Experimental Assessment of Real-Time Brain Stroke Monitoring via a Microwave Imaging Scanner

This paper presents the experimental validation of a microwave imaging system for real-time monitoring of brain stroke in the post-acute stage. The system exploits a low-complexity sensing apparatus and a multi-frequency microwave imaging algorithm with a novel artifact removal feature. Phantoms of a homogeneous anthropomorphic head and an ellipsoidal non-static stroke mimicking target, varying gradually from 0 cm(3) to 60 cm(3), are employed for the experiments. The phantom and the evolving target are filled with appropriate alcohol-based mixtures to mimic the different dielectric properties of the relevant tissue. The microwave imaging scanner operates using a 22-antennas architecture formed by printed flexible antennas with a custom-made matching medium. The system provides 3-D images of the entire brain region, exploiting differential multi-view scattering measures and the distorted Born approximation to build a pre-computed imaging kernel. The results show the system's capability to follow up the continuous progression of hemorrhage and ischemia zones with centimetric spatial resolution and to provide information on whether the stroke is growing or shrinking.