Wireless Neurosensor for Full-Spectrum Electrophysiology Recordings during Free Behavior

SummaryBrain recordings in large animal models and humans typically rely on a tethered connection, which has restricted the spectrum of accessible experimental and clinical applications. To overcome this limitation, we have engineered a compact, lightweight, high data rate wireless neurosensor capable of recording the full spectrum of electrophysiological signals from the cortex of mobile subjects. The wireless communication system exploits a spatially distributed network of synchronized receivers that is scalable to hundreds of channels and vast environments. To demonstrate the versatility of our wireless neurosensor, we monitored cortical neuron populations in freely behaving nonhuman primates during natural locomotion and sleep-wake transitions in ecologically equivalent settings. The interface is electrically safe and compatible with the majority of existing neural probes, which may support previously inaccessible experimental and clinical research

Assessment of Hand Gestures Using Wearable Sensors and Fuzzy Logic

Hand dexterity and motor control are critical in our everyday lives because a significant portion of the daily motions we perform are with our hands and require some degree of repetition and skill. Therefore, development of technologies for hand and extremity rehabilitation is a significant area of research that will directly help patients recovering from hand debilities sustained from causes ranging from stroke and Parkinson’s disease to trauma and common injuries. Cyclic activity recognition and assessment is appropriate for hand and extremity rehabilitation because a majority of our essential motions are cyclic in their nature. For a patient on the road to regaining functional independence with daily skills, the improvement in cyclic motions constitutes an important and quantifiable rehabilitation goal. However, challenges exist with hand rehabilitation sensor technologies preventing acquisition of long-term, continuous, accurate and actionable motion data. These challenges include complicated and uncomfortable system assemblies, and a lack of integration with consumer electronics for easy readout. In our research, we have developed a glove based system where the inertial measurement unit (IMU) sensors are used synergistically with the flexible sensors to minimize the number of IMU sensors. The classification capability of our system is improved by utilizing a fuzzy logic data analysis algorithm. We tested a total of 25 different subjects using a glove-based apparatus to gather data on two-dimensional motions with one accelerometer and three-dimensional motions with one accelerometer and two flexible sensors. Our research provides an approach that has the potential to utilize both activity recognition and activity assessment using simple sensor systems to help patients recover and improve their overall quality of life

The immediate effects of Tai Chi on the postural stability, muscle activity and measures of inferred ankle proprioception of healthy young adults

Tai Chi has often been applied in research among older adults to affect postural stability and proprioception in the lower limbs; however, little is known about the effects Tai Chi may have in these domains among healthy young adults. Therefore, the aim of the present study was to investigate these potential effects. A total of 30 (17 females and 13 males) healthy young adults were randomized to either an experimental group or control group. To assess postural stability, both groups performed a pre-intervention postural stability task under eyes open/closed and firm/foam surface conditions, while center of pressure-based measures of mean sway velocity (MSV) and 95% elliptical area (EA) were collected. Ankle proprioception was inferred using electromyography data from the tibialis anterior and gastrocnemius medialis bilaterally, in addition to, the spectral power within the 0.4 – 0.7 Hz band derived from all data points of COP sway in the anteroposterior direction, which is believed to be sensitive to change in ankle proprioception. For the intervention, the experimental group was engaged in a 15-minute Tai Chi task, while the control group sat comfortably in a chair. Post-intervention measures were then collected using the same protocol as the pre-intervention measures. Four-way ANOVAs were used to determine if the Tai Chi intervention had a significant effect on postural stability, muscle activity, or measures of inferred ankle proprioception. No significant differences were observed between the experimental or control group across pre-/post test measures. These findings suggest that a single 15-minute Tai Chi intervention is not sufficient to produce effects on the postural stability, muscle activity, or ankle proprioception of healthy young adults

Paths and Technologies in the Life Project of People with Disabilities: International Perspectives and Educational Potential

The purpose of this paper was to analyse the core of the quality of life, intended as a complex construct with specific and transversal features. The approach to this issue, by linking it to the great emergency of disability in adulthood, pushes the analysis into deep conceptual pedagogical reflections, which lead the authors\u2019 initial reflections to focus on the theoretical framework related to the quality of life model and subsequently on the identification of some areas of intervention as a tangible application of the quality of life model. New perspectives and innovative potentials for the quality of life of adults with disability are investigated to reach new awareness, which can also be applied in different life contexts. The paper mentions meaningful trajectories, also from the international scene, aiming to guarantee significantly oriented life trajectories

Modeling & Analysis of Design Parameters for Portable Hand Orthoses to Assist Upper Motor Neuron Syndrome Impairments and Prototype Design

Wearable assistive robotics have the potential to address an unmet medical need of reducing disability in individuals with chronic hand impairments due to neurological trauma. Despite myriad prior works, few patients have seen the benefits of such devices. Following application experience with tendon-actuated soft robotic gloves and a collaborator\u27s orthosis with novel flat-spring actuators, we identified two common assumptions regarding hand orthosis design. The first was reliance on incomplete studies of grasping forces during activities of daily living as a basis for design criteria, leading to poor optimization. The second was a neglect of increases in muscle tone following neurological trauma, rendering most devices non-applicable to a large subset of the population. To address these gaps, we measured joint torques during activities of daily living with able-bodied subjects using dexterity representative of orthosis-aided motion. Next, we measured assistive torques needed to extend the fingers of individuals with increased flexor tone following TBI. Finally, we applied this knowledge to design a cable actuated orthosis for assisting finger extension, providing a basis for future work focused on an under-represented subgroup of patients

The clinical utility of the Vivosonic Integrity Auditory Brainstem response system in children with cerebral palsy

Determining auditory functioning in difficult-to-test populations such as cerebral palsy (CP) remains a challenge in paediatric audiology. The auditory brainstem response (ABR) is favoured as the procedure to assess auditory functioning in difficult-to-test populations such as CP. The CP population, however, offers unique challenges for the ABR procedure due to the presence of involuntary muscular movements that may compromise the signal-to-noise ratio (SNR) of the ABR. Conventional ABR technology attempts to improve the SNR by the modification of acquisition parameters e.g. adjusting the low cut filter or implementing stricter artifact rejection criteria. However, such modifications may compromise the waveform morphology of the ABR. Furthermore, sedation or general anesthesia can also be used to improve the SNR by reducing excessive muscular movements. The CP population, however, displays a high risk for developing upper airway obstruction when being sedated or anesthetized. Thus, the feasibility and reliability of the conventional ABR may be compromised when being employed in the CP population. In recent years a novel ABR system, the Vivosonic Integrity (VS) ABR has become clinically available. The device incorporates features such as pre-amplification of the ABR signal, Kalman filtering and wireless recording. These features promise to address the limitations of conventional ABR technology to obtain a reliable recording in the midst of excessive myogenic artifact. The aim of this study was therefore to evaluate the clinical utility of the VS system when assessing a sample of children with CP without the use of sedation. The clinical utility of the VS ABR system was determined by comparing its success rates, the threshold correspondence to behavioural pure tone (PT) thresholds and recording time to a conventional ABR system when using click and 0.5 kHz TB stimuli. A cross-sectional within-subject comparison research design was selected in order to compare thresholds obtained with different procedures. The experimental part of this study was represented by the within-subject control condition where the VS ABR system and the conventional ABR system were simultaneously conducted in each subject. This unique setup was important in the research as equivalent test conditions in terms of EEG and environmental conditions had to be ensured for both ABR systems. 15 CP subjects between the ages of 12 and 18 years were included in the project. A diagnostic audiological test battery including immittance, distortion product otoacoustic emissions and behavioural audiometry was conducted on each subject prior the administration of the ABR procedures. The variability of the audiological test battery results – between the subjects and when compared to previous research – emphasized the heterogeneity of the CP population. Furthermore, more than half of the research sample (53%; n=15) responded inconsistently to behavioural pure tone (PT) stimuli. It was suggested that the severity of physical impairments as well as additional impairments such as mental retardation might have influenced the consistency of the subjects’ responses during behavioural PT audiometry. The ABR results indicated that there were no significant differences with regards to threshold correspondence and recording time between the two ABR systems when using click and 0.5 kHz TB stimuli (p>0.05). With regards to the success rates, the VS system was successful in more cases than the conventional ABR system using click and 0.5 kHz TB stimuli. Although results also showed no statistically significant value for click p=.1121) and 0.5 kHz TB stimuli p=.1648), there was a tendency towards the 95% confidence level in both cases suggesting that the VS ABR system may produce a statistically significant success rate for click as well as for 0.5 kHz TB stimuli, provided a larger sample is tested. The research indicated that, since the VS ABR system was more successful across a wider range of subjects during click-evoked and 0.5 kHz TB recordings, it may increase the clinical usefulness of the ABR especially in terms of hearing screening in the CP population. The research suggested that excessive muscular movements during the recordings influenced not only the VS ABR’s, but also the conventional ABR’s threshold correspondences to PT thresholds as well as the recording time of the measurements. Therefore it may still be necessary to use a light sedative in some CP patients to reduce excessive myogenic interference despite the possible advantages of the VS ABR system.Dissertation (MCommunication Pathology)--University of Pretoria, 2010.Speech-Language Pathology and Audiologyunrestricte

International Conference on NeuroRehabilitation 2012

This volume 3, number 2 gathers a set of articles based on the most outstanding research on accessibility and disability issues that was presented in the International Conference on NeuroRehabilitation 2012 (ICNR).The articles’ research present in this number is centred on the analysis and/or rehabilitation of body impairment most due to brain injury and neurological disorders.JACCES thanks the collaboration of the ICNR members and the research authors and reviewers that have collaborated for making possible that issue