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Volume 29, Issue 8
Displaying 1-23 of 23 articles from this issue
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Mitsuhiro UIKE, Takanori UCHIYAMA, Haruyuki MINAMITANI1993 Volume 29 Issue 8 Pages 858-866
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSNMR spectra are usually obtained from free-induction-decay signals by means of the computationally efficient fast Fourier transform (FFT). However, in spectral analysis by FFT, there are several inherent limitations such as low resolution for the truncated signal, or side lobes due to windowing. Recently, several least-squares alternative methods to the FFT have been proposed to reduce these problems.
A similar limitation can be also observed in the magnetic resonance (MR) image reconstruction. A simplest method would allow for reduced imaging times, through the collection of fewer phase encoding steps. But the limitation of available data leads to truncation artifacts in the FFT reconstruction. These artifacts, which are known as the Gibbs phenomenon in engineering, introduce uncertainty in the discrimination of anatomical details in the MR images. It is possible to reduce truncation artifacts by using low-pass filtering technique, but this produces a severe loss in resolution.
We propose a data extrapolation method for truncation artifact removal. This method is based on a linear prediction approach with singular value decomposition. Reconstruction results from phantom data and clinical data are presented to illustrate the performance of the proposed method.View full abstractDownload PDF (3349K) -
Kazuhiko HAMAMOTO, Tsuyoshi SHIINA1993 Volume 29 Issue 8 Pages 867-875
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAlthough pulse-echo ultrasound images are clinically useful, they are not quantitative and have artifacts since ultrasound does not travel in straight lines through the biological medium which is subject to the acoustic properties such as the diffraction effects caused by the complex structure of the medium.
Computed tomography considering wave diffraction is called “Diffraction Tomography”. We can get the image of “refractive index” quantitatively using diffraction tomography, and it have a merit of reconstructing the higher resolution image than the order of wave length. In clinical uses, however, the range of the incident angles is restricted by various factors, It is therefore important problem how accurate image under this ill-posed condition can be reconstructed.
We applied “Max Entropy Method (MEM)” to ill-posed reconstructed problem of diffraction tomography, in order to restore confused image by MEM combining with iterative revision (IR) in space and frequency domain. Simulation results showed that it is possible to improve the quality of reconstructions more rapidly than the case of using only MEM or IR.View full abstractDownload PDF (3248K) -
Nobuyuki MURAI, Kohyu FUKUNISHI, Hiroyuki UNO1993 Volume 29 Issue 8 Pages 876-882
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe optical recording system with the computer aided experimental support system has been developed to investigate the animal auditory brain functions. The optical recording system with a 12×12 photodiode array as the image sensors has the spatial resolution about 26μm square and the time resolution about 70μs as the sampled-hold rate. The experimental support software system can afford to analyze the dynamical data using time series analysis in order to make a neural processing model from the observed spatio-temporal data. Some new experimental results on the neural dynamics in the guinea pig auditory cortex have been successfully obtained using this system.View full abstractDownload PDF (2298K) -
Yukari TAKAHASHI, Yukio YAMADA, Yasuo HASEGAWA1993 Volume 29 Issue 8 Pages 883-887
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSNear-infrared light is considered to be able to diagnose the oxygenation state of living bodies, and time-resolved spectroscopy is expected to be promising for sophisticated optical tomographic measurement. However, because light is strongly scattered by living tissues, fundamental understanding of scattering characteristics of light through living tissues is needed. In this paper, fundamental experiment using homogeneous samples was carried out for understanding of light propagation and for estimation of scattering and absorption coefficients by time-resolved measurements. The experimental results were compared with numerical results which were obtained by the Monte-Carlo method and the Finite-Element method solving the time-dependent proton diffusion equation. Good agreement between them are obtained.View full abstractDownload PDF (2294K) -
Masaaki MAKIKAWA, Katsunobu IMAI, Takashi SHINDOI, Kazuki TANOOKA, Hit ...1993 Volume 29 Issue 8 Pages 888-895
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is very important to get the change of biosignals in our daily life in order to make a diagnosis and treat patients in the clinical field, and also important to know the mechanism of our body in the research field. We have developed an ambulatory biosignal memory device to get various kinds of biosignal in our daily life away from the laboratory. Our device is a kind of portable battery-driven microprocessor-based computer system, and this system consists of Z80CPU, 64KB memory, real time clock, serial interface, 10 bit resolution A/D converter and optional circuit added according to the aim of measurement.
Here discussed are what such an ambulatory monitoring system should be and of what kind of technological problem should be solved. As a result, it is confirmed first that our ambulatory monitoring device can bring many kinds of useful information about the change of our condition. And at the same time, it is clarified that the insufficiency of memory capacity is the most significant problem of such a digital memory device as our system. Then IC memory card is added as a sub memory, and real time data compression technique is tested here. The result showed that by using these technique, a digital type ambulatory biosignal memory device can have the sufficient memory capacity even in the clinical application.View full abstractDownload PDF (2536K) -
Hirohumi HIRAYAMA, Yuzo FUKUYAMA1993 Volume 29 Issue 8 Pages 896-905
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe challenged to explain how the cardiovascular system was organized and what was the control strategy by optimal control theory. The performance function minimized included the time dependent change of ventricular ejection pressure, time dependent change in the aortic flow rate and the work of ventricle. The reconstructed ventricular ejection pressure and aortic flow curves were comparable with actual measured data obtained from normal human subject and isolated canine left ventricle. The effects of changes in arterial resistance and aortic compliance on ventricular pressure and aortic flow were well reconstructed by present theory. The effects of changes by the end diastolic ventricular volume with stroke volume and the ejection duration on the aortic flow were well reproduced by present study. The behavior of the end ejection pressure could not be represented because of probable change in kinetics of Ca2+ionic and in dynamical properties of cardiac muscle fiber. The changes in weighting coefficients relating to the time dependent changes in ejection pressure and the work of ventricular affected not only the ejection pressure but also aortic flow.
An optimal control theory with present performance function was useful to explain the total control strategy that cardiovascular system would be subjected. A limitation, however, existed that the optimal control theory could not describe. Those were the phenomenons that happening upon molecular level such as kinetic changes in Ca2+ions and individual cardiac muscle fiber.View full abstractDownload PDF (1757K) -
Quantitative Analysis of Hemoglobin ConcentrationShin Won KANG, Haruyuki MINAMITANI, Keisuke SASAKI1993 Volume 29 Issue 8 Pages 906-915
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA simple biochemical sensor using thin-film optical waveguide has been developed to measure and analyze quantitatively some inherent optical properties of biochemical substances. Fundamental structure of the sensor is three-layer slab type of waveguide, in which the waveguide layer consists of thin glass film having 1.761μm or 1.167μm in thickness. Ar and He-Ne lasers are used for the optical source. Theoretical analysis of the sensing principle and sensitivity has been carried out. Preliminary experiment using commercial products of ink-dye solution shows high availability to determine the concentration. The developed sensor has been applied to measure absorption coefficient as well as concentration of deoxyhemoglobin, oxyhemoglobin and carboxyhemoglobin of human red blood cells. It can be used for the measurement even if the sample solution is highly concentrated. The results are fairly well coincided with those obtained by conventional Beer-Lambert's method and verify the availability and advantage of the sensor.View full abstractDownload PDF (2594K) -
Toshiyo TAMURA, Kazuhiko SATO, Takanao HIGUCHI, Tatsuo TOGAWA1993 Volume 29 Issue 8 Pages 916-924
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn apparatus for monitoring prolonged measurement of oxygen uptake with minimum discomfort to the subjects has been developed. The system is based on the open flow-through principle. The subject wears a hood through which air is drawn by an exhaust blower. Oxygen concentration is kept constant by a servo-controlled blower, so that flow rate is essentially proportional to oxygen uptake. The flow rate of the main stream is measured by a time-of-flight flowmeter located in the exhaust hose. Oxygen concentration is measured by a limiting-current oxygen sensor. The signals representing flow rate and oxygen concentration are digitized and stored on a memory chip. All of the equipment is assembled in a small package (wt=3kg) which the subject carries on his back. The memory chip is removed from the portable device after each experiment. Data are transferred from the memory to a microcomputer and then an oxygen uptake trend is estimated. Response of the system to a step input is about 30s. Compared with a commercially available oxygen monitoring system (Magna 88, P. K. Morgan ltd., Rainham, U. K.), the maximum difference was 0.15l/min within an oxygen uptake range of 0.25 to 2.3l/min. The oxygen uptake of exercising human subjects measured with this portable device showed good agreement with that obtained by a conventional oxygen-uptake monitoring system (r=0.973 for cycle ergometer, r=0.932 for treadmill). This portable device was able to measure oxygen uptake in subjects during daily activities, such as driving a car, cycling, and mountain climbing, without any disturbance.View full abstractDownload PDF (2199K) -
Kenichi MINAMI, Eiji OKADA, Yukari YOSHIMURA, Haruyuki MINAMITANI1993 Volume 29 Issue 8 Pages 925-933
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThere are two types of pulmonary hypertension. One of them is primary pulmonary hypertension in which the cause is unknown, and the other is secondary pulmonary hypertension related to congenital heart disease, pulmonary thromboembolism and pulmonary fibrosis. In both cases, the prognosis is severe and various histological changes can be seen in hypertensive pulmonary arteries. Therefore their histological examination is important for the diagnosis of the pulmonary hypertension. In the field of pathology, diagnosis of biopsy materials are carried out based on the results obtained by examining the histology of autopsy materials to evaluate the grade of hypertension, and arterial hypertrophy is generally used for the evaluation. However a great amount of work is required for such analysis, since the method mainly relys on the manual operation.
In this study, a system based on the image processing technique for the quantitative measurement of the arterial hypertrophy is developed. The system is capable of extracting precise image of pulmonary arteries. Also a new method is proposed to estimate the state of the pulmonary arteries before the constriction which is caused by the postmortem decrease of the blood pressure. Using this system, we have measured the grade of the arterial hypertrophy from the hypertensive autopsy material, and obtained histologically well correlated results to the conventional knowledge of the pulmonary hypertension.View full abstractDownload PDF (2003K) -
Toward an Ambulatory Monitoring of Tidal Volume without CalibrationMakoto NOSHIRO, Shinji MIYAZAKI, Keiichi OGAWA, Toshikazu OKAZAWA, Hid ...1993 Volume 29 Issue 8 Pages 934-936
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSComputer simulations show that the shape of closed curves can be reconstructed from the curvatures measured at many points on the original curves, and that as a result, the area of the curves can be measured. An experiment confirms the result of the computer simulations.View full abstractDownload PDF (385K) -
Eiji TOBA, Sadamu SEKIGUCHI1993 Volume 29 Issue 8 Pages 937-939
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA special CA thermo-pile with high sensitivity and fine frequency characteritics, of which the gain is flat to about 10Hz, is developed as a sensor for measurement of human breath condition monitoring system.View full abstractDownload PDF (353K) -
Shunji HIROKAWA1993 Volume 29 Issue 8 Pages 940-948
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe objective of this study is to measure the variation of patellofemoral joint contact pressure under the condition of simulating the variations of the knee flexion angle, and the thigh muscle forces during level walking, climbing and descending stairs. It will compare the results with those of the previous experimental studies in which the thigh muscle forces had been kept constant.
Using the data from the literature and applying a pure mathematical calculation, the values of tensile forces applied to the thigh muscles were determined as a function of knee flexion angle, to simulate various walking conditions. In the experiment, data was obtained by the variation of electrostatic capacity of a specially designed film inserted between the contact surfaces of the patellofemoral joint.
The experimental results demonstrated that when the thigh muscle force was kept constant, the mean contact pressure was almost uniform throughout the whole range of knee flexion, while the contact force showed a dome shape indicating the highest value at about 45° knee flexion. When the values of thigh muscle force and the knee angle simulating various walking conditions were applied, the results demonstrated that the patellofemoral contact pressures were almost constant all of the time of the stance phase of a gait cycle, also the peak values of pressure were almost equal among three kinds of walking. It was also revealed that the articular surface of contact portion where larger contact force occurs produces a smaller curvature.
The patellofemoral articular surfaces are seemingly irregular in shape, however, the complicated shapes may play an important role in moderating steep variations of patellofemoral contact pressure during walking.View full abstractDownload PDF (2246K) -
Ryojun IKEURA, Masanobu NANKYO, Hikaru INOOKA1993 Volume 29 Issue 8 Pages 949-955
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper discusses maneuverability of a control stick using electromyogram (EMG). For simple discussion, step operation is treated. Considering the characteristics of neurons controlling the muscle of a human arm, we divide the step operation into two intervals. One is the transient interval from a start point to a target one. The other is the settling interval to the target point. We find that the maneuverability in the settling interval is important for the step operation. Then, we analyze maneuverability from the viewpoint of the stability of a dynamic model of the muscle and the control stick. It is shown that the improved maneuverability is achieved by increasing the viscosity of the control stick. Then, we define maneuverability index as time integration of the muscle impedance. Using EMG, the index is evaluated experimentally. We confirm that human feels best maneuverability when the index is minimum.View full abstractDownload PDF (2439K) -
Hisao OKA, Tatsuma YAMAMOTO1993 Volume 29 Issue 8 Pages 956-962
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThere is a small movement that is observed on the body surface (Microvibration: MV). It was first reported by H. Rohracher in 1946. Though it is still not cleared why and how the MV occurs, there are some papers about its clinical applications to the diagnosis of various autonomic nervous system condition. In this study, a MV measurement system has been developed. The MV signals are detected by using the acceleration sensors placed on the forehead and thenar. The MV power spectra are calculated by using an autoregressive model. The MV is quantified by the sum and appearance rate of MV spectra. The MV signals are stabilized after 5 minutes from the start of MV measurement. They are independent not only of wrist angle but also of opening and closing of both eyes.
Though there are variations between individuals and body areas in the MV sum, the appearance rate on the forehead MV belongs to S-type (the frequency band 5.5-7.5Hz is superior in the MV spectrum) in nearly 96% of subjects. On the thenar MV, it belongs to N-type (the band 7.5-13Hz is superior) in nearly 79% of subjects. The diurnal change of the forehead MV is almost proportional to the variation of heart rate. The autonomic nervous system affects the MV sum through cardiac function and respiration. The somatic nervous system affects the MV appearance rate through muscle activity. The central nervous system affects both the sum and appearance rate due to the emotions of the subject. Therefore the MV occurrence mechanism is based upon signals from the autonomic, somatic, and central nervous system.View full abstractDownload PDF (3478K) -
Hiroyuki SHINODA, Qihuan GENG, Shuichiro YAMASHITA, Minoru AI, Shigeru ...1993 Volume 29 Issue 8 Pages 963-972
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we describe a structure and an algorithm of a newly developed 3-D deformation measurement system, and show some results of its application to a dental prosthodontical investigation of a human oral soft tissue under various impression pressures.
This system is composed of a fixed TV camera and vertically scanning projectors. The projectors generate a moving 3-D illumination distribution in front of an object. A height difference and a reflectance ratio between two objects are coded in a time difference and an amplitude ratio respectively between two sequences of images of them. Using gradient-based least squares algorithms, we decode these quantities precisely and efficiently. The remarkable advantages of this system are 1) it can be free from occlusion because of its vertical scanning and imaging geometry, 2) it doesn't need any precise geometry except for the reproducibility of the vertical scanning stage, 3) it can measure a height difference between unequal reflectance objects as well as unknownly textured surfaces, and 4) it completes one aerial measurement including computation within only 10 seconds while keeping the 5μm precision and 1mm range-ability.
Using this system, we investigate the influence of the various impression procedures on the magnitude of soft tissue displacement. The principle of this measurement system and the results of this application are presented.View full abstractDownload PDF (4383K) -
Case of PedalingMasaru DANNO, Shoji HAYASHI, Toshiyuki ASAKURA1993 Volume 29 Issue 8 Pages 973-975
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMost efficient bicycle riding under similar tiredness was to get mutching between human and load impedance. This impedance was scarcely found the difference among individuals, and the optimum gear selection for the slop and speed of bicycle could be proved.View full abstractDownload PDF (341K) -
Masashi SATO, Hidetaka IKEUCHI, Tadashi YAMASHITA1993 Volume 29 Issue 8 Pages 976-978
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe systematic errors which are contained in the outputs of a large force plate have bad influences on the numerical integration of force components to study human walking. In this paper, a simple method to decrease the systematic errors is proposed.View full abstractDownload PDF (371K) -
Mieko OHSUGA, Hiromi TERASHITA, Futomi SHIMONO1993 Volume 29 Issue 8 Pages 979-986
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe have been working on the development of the method for quantitative assessment of mental workload (MWL). The quantitative assessment of MWL is helpful for improvement of the usability of various computer systems, the working environment, and the schedule management. Methodological requirements include (1) being able to compare MWL under various working conditions, (2) caputuring the time course of MWL, (3) assessing it in relation to individual differences, and (4) executing assessment without giving subjects extra load. Some autonomic responses meet the first two requirements. They may be the promising measures for MWL if a proper methodology is applied in order to satisfy the 3rd and 4th requirements. In the present paper, we show the results of our basic experiments. The first one concerns the differences in autonomic response patterns among subjects caused by a mental arithmetic, and the second concerns the similarities and differences in them as a function of MWL caused by various tasks. The findings of two experiments suggest the importance of the multidimensional use of the indices which are differently influenced by the two autonomic nervous systems, the exsistence of individual response specificity under metal tasks, the difficulty in prediction for individual response patterns to MWL using those caused by physial tasks. The necessity of careful consideration for respiration and posture at the interpretation of autonomic indices was reaffirmed.View full abstractDownload PDF (1714K) -
Masaji YAMASHITA, Koichi SHIMIZU, Goro MATSUMOTO1993 Volume 29 Issue 8 Pages 987-992
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA non-invasive and ambulatory technique has been devised for the quantitative evaluation of physiological and psychological stresses. The change in diameters of peripheral blood vessels is measured as the change in transmitted intensity of infrared light across an ear auricle. This signal is transmitted to a remote place using another infrared light diffusely reflected from a ceiling and walls of a room. The measurement system to realize this technique has been developed. The sensing part of this system is small and light enough to be equipped on a small experimental animal. The feasibility of this technique was verified in the measurement with a rabbit. Various types of stresses were applied and the responses in peripheral circulation were obtained. The measurement system was modified to be applied to a human subject. The R-R interval of ECG can be measured simultaneously with the peripheral circulation. The agreement between the measured results shows the usefulness of this technique.View full abstractDownload PDF (2109K) -
Hiroaki ISHIZAWA, Masako NAKAMURA, Tsunetomo MATSUZAWA, Toshiyasu TAKA ...1993 Volume 29 Issue 8 Pages 993-999
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe influences of Residual Pesticides for human health or environment have been a very important problem.
The Welfare Ministry of Japan has regulated another 34 standards for the residues, adding to the conventional 26 standards, because the amounts of agricultural products imported from the foreign countries have increased year by year and the consumers' concern for the safety of the agricultural products has increased rapidly.
This study proposes a new nondestructive method to measure the quantity of residual pesticides on vegetable surfaces by FT-IR of attenuated total reflection method.
The main results of this study are as follows.
(1) The active element of residual pesticides can be discriminated by a set of characteristic absorbance bands of pesticide.
(2) An adequate correlation was observed between the A.T.R. method values and conventional G.C. method values.
(3) FT-IR-A.T.R. method takes less time to detect than conventional G.C. method.
(4) These technologies of this study are expected to be very useful to develop a measuring system for the food safety.View full abstractDownload PDF (1252K) -
Tomoyuki AKASHI1993 Volume 29 Issue 8 Pages 1000-1008
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA Fractal method is applied to a bioprocess of Algae and some basic characteristics of the method are investigated with experimental data for 4 kind of Algae. In the growing process of Algae, fractal dimensions are calculated with image data, which are obtained on-line by a microscope and a CCD (Carged Coupled Device) camera.
Spirulina platensis NIES39, 46, Anabaena cylindrica and Chrollera vurgaris are useful Algae for a wastegas bioprocess. Spirulina platensis NIES39, 46 shows a typical complicated growing pattern in each growing phase. The complexity of the pattern is described with a large fractal dimension. The growing patterns are distinguished from each other with the factal dimension in each growing phase. Complexity of simple growing patterns for Anabaena cylindrica or Chlorella vurgaris are described with a small fractal dimesion. Other basic characteristics of the fractal method are also discussed with some experimental results.
The proposed fractal method is useful for an on-line state measurement in a waste-water process or other bioprocess which has a similar complicated growing pattern as Algae.View full abstractDownload PDF (4108K) -
Hideaki KIMATA, Shunshiro OHNISHI, Yutaka KURIOKA1993 Volume 29 Issue 8 Pages 1009-1011
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA leaf of Mimosa pudica was blown by a wind pressure stimulator. As the pressure increased, the waveform of action potential at pulvinule shifted to four types. When the pressure exceeded a threshold, action potentials appeared at sub-pulvinus and petiole.View full abstractDownload PDF (383K) -
Hideyuki AKIYAMA, Kiyoshi TOKO, Kaoru YAMAFUJI, Kenshi HAYASHI1993 Volume 29 Issue 8 Pages 1012-1014
Published: August 31, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSLipid-membrane materials are effective as a transducer of taste sensors. The Langmuir-Blodgett (LB) film was investigated as a candidate of transducer materials. The membrane potential responded to taste substances showing sourness, saltiness and umami with high sensitivity, but scarcely responded to sweet and bitter substances.View full abstractDownload PDF (411K)
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