Title :
A versatile microwave plethysmograph for the monitoring of physiological parameters
Author :
Gentili, Guido Biffi ; Tesi, Vasco ; Linari, Mariano ; Marsili, Massimo
Author_Institution :
Dept. of Electron. & Telecommun., Florence Univ., Italy
Abstract :
A simple microwave technique for in vivo monitoring of human pulmonary and cardiac activity is here presented. The technique is based on detecting the changes in the modulation envelope of amplitude modulated waves passing through the human body. A simplified human chest model was developed, proving an unambiguous correlation between heart blood filling and microwave transmission through the chest. A prototype system for transmittance measurement was realized at the 868.5-MHz operating frequency, demonstrating the feasibility of a small, low cost microwave plethysmograph. In vivo measurements showed a good agreement with numerical simulations.
Keywords :
biomedical equipment; cardiology; electromagnetic wave transmission; lung; microwave measurement; patient monitoring; physiological models; plethysmography; 868.5 MHz; amplitude modulated waves; heart blood filling; in vivo measurements; medical instrumentation; microwave transmission through chest; modulation envelope changes; numerical simulations; physiological parameters monitoring; prototype system; simple microwave technique; transmittance measurement; unambiguous correlation; versatile microwave plethysmograph; Amplitude modulation; Biological system modeling; Biomedical monitoring; Blood; Condition monitoring; Envelope detectors; Heart; Humans; In vivo; Microwave theory and techniques; Computer Simulation; Coronary Circulation; Equipment Design; Heart; Humans; Microwaves; Models, Biological; Plethysmography; Reproducibility of Results; Respiratory Mechanics; Sensitivity and Specificity; Thorax;
Journal_Title :
Biomedical Engineering, IEEE Transactions on
DOI :
10.1109/TBME.2002.803588
