A NIR optical imaging system for breast cancer detection

The paper presents a near-infrared (NIR) optical tissue imaging system, based on the principles of frequency-domain spectroscopy, which uses diffusive photons to detect breast cancer. The light source, a 780 nm laser diode, is modulated at 49.86 MHz. A photomultiplier tube detects the transmitted light and a 50 MHz signal is incorporated to demodulate the detected optical signal. The AC amplitude data is processed by computer, and then the optical mammograms are displayed on a computer screen in real time. Results prove the usefulness of this approach to distinguish between tumor and healthy tissue.