Recent Microwave Nondestructive Measurement in Biomedical Engineering

Recent microwave nondestructive measurement in biomedical engineering are reviewed. A novel method for non-contact monitoring of stress-induced autonomic activation through the back of a chair is developed, using a compact 24 GHz microwave radar (8 × 5 × 3 cm), without large scale equipment and placing a heavy burden on the monitored individual. This method appears to be promising for future monitoring of stress induced autonomic activation of operators and may reduce stress induced accidents. A novel in vitro test of blood analysis based on the measurement of the dielectric properties at microwave frequencies is reported. The measurements were made using rectangular cavity perturbation technique at the S-band of microwave frequency with the different samples of blood obtained from healthy donors as well as from patients. The measurements are in good agreement with clinical analysis. Novel planar type probes were developed to demonstrate the possibility of replacing the existing high cost open-ended coaxial probes. Three probes are developed. The measurement results of each probe showed excellent compatibility with those of the open-ended coaxial probe up to almost 40 GHz. The proposed planar type probes have great potentials for practical medical applications in view of low cost, disposability, and monolithic integration capability with the driving circuits. Finally the technical challenges of microwave nondestructive measurement in biomedical engineering are discussed.