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Ultrasound contrast agents are gas filled microbubbles which produced enhanced echoes in ultrasound imaging thus allowing the acquisition of detailed information on the path of blood. It is theoretically known that the size of a vessel affects the behavior of a microbubble, which could potentially be used to discriminate different sized vessels. This information would be useful in the monitoring of...
A Device to detect for the bladder which is full with urine is designed. The device can measure bladder pressure. The pressure signals are processed. When the pressure exceeds 40cm water column, Pressure signal exceeds a fixed voltage. At the same time, Oscillator sends a signal and the signal transmits to the body surface. The receiver accepts the oscillating signal. Then, the alarm alerts. Liquid...
Steady-state visual evoked potentials (SSVEPs) are widely used in the design of brain-computer interfaces (BCIs). A lot of effort has therefore been devoted to find a fast and reliable way to detect SSVEPs. We study the link between transient and steady-state VEPs and show that it is possible to predict the spectral content of a subject's SSVEPs by simulating trains of transient VEPs. This could lead...
Coupled nonlinear oscillator models of EEG signals during resting eyes-closed and eyes-open conditions are presented based on Duffing-van der Pol oscillator dynamics. The frequency and information entropy contents of the output of the nonlinear model and the actual EEG signal is matched through an optimization algorithm. The framework is used to model and compare EEG signals recorded from Alzheimer's...
A bulk mRNA expression time course can slow or advance modulating in phase the averaged expression of each gene within the cell-cycle. This is also a synchronism induced at the cycle start to recognize periodic genes. Consistent with the above, a novel adaptive phase-locking insight into microarray experiment is provided. The budding-yeast expression of the major role in the cell-division-cycle could...
The characterisation of functional interdependencies of the autonomic nervous system (ANS) stands an evergrowing interest to unveil electroencephalographic (EEG) and Heart Rate Variability (HRV) interactions. This paper presents a biosignal processing approach as a supportive computational resource in the estimation of sleep dynamics. The application of linear, non-linear methods and statistical tests...
It is possible to cause a sensation of light in patients who have lost photoreceptors due to degenerative eye diseases by targeting surviving neurons with electrical stimulation by means of visual prosthetic devices. All stimulation strategies in currently used visual prostheses are open-loop, that is, the stimulation parameters do not depend on the level of activation of neurons surrounding stimulating...
We conceived new oscillometric blood pressure (BP) estimation methods based on physical modeling. The crux of these methods is to simultaneously estimate the arterial stiffness and BP of the patient from a standard oscillometric waveform. Hence, in contrast to previous methods, the BP estimation is specific to the patient at the time of measurement and is robust against arterial stiffening. We conducted...
A statistical analysis of the separability of EEG A-phases, with respect to basal activity, is presented in this study. A-phases are short central events that build up the Cyclic Alternating Pattern (CAP) during sleep. The CAP is a brain phenomenon which is thought to be related to the construction, destruction and instability of sleep stages dynamics. From the EEG signals, segments obtained around...
Neural activity during sharp wave ripples (SWR), short bursts of co-ordinated oscillatory activity in the CA1 region of the rodent hippocampus, is implicated in a variety of memory functions from consolidation to recall. Detection of these events in an algorithmic framework, has thus far relied on simple thresholding techniques with heuristically derived parameters. This study is an investigation...
We describe a novel method for data mining spectro-spatiotemporal network motifs from electrocorticographic (ECoG) data. The method utilizes wavelet feature extraction from ECoG data, generation of compact binary vectors from these features, and binary vector hierarchical clustering. The potential utility of this method in the discovery of recurring neural patterns is demonstrated in an example showing...
The objective of this paper is to design a wireless transponder for antenna-based sensors that can be used to simultaneously measure shear and pressure forces for diabetic foot diagnosis. The transponder will be placed on the top surface of a shoe and consists of sensor antennas and an identification system that transmits information to a receiver by modulating the signal reflected by the antennas...
The forced oscillation technique (FOT) is a non-invasive method to measure the respiratory impedance Z, defined as the complex ratio of transrespiratory pressure P to the airflow at the airway opening Q as a function of frequency. FOT determines Z by superimposing small amplitude pressure oscillations on the normal breathing and measuring the resulting air flow. In this work a new approach for the...
Rhythmic signals in the brain have always intrigued neuroscientists and the cerebellum is not an exception. Cerebellar high-frequency oscillations have been explored over many decades, but underlying mechanisms have remained unclear. In this study, we have recorded spontaneous and evoked potentials from the cerebellar surface with chronically implanted, multi-electrode arrays. Evoked and spontaneous...
Derived from the pioneer ionic Hodgkin-Huxley model and due to its simplicity and richness from a point view of nonlinear dynamics, the FitzHugh-Nagumo model (FHN) is one of the most successful simplified neuron / cardiac cell model. There exist many variations of the original FHN model. Though these FHN type models help to enrich the dynamics of the FHN model, the parameters used in these models...
Up to 30% of epileptic patients have seizures poorly controlled with anti-epileptic drugs alone. Surgical therapy might be beneficial to patients who respond poorly to drug treatments. It is therefore crucial to accurately localize the seizure focus. Neurologists rely heavily on seizures to determine the focus. The invasive recordings usually continue for days or weeks, which is costly and entails...
We have applied wavelet bicoherence (BIC) analysis to human iEEG data to characterize non-linear frequency interactions in the human epileptic brain. Bicoherence changes were most prominent in the gamma (30–80 Hz) frequency band, and allowed for the differentiation between seizure and non-seizure states in all patients studied (n=3). While gamma band BIC values increased during seizure activity, this...
This paper was to study the short time effect of Delta brain oscillation under microcurrent transcutaneous electrical nerve stimulation (MTENS) at ST36 (Zusanli). The 64-channal electroencephalograph (EEG) signals from 12 healthy volunteers were recorded including baseline stage, during stimulation and after stimulation. Autoregressive (AR) Burg method was used to estimate the power spectrum. Then...
The ability to process rapidly-occurring auditory stimuli plays an important role in the mechanisms of language acquisition. For this reason, the research community has begun to investigate infant auditory processing, particularly using the Event Related Potentials (ERP) technique. In this paper we approach this issue by means of time domain and time-frequency domain analysis. For the latter, we propose...
Mutations in the X-linked gene encoding methyl CpG-binding protein 2 (MeCP2) have been linked to a neurodevelopmental disorder known as Rett syndrome. The disorder is associated with a number of symptoms, of which epileptic seizures are common. In this study we examined the presence of high frequency oscillations (HFOs) and their interactions with low frequency oscillations (LFOs) during epileptiform-like...
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