Noninvasive Wearable RF Device Towards Monitoring Brain Atrophy and Lateral Ventricle Enlargement

Alzheimer's disease is the most common form of neurodegenerative disease and a leading cause of dementia today. A pathological effect of Alzheimer's disease is brain atrophy, which is the progressive shrinkage of the brain volume and weight. Another effect of Alzheimer's disease is the enlargement of lateral ventricles in the brain. Currently, MRI and CT scanners can detect and show images of the brain during different stages of Alzheimer's disease. However, its limited accessibility, high costs, and static structure make it inconvenient for some to use. This paper presents the design and novel application of a wearable device comprising of flexible microwave antennas, with an operating frequency range of 800 MHz-2.5 GHz that detects the progression of brain atrophy and lateral ventricle enlargement in patients with Alzheimer's at the earliest stage possible. The operating principle of the antennas are simulated in near field using CST and the device is experimentally validated using lamb brain samples and samples representing cerebral spinal fluid (CSF). The measured reflection coefficients (S
₁₁
) and transmission coefficients (S
₂₁
) were found to correlate with changes in brain volume and changes in CSF volume successfully, thus giving an indication of the progression of Alzheimer's disease in a patient.