Portable Electron Spin Resonance Spectrometer for Real-time Detection and Quantification of Biological Tissue Damage due to Exertion-Induced Oxidative Stress and Ionizing Radiation
Abstract
Realtime monitoring of military personnel stress and exhaustion levels while on active duty is crucial for maximizing efficacy during challenging missions or training activities and ensuring health and safety. Military personnel on missions or during strenuous training may develop significant tissue damage due to exertion induced oxidative stress caused by the formation of reactive oxygen species (ROS). Exposure to ionizing radiation such ultraviolet light from the sun or due to radioactive materials can also result in acute as well as cumulative damage to a multitude of tissues and organs, potentially leading to both health consequences and impaired performance during a mission. The extent to which physical exhaustion or radiation exposure will cumulatively lead to biological tissue damage is not well understood due to a lack of sensors capable of monitoring and quantifying these processes in real-time. The body has various mechanisms for tissue repair, but the ability of these mechanisms to prevent or repair damage due to prolonged exposure to free radicals is unknown. Damage to bodily tissue and biomolecular damage (DNA, proteins, cells) due to ionizing radiation commonly leads to the formation of free radicals, which are highly reactive molecules with unpaired electrons. Excessive amounts of these radicals, whose formation is accelerated by ionizing radiation, can lead to cell injury and death, which in turn contribute to diseases such as cancer, stroke, myocardial infarction, diabetes, and other major disorders. Detecting and measuring these ROS via a portable, non-invasive device can be used to actively monitor physical exertion levels of military personnel and ensure that they stay within healthy physiological limits. We propose to develop an ultra-sensitive, portable, low-power Point-of-Care diagnostic sensor based on Electron Spin Resonance (ESR), which will be capable of directly and noninvasively monitoring free radical concentration in a subjects tissues. ESR is the definitive and most widely used technique for characterizing free radicals. Typical ESR spectrometers require a static magnetic biasing field of around 0.35T, which leads to a resonance of unpaired electrons due to the Zeeman effect at 9.8GHz. Inexpensive neodymium permanent magnets can be readily purchased commercially, which produce surface magnetic fields up to around 0.6T, measure a few cm in diameter, and weigh only tens of grams. Our proposed ESR system will consist of such a small permanent magnet for producing the static biasing field and a fully integrated CMOS sensor chip to analyze the ESR spectrums of biological samples at 9-12GHz. Due to the fully integrated nature of the design, the resulting device will be the first completely portable ESR spectrometry system, shrinking ESR technology and power consumption down by orders of magnitude compared to existing equipment, while maintaining a very high level of sensitivity and being capable of noninvasive interrogation of underlying tissues. We will also develop the first fully integrated and portable pulse-based ESR spectrometer system capable of performing Double Electron Electron Resonance (DEER) experiments for improved sensitivity and specificity. Signal processing and machine learning algorithms will also be developed and evaluated to process the sensor data and track cumulative tissue damage to determine whether patients may be at risk of complications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 04, 2020
- Source ID
- N000142114005
Entities
People
- Constantine Sideris
Organizations
- Office of Naval Research
- United States Navy
- University of Southern California