Catálogo de publicaciones - libros

According to the researches already conducted, although we know that the alcohol affects the human bodies badly, relationship between the reaction of bodies by the mental state and the alcohol still has not been understood well. So, through this investigation we could know that using a GSR instrument Before subjects take in the alcohol, the GSR values are measured to the appointed stimulus or any topic. Then subjects take in a certain of the alcohol, the subjects’ GSR values are measured at a fixed hour. Through the difference between two values, we can understand that the alcohol affects the spiritual part of the human being. Thereby we can know alcohol has effect on man’s reaction system.

Measurement of EEG enabled it to get to know electrophysiological mechanism of brain. Disturbance of consciousness, epilepsia, dementia, cerebrovascular disease and cerebral infarction are included as a useful clinical example of EEG inspection. It is thought that it leads to the early detection and treatment of the above disease by analyzing EEG. However, there is a possibility that artifact may mix in EEG. When the brain wave is measured, the artifact by the heart beat, the blink, muscle noise, line noise, and the eye movement may be contained. The data of the part is rounded down when the characteristic of artifact (the peak of amplitude, frequency component, variance, and gradient) exceed a decided threshold and the recurrent part of other input signals (EOG, EMG, and ECG) is subtracted from measurements, etc. as artifact removal method. And so this study considers the artifact removal that uses Independent Component Analysis (ICA). It doesn’t need other input signals. ICA is a statistical method that is useful for removing artifacts. ICA has various algorithms. FastICA is used in this study. FastICA has the best overall performance in terms of both separation quality and computation times. This study uses and simulates ICA to the measured brain waves. Future work is how to apply the separated brain waves.

This paper describes an approach for classifying electromyographic (EMG) signals using the multilayer perceptrons (MLP’s) and the hidden markov models (HMM’s). In this paper, we propose the combination of MLP’s and HMM’s cascaded structure to increase discrimination rates of myoelectric patterns. Feature sets based upon the short-time Fourier transform, the wavelet transform, and the wavelet packet transform for discriminating signals represent active of motions are applied and compared. This strategy is proposed to overcome weak discrimination and to consider dynamic properties of EMG signlas.

This study investigated the effect of 30% oxygen administration on visuospatial cognitive performance, blood oxygen saturation, and heart rate. Six male (25.8±1.0 years) and six female (23.8±1.9 years) college students were selected as the subjects for this study. Two psychological tests were developed to measure the performance level of visuospatial cognition. The experiment consisted of two runs: one was a visuospatial cognition task, with normal air (21% oxygen) administered and the other was with hyperoxic air (30% oxygen) administered. The experimental sequence in each run consisted of Rest1 (1 min), Control (1 min), Task (4 min), and Rest2 (4 min). Blood oxygen saturation and heart rate were measured throughout the four phases. The results of the visuospatial behavioural analysis reveal that accuracy rates were enhanced with 30% oxygen administration compared to 21% oxygen. When 30% oxygen was supplied, blood oxygen saturation was increased and heart rate was decreased compared to that with 21% oxygen administration. It can be concluded that, during cognitive processing, 30% oxygen administration increased blood oxygen saturation and had a positive effect on visuospatial cognitive performance.

The input to the two-layered Perceptron is Heart Rate Variability (HRV). Apply the input vector, x to input units. Calculate the outputs from hidden layer, net-input values to each unit in the output layer, the outputs, the error terms for output units and error terms for the hidden units. Update weights on output layer and weights on hidden layer. Calculate the error term, E. p=0 and initialize the weights at both layers. (1) W and W) randomly. (2) E-step : Compute the expected hidden targets for the hidden units Z. (3) M-step: Compute W and W. (4) Let p=p+1 and go back to step (2) until certain convergence conditions are satisfied. Using BP algorithm, error at output is ‘0’ for HRV input. The program for training the Perceptron using BP algorithm is written in ‘C’ language. The program for training the Perceptron using ML method is written in MAT LAB. The latter is faster than the former. The training of the Perceptron using ML method yields the 1 layer weights of 15132 and the 2 layer weights of 8.1. Error at output is ‘0’ for HRV input. Since the hidden targets are completely separable, finding the first-layer weights can be done through training M individual neurons simultaneously. The quadratic training error between the output and the desired target is minimized to obtain the new 2 layer weights W. This is equivalent to training the original 2 layer (nonlinear) network is decomposed into training a set of single neurons, which can be done much faster than training original (nonlinear) layer network. Hence the program for training the Perceptron using ML method is faster than the program using BP algorithm.

Transmembrane potential (Vm) recordings not from isolated cells may be dominated by different types of noise, and the filtering algorithms usually applied for noise suppression of Vm recordings often result in a signal of poor SNR (signal to noise ratio). Conventional filtering algorithms resulted in flattening of Vm deflections and unacceptable time delay. We solved this problem using morphological operators and adaptive alpha-trimmed mean filtering (OMATF) to restore corrupted signal. We applied several filtering approaches in intracellular recordings of T4 (L-thyroxine) hyperpolarization in Sertoli cells, from immature rat tests. The intracellular recording of the Sertoli cells commenced using 2.5 M KCl filled micropipetteds in conjunction with an electrometer, the Vm was amplified by direct current (DC). The amplified signal was displayed and recorded on a digital oscilloscope, the Vm was measured and directly in an intervals of 5 seconds using the electrometer. The aim of the present work was to compare the result of filtering the Vm with: OMATF; Moving Average; Morphological operators alone.

To investigate the correlation between light scattering and tissue viability for brains, we performed multiwavelength diffuse reflectance measurement with perfused brains of rats, in which the reduction level of CuA in cytochrome oxidase was used as an indicator of brain tissue viability. Diffuse reflectance intensity at 620 nm, an isosbestic point of the oxidation-reduction state of cytochrome oxidase, was detected as a scattering signal, while relative diffuse reflectance intensity at 800 nm to that at 620 nm was measured to monitor the absorption change due to the reduction of CuA. After starting perfusion, the scattering signal showed a drastic, triphasic change (increase, decrease and increase) in the time range of 220 – 310 s. After this triphasic change, the scattering signal increased slowly until the end of the measurement (∼ 500 s). The reduction of CuA started and proceeded rapidly during the triphasic scattering change (270 – 310 s). Before and after the triphasic change, we found that light scattering highly correlated with the reduction level of CuA; loss of tissue viability was accompanied by increase in light scattering. These results suggest that the detection of triphasic scattering change is useful to predict loss of tissue viability in brains.

Sterilization technology is absolutely essential for our daily life. For example, it is used for water and sewerage system, foods, and medicine. Method that widely used for sterilization are using drug, heating, ultraviolet (UV) radiation, and ozone. Chlorine is used extensively in sterilization because of its easiness and low cost. Using chlorine has some adverse effects such as alteration of quality of the target. Also it is bad for environment discharge water sterilized by drug to rivers and oceans. Conventional method for UV sterilization is using UV lamps. It is used to sterilize workspaces and tools used in biology laboratories and medical facilities. Low pressure mercury-vapor lamps emit 254 nm wavelength of UV which coincides very well with peaks of the germicidal effectiveness curve (i.e., effectiveness for UV absorption by DNA). Low pressure mercury-vapor lamps contains mercury and it has harmful effects to an environment and human body. In this study, we investigate effects of high-intensity ultraviolet light-emitting diode (UV LED) on E. coli and Vibrio parahaemolyticus. Aside from mercury-free, UV LED is low consumption. Exposure time of the UV is varied from 5 to 60 minutes. The wavelength of UV LED used is 365nm, its output is 15mW, and exposure distance between the UV LED and bacteria is 20mm. The result showed that germicidal effects for 100% of E.coli and 100% of Vibrio parahaemolyticus took 30 minutes and 10 minutes, respectively. These results suggest that the UV LED has sterilized effects.

The changes of the periodontal ligament according to orthodontic forces were evaluated by using optical coherence tomography. We have imaged periodontal ligament spaces of mandibular teeth both in a human dry skull and in postmortem beagles with applying different distraction force with different levels, 0 gm, 10 gm, and 30 gm on mandibular anterior teeth of white rats. We showed that the periodontal ligament due to external force was very sensitive to the orthodontic force, and the minute structural change could be imaged with optical biopsy technique or OCT. Although the experimental results were the pilot study, these preliminary results might be applicable for establishing the proper criteria in clinical dental treatment presenting clearly visualized proofs with OCT images. With exploiting the real-time imaging function of OCT, we could expect that the optical imaging technique can monitor dynamically the sequential changes of periodontal ligament in human teeth as well as in animal teeth.

NIR (near infrared) spectroscopic analysis was used to distinguish between cancer tissue and normal tissue. Pure cancer tissue versus normal tissue and cancer tissue surrounded by skin versus normal tissue were taken from 14 nude mice. The tissue samples were measured using spectroscopy at wavelengths between 400 and 2500 nm. In addition, principle component analysis (PCA) was carried out and difference between the sample groups was verified using regression analysis. According to the PCA results, there were two types of components. The greatest loading values were seen around 1250–350 nm, 1550–1650 nm, 1850–1950 nm, and 2100–2200 nm. These values are largely in accordance with the known absorption and oscillation area of methyl. Regression analysis of pure cancer tissue versus normal tissue, resulted in a correlation (R) of 0.94, with a standard error of 0.18. In the case of cancer tissue surrounded by skin versus normal tissue, the correlation was 0.85 with an error of 0.31. These results confirm that it is possible to detect cancer tissue using a NIR spectroscopy due to anomalous methylation patterns.