Patent ID: 6775565
Filing Date: 2004-08-10
Classification: A61B

Abstract:
An imaging apparatus for representing an image of concentration ratios between hemoglobin and oxyhemoglobin in blood, with different measuring values being represented with different colors and/or gray shades, comprisinga light source capable of irradiating the object with light, which light comprises at least three wavelengths &lgr;1, &lgr;2 and &lgr;3, wherein &lgr;1 is in the wavelength range of 600 to 700 nm, with a preference for 660 nm, &lgr;2 is in the wavelength range of 900 to 1000 nm, with a preference for 940 nm, and &lgr;3 is in the wavelength range of 790 to 830 nm, with a preference for 810 nm; detection means for at least detecting the intensity of light emitted by the object at the respective wavelengths &lgr;1, &lgr;2 and &lgr;3, resulting in detection signals S1, S2 and S3; a processing unit for calculating an optical image of the pattern of concentration ratios, from the respective signals S1, S2 and S3; display means for displaying the calculated optical image; characterized in that the detection means comprise: a 3CCD camera comprising three CCDs and three filters, wherein each filter is for receiving on one of said three CCDs one of said wavelengths &lgr;1, &lgr;2, &lgr;3, and one of red, green and blue optical ranges, the three CCDs of said camera generating three simultaneous signals S1, S2, S3 respectively, to be processed in said processing unit, thereby representing a virtually instantaneous image of the region of interest, the apparatus further being arranged for forming an image of visible light from said red, green and blue optical ranges, wherein the pattern of concentration ratios is projected in one overlapping image with the visible image.