Electronic endoscope system and processor unit thereof, and method for obtaining blood vessel information

Abstract

Ina special light mode, first to fourth special images are captured under first to fourth special light being narrow band light. A brightness ratio calculator extracts a blood vessel area containing a blood vessel from each special image. The brightness ratio calculator calculates first to fourth brightness ratios from the special images on every pixel within the blood vessel area. A depth and hemoglobin index calculator calculates the depth of the blood vessel and a hemoglobin index corresponding to the first and second brightness ratios, based on a correlation between the depth of the blood vessel and the hemoglobin index stored in advance. A depth and oxygen saturation calculator calculates an oxygen saturation level corresponding to the third and fourth brightness ratios, based on a correlation between the depth of the blood vessel and the oxygen saturation level stored in advance.

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