Handheld Electromagnetic Scanner for Deep Vein Thrombosis Detection and Monitoring

Deep Vein Thrombosis (DVT) is a blood clot that is formed in a deep vein, particularly in one of the large leg veins. To avoid serious consequences, DVT requires early detection, timely medication, and daily monitoring. Thus, a handheld scanner based on electromagnetic techniques is proposed to meet those requirements. The device houses a four-channel body-matched antenna array. Each channel consists of two slotted patch antennas fed through an equal power divider. To enhance isolation between antenna elements and improve directionality, each element is embedded within a substrate-integrated waveguide. Moreover, each channel is orthogonal to the others to achieve radiation diversity. The antenna array covers the ultra-wideband (1.2-10 GHz), and thus achieves the required penetration and resolution to detect clots in deep veins. Each channel exhibits symmetrical and unidirectional radiation patterns that produce a stable main beam directed to the imaging domain with a front-to-back ratio and penetration efficiency of more than 18 dB and 80%, respectively. Since most DVT cases occur in the lower limbs, near the knees, the device is tested on knee phantoms. A double-stage confocal imaging algorithm is used to generate two-dimensional images of the knee in axial and sagittal planes. The simulated and experimental results show that small (3.5 mm) and multiple DVT clotting can be successfully detected, indicating the clinical potential of the device.