Investigation of the Dielectric Properties for Brain and Blood Phantoms

In the medical field, microwave detection is used to diagnose medical conditions by observing the variations in the electromagnetic properties of biological tissues. This method offers advantages such as low radiation and real-time processing. Accurate dielectric constant measurement is critical for advancing microwave detection research. In dielectric constant measurement, physical phantoms and precise measurement methods are particularly important. This study investigates the preparation of brain and blood phantoms using polyvinyl pyrrolidone (PVP) and sucrose based on the 4-Cole-Cole model and analyzes their dielectric properties across a frequency sweep. The dielectric constants of porcine brain and blood were measured using a single-ended coaxial method with a vector network analyzer. Comparisons with theoretical data validated the method's accuracy. This study further compares the dielectric property variations of PVP-based and sucrose-based phantoms in the frequency band from 500 MHz to 2000 MHz. The results indicate that the phantoms configured with PVP exhibit greater stability in dielectric constants compared to those configured with sucrose. Additionally, the effect of standing time on the phantoms is minimal, making it more suitable for the experimental requirements of microwave detection technology,