Design and Evaluation of Wearable Multimodal RF Sensing System for Vascular Dementia Detection

Vascular dementia is the second most common form of dementia and a leading cause of death. Brain stroke and brain atrophy are the major degenerative pathologies associated with vascular dementia. Timely detection of these progressive pathologies is critical to avoid brain damage. Brain imaging is an important diagnostic tool and determines future treatment options available to the patient. Traditional medical technologies are expensive, require extensive supervision and are not easily accessible. This article presents a novel concept of low- complexity wearable sensing system for the detection of brain stroke and brain atrophy using RF sensors. This multimodal RF sensing system provides a first-of-its-kind RF sensing solution for the detection of cerebral blood density variations and blood clots at an initial stage of neurodegeneration. A customized microwave imaging algorithm is presented for the reconstruction of images in affected areas of the brain. Designs are validated using software simulations and hardware modeling. Fabricated sensors are experimentally validated and can effectively detect blood density variation (1050 +/- 50 Kg/m(3)), artificial stroke targets with a volume of 27 mm(3) and density of 1025-1050 Kg/m(3), and brain atrophy with a cavity of 58 mm(3) within a realistic brain phantom. The safety of the proposed wearable RF sensing system is studied through the evaluation of the Specific Absorption Rate (SAR < 1.4 W/Kg, 100 mW) and thermal conductivity of the brain (<0.152 C-degrees). The results indicate that the device is viable as an efficient, portable, and low-cost substitute for vascular dementia detection.