Enhanced Blood Vessels in Laparoscopy by Using Narrow-Band Imaging

In laparoscopic surgeries, because of lack of tactile sensation and 3D visual feedback, it is difficult to identify the position of blood vessels intraoperatively. An accidental injury to a blood vessel could result in change of laparoscopic procedures to open surgery. A noninvasive, reliable, and economical method to detect blood vessels during laparoscopic and endoscopic procedures would be very useful. In this study we have examined the usefulness of narrow-band imaging. The contrasts and color differences between the blood vessels and the adjacent tissues were measured using narrow-band imaging and conventional broadband imaging. Wilcoxon signed-rank test was used as a statistical test for evaluating the differences between the two groups. By using narrow-band illumination of 530-550 nm, the contrast of the blood vessels was greatly improved. The performance of this technique is evaluated for detection of the artery and vein in the laparoscopic surgery on a pig. The results demonstrated a statistically significant difference with narrow band images, which have a higher contrast and higher color difference than the conventional images. The result shows that in narrow band images, we have lesser color difference standard deviation. The contrast in narrow band images is about twice that of the conventional images.