65 research outputs found
ケイタイガタ ケツリュウ ケイソク ソウチ ノ カイハツ ト ソノ オウヨウ
A system monitoring blood flow velocities in the carotid artery has been developed. A continuousDoppler method is used to make elecronic circuits simple. It can be used handily owing toa small size and telemetry. The system is applied for measuring the carotid blood flow velocitiesof human. One of interesting results is that the blood flow velocity waveforms of persons withphysical exercise are different properly from those of persons without ecercise. The developedsystem may therefore be useful for evaluating the effects of physical exercise
Arterial Blood Velocity Measurement by Portable Wireless System for Healthcare Evaluation: the Related Effects and Significant Reference Data
Non
Change of blood flow in common carotid artery during physical exercise stress: evaluation for aerobic exercise intervention
Exercise training is able to alter cardiovascular fitness. Treadmill exercise testing currently is commonly used in the clinical method of evaluating a subject's functional capacity and aerobic fitness. In this chapter, a fundamental understanding of age-associated normohemodynamic state is described for comparison data and for an improved means of aerobic exercise fitness and performance. These data may contribute to effective and efficient prevention and treatment of cardiovascular disease in older persons. The change of blood flow velocity and parameters in the common carotid artery (CCA) during treadmill exercise is reviewed to describe the effect on significant physiological functions. Increase of blood flow velocity and its parameters in CCA during physical exercise is related to increase of arterial blood pressure (ABP), which may be due to elevation of the cerebral perfusion pressure and then contribute in part to the increase in cerebral blood flow (CBF). Aerobic exercise training could improve the age-associated decreases in blood flow velocity waveforms of CCA after a 1-month exercise intervention program. Regular aerobic exercise training is an effective approach to diminish the age-associated decrease in CCA blood flow velocities in healthy older adults and partially restore the reductions of blood flow velocity in previously sedentary young men. The potential benefit of regular physical activity would be in the primary prevention of age-associated decreases in blood velocity waveforms. © 2010 by Nova Science Publishers, Inc. All rights reserved
Portable blood flow velocimetry for health care monitoring
The purpose of this book is to provide a detailed explanation on the construction of a portable Doppler ultrasound system for medical application. It is hoped that researchers and the general public will benefit from reading this book to help them to better understand the basics and application of Doppler ultrasound system especially in the clinical setting. Included are data from several experiments involving the portable Doppler ultrasound system to analyse blood velocity in common carotid arteries in subjects with various medical and physical backgrounds. The focus is mainly on blood velocities in common carotid artery and how the information could be used to evaluate the risk of cardiovascular disease in hypertensive patients. The experiments include the association of regular exercise in improving blood velocities to manage the risk of hypertension and cardiovascular disease
Effect of exposure to an extremely low frequency- electromagnetic field on the cellular collagen with respect to signaling pathways in osteoblast-like cells
The effect of exposure to extremely low frequency-electromagnetic field (ELFEMF : 3 mT, 60 Hz) on differentiation of mouse osteoblast-like MC3T3-E1 cells was examined together with addition of insulin-like growth factor I (IGF-I). As a marker of the differentiation, the cellular collagen content was determined by the absorbance of Sirius red-stained cells measured at the wavelength of 510-520 nm with an imaging microspectroscopy. Exposure to ELF-EMF increased significantly the collagen in the cells. Treatment with PD98059, an inhibitor of extracellular signal-regulated kinase 1/2 (ERK1/2) activation, reduced the collagen in all of the cells examined on control, IGF-I addition and ELFEMF exposure, however, PD98059 did not prevent the increase in the collagen caused by ELF-EMF exposure, and IGF-I also increased the collagen in the presence of the inhibitor. When phosphatidylinositol 3-kinase (PI3K) pathway was inhibited by LY294002, the increase in collagen induced by ELF-EMF exposure was accelerated, however, the increase in collagen observed by IGF-I addition was suppressed. Treatment with SB203580, an inhibitor of p38 mitogen-activated protein kinase (p38 MAPK), suppressed the increase in the collagen induced by ELF-EMF exposure, whereas IGF-I addition increased the collagen in the presence of the inhibitor. These results suggested that collagen synthesis stimulated by ELF-EMF exposure was carried out by the participation of p38 MAPK pathway, and that PI3K pathway may have the role to suppress the collagen synthesis induced by ELF-EMF exposure, and that the suppression of the PI3K pathway may allow the acceleration of the collagen synthesis
BP ニューラル ネットワーク オ モチイタ サーカディアン リズムゲン ノ システム ドウテイ
Almost all land animals coordinate their behavior with circadian rhythms, matching their functions to the daily cycles of lightness and darkness that result from the rotation of the earth corresponding to 24 hours. Through external stimuli, such as dairy life activities or other sources from our environment may influence the internal rhythmicity of sleep and waking properties. However, the rhythms are regulated to keep their activity constant by homeostasis while fluctuating by incessant influences of external forces. A modeling study has been developed to identify homeostatic dynamics properties underlying a circadian rhythm activity of sleep and wake data measured from normal subjects, using an MA (Moving Average) model associated with backpropagation (BP) algorithm. As a result, we found out that the neural network can capture the regularity and irregularity components included in the data. The order of MA neural network model depends on subject’s behavior. The last two data are usually dominant in the case without strong external forces. The adaptive changes of the dynamics are evaluated by the change of weight vectors, a kind of internal representation of the trained network. The dynamics is kept in a steady state for more than 20 days. Identified properties reflect the subject’s behavior, and hence may be useful for medical diagnoses of disorders related to circadian rhythms
Biomedical telemetry: technology and applications
Telemetry is a technology that allows the remote measurement and reporting of information of interest to the system designer or operator. Telemetry typically refers to wireless communications, but can also refer to data transferred over other media, such as a telephone or computer network or via an optical link. This book provides a brief overview of the telemetric technique and how it has evolved over the years as well as its numerous applications.
By providing the geographical location of animals, and sometimes concurrently allowing the registration of other parameters (e.g. activity, temperature), this technique is often used to study home-range size and shape, habitat selection etc.
Medical telemetry may be defined as "the measurement and recording of physiological parameters and other patient-related information via radiated bi- or unidirectional electromagnetic signals." This book discusses the telemetric devices that can be coupled with biosensors and microsensors that generate electrical signals related to electrochemical processes.
The engagement of fisheries and polar biologists in acoustic telemetry studies on inshore polar fish is explored by sharing their experiences of the issues surrounding environmental constraint, equipment limitations, tracking protocols, choice of species, and safety in the field.
Different steps taken for the telemetric system to record the electroencephalogram (EEG) from adult freely moving rats are described. This novel telemetric system was also used to record brain activity in small animals.
The development of a cost-effective telemetric system is addressed, through a combination of a wireless microphone for signal transmission and a computer sound card for recording of signals in the audible range. Finally, the telemetry of body temperature for long-term recordings of breathing is described
Visceral fat accumulation influenced blood flow velocity in hypertensive subjects
Arterial function measurements are widely used as surrogate markers of cardiovascular disease. However, it is unknown whether non-pathological factor may influence these measurements in particularly blood velocity function. The aim of current study was to investigate the relationship between visceral fat (VF) accumulation and hypertension incidence. The study evaluated the changes of blood velocity waveforms among normotensive and hypertensive subjects. One hundred twenty six individuals were classified into three groups which are lower VF, middle VF and higher VF regarding on their VF level. Resistive index (RI), velocity reflection index (VRI) and vascular elastic recoil index (VEI) were calculated from the 3 minutes assemble average of envelope waveform. The VF accumulation was higher in hypertensive than normotensive subjects. Peak systolic (S1), peak diastolic (D), VRI and VEI modulated significantly (P < 0.05) in higher VF compared to lower VF groups. RI and VRI show significantly different in hypertensive compared to normotensive groups. In conclusion, increased VF influences hypertension incidence and blood velocity regulation
Anxiety affects the amplitudes of red and green colorelicited flash visual evoked potentials in humans
It has been reported that negative emotional changes and conditions affect the
visual faculties of humans at the neural level. On the other hand, the effects of emotion
on color perception in particular, which are based on evoked potentials, are unknown. In
the present study, we investigated whether different anxiety levels affect the color information processing for each of 3 wavelengths by using flash visual evoked potentials (FVEPs) and State-Trait Anxiety Inventory. In results, significant positive correlations were observed between FVEP amplitudes and state or trait anxiety scores in the long (sensed as red) and middle (sensed as green) wavelengths. On the other hand, short-wavelength-evoked FVEPs were not correlated with anxiety level. Our results suggest that negative emotional conditions may affect color sense processing in humans
Basic study of new diagnostic modality according to noninvasive measurement of the electrical conductivity of tissues
The purposes of this study were to estimate the electrical conductivity of tissues by non-invasively measuring the electrical bio-impedance, to develop a new method for tissue diagnosis, i.e., electrical impedance tomography (EIT). Tissue models were first designed taking into consideration the distribution of the fat tissue, muscle and bone in the human forearm, and then the intra-tissue distributions of electrical potential and field, and the electrical impedance in the models was theoretically analyzed by the three-dimensional finite element method. The electrical impedance of both forearms was measured in healthy human subjects, and estimated the electrical conductivity of individual local tissues. The results of the analysis showed that the distributions of electrical potential and field were affected by the presence of fat tissue but not by the presence or absence of bone. In addition, as a result of calculation of the electrical resistance of the extracellular fluid (Re) in each model, it was found that the value of bio-impedance was influenced by the presence of fat tissue, and the value of bio-impedance was increased by the intervention of a fat layer.
The electrical conductivity estimated by fitting the observed values to the values obtained by finite element analysis was 0.40 S/m and 0.15 S/m for male muscle and fat tissue, and 0.35 S/m and 0.11 S/m for female muscle and fat tissue, respectively. The sex difference in the slope of linear approximation in the estimation of electrical conductivity of the males and females was thought to be due to sex differences in the properties and structure of fat tissue. These results suggest that local tissues can be diagnosed differentially and electrically by percutaneous measurement of local bio-impedance and subsequent estimation of the electrical conductivity of each tissue
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