MALARIA CLAIMS THE LIVES of an estimated one to three million people every year. No vaccine is available for this infectious disease. With early diagnosis, however, patients have a better chance of responding to drug treatments. A method of detecting malaria at its onset has been developed by Anil Lonappan, Vinu Thomas, Joe Jacob, and K.T. Mathew from India's Cochin University of Science and Technology with C. Rajasekaran from the Medical College in Trivandrum. The approach is based on the measurement of the dielectric properties of blood at microwave frequencies.
The researchers made measurements at S-band using a rectangular cavity perturbation technique with blood samples from both healthy donors and malaria patients. This simple, fast, and accurate technique requires small samples of blood to measure dielectric properties. Appreciable differences were found in the dielectric properties of healthy patient samples compared to infected samples in the specified frequency band. The experimental setup comprised a transmission-type S-band rectangular cavity resonator and HP 8714 ET network analyzer from Agilent Technologies.
The cavity resonator is a transmission line with one or both ends closed. The number of resonant frequencies is determined by the resonator's length. When a material is introduced into a resonant cavity, the cavity field distribution and resonant frequency are changed depending on the material's shape, electromagnetic properties, and position in the cavity fields. See "A Novel Method of Detecting Malaria Using Microwaves," Microwave And Optical Technology Letters, April 2009, p. 915.