A Unique Device to Measure Radiation Dose and Homogeneity of Exposure Following a Large-Scale Ionizing Radiation Event - ABSTRACT: Our project will deliver a field-ready, physically-based biodosimetry device capable of accurately estimating radiation doses in the range of 0–10 Gy within ±0.5 Gy and estimate the homogeneity of the irradiation using in vivo measurements of human nails. The device utilizes electron paramagnetic resonance (EPR) and incorporates advanced spectrometer architecture, implementing novel probe design, and cutting-edge signal processing techniques to achieve high sensitivity and reliability, enabling rapid and efficient triage in emergency situations. Our innovative and non-invasive approach addresses the critical need for accurate, on-site radiation dose assessment in the event of a radiological or nuclear incident. Within 5 minutes, an in vivo measurement of a fingernail and/or toenail provides a radiation dose assessment without the need for nail clipping. This physically-based method complements biologically-based biodosimetry methods and is minimally perturbed by health-related factors. The project aims to enhance biodosimetry capabilities by improving sensitivity through implementing novel probe geometries, a superheterodyne spectrometer architecture, and advanced signal processing techniques. User-friendly software will be developed to streamline the operation of the biodosimetry device, including an intuitive interface suitable for non-expert operators and a convolutional neural network to accurately estimate radiation dose from the EPR signals. Standardization and establishing the readiness of the device for its intended use will be achieved by establishing a dose curve using irradiated cadaver digits and validating the approach in irradiated patients. A dose-phantom for testing the device on healthy human volunteers will be developed using an inert sample (India ink) in a polystyrene matrix. The impact on dose responses with respect to variations in nail curvature, thickness, hydration, occurrence of background signals, and demographic variations will be characterized using the dose-phantom on nails of unirradiated volunteers. Rigorous testing and validation will be conducted using polyacrylamide phantoms, healthy human volunteers, and irradiated cadaver hands and feet to validate performance and establish a robust calibration procedure. The final device will be compact, portable, and capable of simultaneous measurements on multiple digits, enabling rapid and efficient triage in emergency situations. The measurements of multiple digits add a very important capability, detection and characterization of heterogeneity of exposure. Because of the stability of the RIS the method also can be used to characterize long term-risk for irradiated survivors. Completion of this project will deliver a critical tool for assessing radiation exposure in individuals, facilitating timely medical decision-making, and ultimately improving outcomes for those affected by large-scale radiological incidents. Our in vivo nail biodosimetry device developed through this project will be ready for deployment and integration into existing emergency response protocols, significantly enhancing our nation's preparedness for potential radiological emergencies.
