Current generation video endoscopes. A critical evaluation.

Video endoscopy is the latest technical advance in the observation of the gastrointestinal tract. In 2 years, three video endoscope systems have emerged to develop the field of digital imaging. In order to accurately assess the rapidly changing technology, these state of the art systems were "bench" tested in an electronics laboratory to objectively compare resolution, brightness (luminosity), color intensity (chroma), and field of view. All systems were excellent, surpassing the professional broadcasting minimum standards for the adequate discrimination of objects and colors. The Welch Allyn Video-Endoscope originated video endoscopy continued to demonstrate a superior resolution; however this was at the expense of a significantly more narrow field of view, relative to the two newer systems. Although all systems have adequate luminosity and chroma, there were differences in the maximum amounts of luminosity and chroma. This is reflected in the observation that the most recently introduced system, Olympus Endoscopic Video Information System had relatively low levels of light beyond 9 cm from the tip, while the other systems had ample illumination. This report on the relative advantages of each system is based on the interpretations, implications, and practical applications of these findings.