Current source and digital demodulation technique in EIT system based on FPGA
10.3760/cma.j.issn.1673-4181.2012.02.006
- VernacularTitle:一种基于FPGA的EIT电流源和数字解调方法
- Author:
Huiling HAO
;
Dechun ZHAO
;
Hong SHA
- Publication Type:Journal Article
- Keywords:
Electrical impedance tomography;
Current source;
Field programmable gate array;
Digital demodulation
- From:
International Journal of Biomedical Engineering
2012;35(2):90-93
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveA general experiment platform of electrical impedance tomography(EIT) based on field programmable gate array(FPGA) was designed to meet the requirements of EIT digital measurement.A digital current source and the research on digital demodulation method was completed.MethodsFor construction of the experiment platform,DDS module,D/A and A/D interface module,digital demodulation module and RS-232 communication module were all integrated in one FPGA chip.ResultsThe source can provide multi-frequency excitation signals of 2 mA in the range of 6.1-390.6 kHz.The output impedance of the source was higher than 190 kΩ.Both the real and the virtual information of measured impedance could be extracted.ConclusionMeasurements based on bioimpedance-equivalent circuit model verified the validity of the platform.The research results of this paper provides a foundation for the construction of a practical EIT system.
