Introduction Impedance cardiography is a noninvasive technique for monitoring the changes in the electrical impedance of the thorax z(t), caused by variation in the blood volume during the cardiac cycle [1]. Time derivative of the thoracic impedance is known as the impedance cardiogram (ICG) and it is used for estimating the ventricular ejection time (Tlvet), the negative peak of ICG ((-dz/dt)m...

OBJECTIVE To investigate whether perioperative changes in bioelectrical impedance reflect the severity of illness in pediatric patients after heart surgery. DESIGN Prospective, controlled study. SETTING University-affiliated children's hospital. PATIENTS A total of 107 patients admitted to a pediatric intensive care unit after congenital heart surgery. INTERVENTIONS None. MEASUREMENTS...

This paper describes a pattern recognition approach aiming to estimate fuel cell duration time from electrochemical impedance spectroscopy measurements. It consists in first extracting features from both real and imaginary parts of the impedance spectrum. A parametric model is considered in the case of the real part, whereas regression model with latent variables is used in the latter case. The...

In this paper we propose the estimation of the characteristic impedance and the effective dielectric constant of microstrip line using quasi static analysis and performances are predicted using theoretical analysis. Numerically efficient and accurate formulae based on the quasi static method for the analysis of microstrip line structures are presented. The analysis formulas for microstrip line ...

This paper presents theoretical estimation of the conducted electromagnetic emissions from a SMPS, based on Fourier analysis. The theory is applied to a buck converter. The comparison between the theoretically estimated and measured EMI shows that the CM EMI was well predicted. Up to 3 MHz the measured DM noise was much lower than the predicted one, which could be because of unknown DM noise so...

This work is related to interfacial phase bounadry estimation in sedimentation monitoring using electrical impedance tomography. The fluid is assumed to settle into three different phases separated by sharp interfacial boundary. The time evolution of the phase interface gives important information about the sedimentation process which can be used to control and optimize the sedimentation proces...

This paper focuses on a hybrid islanding detection algorithm for parallel-inverters-based microgrids. The proposed algorithm is implemented on the unit ensuring the control of the intelligent bypass switch connecting or disconnecting the microgrid from the utility. This method employs a grid impedance estimation technique that uses resonance excitation once grid fault occurs. It includes two st...

In this paper, we consider a dual channel signal model with common frequency that is appropriate in a plurality of measurement setups, including impedance measurements and imbalance measurement in direct conversion RF receivers. We investigate on a new approach and present analysis of parameter estimation, specifically the seven parameter dual channel sine fit in which the signals from both cha...

Understanding the milliscale (temporal and spatial) dynamics of the human brain activity requires high-resolution modeling of head electromagnetics and source localization of EEG data. We have developed an automated environment to construct individualized computational head models from image segmentation and to estimate conductivity parameters using electrical impedance tomography methods. Algo...

When input impedance is determined by means of the forced oscillation technique, part of the oscillatory flow measured at the mouth is lost in the motion of the upper airway wall acting as a shunt. This is avoided by applying the oscillations around the subject's head (head generator) rather than at the mouth (conventional technique). In seven wheezing infants, we compared both techniques to es...