Fig. 5.

Graphic illustration of the frame sequential multispectral fluorescence imaging technique. Each of the red, green, and blue lasers was turned on individually and sequentially. Meanwhile, red reflectance, PM red fluorescence, and FL green fluorescence were received in the detection channels sequentially at 10 (30/3) Hz. The red reflectance frames were acquired to enable the Distance Compensation (DC) algorithm for quantitative fluorescence imaging. When the DC algorithm is not needed for the application, only PM red and FL green fluorescence are acquired at 15 (30/2) Hz. In normal operation, red, green, and blue reflectance are used for conventional “white light” color imaging.