68 results on '"Toshifumi Sugiura"'
Search Results
2. Wearable ECG recorder with acceleration sensors for monitoring daily stress: Office work simulation study.
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Yoshio Okada, Tsuyoshi Yi Yoto, Taka-aki Suzuki, Satoshi Sakuragawa, and Toshifumi Sugiura
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- 2013
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3. An Assessment Tool for Effective Monitoring of Autonomic Nervous System Activity in Healthy People.
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Takuto Yanagida, Yoshimitsu Okita, Harunobu Nakamura, Toshifumi Sugiura, and Hidenori Mimura
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- 2014
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4. Stochastic diffusion control for gene-regulating protein particles.
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Hirohumi Hirayama, Yoshimitsu Okita, and Toshifumi Sugiura
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- 2001
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5. An Application for Diagnosis by Chaotic Approach (An Application to Discrimination of Arrhythmia).
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Tadashi Iokibe, Masaya Koyama, and Toshifumi Sugiura
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- 1996
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6. Psychological Response to Sound Stimuli Evaluated by EEG
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Isao Takahashi, Xi Chen, Toshifumi Sugiura, Hisashi Hirata, and Yoshimitsu Okita
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medicine.medical_specialty ,Psychological response ,medicine.diagnostic_test ,Physiology ,General Neuroscience ,Audiology ,Stimulus (physiology) ,Electroencephalography ,Alpha wave ,Developmental psychology ,Correlation ,Neuropsychology and Physiological Psychology ,medicine ,Psychology - Abstract
Abstract. Psychological responses to two kinds of sound stimuli (scary and soothing), as assessed by the Anterior Asymmetry and Emotion (AAE) and Comfort Vector (CV) models which are based on the prefrontal alpha wave, were investigated and the relation between their results is discussed. For the scary sound stimulus, subjects who showed greater withdrawal motivation (AAE) displayed a decreased pleasant state (CV), while subjects who showed higher approach motivation displayed opposite affective direction. There was a correlation between the AAE and CV models for the scary stimulus, but no correlation for the soothing stimulus. Both motivational and affective states could be evaluated by a combination of AAE and CV models. We suggest that joint consideration of these two models could lead to the multifaceted evaluation of a psychological state.
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- 2015
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7. An Assessment Tool for Effective Monitoring of Autonomic Nervous System Activity in Healthy People
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Harunobu Nakamura, Takuto Yanagida, Hidenori Mimura, Toshifumi Sugiura, and Yoshimitsu Okita
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Human-Computer Interaction ,medicine.medical_specialty ,Autonomic nervous system ,Physical medicine and rehabilitation ,Artificial Intelligence ,Computer science ,medicine ,Computer Vision and Pattern Recognition - Abstract
This paper proposes an application that analyzes and displays electrocardiograms (ECG; electrical activity of the heart over time) and plethysmograms (PTG; pulse waves produced by the heart pumping blood to the periphery) measured simultaneously. Recently in developed countries, chronic conditions typified by lifestyle-related diseases have become the leading cause of death. Simplified monitoring of the condition can be an effective approach to disease prevention and health promotion. We have focused on autonomic nervous system activity (ANSA) because it responds to stress as well as to changes in dietary patterns, and is correlated with hypertension, the source of some diseases, such as coronary disease. In this paper, we deal with both ECGs and PTGs as part of the biological data that reflects ANSA. The proposed application enables doctors to seamlessly negotiate analyzed waveforms and index charts of ECGs and PTGs in sync with each other. It also helps them comprehend the transition of ANSA. It offers a user interface (UI) that enables doctors to observe the two measures and the relationship between them for a quick assessment of ANSA; the sonification function of the ECG indices is implemented for providing the multi-modality of the UI. An experiment was conducted to confirm the feasibility of the analysis method of the application.
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- 2014
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8. New Evaluation Method of Muscle Anti-Fatigue Effect
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Teruhiko Fuwa, Hirohisa Kishi, Toshifumi Sugiura, and Daiki Kubomura
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business.industry ,Evaluation methods ,Medicine ,business ,Biomedical engineering - Published
- 2014
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9. Verification of anti-fatigue effect of anserine by angle fatigue indicator based on median frequency changes of electromyograms
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Toshifumi Sugiura, Daiki Kubomura, and Hirohisa Kishi
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anserine ,electromyogram ,Anserine ,Medicine (miscellaneous) ,lcsh:TX341-641 ,Rectus femoris muscle ,Isometric exercise ,Biochemistry ,chemistry.chemical_compound ,Animal science ,Median frequency ,medicine ,Bonito ,lcsh:R5-920 ,Nutrition and Dietetics ,Muscle fatigue ,Fish extract ,Skeletal muscle ,Anatomy ,medicine.anatomical_structure ,chemistry ,muscle fatigue ,lcsh:Medicine (General) ,lcsh:Nutrition. Foods and food supply ,Food Science ,median frequency power - Abstract
Objective : Anserine, which is abundant in avian species and in a wide range of fish such as bonito and tuna, is reported to have anti-fatigue effect. Although chicken soup and bonito soup is traditionally used to recover from physical fatigue, it is generally difficult to verify the effect in humans. This study was to directly demonstrate the anti-fatigue effect of oceanic anserine in humans. Methods : Edible-grade anserine was purified from fish extract with food-grade reagents. Subjects were 17 healthy male volunteers (35.5 ± 5 yr., 75.5 ± 5.0 kg). Each subject performed the isometric exercise tolerance test (ETT) on the rectus femoris muscle twice (Ex_1, Ex_2) both for anserine and water conditions on a different day. Median frequency changes (MDF) during ETTs were calculated and regression curves were calculated over a frequency range of 21-214 Hz. The difference, or angle, between the slopes of Ex_1 and Ex_2 MDF regression curves, which corresponds to the degree of fatigue, was defined as an angle fatigue index and compared between anserine and water intake conditions. Results : MDF decreased during ETTs in most patients and the slopes of regression curves were larger in Ex_2 than in Ex_1. Angle fatigue index for water (control) was significantly larger than that for anserine (p
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- 2013
10. Psychological Responses to Sound Stimuli Evaluated by Alpha Wave Fluctuations
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Isao Takahashi, Xi Chen, Toshifumi Sugiura, Hisashi Hirata, and Yoshimitsu Okita
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medicine.medical_specialty ,geography ,geography.geographical_feature_category ,Physiology ,General Neuroscience ,Physical Comfort ,Audiology ,Alpha wave ,medicine.disease_cause ,Developmental psychology ,Neuropsychology and Physiological Psychology ,Mood ,Graduate students ,Alpha rhythm ,Auditory stimulation ,medicine ,Psychological stress ,Psychology ,Sound (geography) - Abstract
Evaluation of psychological stress or state of mind remains an important problem. The anterior asymmetry and emotion model (AAE model) is a conventional and widely used method to sort baseline affective styles (approach or withdrawal) based on asymmetry of the activity in prefrontal cortices. Another method is to use alpha wave fluctuations at the frontal poles, as proposed by Yoshida. This method estimates state of mind as one point on a comfort level surface with pleasant-unpleasant and excited-calm axes that are normal to each other. The aim of this paper is to investigate the validity of the Yoshida method through the psychological responses to sound stimuli. Twenty-two healthy graduate students listened to two kinds of sound clips (scary and soothing) to induce negative and positive emotional states. The results showed that there are significant differences between the responses to scary and soothing sound stimuli in both unpleasant and excited mood states. Compared with baseline, increases in unpleasant and excited mood states were found in response to scary stimuli. However, no significant changes from the baseline state were observed in response to the soothing sound stimulus. These results suggest that the fluctuation of alpha waves recorded at both frontal poles is a valid index for the evaluation of psychological state of mind, especially for negative stimulation. Future study plans include investigating a possible relationship between the AAE model and the Yoshida method.
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- 2013
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11. Effects of Vegetable Containing Gamma-Aminobutyric Acid on the Cardiac Autonomic Nervous System in Healthy Young People
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Yoshimitsu Okita, Harunobu Nakamura, Terumi Takaoka, Toshifumi Sugiura, Katsuyasu Kouda, Motohiko Kimura, and Isao Takahashi
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Male ,medicine.medical_specialty ,Cardiac output ,Physiology ,Blood Pressure ,Human Factors and Ergonomics ,Pharmacology ,Autonomic Nervous System ,Cardiovascular System ,law.invention ,Young Adult ,Double-Blind Method ,Randomized controlled trial ,Heart Rate ,law ,Physiology (medical) ,Internal medicine ,Vegetables ,Heart rate ,medicine ,Humans ,Heart rate variability ,Orthopedics and Sports Medicine ,Cardiac Output ,gamma-Aminobutyric Acid ,Analysis of Variance ,Cross-Over Studies ,business.industry ,Public Health, Environmental and Occupational Health ,Stroke Volume ,Stroke volume ,Crossover study ,Autonomic nervous system ,Blood pressure ,Anthropology ,Cardiology ,Vascular Resistance ,business ,Tablets - Abstract
The aim of this study was to investigate the effects of vegetable tablets containing Gamma-Aminobutyric Acid (GABA) intake on cardiovascular response and the autonomic nervous system in young adults. In a double-blind, randomized controlled trial, 7 healthy subjects were assigned to take vegetable tablets (10 g/trial) or control tablets (10 g/trial). We measured heart rate (HR), systolic and diastolic blood pressure, stroke volume, cardiac output, total peripheral resistance index, and the low- and high-frequency oscillatory components of heart rate variability (HRV). Two major spectral components were examined at low-frequency (LF: 0.04-0.15 Hz) and high-frequency (HF: 0.15-0.4 Hz) bands to indicate HRV. There were significant interactions in HR (p
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- 2009
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12. FRONTAL EEG ASYMMETRY AND COMFORT LEVEL ASSESSMENT BY THE YOSHIDA METHOD
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Yoshimitsu Okita, Hideo Etho, Isao Takahasi, Atsunori Fujii, Yusuke Akiyama, Mananori Tauchi, and Toshifumi Sugiura
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medicine.medical_specialty ,Odor ,medicine.diagnostic_test ,medicine ,Eeg asymmetry ,Audiology ,Electroencephalography ,Psychology - Published
- 2009
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13. Picture therapy and the evaluation of its effect on relaxation by salivary cortisol(Miscellaneous)
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Yoshimi, NAKAMICHI, Michikazu, SAMEJIMA, Shouzhi, GU, and Toshifumi, SUGIURA
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QOL ,絵画療法 ,非言語コミュニケーション唾液コルチゾール ,脳 - Abstract
絵画療法は、手、指、脳の働きを適度に緊張・緩和させるので、血液循環が良くなり、特に脳の前頭葉の部分を刺激し、神経伝達物質(ドーパミン)が放出され、浄化作用(カタルシス)を促す。適度な集中をくり返すことは、身体や脳の機能回復にも役立つ。どんな作品にしようかと図案構成をすることが、脳の思考回路を活発にする。絵画制作を通して自己表現をし、充実感、達成感を味わうことで情緒の安定を図ることが出来る。また、お互いの作品を認め合うことで、コミュニケーションが深まり、信頼関係が生まれる。そこには、言語としてのコミュニケーションだけではなく、非言語コミュニケーションも含まれる。この様な個別支援は生きがい支援となり、生活の質(QOL=Quality of Life)の向上を促す。絵画療法が、具体的な身体的な変化を生み出していることを、唾液中のコルチゾールを測定することで、確認することが出来た。
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- 2006
14. Event-related potentials in a memory scan task concerned with movement directions
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Toshifumi Sugiura, Motohiko Kimura, Yoshimitsu Okita, Noboru Ohki, Teruhisa Kazui, Isao Takahashi, and Tetsuo Kobayashi
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medicine.medical_specialty ,Working memory ,Movement (music) ,General Medicine ,Audiology ,Occipital region ,Developmental psychology ,Task (project management) ,Event-related potential ,medicine ,Parietal region ,Psychology ,psychological phenomena and processes ,Entire head - Abstract
To study brain mechanisms of memory scan, we have measured event-related potentials (ERPs) during the execution of a Sternberg task concerned with movement directions of random dot patterns (RDPs). Five healthy male subjects participated in the experiment. Event-related potentials were recorded at 20 electrode positions over the entire head. A prominent positive ERP component peaking at 380–390 ms known as P300 was observed in the parietal region after the presentation of the probe moving random dot pattern, whereas the P300 was not observed after the presentation of a control stationary RDP. On the other hand, a positive ERP component peaking at 127 ms was commonly observed in the occipital region after the presentation of both moving and control stationary RDPs. These findings suggest that P300 may reflect cortical activities related to the memory scan of movement directions of RDP.
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- 2004
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15. Potential Distribution Analysis around DNA as a Micro Bio Machine
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Hirohumi Hirayama, Yoshimitsu Okita, and Toshifumi Sugiura
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symbols.namesake ,Distribution (number theory) ,Chemistry ,Debye–Hückel equation ,Quantum mechanics ,symbols ,Statistical physics - Published
- 2002
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16. Application of H2 Control for Evaluating the Ion Channel Gating on Excitable Cellular Membranes
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Hirohumi Hirayama, Yoshimitsu Okita, and Toshifumi Sugiura
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Membrane ,Materials science ,Voltage-gated ion channel ,Analytical chemistry ,Biophysics ,Gating ,Ion channel ,Ion channel gating - Published
- 2002
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17. Introduction of a Method for Computing Electrostatic Potential Distribution around a DNA Molecule by a Cylinder Model
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Hirohumi Hirayama, Toshifumi Sugiura, Yoshimitsu Okita, Teruhisa Kazui, and Toshihiro Nishimura
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Physics ,symbols.namesake ,Classical mechanics ,Distribution (number theory) ,Debye–Hückel equation ,symbols ,Cylinder ,Molecule ,A-DNA ,Electrical and Electronic Engineering ,Molecular physics ,Debye length - Published
- 2002
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18. Stochastic diffusion control for gene-regulating protein particles
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Yoshimitsu Okita, Toshifumi Sugiura, and Hirohumi Hirayama
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Physics ,Molecular diffusion ,Diffusion equation ,Flux (metallurgy) ,Laplace transform ,Artificial Intelligence ,Anomalous diffusion ,Control theory ,Diffusion-controlled reaction ,Impulse (physics) ,Molecular physics ,Fick's laws of diffusion ,General Biochemistry, Genetics and Molecular Biology - Abstract
We introduce a precise analytical method for computing the temporal changes in concentration and fluxes of gene-regulating repressor protein particles. The temporal changes in repressor particle concentration is described by an integral-differential diffusion equation in cylindrical coordinates. The equation consists of the memory-less first-time-arrival probability and the integration of the return probability of the particles to the operator region of the DNA. By using the Laplace transformation, we could derive analytical forms of the temporal changes in concentration and flux in a radial direction, the total flux, and the first-time-arrival probability. We also computed the impulse responses of the first-time-arrival probability of the repressor to the sink. The computed diffusion of the repressor particles decreased rapidly from the onset of the reaction. As the diffusion constant in the medium around the DNA increased, the first-time-arrival probability, the diffusion, and the flux of the particles decreased, while the total flux into the target sink increased. As the chemical factor became predominantly a diffusion factor, the first-time-arrival probability, the diffusion, and the flux of the particles decreased. As the dissociation rate of the particles increased, the flux into the sink increased. The number of dissociated particles was significantly more influenced by the chemical factor than by the diffusion. The first-time-arrival probability oscillated significantly at the onest of the reaction. When this method has been extended, it will be available for predicing genetic expression and creating artificial life.
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- 2001
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19. Monitoring of deep brain temperature in infants using multi-frequency microwave radiometry and thermal modelling
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van Gmj Gerard Leeuwen, D. Azzopardi, Toshifumi Sugiura, S. Mizushina, A.D. Edwards, van de Jb Kamer, Jeffrey Hand, and K. Maruyama
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Brightness ,Models, Statistical ,Materials science ,Observational error ,Radiological and Ultrasound Technology ,Computer simulation ,business.industry ,Quantitative Biology::Tissues and Organs ,Acoustics ,Instrumentation ,Microwave radiometer ,Infant, Newborn ,Temperature ,Brain ,Models, Theoretical ,Statistical fluctuations ,Body Temperature ,Brightness temperature ,Humans ,Radiology, Nuclear Medicine and imaging ,Microwaves ,Radiometry ,Telecommunications ,business ,Microwave - Abstract
In this study we present a design for a multi-frequency microwave radiometer aimed at prolonged monitoring of deep brain temperature in newborn infants and suitable for use during hypothermic neural rescue therapy. We identify appropriate hardware to measure brightness temperature and evaluate the accuracy of the measurements. We describe a method to estimate the tissue temperature distribution from measured brightness temperatures which uses the results of numerical simulations of the tissue temperature as well as the propagation of the microwaves in a realistic detailed three-dimensional infant head model. The temperature retrieval method is then used to evaluate how the statistical fluctuations in the measured brightness temperatures limit the confidence interval for the estimated temperature: for an 18 degrees C temperature differential between cooled surface and deep brain we found a standard error in the estimated central brain temperature of 0.75 degrees C. Evaluation of the systematic errors arising from inaccuracies in model parameters showed that realistic deviations in tissue parameters have little impact compared to uncertainty in the thickness of the bolus between the receiving antenna and the infant's head or in the skull thickness. This highlights the need to pay particular attention to these latter parameters in future practical implementation of the technique.
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- 2001
20. Feasibility of noninvasive measurement of deep brain temperature in newborn infants by multifrequency microwave radiometry
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Toshifumi Sugiura, G.M.J. van Leeuwen, D. Land, Jeffrey Hand, K. Maruyma, Gaetano Marrocco, S. Mizushina, D. Azzopardi, A.D. Edwards, F. Bardati, and Cardiovascular Biomechanics
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Physics ,Brightness ,Radiation ,Radiometer ,business.industry ,Acoustics ,Monte Carlo method ,Condensed Matter Physics ,Temperature measurement ,Optics ,Brightness temperature ,Range (statistics) ,Radiometry ,Electrical and Electronic Engineering ,Antenna (radio) ,business - Abstract
Clinical studies of hypothermal neural rescue therapy for newborn infants who have suffered hypoxia-ischaemia are currently hindered by the difficulty in measuring deep brain temperature. This paper addresses: the specific requirements for this measurement problem, the design of a proposed radiometer system, a method for retrieving the temperature profile within the cooled head, and an estimation of the precision of the measurement of deep brain temperature using the technique. A five-frequency-band radiometer with a contact-type antenna operating within the range 1-4 GHz is proposed to obtain brightness temperatures corresponding to temperature profiles predicted by a realistic thermal model of the cooled baby head. The problems of retrieving the temperature profile from this set of brightness temperatures, and the estimation of its precision, are solved using a combination of model fitting and Monte Carlo techniques. The results of this paper show that the proposed technique is feasible, that it is expected to provide a good estimate of the temperature profile within the cooled baby-head, and that the estimated precision (2/spl sigma/) of the temperature measured in the deep brain structures is better than 0.8 K, depending upon the estimation procedure used.
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- 2000
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21. Heart Rate and Electroencephalogram Changes Caused by Finger Acupressure on Planta Pedis
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Yoshimitsu Okita, Hiroko Horiguchi, Michikazu Samejima, Kiyoko Sugahara, Atsunori Fujii, Chisako Takeda, and Toshifumi Sugiura
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Adult ,Male ,Physiology ,Human Factors and Ergonomics ,Acupressure ,Brain waves ,Electroencephalography ,Fingers ,Heart Rate ,Physiology (medical) ,Heart rate ,Humans ,Medicine ,Orthopedics and Sports Medicine ,Electrode placement ,medicine.diagnostic_test ,Foot ,business.industry ,Public Health, Environmental and Occupational Health ,Anthropology ,Anesthesia ,Female ,business ,Acupuncture Points - Abstract
Preliminary experiments were carried out to investigate the feasibility of using an electroencephalogram and heart rates to evaluate the efficacy of finger acupressure on the key points of planta pedis (both soles). Continuous electroencephalograms were recorded from 19 electrodes based on the International 10-20 electrode placement system on 22 university students (21+/-2.3 years). Spectral power changes were obtained at each electrode site. The power of the alpha1 frequency range (8-10 Hz) increased slightly during acupressure although no statistical significance was observed, while heart rates decreased in all subjects (p
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- 2007
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22. A self-tuning effect of membership functions in a fuzzy-logic-based cardiac pacing system
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T. Kazui, Toshifumi Sugiura, Yukio Harada, and N. Sugiura
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Pacemaker, Artificial ,Engineering ,Time Factors ,Cardiac pacing ,business.industry ,Respiration ,Rate regulation ,Models, Cardiovascular ,Biomedical Engineering ,Self-tuning ,Process (computing) ,General Medicine ,Fuzzy logic ,Fuzzy Logic ,Heart Rate ,Control theory ,Exercise Test ,Humans ,ComputerSystemsOrganization_SPECIAL-PURPOSEANDAPPLICATION-BASEDSYSTEMS ,Oximetry ,Artificial intelligence ,business ,Realization (systems) ,Membership function ,Respiratory minute volume - Abstract
This paper describes a self-tuning method of membership functions in a fuzzy-logic-based cardiac pacing system and validates its feasibility in a double sensor system which has minute ventilation and oxygen saturation level as its guides for the rate regulation. Though the agreement between the pacing rates (fuzzy rates) calculated with three linguistic variables for each parameter and the target rates were not satisfactory, it was improved significantly by tuning the membership functions. Almost the same evaluated values with those obtained by using six linguistic variables for each parameter were obtained. Time required for the self-tuning process was about 40 s (386CPU, 20 MHz) which was fast enough for the system. The smaller number of linguistic labels results in a smaller number of rules, which is beneficial in implantable cardiac pacemakers with limited memory capacity. A fuzzy-logic-based cardiac pacing system is promising for the realization of custom-made cardiac pacemakers.
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- 1998
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23. Wearable ECG recorder with acceleration sensors for monitoring daily stress: office work simulation study
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T. Y. Yoto, Satoshi Sakuragawa, Y. Okada, Taka-aki Suzuki, and Toshifumi Sugiura
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Male ,Engineering ,Data processing ,Miniaturization ,business.industry ,Remote patient monitoring ,Wearable computer ,Byte ,Signal Processing, Computer-Assisted ,Accelerometer ,Autonomic Nervous System ,Acceleration ,Electrocardiography ,Young Adult ,Microcomputer ,Accelerometry ,Bispectral analysis ,Humans ,Computer Simulation ,business ,Electrodes ,Computer hardware ,Stress, Psychological ,Monitoring, Physiologic - Abstract
A small and light-weight wearable electrocardiograph (ECG) equipment with a tri-axis accelerometer (x, y and z-axis) was developed for prolonged monitoring of everyday stress. It consists of an amplifier, a microcomputer with an AD converter, a triaxial accelerometer, and a memory card. Four parameters can be sampled at 1 kHz for more than 24 h and a maximum of 27 h with a default battery and a memory card of one giga byte (1 GB). Off-line data processing includes motion information along three axes and autonomic nervous system (ANS) activity bispectral analysis and the tone-entropy method (T-E method) from HRV data. The availability of the system was tested through simulated office work and three-day monitoring by replacing the battery and the memory card every 24 h. Both short-term and circadian rhythms of ANS activity were clearly observed. In addition, sympathetic nervous activities gradually increased from the second to the third day. The experimental data presented verifies the functionality of the proposed system.
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- 2013
24. An Application for Diagnosis by Chaotic Approach (An Application to Discrimination of Arrhythmia)
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Masaya Koyama, Toshifumi Sugiura, and Tadashi Iokibe
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CHAOS (operating system) ,symbols.namesake ,General Computer Science ,Computer science ,cardiovascular system ,Chaotic ,symbols ,Electronic engineering ,cardiovascular diseases ,Statistical physics ,Lyapunov exponent ,Electrical and Electronic Engineering ,Fractal dimension - Abstract
In a healthy state, the human heart beat shows an extensive spectrum and its attractor has a chaotic orbit. However, in a damaged state, fluctuations in the heart beat become periodical. An Implantable Cardioverter/Difibrillator (ICD), along with an implanted pace maker until in either the subcutaneous chest wall, or subpectoral or subcutaneous abdomen, or sub-muscles rectus abdominis serve to detect abnormalities and eliminate them quickly. The abnormalities affected include: ventricular fibrillation (non-regulated electrical activity in a ventricle) and other arrhythmia, such as ventricular tachycardia (VT) or supra ventricular tachycardia (SVT). There are two methods for detecting arrhythmia available with the present ICD. One is to investigate the heart beat or period, and the other is to investigate the electrocardiographic wave. However, the employment of these techniques, either singly or in combination, doesn't always provide the required accuracy. This paper describes traditional analysis methods and the problems of ICD in brief. Subsequently, it discusses the chaotic approach. Finally, the results suitable for real testing, as well as future topics, are presented.
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- 1996
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25. A Method for Discrimination of Arrhythmia by Chaotic Approach
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Tadashi Iokibe, Shoji Murata, Masaya Koyama, and Toshifumi Sugiura
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Computer science ,business.industry ,Chaotic ,Pattern recognition ,Artificial intelligence ,business - Published
- 1996
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26. Five-band microwave radiometer system for noninvasive brain temperature measurement in newborn babies: Phantom experiment and confidence interval
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Hisashi Hirata, S. Mizushina, J. M. J. Van Leeuwen, Toshifumi Sugiura, and Jeffrey Hand
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Accuracy and precision ,Materials science ,business.industry ,Microwave radiometer ,Condensed Matter Physics ,Temperature measurement ,Imaging phantom ,Optics ,Thermocouple ,Calibration ,General Earth and Planetary Sciences ,Radiometry ,Electrical and Electronic Engineering ,business ,Microwave ,Remote sensing - Abstract
[1] Clinical trials of hypothermic brain treatment for newborn babies are currently hindered by the difficulty in measuring deep brain temperatures. As one of the possible methods for noninvasive and continuous temperature monitoring that is completely passive and inherently safe is passive microwave radiometry (MWR). We have developed a five-band microwave radiometer system with a single dual-polarized, rectangular waveguide antenna operating within the 1–4 GHz range and a method for retrieving the temperature profile from five radiometric brightness temperatures. This paper addresses (1) the temperature calibration for five microwave receivers, (2) the measurement experiment using a phantom model that mimics the temperature profile in a newborn baby, and (3) the feasibility for noninvasive monitoring of deep brain temperatures. Temperature resolutions were 0.103, 0.129, 0.138, 0.105 and 0.111 K for 1.2, 1.65, 2.3, 3.0 and 3.6 GHz receivers, respectively. The precision of temperature estimation (2σ confidence interval) was about 0.7°C at a 5-cm depth from the phantom surface. Accuracy, which is the difference between the estimated temperature using this system and the measured temperature by a thermocouple at a depth of 5 cm, was about 2°C. The current result is not satisfactory for clinical application because the clinical requirement for accuracy must be better than 1°C for both precision and accuracy at a depth of 5 cm. Since a couple of possible causes for this inaccuracy have been identified, we believe that the system can take a step closer to the clinical application of MWR for hypothermic rescue treatment.
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- 2011
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27. Wearable ECG Recorder with Acceleration Sensors for Measuring Daily Stress
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H. Mineta, T. Y. Yoto, Satoshi Sakuragawa, Taka-aki Suzuki, Y. Okada, and Toshifumi Sugiura
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Autonomic nervous system ,Engineering ,Acceleration ,business.industry ,Amplifier ,Microcomputer ,Real-time computing ,Wearable computer ,Battery (vacuum tube) ,Body movement ,business ,Accelerometer ,Simulation - Abstract
A small and light-weight wearable electrocardiograph (ECG) equipment with three accelerometers (x, y and zaxis) was developed for prolonged monitoring of autonomic nervous system in daily life. It consists of an amplifier, a bandpass filter, a microcomputer with an AD converter, a triaxial accelerometer, and a memory card. Four parameters can be sampled at 1 kHz (10 bits) for more than 24 hours, maximum 27 hours, with a default battery and a memory card (1 GB). The availability of the system was tested for three subjects for three days by replacing the battery and the memory card every 24 hours under each environment. Both short-term and circadian rhythms of the autonomic nervous system were clearly observed. The change of the autonomic nervous system from body movement (i.e. walking or turning over) was observed by check acceleration data. The feasibility of the application in clinical practice is also discussed.
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- 2011
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28. Unpleasant odor accelerates the sound processing in brain
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Isao Takahashi, Toshifumi Sugiura, Y. Mizutani, Xi Chen, Hisashi Hirata, and Meicong Xu
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medicine.medical_specialty ,Neuropsychology and Physiological Psychology ,Odor ,Computer science ,Physiology (medical) ,General Neuroscience ,medicine ,Audiology ,Audio signal processing ,computer.software_genre ,computer - Published
- 2014
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29. Retrieval of Temperature-Depth Profiles in Biological Objects from Multi-Frequency Microwave Radiometric Data
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Hiroyuki Ohba, Shizuo Mizushina, T. Shimizu, Masahiro Kinomura, K. Suzuki, and Toshifumi Sugiura
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Accuracy and precision ,Radiometer ,Materials science ,business.industry ,Microwave radiometer ,Monte Carlo method ,General Physics and Astronomy ,Imaging phantom ,Electronic, Optical and Magnetic Materials ,Optics ,Brightness temperature ,Radiometry ,Electrical and Electronic Engineering ,business ,Microwave - Abstract
A method of retrieving a temperature-depth profile in biological object from a set of multi-frequency microwave radiometric data has been developed. The method is a combination of model-fitting and Monte Carlo techniques and is capable of estimating a profile and its confidence interval as a function of the depth. We use 2σ -intervals as a measure of the precision of tissue temperature measurements. The method was tested and supported by an experiment in which temperature distributions in a muscle equivalent agar phantom were measured using a 5-band, 1-3.8 GHz radiometer with the brightness temperature resolution of 0.05-0.07 K. A typical result of the experiment showed that 2σ -intervals were 1 K or less for 0 < z < 3 cm, 1.4 K at z = 4 cm, and 3 K at z = 5 cm. A numerical simulation study was made using this technique to assess effects of the selection of measurement frequencies, number of frequency bands, brightness temperature resolution of radiometer and thickness of fat layer on the precision. Resul...
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- 1993
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30. Development of a Wearable ECG Recorder for Measuring Daily Stress
- Author
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Yi-Tsuyoshi Yoto, Toshifumi Sugiura, Satoshi Sakuragawa, Taka-aki Suzuki, and Yosiho Okada
- Subjects
Battery (electricity) ,Autonomic nervous system ,Data acquisition ,Rhythm ,business.industry ,Computer science ,Embedded system ,Microcomputer ,Wearable computer ,Heart rate variability ,Circadian rhythm ,business ,Simulation - Abstract
The purpose of the study is to show the feasibility of a light-weight wearable electrocardiograph with three accelero-meters for monitoring stress in everyday life. It consists of an amplifier, a band pass filter, a microcomputer with an AD converter, a triaxial accelerometer, and a memory card. An ECG and three accelerations are sampled at 1 kHz for more than 24 hours, maximum 27 hours with a default battery and a memory card. The heart rate variability analysis program detects R waves and determines R-R intervals for 24 hours by a data acquisition algorithm. An algorithm was also developed. It was designed to reduce motion artifacts induced by body movements on ECG. Autonomic nervous activity levels are calculated based on the heart rate variability spectrum analysis. The availability of the system was tested for three subjects for three days by replacing the battery and memory card every 24 hours under each environment. Both short time rhythms and a circadian rhythm of autonomic nervous system were clearly observed. The feasibility of the system for monitoring the long-term stress level is discussed.
- Published
- 2010
- Full Text
- View/download PDF
31. Comparison of different pointing methods for sound localizability measurement in the vision impaired subjects
- Author
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Yudai Ohsugi, Toshifumi Sugiura, Yuki Yamamoto, Masaki Tauchi, Atsunori Fujii, and Takabun Nakamura
- Subjects
Sound localization ,Adult ,Male ,medicine.medical_specialty ,Physiology ,Movement ,Visual impairment ,Human Factors and Ergonomics ,Audiology ,Blindness ,Fingers ,Physiology (medical) ,Orientation ,medicine ,Humans ,Orthopedics and Sports Medicine ,Sound Localization ,Mathematics ,Sound (medical instrument) ,Communication ,Dark room ,business.industry ,Significant difference ,Public Health, Environmental and Occupational Health ,Trunk ,Azimuth ,Low vision ,Anthropology ,Space Perception ,Female ,medicine.symptom ,business - Abstract
In order to find out the most suitable and accurate pointing methods to study the sound localizability of persons with visual impairment, we compared the accuracy of three different pointing methods for indicating the direction of sound sources in a semi-anechoic dark room. Six subjects with visual impairment (two totally blind and four with low vision) participated in this experiment. The three pointing methods employed were (1) directing the face, (2) directing the body trunk on a revolving chair and (3) indicating a tactile cue placed horizontally in front of the subject. Seven sound emitters were arranged in a semicircle 2.0 m from the subject, 0 degrees to +/-80 degrees of the subject's midline, at a height of 1.2 m. The accuracy of the pointing methods was evaluated by measuring the deviation between the angle of the target sound source and that of the subject's response. The result was that all methods indicated that as the angle of the sound source increased from midline, the accuracy decreased. The deviations recorded toward the left and the right of midline were symmetrical. In the whole frontal area (-80 degrees to +80 degrees from midline), both the tactile cue and the body trunk methods were more accurate than the face-pointing method. There was no significant difference in the center (-40 degrees to +40 degrees from midline). In the periphery (-80 degrees and +80 degrees ), the tactile cue pointing method was the most accurate of all and the body trunk method was the next best. These results suggest that the most suitable pointing methods to study the sound localizability of the frontal azimuth for subjects who are visually impaired are the tactile cue and the body trunk methods because of their higher accuracy in the periphery.
- Published
- 2007
32. Application Of Fuzzy Sets For Rate Regulation In Rate-adaptive Cardiac Pacing Based On A Combination Of Minute Ventilation And Oxygen Saturation
- Author
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S. Mizushina, M. Kimura, Y. Harada, and Toshifumi Sugiura
- Subjects
Computer science ,medicine.medical_treatment ,Fuzzy set ,Fuzzy logic ,Cardiac pacemaker ,law.invention ,Control theory ,law ,Control system ,Heart rate ,Ventilation (architecture) ,medicine ,Oxygen saturation ,Respiratory minute volume ,Oxygen saturation (medicine) - Abstract
In this gaper we propose to use fuzzy sets to the rate control in a multisensor rate adaptive cardiac pacemaker system. The logic was applied to the rate determination tased on minute ventilation and oxygen saturation during walking.
- Published
- 2005
- Full Text
- View/download PDF
33. Electromagnetic field simulation around implantable cardiac pacemakers caused by EAS system
- Author
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Y. Bannno, M. Takeda, Toshifumi Sugiura, Motohiko Kimura, Hisashi Hirata, and Yoshimitsu Okita
- Subjects
Electromagnetic field ,Physics ,Ventricular lead ,business.industry ,Electrical engineering ,Radio frequency ,business ,Electromagnetic interference ,Voltage - Abstract
One of the recent problems for pacemaker (PM) patients is an anti-shoplifting system which is called the electronic article surveillance (EAS) system. Electromagnetic field patterns of the two types of EAS system, radio frequency (RF) and electromagnetic (EM) systems, are simulated with in Irnich model which consists of saline and a pacemaker. The voltage differences induced between a PM casing main body and the tips of pacing leads and those between both leads (ventricular and atrium) are estimated. The voltages induced between PM body and the ventricular lead are about 300 mV and 1 mV by RF and EM systems, respectively. Considering the input characteristics of the PM circuit, these voltages will not bring about serious errors in the PM system if the patient goes through the EAS gate at a normal pace. Acousto-magnetic EAS systems which use lower frequencies may be more harmful to the PM system.
- Published
- 2005
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- View/download PDF
34. Development state of multifrequeney microwave radiometer system for noninvasive measurement of infant's deep brain temperatures
- Author
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A. Hashizume, S. Hoshino, Toshifumi Sugiura, Yoshimitsu Okita, Hisashi Hirata, and Y. Kouno
- Subjects
Physics ,Background noise ,Data processing ,Microwave radiometer ,Calibration ,Radiometry ,Brain temperature monitoring ,Microwave radiometry ,Temperature measurement ,Remote sensing - Abstract
Hypothermia is proposed as a treatment for hypoxia-ischemia in newborn infants who suffer serious cerebral injury or die, if they are brought back early. In this treatment the deep brain temperature monitoring which is noninvasive and continuous is required. Multifrequency microwave radiometry (MWR) is one of the promising candidates for that purpose, and we have been developing a five-band microwave radiometer system and appropriate data processing methods. This paper is to describe the current status of a newly designed MWR system which operates in a normal room with various electromagnetic background noise. Temperature resolutions of the five receivers were obtained by a calibration experiment using a temperature-controlled water-bath. The results of a temperature retrieval simulation experiment is also presented.
- Published
- 2005
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35. A Three-Band Microwave Radiometer System for Noninvasive Measurement of the Temperature at Various Depths
- Author
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Toshifumi Sugiura, Shizuo Mizushina, and Y. Hamamura
- Subjects
Temperature control ,Radiometer ,Materials science ,Bandwidth (signal processing) ,Microwave radiometer ,Radiometry ,Biological body ,Microwave radiometry ,Temperature measurement ,Remote sensing - Abstract
An experimental three-band (1.5,2.5,3.5+-0.5GHz) radiometer system and a data analysis procedure have been developed for noninvasive measurement of the temperature at various depths in a biological body. Using them, we made temperature measurement experiments on the abdominal region of rabbits. The results of the experiments demonstrate the feasibility of the multifrequency radiometry for this purpose.
- Published
- 2005
- Full Text
- View/download PDF
36. Five-band microwave radiometer system for non-invasive measurement of brain temperature in new-born infants: system calibration and its feasibility
- Author
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Toshifumi Sugiura, Hisashi Hirata, Jeffrey Hand, A. Hashizume, S. Mizushina, Yoshimitsu Okita, and Y. Kouno
- Subjects
Physics ,Radiometer ,Electromagnetic environment ,Waveguide antennas ,Non invasive ,Microwave radiometer ,Bandwidth (signal processing) ,Microwave radiometry ,Radiometric measurement ,Remote sensing - Abstract
Recent simulation studies have shown that a technique of multi-frequency microwave radiometry is feasible for non-invasive measurement of deep brain temperatures in the new-born infants. A five-band microwave radiometer system has been developed, and its operation in a normal electromagnetic environment is checked. Five receivers operating with a waveguide antenna and at center frequencies of 1.2, 1.65, 2.3, 3.0 and 3.6 GHz (0.4 GHz bandwidth) are calibrated using a temperature-controlled water-bath. Temperature resolutions obtained for each receiver are 0.183, 0.273, 0.148, 0.108 and 0.118 K, respectively. A temperature retrieval simulation based on these resolutions and the previously proposed algorithm shows that the confidence interval, as produced by thermal noise, is 0.62 K for the retrieved central brain temperature. If the conductivity of brain is estimated wrong by 10 %, this will result in an error of 0.3 - 0.4 K. The result of this work is encouraging for realization of radiometric measurement of temperature profile in a baby's head.
- Published
- 2005
- Full Text
- View/download PDF
37. Effects of water-filled bolus on the precision of microwave radiometric measurements of temperatures in biological structures
- Author
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Toshifumi Sugiura, Shizuo Mizushina, K. Matsui, Y. Hamamura, and M. Matsuda
- Subjects
Brightness ,Materials science ,Optics ,Bolus (medicine) ,Distilled water ,business.industry ,Radiometry ,Radiometric dating ,business ,Electromagnetic heating ,Temperature measurement ,Microwave - Abstract
An assessment is made of the degradation that is caused by a water-filled bolus in the precision of tissue temperature measured noninvasively by a five-band microwave radiometry scheme. The precision is expressed in terms of the confidence interval of tissue temperature estimated from a set of five brightness temperatures measured with an experimental instrument operating at center frequencies of 1.2, 1.8, 2.5, 2.9, and 3.6 GHz, with a 0.4-GHz bandwidth. Results show that degradation due to a bolus having a thickness of about 1 cm is small when it is filled with deionized or distilled water. It is concluded that the use of water-filled bolus is permissible for microwave radiometric measurement. This is of a practical importance when the technique is used in combination with electromagnetic heating for hyperthermic treatment of cancer. >
- Published
- 2002
- Full Text
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38. Automatic discrimination of arrhythmia waveforms using fuzzy logic
- Author
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Hisashi Hirata, T. Kazui, Toshifumi Sugiura, and Y. Harada
- Subjects
Variation ratio ,medicine.medical_specialty ,medicine.diagnostic_test ,Defibrillation ,medicine.medical_treatment ,Ventricular tachycardia ,medicine.disease ,Fuzzy logic ,QRS complex ,Internal medicine ,Ventricular fibrillation ,cardiovascular system ,medicine ,Cardiology ,Waveform ,cardiovascular diseases ,Electrocardiography ,Mathematics - Abstract
A method was proposed for discrimination of ventricular arrhythmias using fuzzy logic. The classifier uses four features of ECG waveforms; amplitude variation ratio, interval variation ratio, peak sharpness, QRS complex width, and assigns each waveform a number of 0-100. The performance of the algorithm was evaluated on the surface and intracardiac electrocardiograms of ventricular tachycardia (VT), ventricular fibrillation (VF) and normal sinus rhythm (NSR) in mongrel dogs. NSRs were evaluated 90-100 while VFs less than 10. VTs were assigned the numbers of 30-75. An automatic detection and defibrillation experiment was performed with this algorithm.
- Published
- 2002
- Full Text
- View/download PDF
39. Chaotic approach to the quantitative analysis of Parkinson's disease
- Author
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K. Sugiyama, Toshifumi Sugiura, T. Yokoyama, and N. Sugiura
- Subjects
Parkinson's disease ,business.industry ,Chaotic ,Pattern recognition ,medicine.disease ,Fractal dimension ,Fractal ,Dimension (vector space) ,Phase space ,Finger tapping ,medicine ,Tapping ,Artificial intelligence ,business ,Simulation ,Mathematics - Abstract
A chaotic approach was applied to the quantitative analysis of Parkinson's disease (PD). Finger tapping tests were performed to analyze the degree of bradykinesia in PD patients. The voltage variation obtained from the tapping tests was sampled at 200 Hz, and the data for 15 seconds were used in the analysis. Sampled data were embedded into the phase space with various combinations of the dimension and delay time. The embedding dimension and the delay time used in this study were 16 and 13, respectively. Fractal dimension of 5 PD patients was calculated in the phase space and compared with those of 5 volunteers.
- Published
- 2002
- Full Text
- View/download PDF
40. Evaluation of emotional response to affective picture stimulations by AAE and comfort vector models
- Author
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Hisashi Hirata, Xi Chen, Yoshimitsu Okita, Isao Takahashi, and Toshifumi Sugiura
- Subjects
Communication ,Neuropsychology and Physiological Psychology ,business.industry ,Physiology (medical) ,General Neuroscience ,Vector (epidemiology) ,Psychology ,business - Published
- 2014
- Full Text
- View/download PDF
41. Development of systems for measuring and analyzing autonomic nerve activity using LabView and its application
- Author
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Yutaka Taira, Motoko Takaoka, Kumiko Ohara, Toshifumi Sugiura, Motohiko Kimura, Yoshimitsu Okita, Kazuhiko Ishihara, and Harunobu Nakamura
- Subjects
Neuropsychology and Physiological Psychology ,Autonomic nerve ,Computer science ,Physiology (medical) ,General Neuroscience ,Neuroscience - Published
- 2014
- Full Text
- View/download PDF
42. Effects of the smell of young barley grass on autonomic nervous system
- Author
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Harunobu Nakamura, Yoshimitsu Okita, Toshifumi Sugiura, Motohiko Kimura, Yasuyuki Aotsuka, Momoe Ukeguchi, and Isao Takahashi
- Subjects
Autonomic nervous system ,Neuropsychology and Physiological Psychology ,Physiology (medical) ,General Neuroscience ,BARLEY GRASS ,Physiology ,Biology - Published
- 2014
- Full Text
- View/download PDF
43. P2-22 Effects of the odor of green young barley grass extract on central and autonomic nervous system function
- Author
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Y. Aotsuka, H. Nakamura, M. Ukeguchi, Toshifumi Sugiura, K. Kouda, M. Kimura, and Yoshimitsu Okita
- Subjects
medicine.medical_specialty ,Biology ,Sensory Systems ,Autonomic nervous system ,Endocrinology ,Neurology ,Odor ,Physiology (medical) ,Internal medicine ,BARLEY GRASS ,medicine ,Neurology (clinical) ,Neuroscience ,Function (biology) - Published
- 2010
- Full Text
- View/download PDF
44. P24-10 On emotional effects of odors of squeezed organic kale leaf based on EEGs and heart rate variability
- Author
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Yoshimitsu Okita, Tetsuo Kobayashi, M. Kimura, H. Nakamura, Isao Takahashi, T. Takaoka, Toshifumi Sugiura, and K. Kouda
- Subjects
Animal science ,Neurology ,Physiology (medical) ,Heart rate variability ,Neurology (clinical) ,Biology ,Sensory Systems - Published
- 2010
- Full Text
- View/download PDF
45. [Untitled]
- Author
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Yoshio Okada, Kayoko Shimoi, Taka-aki Suzuki, Hiroyuki Sakakibara, Toshifumi Sugiura, Tsuyoshi Yi Yoto, and Satoshi Sakuragawa
- Subjects
QRS complex ,Data processing ,Acceleration ,Computer science ,Microcomputer ,Amplifier ,Real-time computing ,Biomedical Engineering ,Heart rate variability ,Wearable computer ,General Medicine ,Accelerometer - Abstract
A small and light-weight wearable electrocardiograph (ECG) device with three accelerometers (x, y, and z axis) was developed for prolonged monitoring of everyday stress. It consists of an amplifier, a microcomputer with an analog/digital converter, a tri-axial accelerometer, and a memory card. Four parameters can be sampled at 1 kHz for a maximum of 27 h with the default battery and a 1 GB memory card. An algorithm for the reliable and clear detection of R wave peaks of ECG was also developed for accurate heart rate variability (HRV) analysis. The algorithm reduces ECG motion artifacts induced by body movements. Off-line data processing includes autonomic nervous system (ANS) activity bi-spectral analysis and the application of the tone-entropy method to HRV data. The availability of the system was tested through simulated office work and three-day monitoring. Both short-term and circadian rhythms of ANS activity were clearly observed. The experimental data verifies the functionality of the proposed system.
- Published
- 2013
- Full Text
- View/download PDF
46. Temperature profiling in biological objects with multifrequency microwave radiometry
- Author
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Hiroyuki Ohba, Toshifumi Sugiura, Masahiro Kinomura, Shizuo Mizushina, and Katsumi Abe
- Subjects
Physics ,Optics ,Radiometer ,Thermal radiation ,business.industry ,Optical engineering ,Brightness temperature ,Monte Carlo method ,Radiometry ,Radiation ,business ,Imaging phantom ,Remote sensing - Abstract
A method of temperature profiling in biological objects is described. In this method, thermal radiation from the object is measured as the brightness temperature by a multi-channel, topically five, 1 - 4 GHz radiometer via a contact-type, dielectric loaded waveguide antenna with a 15 X 20 mm2 aperture. Coupling between the antenna and the object is analyzed under 1-dimensional approximation. The radiometric data are analyzed by a combined method of model fitting and Monte Carlo techniques to retrieve a temperature profile in tissue and its 2 (sigma) -intervals along the axis of the antenna view field. The method has been tested by numerical simulation and agar phantom experiments to demonstrate its capability of temperature profiling in muscle with 2(sigma)
- Published
- 1994
- Full Text
- View/download PDF
47. P4-11 Effects of odor on event-related potential (P300) and pleasantness
- Author
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Toshifumi Sugiura, Hisashi Hirata, Isao Takahashi, Yoshimitsu Okita, and H. Akimoto
- Subjects
medicine.medical_specialty ,Neurology ,Odor ,Event-related potential ,Physiology (medical) ,medicine ,Neurology (clinical) ,Audiology ,Psychology ,Sensory Systems - Published
- 2010
- Full Text
- View/download PDF
48. A fuzzy approach to the rate control in an artificial cardiac pacemaker regulated by respiratory rate and temperature: a preliminary report
- Author
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Y. Fukui, Shizuo Mizushina, Yukio Harada, Toshifumi Sugiura, and Motohiko Kimura
- Subjects
medicine.medical_specialty ,Respiratory rate ,medicine.medical_treatment ,Biomedical Engineering ,Temperature a ,Fuzzy logic ,Cardiac pacemaker ,law.invention ,Body Temperature ,Dogs ,Preliminary report ,law ,Heart Rate ,Internal medicine ,medicine ,Fuzzy reasoning ,Animals ,business.industry ,Respiration ,Cardiac Pacing, Artificial ,Rate control ,General Medicine ,Cardiology ,Artificial cardiac pacemaker ,business ,Algorithms ,Biomedical engineering - Abstract
Fuzzy theory was applied to the rate control of a cardiac pacemaker which uses two parameters, respiratory rate and temperature, as the parameters for rate regulation. Using 25 fuzzy reasoning rules derived from five mongrel dogs, the pacing rates in three animals were calculated and compared with the intrinsic heart rates. It is concluded that the fuzzy method is well suited for the rate determination of a multi-parameter rate-responsive cardiac pacemaker.
- Published
- 1991
49. Glued Carbon Fiber Electrodes for Diaphragm Pacing
- Author
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Yukio Harada, Morio Togawa, Yoshihito Fukui, Toshifumi Sugiura, and Motohiko Kimura
- Subjects
Contraction (grammar) ,Threshold current ,Materials science ,Diaphragm ,Biomedical Engineering ,Carbon fibers ,Medicine (miscellaneous) ,Fibrin Tissue Adhesive ,Electric Stimulation Therapy ,Bioengineering ,Biomaterials ,Dogs ,Animals ,Fibrin glue ,Mongrel dogs ,Equipment Design ,General Medicine ,musculoskeletal system ,Carbon ,Electrodes, Implanted ,Phrenic Nerve ,Diaphragm pacing ,visual_art ,Anesthesia ,Electrode ,visual_art.visual_art_medium ,Biomedical engineering - Abstract
Carbon fibers with fibrin glue were used as electrodes for diaphragm pacing. The electrodes were applied to three mongrel dogs and the effectiveness was tested. The carbon leads were glued to phrenic nerves by means of the fibrinogen and thrombin bilaterally. The tidal volumes and threshold current level for stimulation were measured at various time up to 9 weeks after implantation. Effective contraction of diaphragm were observed for 9 weeks. By using this electrode, the exfoliation of the nerve is not necessary, the nerve can be maintained in an intact state, and the risk of the implanting operation can be minimized.
- Published
- 1990
- Full Text
- View/download PDF
50. Operating limits of heat pump using adsorption of structural active carbon/water vapour
- Author
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Fujio Watanabe, Chisato Marumo, Masanobu Hasatani, and Toshifumi Sugiura
- Subjects
Active carbon ,Adsorption ,Chemical engineering ,Chemistry ,law ,General Chemical Engineering ,Adsorption equilibrium ,Thermodynamics ,General Chemistry ,Thermal energy storage ,Water vapor ,Heat pump ,law.invention - Abstract
PVF成形体より種々の条件下で製造した構造状活性炭 (SAC) の減圧下, 303~343Kにおける水蒸気吸着平衡の測定を行い, 既往の結果との比較ならびに本吸着系のヒートポンプへの適用性の検討を行った.1) 本SACは充分な水蒸気吸着容量を有する.2) 吸着平衡関係は2種に大別でき, PVF成形体を炭化・低賦活したSAC (Group-I) では低相対圧 (φ) 域での立ち上りとφの上昇に伴うゆるやかな吸着量の増大, 高賦活SAC (Group-II) ではφ≅0.5での急峻な立ち上りを示す.3) Group-Iの中でも低賦活SACは吸・脱着の可逆性に優れ, これをヒートポンプへ適用した場合, 汲み上げ温度差を大きくとれることがわかり, 本SACが吸着ヒートポンプの蓄熱材として使用しうることを明らかにした.
- Published
- 1989
- Full Text
- View/download PDF
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