement disorders as a consequence of neurological injuries. Potential areas of future and further research are presented in the Discussion section.

Kinematic metrics based on the virtual reality system Toyra as an assessment of the upper limb rehabilitation in people with spinal cord injury.

The aim of this study was to develop new strategies based on virtual reality that can provide additional information to clinicians for the rehabilitation assessment. Virtual reality system Toyra has been used to record kinematic information of 15 patients with cervical spinal cord injury (SCI) while performing evaluation sessions using the mentioned system. Positive correlation, with a moderate and very strong association, has been found between clinical scales and kinematic data, considering only the subscales more closely related to the upper limb function. A set of metrics was defined combining these kinematic data to obtain parameters of reaching amplitude, joint amplitude, agility, accuracy, and repeatability during the evaluation sessions of the virtual reality system Toyra. Strong and moderate correlations have been also found between the metrics reaching and joint amplitude and the clinical scales.

A novel motion tracking system for evaluation of functional rehabilitation of the upper limbs.

Upper limb function impairment is one of the most common sequelae of central nervous system injury, especially in stroke patients and when spinal cord injury produces tetraplegia. Conventional assessment methods cannot provide objective evaluation of patient performance and the tiveness of therapies. The most common assessment tools are based on rating scales, which are inefficient when measuring small changes and can yield subjective bias. In this study, we designed an inertial sensor-based monitoring system composed of five sensors to measure and analyze the complex movements of the upper limbs, which are common in activities of daily living. We developed a kinematic model with nine degrees of freedom to analyze upper limb and head movements in three dimensions. This system was then validated using a commercial optoelectronic system. These findings suggest that an inertial sensor-based motion tracking system can be used in patients who have upper limb impairment through data integration with a virtual reality-based neuroretation system.