A flexible endoscope system for dual-mode intracavity investigations

A flexible fiber optic endoscope system for investigations in medical cavities using specially designed probe distal and proximal ends so as to facilitate speckle correlation analysis and simultaneous cavity imaging is presented in this paper. The design of the endoscope probe and associated detection system facilitating the analysis of deformation components and their derivatives in cavity surfaces is discussed. The distal end of the probe consists of a single fiber optic port for illumination and an imaging lens-image fiber unit for imaging the reflected speckle pattern from the cavity surface. An optical component selection unit is designed and used at the probe proximal end, for switching between deformation and derivative configurations. Theoretical analysis regarding speckle fringe formation on curved surfaces, for out-of-plane and shear configurations are discussed. Preliminary experimental investigations using the developed probe on inner surfaces of curved phantom tissue specimens are carried out for the abnormal growth detection and the results are analyzed. The obtained experimental results are compared with the developed theory. This probe system and its associated concepts may later lead into the improvements of currently used surgical assisted endoscopic techniques for early cancer diagnosis.