Fig. 1: The SPE system.
From: Surgical polarimetric endoscopy for the detection of laryngeal cancer
a, Design of the handheld endoscope device in the SPE system and schematic of DoFP-LP camera. QWP: quarter waveplate. DoFP-LP incorporates an array of micro-linear polarizers on the top of the photodiode array. Every block of four adjacent array elements comprises 90°, 45°, 135° and 0° angled micro-linear polarizers directly above four photodiodes that constitute a super-pixel. b, Photo of the handheld endoscope part of the SPE system. c, Schematic: intra-operative imaging of larynx with the SPE system. d, Endoscopic polarizing tip attachment, compared with a 20 pence coin. Scale bar is 10 mm. e, The polarization properties (from left to right: retardance, diattenuation and depolarization; unitless) of the imaging channel of the rigid endoscope used in the SPE system. f, Image processing pipeline. g,h, Intensity reference images obtained from SPE imaging of a negative 1951 USAF target under depolarization (dep) (g) and retardance (ret) (h) modes. i, The spread functions of a three-line grid in the target extracted from the red horizontal line in g and blue horizontal line in h.
