25 research outputs found
Clinical disorders affecting mesopic vision
Vision in the mesopic range is affected by a number of inherited and acquired clinical disorders. We review these conditions and summarize the historical background, describing the clinical characteristics alongside the genetic basis and molecular biological mechanisms giving rise to rod and cone dysfunction relevant to twilight vision. The current diagnostic gold standards for each disease are discussed and curative and symptomatic treatment strategies are summarized
Comparative theoretical and experimental study of a Shack-Hartmann and a Phase Diversity SENSOR, for high-precision wavefront sensing dedicated to Space Active Optics
International audienceThe RASCASSE project was commissioned by the french spatial agency (CNES) to study a critical element of the next-generation of Earth-imaging satellites: the wavefront sensor, which is a key subsystem of active optics. The project involved ONERA and Thales Alenia Space (TAS) to study the analyzers, and LAM to design and implement the experiment.At ONERA, we first performed end-to-end simulations of a Shack-Hartmann and a Phase Diversity wavefront sensor on both a point source and extended scenes, with realistic wavefronts supplied by TAS. Then we studied the sensitivity of the sensors and the optimization of their design as a function of several parameters, such as: the strength and the type of aberrations, the image subsampling, the aperture shape, the signal-to-noise ratio, the spectral bandwidth, the type of scene, etc..Finally, we performed experimental measurements on the bench at lam, where both analyzers were run concurrently. The precision we achieved was better than 1 nm rms per measured Zernike mode, for both types of analyzers
Dissociation of tracheoesophageal fistulas with subtotal resection of the trachea for its stenosis
At present, the number of patients who had lung ventilation is growing. One of complications is a tracheoesophageal fistula accompanied by cicatricial stenosis of the trachea. In the past no treatment was offered for such patients, or they had to undergo prolonged stage-by-stage therapy. Our clinical observation shows modern possibilities of surgical service for such patients