<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Alternating current sources are mainly used in bioelectrical impedance devices. Nowadays 50 – 100 kHz bioelectrical impedance devices are commonly used for body composition analysis. High frequency bioelectrical impedance analysis devices are mostly used in bioimpedance tomography and blood analysis. High speed op-amps and voltage comparators are used in this circuit. Direct current feedback is used to prevent delay. An N-Channel J-FET transistor was used to establish the voltage controlled gain amplifier (VCG). A sine wave signal has been applied as input voltage. The value of this signal should be constant in 170 mV rms to keep the output current in about 1 mA rms. Four frequencies; 100 kHz, 1 MHz, 2 MHz and 3.2 MHz were applied to the circuit and the current was measured for different load resistances. The results showed that the current was stable for changes in the resistor load, bouncing around an average point as a result of <italic>bouncing</italic> DC feedback.</p></abstract>

Alternating current sources are mainly used in bioelectrical impedance devices. Nowadays 50 – 100 kHz bioelectrical impedance devices are commonly used for body composition analysis. High frequency bioelectrical impedance analysis devices are mostly used in bioimpedance tomography and blood analysis. High speed op-amps and voltage comparators are used in this circuit. Direct current feedback is used to prevent delay. An N-Channel J-FET transistor was used to establish the voltage controlled gain amplifier (VCG). A sine wave signal has been applied as input voltage. The value of this signal should be constant in 170 mV rms to keep the output current in about 1 mA rms. Four frequencies; 100 kHz, 1 MHz, 2 MHz and 3.2 MHz were applied to the circuit and the current was measured for different load resistances. The results showed that the current was stable for changes in the resistor load, bouncing around an average point as a result of bouncing DC feedback.

DC feedback for wide band frequency fixed current source

Journal of Electrical Bioimpedance

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"DC feedback for wide band frequency fixed current source"}

Alternating current sources are mainly used in bioelectrical impedance devices. Nowadays 50 – 100 kHz bioelectrical impedance devices are commonly used for...

DC feedback for wide band frequency fixed current source

Article Category: Articles

Published Online: Mar 22, 2013

Page range: 33 - 37

Received: Feb 22, 2012

DOI: https://doi.org/10.5617/jeb.294

Keywords
Bioimpedance analysis, wide band frequency, body composition, blood analysis, medical devices

© 2013 Aoday H. Al-Rawi, W. M. A. Ibrahim and Eraj Humayun Mirza, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

DC feedback for wide band frequency fixed current source

Article Category: Articles

Published Online: Mar 22, 2013

Page range: 33 - 37

Received: Feb 22, 2012

DOI: https://doi.org/10.5617/jeb.294

KeywordsBioimpedance analysis, wide band frequency, body composition, blood analysis, medical devices

© 2013 Aoday H. Al-Rawi, W. M. A. Ibrahim and Eraj Humayun Mirza, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Bioimpedance analysis, wide band frequency, body composition, blood analysis, medical devices