Satoki P. Ninomija

On an image processing of eye blinking to monitor awakening levels of human beings

The main goal of the present study was to design and examine a system to monitor awakening levels of human beings using the image processing technique to recognize eye blinking. This problem was divided into two sub-problems; to obtain images by decreasing noise and simplify the images, and to detect whether eyes were closed or opened. A filtering technique and the automatic threshold determination method were used to solve the former sub-problem and the automatic detection system was designed for the latter sub-problem. To examine the reliability of the designed system, a comparison between the result detected by the system and that detected by a sensor using electroencephalograms (EEGs) was made.

Evaluating dynamic changes of driver's awakening level by grouped /spl alpha/ waves

Describes the system of automatically detecting grouped /spl alpha/ waves of EEGs using a convolution with special weighting factors such as moving average methods. A drop of human awakening level has a close relation to appearances of grouped /spl alpha/ waves. Then using this system, it is possible to detect drivers low awakening condition and prevent traffic accidents caused by this condition. The system has two important points. The first, because actual data contain various kinds of noise, this system separates grouped /spl alpha/ waves from those. The second, the system detects this condition as soon as grouped /spl alpha/ waves appear. As the result of analyzing actual EEGs taken during driving a car, we find out the fact that intervals of grouped /spl alpha/ waves appearance fluctuate.

On the use of statistics for representing the knowledge acquired from experts in a medical consulting system

For making medical consulting systems, it is important and significant to select and devise the method for representing the knowledge acquired from professional experts. As quantities of data required for consultation are increasing according to the progress of medical science, we have to introduce some new kinds of statistics into a medical consultation system. From another point of view, since the process of diagnosis of experts is considered to be a kind of effective model for compressing (or condensing) data quantitatively and qualitatively, we discuss the use of statistics for representing the knowledge acquired from experts from the standpoint of data compression.

A time variation of professional driver's EEG in monotonous work

An experiment was conducted on five subjects to determine the time it takes for slow alpha wave activity to appear during monotonous tasks. The experiment measured the time of response to digits appearing on a screen and the time of appearance of slow waves in the electroencephalograms (EEGs). Two professional automobile drivers were tested, as well as one maintenance technician and two students for comparison. The EEGs were analyzed using the autoregressive method. The results are presented and discussed.<<ETX>>

An improvement of automatic SVR detecting system (AUTSVRN) for infants

A slow vertex response (SVR) is one of the auditory evoked responses measured through electroencephalography (EEG) by the summation method. The authors have previously developed a medical consulting system for detecting SVRs that identify sleep stages of the EEG for adults, using the summation system. In order to improve the system for infants, they propose a coded summation method to obtain a SVR. The method has higher reliability and ability to decompose the SVR, and the number of summations needed is 1/4 approximately 1/10 of that of the conventional summation method.<<ETX>>

The Arresting Effect Of Fragrance On Inclining Sleep

In this paper we describe the arresting effect of fragrance on inclining sleep(The inclination to sleep), and list some of the basic data. It has been firmly established that Grouped Slow Alpha Wave appear in the EEG(e1ectroencephalogram) when one falls into the state of inclining sleep, indicating a drop of brain activity. It has also been reported in recent studies, that the stimulus of fragrance has various biological effects on human beings. An experiment, arresting the effect of inclining sleep followed with a drop in brain activity, was performed. The results were estimated by using Grouped Slow Alpha Waves. The fragrance stimuli in this experiment were Lemon, Jasmine and Lavender, and the results were as follows:

The relationship between arm movement and walking stability in bipedal walking

Research about bipedal locomotion is advanced in all fields at present. For research of those fields, a quantitative analysis of human walking characteristics is indispensable. However, bipedal locomotion analysis has been performed focusing on lower limbs, and, research on arm swing operation has not been performed; nevertheless its importance is generally known. The reason for its omission is the assumption that the arm is not a necessary part for locomotion. However, it can be guessed that the arm swing operation, having done a certain role in the stability of a walk, is very unstable physically. When running, the human clearly draws the arm greatly and quickly. This suggests that the arm swing operation is related with the change of walking form and movement speed of the locomotion, and it influences the stability of a walk. This method becomes a useful analysis technique also not only to the above-mentioned research but to sport kinematics research etc., if the relations to this arm swing operation and the stability of a walk is quantitatively understood. In this study, the relationship between arm swing operation in bipedal locomotion and stability of the walking was noticed.

A coded summation method to measure evoked responses of human beings

Human Beings have several kinds of responses evoked by different kinds of stimuli. Examples include auditory evoked responses, visual evoked responses, and etc. Evoked responses appear in electroencephalograms (EEGs) and are measured by an EEG. These evoked responses have a smaller amplitude wave and an averaged summation method (ASM) is widely used to measure this phenomenon. The ASM, however, is not entirely suitable to measure a signal hidden behind nonstationary data with a high ratio. Because the number of average summation cycles has to increase in order to improve the signal-to-noise ratio, increased time is required to measure a signal. The nonstationarity of data also increases the danger that a measured signal has several distortions caused by nonstationarity. These facts indicate the necessity for a short period measurement to obtain an evoked response. At the same time, the short period measurement realizes a reduction of load for measured person.In this paper, a process called a coded summation method (CSM) is proposed. This method has the ability to measure an evoked response within 1/4, ∼ 1/12 of the time that is required by the usual ASM. The CSM transforms the original data into codes and then follows with a summation and an averaging for the coded data. The CSM is applied to two kinds of actual cases; the measurement of auditory slow vertex responses and visual evoked responses. Through the trials and discussions about the results in these two cases, an algorithm is derived to determine several CSM parameters the effectiveness of CSM is evaluated by being compared with the traditional ASM technique.

A study about relation between monotonous work and somnolence

Many subjects tend to fall into somnolence as they continue monotonous work. This report covers some noteworthy fact found in the lengths of time for the subjects to begin to doze. Our earlier research has made it clear that the occurance of grouped-α-wave can be used as an indication of somnolence in which the level of brain activities drops low. Needless to say, such time varies from one person to another. However, our experiment shows that most subjects, who slept for proper lengths of time the night before but who have not been specially trained for staying awake, begin to fall into somnolence in 20 to 30 minutes after starting work.

Statistical approaches to nonstationary EEGs for the detection of slow vertex responses

A slow vertex response (SVR) is an electric auditory evoked response used for an objective hearing power test. One of the aims of an objective hearing power test is to find infants whose hearing is less than that of normal infants. Early medical treatment is important for infants with a loss of hearing so that they do not have retarded growth. To measure SVRs, we generally use the averaged summation method of an electroencephalogram (EEG), because the signal-to-noise ratio (SVR to EEG and etc.) is very poor. To increase the reliability and stability of measured SVRs, and at the same time, to make the burden of testing light, it is necessary to device an effective measurement method of SVR. Two factors must be considered: (1) SVR waveforms change following the changes of EEGs caused by sleeping and (2) EEGs are considered as nonstationary data in prolonged measurement. In this paper, five statistical methods are used on two different models; a stationary model and a nonstationary model. Through the comparison of waves obtained by each method, we will clarify the statistical characteristics of the original data (EEGs including SVRs), and consider the conditions that effect the measurement method of an SVR.