Wireless Bioelectronic System Design & Optimization
Interconnected and Integrated Bioelectronics Lab Research Project
Electrolyte imbalances are critical factors in major organ failure, contributing to an average of 13 deaths daily in the United States. Thus, developing an accurate, real-time in-body biochemical sensing system is vital for effective disease management and early organ failure detection. Current methodologies' limitations are: 1) blood draws are time-consuming, one-time measurements; 2) wearable biosensors have detection delays with limited sensing capabilities; and 3) current implantables are bulky, battery-powered, with limited selectivity. We are developing a battery-free, implantable biochemical sensing system designed for localized organ monitoring. The system includes a flexible wearable paired with a passive implantable that uses inductive coupling for wireless power transfer and data transmission. We were previously challenged with low sensitivity, poor sensor performance, and vulnerability to distance-induced distortions on the signal. Here, we introduce an optimized dual-pair system that accurately measures the sensor response by removing baseline variations caused by distance distortions. Our approach leverages a reference implantable to reject environmental variations, thereby enabling isolation of the sensor response. The implantable was redesigned to minimize sensor noise, achieving a 4x improvement in signal-to-noise ratio. Mathematically informed impedance matching enhanced the system's sensitivity by 340%, and the wearable was further miniaturized by 32%. Mathematical modeling paired with a distance rejection algorithm provided accurate vertical distance prediction and enabled the back-calculation of the analyte concentration from the sensor. This work validates a low-noise, high-sensitivity wireless sensing system that resolves a critical barrier by removing environmental variations from sensor readings, enabling accurate in-body concentration determination.
