System and method for post-exposure dosimetry using electron paramagnetic resonance spectroscopy of teeth

A method for estimating dose in subjects to be triaged according to radiation dose comprising:

• placing a resonator on an unextracted tooth of a subject, the resonator being magnetically coupled to a coupler attached to a radio frequency measuring device, the resonator comprising a loop and two capacitors, the resonator comprising a loop and two capacitors formed in metal layers on a flexible printed-circuit substrate;
• applying a magnetic field to the unextracted tooth of the subject by positioning a head of the subject containing the unextracted tooth between poles of a magnet;
• measuring at least one EPR spectrum of the unextracted tooth of the subject in the magnetic field by applying signals from a radio frequency source and using the radio frequency measuring device to determine responses of the unextracted tooth to the signals, the EPR spectrum being determined by sweeping either a frequency of the signals from the radio frequency source or a strength of the magnetic field;
• and
• using a processing system to estimate whole-body radiation dose of the subject from the measured EPR spectra,
• wherein the a magnet adapted to be positioned at least a first angle and at a second angle with respect to the subject's unextracted tooth, wherein the step of measuring at least one EPR spectra comprises measuring first EPR spectra with the magnet at the first angle and measuring second EPR spectra with the magnet at the second angle, and wherein estimating whole body radiation dose is performed by using both the first and second EPR spectra in computing the radiation dose.

Apparatus for performing electron paramagnetic resonance (EPR) spectrometry in teeth in vivo comprising:

• a magnet having sufficient space between poles for a subject's head to be positioned between the poles;
• at least one resonator having a loop and two capacitors formed in metal layers on a printed circuit substrate and adapted for placement adjacent to at least one tooth of the subject;
• a radio frequency measuring device adapted for determining at least one EPR spectrum;
• a processing system for computing a radiation dose based upon the EPR spectrum, and;
• an apparatus for outputting the radiation dose;
• the at least one resonator coupled inductively to a loop antenna the loop antenna coupled through:
• a first section of high-impedance coaxial cable of length approximately one-quarter wavelength having, at a first end, a center conductor of the first section of high impedance coaxial cable coupled to the loop antenna, and at a second end the center conductor of the first section of high-impedance coaxial cable coupled to an adjustment capacitor;
• a second section of high-impedance coaxial cable of length approximately three-quarter wavelength having, at a first end, a center conductor of the second section of the high impedance coaxial coupled to the loop antenna, and at a second end the center conductor of the second section of high-impedance coaxial cable coupled to the adjustment capacitor;
• a third section of high-impedance coaxial cable of length approximately three-quarter wavelength having, at a first end, a center conductor of the third section of high impedance coaxial cable coupled to the adjustment capacitor, and at a second end the center conductor of the third section of high-impedance coaxial cable is coupled to a center conductor of a coaxial transmission line coupled to the radio frequency measuring device.