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Empirical mode decomposition (EMD) is a recently introduced tool for decomposing signals into so-called intrinsic mode functions (IMF). These IMF represent the data by means of oscillating waves with local zero mean. In some sense the decomposition can be compared with a time-varying filter bank, i.e., signals are decomposed using band limited filters with band widths that vary in time. The main attribute...
Electrocardiographic (ECG) analysis plays an important role in safety assessment during new drug development and in clinical diagnosis. The pre-processing of ECG analysis consists of low-frequency baseline wander (BW) correction and high-frequency artifact noise reduction from the raw ECG. We present approaches for BW correction and de-noising based on discrete wavelet transformation (DWT). We estimate...
New algorithm for quantifying the variation in the QT interval of ECG recording is presented. The algorithm is based on the principal component regression where the eigenvectors of the data correlation matrix are calculated. The eigenvectors are then used for calculation of the principal components and one of them is selected to represent the information about T wave variation. The algorithm is tested...
Evoked potentials are usually embedded in the ongoing electroencephalogram with a very low signal-to-noise ratio. The neural network filtering technique which has the advantage of complex mapping is one of the applicable methods for evoked potentials estimation. The backpropagation algorithm based on second order statistics is commonly used to adapt neural network filters. However it is easily influenced...
For any respiratory sound analysis or assessment, respiratory flow must also be measured simultaneously with the sounds. However, due to difficulties and/or inaccuracy of the most flow measurement techniques, several researchers have attempted to estimate flow from respiratory sounds. However, all of the proposed methods heavily depend on the availability of different rates of flow for calibration...
This study investigates the possibility of using the normalized time-domain features of electrocardiogram (ECG) for improving the capability of human identification. For this purpose, we measured lead-1 rest ECG (normal heart rate) and physically active one (fast heart rate) from the pre-selected group. The characteristic points on the ECG waveform, P, QRS, T are extracted in terms of its time location...
We constructed an impedance spectroscopy measurement system based on frequency response analyzer. Using four-terminal method, we measured impedance spectroscopy of rabbit different tissues in vitro within 5 to 360 minutes after excision at the frequency range from 1Hz to 1MHz. According to the measurement results, we analyzed the changes of characteristic parameters (Ro, Rinfin, fc and alpha) of different...
Electrical stimulation on the posterior tibial nerve is commonly used in the measurement of somatosensory evoked potential (SEP). To improve the efficiency of stimulation, the potential field and current density distributions under the surface electrodes were simulated with a three layer theoretical model. The mirror method was used to analyze the potential field of point charge. Integration of the...
The aim of this study is to investigate how firing patterns of neuron in hippocampus change with coupling effect between soma and dendrite via simulation of single neuron firings by a two-compartment (soma-dendrite) model. The results will help to understand how firing patterns relative to synaptic plasticity in further study. The neuron model used in this study consisted two compartments: the soma...
Today ABR (ABR: auditory brainstem responses) characteristics are widely and qualitatively used, and they are mainly used for clinical application of a consciousness obstacle, brain death and some consciousness level, vegetative state and so on, as the very useful inspection method. Until now, many various characteristics and models about these brain waves have been reported. But the theories and...
Unintentional falls are a common cause of severe injury in the elderly population. By introducing small, non-invasive sensor motes in conjunction with a wireless network, the Ivy Project aims to provide a path towards more independent living for the elderly. Using a small device worn on the waist and a network of fixed motes in the home environment, we can detect the occurrence of a fall and the location...
The main purpose of this paper is to develop a theoretical tool in order to fundamentally characterize the performance of Myocardial elastography and identify the optimal parameters to be used for the more reliable detection of ischemia or infarction. A complete representation of the left-ventricular function throughout an entire cardiac cycle was previously demonstrated through the use of a 3D finite-element...
Tissue stiffness is generally known to be associated with pathologic changes. Ultrasound indentation is able to assess the mechanical properties of soft tissues. Conventional ultrasound indentation devices use rigid flat-ended transducers to directly contact with the tissues and typically operate in the frequency ranging between 2 M Hz and 10 MHz. This paper introduced a novel ultrasound indentation...
Cardiac arrhythmia is a class of serious heart diseases that threatens many people. Current arrhythmias diagnostic techniques seem to be partially efficient due to the application limitations either in time or in space. The paper presents a real-time continuous arrhythmias detection system (RECAD) platform based on the wireless sensor network technology. This system provides long-term real-time surveillance...
Vessel boundary detection and 3D modeling is a difficult but necessary task in analyzing the mechanics of inflammation and the structure of the microvasculature. We present in this paper a method of analyzing this structure by the means of the deformable model (using GVF Snake) for vessel boundary detection and three-dimensional reconstruction. For this purpose, we used a virtual vessel model and...
It is said that sleep apnea syndrome is one of the main causes of airplane, train and car accidents. We have developed a non-contact breathing measurement system which diagnoses not only sleep apnea syndrome but also other sleep disorders. This system calculates the amount of the volume change and makes the movement of the outside of the body by the breath motion visible. If the patient is breathing...
Quantitative analysis of myocardial perfusion requires detection of myocardial boundaries in many short-axis MR images. Manual tracing of myocardial boundaries is a time-consuming and tedious task, which may limit the clinical use of quantitative analysis. In this paper, we propose an automatic detection algorithm based on active contours. For initialization, starting contours need to be defined....
Correctly counting the live cells plays a great role in the ectogenetic anti-virus experiment. According to the irregular shape and arbitrary size of the wall pasted Hela cells overlapping each other, we propose a scheme to segment and count the cells using Gabor filter with different parameters and morphological operation. Experiments reveal that filters with different parameters will lead to different...
The objective of this study was to develop a standardized protocol for the capturing and analysis of endoscopy digital images for subsequent use in a computer aided diagnosis (CAD) system in gynaecological cancer. Images were captured at optimum illumination and focus at 720times576 pixels using 24 bits color in the following cases: (i) for a variety of testing targets from a color palette with known...
Computed tomography has played a key role in bone structure imaging for over two decades. However, when a metal implant present in the sample, the reconstructions are seriously distorted by artefacts, and no method has successfully met the clinical demands. This paper presents a new method for partial reconstruction in computed tomography. The metal implant is reconstructed separately and the correspondence...
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