A symmetrical independent antenna pair sensor for dynamic monitoring of ischemia stroke

Unlike intracerebral hemorrhage (ICH), the initial intracranial dielectric constant changes in IS are subtle and difficult to detect. Considering that the brain is approximately axisymmetric and the IS-affected hemisphere does not impact the healthy hemisphere, this study proposes a symmetric independent antenna pair (SIAP) sensor. The SIAP sensor consists of two inverted F-antennas positioned symmetrically at 150°, with additional shielding on the ground plane to minimize crosstalk. A realistic brain anatomical model was developed to analyze its Front to Back Ratio (FBR) performance and electromagnetic (EM) wave energy distribution. Subsequently, electromagnetic simulation experiments specific to IS were conducted. Additionally, experiments on rabbits with IS and ICH were carried out. The observed trends in S11 amplitude changes between the ICH and IS groups were distinct, with changes significantly higher in the ICH group compared to the IS group, yet both markedly higher than in the healthy state. This further validates the sensor’s capacity to differentiate between ICH and IS. Notably, animal experiments have underscored the sensor’s capacity to identify compensatory increases in cerebral blood flow in the unaffected hemisphere post-cerebral ischemia. These findings underscore the potential of the SIAP sensor as a novel approach for swift and accurate IS diagnosis and real-time monitoring.