Wide Band frequency fixed current source for BIT and BIA
Document Type
Conference Item
Publication Date
1-1-2009
Abstract
High frequency bioelectrical impedance analysis devices are mostly used in Bioimpedance tomography and blood analysis. Nowadays 50 - 100 KHz bioelectrical impedance devices are commonly used for body composition analysis. AD8130 or AD 8129 deferential op-amp is used in this paper. These two op-amps offer high output impedances at low frequencies because of the amplifiers' good low-frequency CMRR (common-mode-rejection ratios). At higher frequencies, decreasing CMRR, inherent output capacitances, and slew-rate limitations prevent realization of high-quality current sources. 170 mV sine wave signal is used as input voltage considering the current should be no more than 1 mA. Four frequencies of 100 KHz, 1 MHz, 2 MHz and 3.2 MHz are applied to the circuit and by changing the load resistor, the current is measured. The result shows the current stable during the load resistor changing.
Keywords
Bio-impedance, Bioelectrical impedance, Bioelectrical impedance analysis, Blood analysis, Body composition analysis, Common-mode rejection ratios, Commonly used, Current sources, Fixed current, High frequency, High output, High quality, Higher frequencies, Input voltages, Load resistors, Low frequency, Sine-wave signals, Slew-rate, Wide band frequencies
Divisions
fac_eng
Event Title
World Congress on Medical Physics and Biomedical Engineering,Diagnostic Imaging
Event Location
Munich, Germany
Event Dates
7 -12 September 2009
Event Type
conference
Additional Information
Volume 25 Issue 2 ISSN: 16800737 ISBN: 978-364203878 DOI: 10.1007/978-3-642-03879-2-146