“…Due to limited working volume, many SI endoscopic designs do not consider the baseline between projector and the camera but use a common beam-splitter between them, resulting in nonuniform depth accuracy and restricted range of 3-D measurement, 22 or providing only perceptual depth measurement 23 , 24 . Most efforts applying SI in confined spaces, such as fiber or endoscope, 25 – 27 have been reported with static and nontissue objects 28 . Some highlighted studies of 3-D reconstruction on tissue use high-power light grids with unique spectrum and triangulate the light-of-sight rays from the light source to the camera on tissue features 29 – 31 with submillimeter accuracy.…”