Ultrasound and Endoscopic Image Overlay System by Detecting Laparoscopic Ultrasound Probe Flexion

Abstract

In laparoscopic surgery, to identify the location of the lesion and the blood vessels inside organs, an ultrasound probe which can be inserted through small incision is used. However, since surgeons must observe the laparoscopic and t ultrasound images at the same time, it is difficul to understand the correspondence between the ultrasound image and the real space. Therefore, to recognize the correspondence between the two images intuitively, we developed a system for overlaying an ultrasound image on the laparoscopic image. Since the tip of the probe is flexed freely, we got the probe tip position and orientation using a method for detecting the probe angle of laparoscopic image. As results of experiment using a wire phantom, overlaying error of ultrasound images was 6.9 pixel. Further, the rate of probe angle detection was 83.1% in animal experiments performed laparoscopically.