What is it about?
Current source is the key core in bioimpedance systems for accurately investigate tissue behavior. We have demonstrated that a higher accuracy of current source can be achieved by implementing a close loop control. This improved current source can be used together with multiplexer used in electrical impedance tomography by resulting in a wider applications and this might improve the accuracy of the reconstructed images.
Featured Image
Photo by Spencer on Unsplash
Why is it important?
Our results showed that it is possible to increase the performance in current source used in multiplexed system, such as in electrical impedance tomography (EIT). Thus, the quality of the EIT images can be better generated into comparison of using other type of current source as a excitation source.
Perspectives
It is very difficult to decide which current excitation gives the better expected performance. It is a simple idea and feasible to be built in a short period of time. The use of multiplexer sometimes cannot be avoided. I hope that this article may help the designer of electrical impedance tomagraphs when selecting the excitation source of the project.
Dr Pedro Bertemes-Filho
Universidade do Estado de Santa Catarina
Read the Original
This page is a summary of: Mirrored enhanced Howland current source with feedback control, Review of Scientific Instruments, February 2019, American Institute of Physics,
DOI: 10.1063/1.5079872.
You can read the full text:
Resources
Block diagram
Block diagram of a current-to-voltage feedback system with a stray element (MUX).
Circuit schematic of the MEHCS
Circuit schematic of the MEHCS circuit with feedback control, where Vin is the input signal, FCU is the feedback control unit, RLoad is the load resistor, and Zout is the circuit output impedance seen from the load position.
Output voltage of the multiplexed MEHCS
Output voltage of the multiplexed MEHCS with/without FCU as a function of loading in three frequencies, 100 Hz (a), 10 kHz (b), and 1 MHz (c).
Output voltage of the MEHCS as a function of frequency
Output voltage of the MEHCS with/without FCU and without MUX as a function of loading in four frequencies, 100 Hz (a), 10 kHz (b), 1 MHz (c), and 10 MHz (d).
Contributors
The following have contributed to this page
