Non-invasive In-vivo sensing of metabolites with a novel Optoacoustic Spectroscope in the SWIR

In this work we developed a novel near-infrared two-path optoacoustic spectrometer (NiR-TAOS) that could sense OA intensity changes due to metabolite concentration changes in-vivo. The main aim of dividing the optical path in two is 1) perform real time correction of the laser emission profile of the laser source at different wavelengths and, 2) perform pulse to pulse correction to remove laser beam fluctuation and instability to increase signal to noise ratio. Signal to noise ratio improvement was significant not only at spectral peaks, but also at all other wavelengths. The system can be used for broad applications in biomedical measurements such as various metabolites in the SWIR.