Das Polylaryngoskop von Brünings 1913, genannt das „Neunauge”, und andere frühe Versuche, laryngoskopische Befunde zu demonstrieren

Abstract

Since the invention of otoscopy and laryngoscopy in the middle of the 19th century attempts have been made at demonstrating the findings live to a number of co-observers. Efforts to project the image onto a ground glass screen failed because of the faint light available at the time and the small scale of magnification which could not be increased at will due to lack of depth of focus. Such attempts by Killian in 1893 and others are quoted. W. Brünings in Jena in 1913 devised an instrument that enabled the observer and eight co-observers to see a direct uninverted image of the larynx or the tympanic membrane simultaneously in identical brightness and size. A movable mark on one of the lenses served as a pointer. Various optical equipment permitted a twofold or threefold magnification, stereoscopic and stroboscopic examination. Apart from the technical details an anecdotal report is given of Brünings' presentation and practical demonstration of his apparatus at the 20th meeting of the German Laryngological Society in 1913. The instrument was quite popular in training hospitals between the two world wars. It was only in 1937 that an adapted version of it was introduced in ophthalmology.