How Electronics Changed Impedance Measurements (Corrected 5/04)
نویسنده
چکیده
This is a history of commercial instruments that measure impedance from the 1930s to the present day. It concentrates on general-purpose and production-test bridges and meters that measure resistance, capacitance and inductance at low frequencies. It intends to show how electronics has changed these electrical measurements just as it changed all other technologies.
منابع مشابه
Influence of ambient temperature on whole body and segmental bioimpedance spectroscopy measurements
Bioimpedance spectroscopy (BIS) measurements are easy to implement and could be used for continuous monitoring. However, several factors (e.g. environment temperature) influence the measurements limiting the accuracy of the technology. Changes in skin temperature produced by changes in ambient temperature are related with changes in skin blood flow and skin impedance. It is assumed that skin im...
متن کاملElectrical Structure of Biological Cells and Tissues: impedance spectroscopy, stereology, and singular perturbation theory
Impedance Spectroscopy resolves electrical properties into uncorrelated variables, as a function of frequency, with exquisite resolution. Separation is robust and most useful when the system is linear. Impedance spectroscopy combined with appropriate structural knowledge provides insight into pathways for current flow, with more success than other methods. Biological applications of impedance s...
متن کاملThe impact of chronic hemodialysis on QT dispersion corrected QTdispersion and maximum QT-dispersion
Introduction: Sudden cardiac death is common in patients on hemodialysis and may occur in the immediate postdialysis period when ventricular premature complexes are common. QT dispersion reflecting hetovogelity in ventricle repolarization has been used for predicting patients with risk of malignant arrhythmia and sudden death. The purpose of the study was to assess the effect of hemodialysis on...
متن کاملWavelet analysis of GRACE K-band range rate measurements related to Urmia Basin
Space-borne gravity data from Gravity Recovery and Climate Experiment (GRACE), as well as some other in situ and remotely sensed satellite data have been used to determine water storage changes in Lake Urmia Basin (Iran). As usual, the GRACE products are derived from precise inter-satellite range rate measurements converted to different formats such as spherical harmonic coefficients and equiva...
متن کاملPulmonary Mechanics by Spectral Analysis
The magnitude (1Z,81) and phase angle (0r8) of the total respiratory impedance (Zr,), from 3 to 45 Hz, were rapidly obtained by a modification of the forced oscillation method, in which a random noise pressure wave is imposed on the respiratory system at the mouth and compared to the induced random flow using Fourier and spectral analysis. No significant amplitude or phase errors were introduce...
متن کامل