Fig. 3

Surgical scenario simulation using human model and ICG solution phantom with operating room lights on. a An experienced user is detecting PG phantom simulated by ICG solution. b Phantom preparation process: ICG solution simulated PG and pure water as negative control buried in RTV silicone. c Phantom: cup 1 is installed at a tilt angle to simulate PG covered by adipose. Cup 2 is a flat-bottom cup to simulate PG exposed completely. Cup 3 and cup 4 are filled with water. d Simulated PG is delineated by FSP in situ projection image (area in black circle) and compared with the simulated PG area fitted based on the fluorescence image obtained by the LSFI. e Fluorescence intensity distribution measured by the LSFI. f Fluorescence intensity distribution measured by FSP. g Probability to be parathyroid gland represented by autofluorescence intensity normalized to background, in situ projected onto PG phantom by pseudo-color image, red arrow indicates higher probability and green arrow indicates lower probability. h Fluorescence intensity attenuates exponentially along cup 1 as thickness of overlapped silicone increases. (i) The center distance bias of fitted area is about 0.36 mm and area overlap represented by IoU is about 76.6% (n = 10)