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OBJECTIVE@#Exploring the effectiveness of using EEG linear and nonlinear features for accessing mental workload in different tasks.@*METHODS@#Working memory tasks with different information types and various mental loads were designed based on N-Back paradigm. EEG signals from 18 normal adults were acquired when tasks were being performed. Linear and nonlinear features of EEGs were then extracted. Indices that can effectively reflect mental workload levels were selected by using multivariate analysis of variance statistical approach.@*RESULTS@#With the increment of task load, power of frontal Theta, Theta/Alpha ratio, and sample entropies (scales>10) in parietal regions increased significantly first and decreased slightly then, while the power of central-parietal Alpha decreased significantly first and increased slightly then. No difference in power of frontal Theta, central-parietal Alpha, and sample entropies (scales>10) of parietal regions were found between verbal and object tasks, as well as between two spatial tasks. No difference of frontal Theta/Alpha ratio was found in all the four tasks.@*CONCLUSIONS@#The results can provide evidence for the mental workload evaluation in tasks with different information types.
Subject(s)
Electroencephalography , Memory, Short-Term , WorkloadABSTRACT
Aging is a major risk factor for diseases such as osteoarthritis (OA) and osteoporosis. However, they are not necessarily the results of aging, and the relationship between changes in bone and cartilage associated with aging and disease progression is still unclear. Studies have shown that the development and progression of OA is not a simple cartilage wear process, while its occurrence involves complex biological, chemical and mechanical changes in the tissues of the entire joint, especially the interaction of mechanics and biochemistry between cartilage and subchondral bone. Aging contributes to the occurrence and development of OA, but it is not the cause of OA. Changes associated with aging provide a foundation for OA to start, making joints more susceptible to other factors such as abnormal biomechanics and biochemistry, thereby promoting the development of OA. Therefore, understanding the basic mechanisms by which aging affects joint tissue may provide new targets for slowing or preventing the development of OA. In this paper, the related research progresses are reviewed from three aspects, i.e. age-related changes in cartilage and subchondral bone, mechanical conduction and angiogenesis.
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<p><b>OBJECTIVE</b>To propose a square's ring motion stimulation based on steady-state motion visual evoked potential, and compare it with the commonly used visual stimulation modes (Newton's ring motion, square flicker and circular flicker).</p><p><b>METHODS</b>EEG signals were collected while 9 experimental subjects gazing at four stimulation and pattern analyzed by Canonical Correlation Analysis (CCA). Stimulation were evaluated by recognition accuracy and subjective scores.</p><p><b>RESULTS</b>The classification accuracies of SSVEP elicited by the square's ring motion(82.8%±14.1%) and Newton's ring(83.3%±11.5%) have no significant difference between them, which are lower than that of the square flicker(98.3%±4.1%) and the circular flicker(99.2%±1.8%). The shape of the figure has no significant influence on the classification accuracy either in motion mode or flicker mode. The comfort of the square's ring motion is higher than the other three stimulation according to subjective scores.</p><p><b>CONCLUSIONS</b>The square's ring motion can elicit EEG and reduce the discomfort caused by flicker modes. The square's ring motion can be used as a visual stimulation in SSMVEP-based BCI system.</p>
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This paper proposed a rehabilitation training system with electromyography (sEMG) feedback for stroke patients based on ARM embedded system and LabVIEW. The system can achieve real-time acquisition, processing and dualview of multi-channel sEMGs and compute related sEMG parameters including iEMG, RMS, MPF and co-contraction ratio. The system was detected by clinical experiments and related inspection department. The result showed that the system is functional, interactive and in accordance with the relevant standards for medical devices so that it can fully satisfy the clinical demands. In addition, the system can help doctors to master the training state of the patient more effectively in a real-time and quantitative way that is direct to improve the training programs of stroke patients.
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Humans , Electromyography , Neurofeedback , Stroke RehabilitationABSTRACT
This paper proposed a mobile vital-signs monitoring system based on ZigBee localization and wireless transmission technology for the elderly in nursing home. The system can monitor the vital-signs (pulse, ECG and blood oxygen), localize human body and warn in emergency. The validity and accuracy of this system were testified by the experiments of mobile acquisition and storage of pulse. In these experiments, the measurement of pulse ranged from 50 to 170 time a minute, the mean error of which was less than 3%. The mean error of localizing was less than 4 m. And the data transmission rate was 250 kbps. The system, which effectively conducts the real-time monitoring of the health and safety situation for the elderly, has a great significance for protecting the elderly's life safety.
Subject(s)
Aged , Humans , Equipment Design , Homes for the Aged , Monitoring, Physiologic , Nursing HomesABSTRACT
@# Spinal cord injury is very high morbidity trauma, seriously affecting the survival and health of patients. To establish a standard animal model has a great significance for studying SCI pathogenesis and pathological changes. A spinal cord injury device for experimental animal was presented in this paper. It can implement fixed-point and fixed-quantity impact by new design. It also can create many animal models of different levels injury. More importantly, it has many advantages such as simple to operate, free from human disturbance, high accuracy and reproducibility. Finally, some existing constraints and challenges about the animal spinal cord injury models made by the device were discussed.
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Subtle changes in structure or composition can lead to degeneration of articular cartilage such as in osteoarthritis, so it is significant to study the materials attribute of the degenerating articular cartilage. A new transient ultrasonic technique was introduced into this study for measuring the swelling effects of the degenerated cartilage. The swelling-induced strain was calculated based on the measurement result, and then the uniaxial module of the articular cartilag was extracted using Narmoneva's triphasic model. The ultrasonic observation showed that the strains induced by the nonuniform swelling are depth-dependent, and the strains are small in the deep zone and big in the middle and surface zones. The uniaxial modulus also revealed that the cartilage in the deep zone (E1 = 12.20) is harder than that in surface zone (E2 = 0.15). These results suggest that the transient ultrasound technique accompanied by triphasic model provides a quantitative means to study the degeneration of articular cartilage.
Subject(s)
Humans , Cartilage Diseases , Diagnostic Imaging , Cartilage, Articular , Diagnostic Imaging , Computer Simulation , Edema , Diagnostic Imaging , Models, Biological , Osmotic Pressure , UltrasonographyABSTRACT
Objective To study the material attribute of articular cartilage.Methods An improved 4 parameters inhomogeneous triphasic model based on 3 parameters model was developed to estimate the uniaxial modulus Ha of cartilage and to predict the swelling pattern of cartilage.Results The results showed that more accurate uniaxial modulus can be extracted using 4 parameters inhomogeneous triphasic model,and the predicted results appeared to match the experimental strain data better than other models.Conclusion Inhomogeneous 4 parameters triphasic model can describe the depth-dependent material attribute of articular cartilage more exactly.