Endoscopic double-pulse electronic-speckle-pattern interferometer for technical and medical intracavity inspection

An endoscope electronic-speckle-pattern interferometer (ESPI) camera system is presented that can be applied to examinations of technical objects as w ell as for in vitro and in vivo minimal invasive medical diagnostics. Integ ration of optical fibers for the guidance of a cw-laser beam and an endosco pic imaging system yield a compact ESPI system that opens up new possibilit ies for highly sensitive interferometric intracavity inspection under handh eld conditions. A CCD camera in combination with a fast frame-grabber syste m allows dynamic image subtractions at a frequency rate of as much as 25 Hz with high fringe contrast. Results from investigations of technical object s and biological objects in vitro and in vivo are obtained. In endoscopic m inimal invasive therapy this method could substitute for the missing operat or's tactile contact with the treated tissue by replacing it with visual in formation (endoscopic taction). (C) 2000 Optical Society of America. OCIS c odes: 120.3180, 120.4290.