Microgels-Based Electromagnetic Nanosensor Network for Blood Glucose Monitoring

Electromagnetic nanosensor network (ENSN) is an innovative technological concept that focuses on using electromagnetic technologies like microwaves and millimeter-waves for advanced biomedical applications. ENSNs enable highly sensitive detection of a phenomenon of interest (POI) through electromagnetic radiation. ENSNs are composed of interconnected nanoscale sensors that utilize electromagnetic principles to sense and communicate useful low-level physiological signals within the body. This article presents a novel microgels-based ENSN for microwave glucose monitoring, and the research contributions can be summarized into two main aspects. First, a new type of microgel-based sensor (MBS) sensitive to microenvironmental conditions is manufactured, and a comprehensive material characterization of dielectric constant is performed. The corresponding models provide critical insights into the potential biomedical applications of the microgels. Second, a microgels-oriented ENSN system is proposed to enable the acquisition of human physiological signals, including manufactured implantable and external sensors (i.e., MBSs and antennas), related circuits, and miniaturized signal transceivers. Moreover, a novel sensing strategy based on machine learning is proposed for accurate disease feature recognition using multiple pairs of sensors, which includes a differential sensing step to eliminate unwanted interference due to tissue heterogeneity and a data fusion step to improve system reliability. To verify the proposed ENSN, the feasibility of classifying blood glucose between hyperglycemia and hypoglycemia is investigated. By incorporating the microgels-based sensor, the proposed system significantly outperforms traditional microwave medical sensing (MMS) methods using only the external electromagnetic sensor (EMS), achieving remarkable 46% and 53% improvements in numerical and experimental classification performance.