Optical filter for providing the required illumination to enable narrow band imaging

This paper presents the design, fabrication and characterization of two Fabry Perot type optical filters (415 nm and 540 nm) for enabling Narrow Band Imaging (NBI) in medical devices (MD). The two-colour illumination should satisfy a highly specific optical design, which is composed of a thin-film optical filter stack of titanium dioxide (TiO2 ) and silicon dioxide (SiO2 ) thin-films and commercially available light-emitting diodes (LEDs). The short-wavelength design is the most critical and simulations show a maximum relative optical output of 21 % at 415 nm with Full-Width-Half-Maximum (FWHM) of 13 nm for a blue LED with the designed optical filter, which is confirmed by experiment. The green light simulations show a maximum relative optical output of 34 % with FWHM 36 nm at 540 nm. The TiO2 and SiO2 thin films were fully characterized.This work was supported by Marie Curie Intra European Fellowship within the 7th European Community Framework Programme - FP7-PEOPLE-2012-IEF-328490. Manuel Silva was supported by the Portuguese Foundation for Science and Technology under Grant SFRH/BD/81295/2011

Is alcohol consumption associated with gastroesophageal reflux disease?*

Gastroesophageal reflux disease (GERD) is one of the most common disorders with an increasing incidence and prevalence. Alcohol consumption may be a risk factor for GERD; however, the relationship remains to be fully elucidated. The results of different studies are diverse and contradictory. Systematic investigations concerning this matter are inappropriate and further well-designed prospective studies are needed to clarify the effect of alcohol on GERD