Data Acquisition System for Doppler Radar Vital-Sign Monitor

Author

Vergara, A.M. ; Lubecke, Victor M.

Author_Institution

Univ. of Hawaii, Manoa

fYear

2007

fDate

22-26 Aug. 2007

Firstpage

2269

Lastpage

2272

Abstract

Automatic gain control (AGC) units increase the dynamic range of a system to compensate for the limited dynamic range of analog to digital converters. This problem is compounded in wireless systems in which large changes in signal strength are effects of a changing environment. These issues are evident in the direct-conversion Doppler radar vital- sign monitor. Utilizing microwave radar signals reflecting off a human subject, a two-channel quadrature receiver can detect periodic movement resulting from cardio-pulmonary activity. The quadrature signal is analyzed using an arctangent demodulation that extracts vital phase information. A data acquisition (DAQ) system is proposed to deal with issues inherent in arctangent demodulation of a quadrature radar signal.

Keywords

Doppler radar; analogue-digital conversion; automatic gain control; biomedical electronics; biomedical measurement; cardiology; data acquisition; demodulation; microwave measurement; patient monitoring; Doppler radar vital-sign monitor; analog-to-digital converters; arctangent demodulation; automatic gain control; cardio-pulmonary activity; data acquisition system; microwave radar signals; periodic movement detection; quadrature radar signal; signal strength; two-channel quadrature receiver; wireless systems; Analog-digital conversion; Cardiology; Data acquisition; Demodulation; Doppler radar; Dynamic range; Gain control; Humans; Monitoring; Radar detection; Algorithms; Cardiovascular System; Computer Simulation; Doppler Effect; Equipment Design; Humans; Microwaves; Models, Theoretical; Monitoring, Physiologic; Programming Languages; Radar; Respiratory System; Signal Processing, Computer-Assisted; Software Design; Time Factors;

fLanguage

English

Publisher

ieee

Conference_Titel

Engineering in Medicine and Biology Society, 2007. EMBS 2007. 29th Annual International Conference of the IEEE

Conference_Location

Lyon

ISSN

1557-170X

Print_ISBN

978-1-4244-0787-3

Type

conf

DOI

10.1109/IEMBS.2007.4352777

Filename

4352777