Abstract
CIGS (Cu-In-Ga-Se) has higher sensitivity than silicon that is conventionally used in CCD/CMOS camera, over a wide wavelength range from visible to infrared (IR) light. In this study, we quantitatively investigated the contrast of subcutaneous veins in the CIGS IR images. IR images of three student's forearm were taken with seven different wavelength (770, 780, 810, 830, 950, 1064, 1100 nm) using interference filters and halogen illumination sources in reflectance manner. The contrast was calculated as a ratio of 12 digit illumination intensity at veins to adjacent points; then the average of contrasts over ten areas in an image was calculated to make a single value. As a result, IR image of 830 nm showed the highest contrast 0.87, whereas the contrast at 770 and 1064 nm were found to be almost the same value of 0.95 in all students. Finally, subcutaneous veins were successfully enhanced in IR image of 830 nm, basically, by subtracting intensities in the image of 770 nm at each pixel. The images may benefit for gaining venous access and vascular surgery.
