Recent advances in microscopic detection techniques include
fluorescence spectroscopy, fibred confocal microscopy and optical coher-
ence tomography. These methods can be integrated with miniaturised
probes to assist endoscopy, thus enabling diseases to be detected at an
early and pre-invasive stage, forgoing the need for histopathological sam-
ples and off-line analysis. Since optical-based biopsy does not leave vis-
ible marks after sampling, it is important to track the biopsy sites to
enable accurate retargeting and subsequent serial examination. In this
paper, a novel approach is proposed for pathological site retargeting in
gastroscopic examinations. The proposed method is based on affine defor-
mation modelling with geometrical association combined with cascaded
online learning and tracking. It provides online in vivo retargeting, and is able to track pathological sites in the presence of tissue deformation. It is also robust to partial occlusions and can be applied to a range of imaging probes including confocal laser endomicroscopy.