Patent ID: 11141087

Abstract:
A sensor device which is adapted for detecting target molecules in-vitro and in-vivo, comprises a MIR source for exciting the target species and a probe beam with split frequency to measure the effect of excitation. The latter uses a heterodyne interferometer operating at a beat frequency ˜ KHz. to MHz. The photo-thermal excitation of target species leads to refractive index change. The RI change produces probe beam displacement and is measured using a 1) grating heterodyne interferometer, 2) grating deflection amplifier and 3) evanescent field heterodyne interferometer. The measured RI change can be related to specie concentration change in target volume. Furthermore, a sensing method for detecting HbA1c concentration and its change with thermal excitation is described in terms of phase shift of the OCT spectrum obtained with spectral domain optical coherence tomography (SD-OCT).