Fig. 3.

Examples comparing “prototypes” and “products.” (a) First version of fluorescence imager with point spectroscopy (left: in use to guide brain tumor surgery, right: optical schematic), (b) after reengineering into a compact multispectral “ratiometric” imaging device, but excluding point spectroscopy (left: in use during prostate cancer surgery, right-optical schematic), (c) first prototype of cell phone camera-based fluorescence imager used in clinical trials, (d) re-engineered commercial version (courtesy of Moleculight Inc. Toronto. Canada).