Geometric Calibration of an OCT Imaging System

This paper deals with an OCT (optical coherence tomography) geometric calibration method. OCT medical imaging system has received a growing interest during the last two decades. In medical purposes, OCT images are generally called optical biopsies which allows in-vivo investigation almost similar to a histopathological study. The physician can rely on the OCT images to establish a rapid and direct diagnosis. But the OCT images formation suffered numerous distortions due in particular to the optical path, from the source to the viewed sample passing through the two reflecting mirrors and a scan objective. The obtained optical biopsies include several spectral and geometric distortions. The proposed calibration model aims to compensate the geometrical ones. More precisely, two models were developed allowing the correction of both 2D images (B-Scan slices) and 3D images (volume). These models were experimentally validated (in both artificial and biological samples) using a spectral domain OCT system. It has demonstrated a significant enhancement of the OCT images accuracy.