An Experimental Study and Modeling of Water Condensation to Eliminate Fogging on Endoscope Lenses, Using A New, Hyper-Hydrophilic Coating Called KnoxFog™*

Lenses in laparoscopes, arthroscopes, laryngoscopes, and gastro-endoscopes fog during closed-body surgery due to the evaporation of bodily fluids and the temperature gradient between the body and the operating room. Surgeons must repeatedly remove, clean, and reinsert these scopes that are obscured by fog. As a result, surgery duration, infection risks, and scarring from air exposure increase. Current methods trying to address fogging introduce other complications. Acidic alcohol-based coatings irritate tissue and quickly evaporate while heating endoscopes requires reheating every 5 to 20 minutes.

A new approach is to use a hyper-hydrophilic ^[1,3] anti-fog gel to coat the lens. Previous super-hydrophilic ^[2] anti-fog fluids flatten the water condensate but get washed away by the water build-up. This new hyper-hydrophilic gel coating, called KnoxFog™,  instantaneously creates an anti-fog thin solid film that both flattens the water condensate and absorbs it, thereby eliminating the need for drying and significantly increasing the duration of the antifog effect for hours. This new gel is bio-compatible, non-toxic, pH neutral (7.2-7.4), and long-lasting.  KnoxFog™ is applied via a sterile applicator specifically designed for endoscope lenses - called ClearEndoscope™ - to consistently and effectively deliver uniform antifog thin solid films. These films are 99% transparent and free of optical distortion. The combination of KnoxFog™ and ClearEndoscope™ is a new surgical device called FogBan™.