HBS: a Handheld Breast Cancer detector based on frequency domain photon migration with full heterodyne

HBS, for Handheld Breast Scanner, is a miniature medical instrument for non-invasive breast cancer detection based on the principle of frequency domain photon migration spectroscopy. It performs content-based analysis by deriving scattering and absorption coefficients from amplitude and phase differences in backscattered, broadband-modulated (10 MHz to 1 GHz) near-infrared light. This paper reports improvements made in the latest HBS design over the previous design, called the Mini-FDPM. First, it uses full heterodyne detection to significantly improve the sensitivity, so that fiber coupling can be used instead of being limited to direct laser contact only. Second, the new firmware called Tapper accelerates the control speed while enabling HBSs to form a network. Experimental results show that HBS to have similar accuracy to the reference design, Laser Breast Scanner (LBS) currently in clinical trials.