Microendoscopic Surgery of Middle Ear and Petrous Bone: Benefits Analysis

Objectives: Endoscopy has become routinely used in middle ear surgery. The aim of this study is to analyze where this tool may complement the traditional microscopic approach. This is a retrospective study done in single tertiary hospital. Methods: We reviewed 342 middle ear/petrous bone surgical procedures performed between 2005 and 2015. Only cases in which both microscopic and endoscope-assisted techniques were used have been included. Sixty-six patients received this double-technique surgery: 51 (77.2%) had middle ear/mastoid and petrous bone cholesteatomas (46 middle ear and mastoid and 5 acquired/congenital petrous bone cholesteatomas), 5 (7.5%) had glomus tympanicum tumors (GTT), 4 (6%) had an ossicular chain dislocation, 3 (4.5%) had purulent chronic otitis media, 2 (3%) had tympanosclerosis, and 1 (1.5%) had an ossicular chain malformation. Results: The endoscope was helpful to remove disease remnants not accessible by microscope in 41 (62%) of the cases; 37 (90%) were cholesteatomas, 3 (7%) were GTT, and only 1 (3%) was an open tympanosclerosis. In the remaining 25 (37.8%) cases, the endoscope was useful only to visualize the cavity since the microscope had already been successful in removing the entire lesion. Conclusions: The endoscopy can add valuable information and support to the usual microscope approach alone. The consensus of a single best technique does not yet exist, but the physician should choose the best modality or combination of modalities in order to cure the patient and prevent any possible complications or recurrence of the pathology

Characterization of bipartite states using a single homodyne detector

We suggest a scheme to reconstruct the covariance matrix of a two-mode state using a single homodyne detector plus a polarizing beam splitter and a polarization rotator. It can be used to fully characterize bipartite Gaussian states and to extract relevant informations on generic states.Comment: 7 pages, 1 figur

Low loss coatings for the VIRGO large mirrors

présentée par L. PinardThe goal of the VIRGO program is to build a giant Michelson type interferometer (3 kilometer long arms) to detect gravitational waves. Large optical components (350 mm in diameter), having extremely low loss at 1064 nm, are needed. Today, the Ion beam Sputtering is the only deposition technique able to produce optical components with such performances. Consequently, a large ion beam sputtering deposition system was built to coat large optics up to 700 mm in diameter. The performances of this coater are described in term of layer uniformity on large scale and optical losses (absorption and scattering characterization). The VIRGO interferometer needs six main mirrors. The first set was ready in June 2002 and its installation is in progress on the VIRGO site (Italy). The optical performances of this first set are discussed. The requirements at 1064 nm are all satisfied. Indeed, the absorption level is close to 1 ppm (part per million), the scattering is lower than 5 ppm and the R.M.S. wavefront of these optics is lower than 8 nm on 150 mm in diameter. Finally, some solutions are proposed to further improve these performances, especially the absorption level (lower than 0.1 ppm) and the mechanical quality factor Q of the mirrors (thermal noise reduction)