Ultrasonic medical images is well established as an important diagnostic tool nowadays. Quantitative ultrasonic images, nevertheless, have not reached a clinical use. The cause of this are the peculiar propagation of ...
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Ultrasonic medical images is well established as an important diagnostic tool nowadays. Quantitative ultrasonic images, nevertheless, have not reached a clinical use. The cause of this are the peculiar propagation of ultrasonic waves in the biological tissues. This paper presents a: pulse-echo technique to estimate thickness and ultrasound wave velocity in multilayered media. Results of 8 experiments with an aluminum cylinder (thickness: 60 mm, diameter: 120 mm) phantom are presented and discussed.
Eight hemodialysis were monitored with the objective of detecting the onset of arterial hypotension. Electrical impedance measurements were obtained from the lower limbs together with body weight changes and arterial ...
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Eight hemodialysis were monitored with the objective of detecting the onset of arterial hypotension. Electrical impedance measurements were obtained from the lower limbs together with body weight changes and arterial pressure at regular time intervals. Heart rate, stroke volume, mean blood flow, peripheral vascular resistance, the peak of the first derivative of the impedance signal and " O " wave amplitude were extracted from dZ/dt Clinical hypotension or drops in mean arterial blood pressure of more than 30 mmHg were observed in 6 HD. A multivariate regression model using body weight changes and peak dZ/dt suggests that it is possible to predict changes in arterial pressure with 6% error with an anticipation of up to 30 minutes in the phase of hemodialysis. The correlation obtained between basal impedance and body weight (r = 0.92, p< 0.001) indicates that the former might be used as a substitute for direct measurements of body weight.
A microcomputer-based system for mapping the brain electrical activity after source derivation has been developed. The EEG data are obtained as a set of up to 16 unipolar derivations, sampled and displayed in real tim...
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