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Article
Extraction of the Mayer wave component in blood pressure from the instantaneous phase difference between electrocardiograms and photoplethysmograms
To analyze the human baroreflex function noninvasively, a beat-by-beat blood pressure signal is often measured by tonometry or plethysmogram using continuous blood pressure sensors. However, these sensors are ...
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Chapter and Conference Paper
Relationship between Physiological Indices and a Subjective Score in Evaluating Visually Induced Motion Sickness
Visual environments are evolving rapidly along with the popularization of high resolution and wide field-of-view displays. However, there is a concern that these environments may give negative effects on viewe...
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Article
Open AccessEvaluation of adaptation to visually induced motion sickness based on the maximum cross-correlation between pulse transmission time and heart rate
Computer graphics and virtual reality techniques are useful to develop automatic and effective rehabilitation systems. However, a kind of virtual environment including unstable visual images presented to wide ...
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Chapter and Conference Paper
Independent Component Analysis of Finger Photoplethysmography for Evaluating Effects of Visually-Induced Motion Sickness
To evaluate the effects of visually-induced motion sickness that induces symptoms related to the autonomic nervous activity, we proposed a new method for obtaining the physiological index ρ ...
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Chapter and Conference Paper
Acoustic and Mechanical Properties of Aortic Aneurysms Assessed by Scanning Acoustic Microscopy
Inflammation is very important in the pathophysiology of atherosclerosis and aortic aneurysm. Macrophages are often found in both lesions by normal optical microscopy and their secreting materials, matrix meta...
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Article
Evaluation of wall motion abnormality by comparing values of cardiac output obtained by M-mode and Doppler echocardiography: Parameter revealing wall motion abnormality in stress echocardiography
Dobutamine and dipyridamole stress echocardiographies are both well able to detect myocardial ischemia resulting from coronary diseases by recognizing the regional wall motion abnormality (WMA). Here we report...
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Chapter
Acoustic Microscopy Evaluation of Endothelial Cells Modulated by Fluid Shear Stress
Scanning acoustic microscopy (SAM) was applied to assess the change of shape and acoustical parameter of the endothelium after exposure to the shear stress. SAM is useful for assessing the properties of the li...
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Chapter
Detecting Cardiac Allograft Rejection by Acoustic Microscopy
Heart transplantation is widely accepted as the treatment of end-stage heart failure such as dilated cardiomyopathy or ischemic cardiomyopathy. After the successful transplant surgery, the recipients still nee...
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Chapter
Influence of fat Components and Tissue Preparation on the High Frequency Acoustic Properties
Scanning acoustic microscopy (SAM) provides the physical properties of tissues at the microscopic level that cannot be obtained by optical microscopy and it also provides some useful information for understand...
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Article
Sign of wall motion abnormality observed in wall thickness change, excursion, and stroke volume obtained by M-mode: The parameter revealing wall motion abnormality in stress echocardiography (2)
To improve the evaluation of regional wall motion abnormalities (WMA) during stress echocardiography, the parameters of the wall thickness change, excursion and stroke volume, with time-dependent changes in tw...
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Article
Application of Scanning Acoustic Microscopy for Assessing Stress Distribution in Atherosclerotic Plaque
Scanning acoustic microscopy (SAM) was equipped to assess the acoustic properties of normal and atherosclerotic coronary arteries. The SAM image in the atherosclerotic lesion clearly demonstrated that the soun...
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Article
Treatment of multiple organ failure by a totally implantable ventricular assist device
Multiple organ failure (MOF) becomes an important problem during clinical use of the ventricular assist device (VAD). To improve the clinical record of the VAD, the function of other organs may be vitally impo...
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Chapter and Conference Paper
Fractal Dimension Analysis of Heart Rate Variability with Left Ventricular Assist Device
We analyzed heart rate variability by nonlinear mathematics, including fractal theory, to evaluate the hemodynamic stability of left ventricular assistance. A left ventricular assist device (LVAD) was implante...
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Chapter and Conference Paper
Sympathetic Nerve Adjustment to Artificial Circulation
To analyze the dynamical behavior of the autonomic nervous system while being driven by an artificial heart, sympathetic nerve discharges were analyzed by the use of nonlinear mathematics, including chaos and ...
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Chapter and Conference Paper
Parameter Optimization Approach to Estimation of E max Under Cardiac Assistance
A new method for less invasive and beat-by-beat estimation of the maximum ventricular elastance (E max) is proposed. The method (parameter optimization method) needs only two measurements: aortic pr...
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Chapter and Conference Paper
Application of Adaptive Pole Assignment Method to Vascular Resistance-Based Control for Total Artificial Heart
A new vascular resistance based adaptive controller has been developed. A primary function of this controller is automatic adaptation for changes in cardiovascular dynamics with time, or for variation among in...
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Chapter
Visualization of Living Cells by Acoustic Microscopy
With the development of molecular biology, there is an increasing need to observe the morphology of the cultured cells, which are known to change their properties or to transform themselves in the process of c...
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Chapter and Conference Paper
Less Invasive Method for Estimating E max Under Cardiac Assistance — Angular Frequency Method
A new less invasive method for estimating the maximum elastance (E max ) of the ventricle under cardiac assistance without direct measurement of the left ventric...
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Chapter and Conference Paper
Fractal Dimension Analysis of Chaos in Hemodynamics with Artificial Heart
To analyze the hemodynamic parameters in prosthetic circulation as a complete entity, not as a decomposed entity, non-linear mathematical techniques, including chaos and fractal theory, were utilized. Two pneu...
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Article
Differentiation of transiently ischemic from infarcted myocardium by Thallium-201 exercises scintigram after active ergometer rehabilitation
It has been frequently reported that while myocardial viability is neglected in conventional methods of diagnosis such as left ventriculography, ECG, and exercise thallium-201 myocardial scintigraphy (Ex-Tl), ...
