Fig. 3.

Examples of some portable/wearable FD-NIRS systems. (a) The portable FD-NIRS system for breast cancer detection described by Chen et al. This figure is taken with permission from [40]. (b) The FDPM instrument described by O’Sullivan et al. The subfigure on the left demonstrates the integrated probe containing a three-wavelength VCSEL package and a 3-mm diameter circular APD. This figure is taken with permission from [42]. (c) The schematic of the digital FD-DOS described by Torjesen, Istfan and Roblyer. The subfigure on the right demonstrates the core electronics of the system. This figure is taken with permission from [46].