Exploratory investigation of virtual lesions in gastrointestinal endoscopy using a novel phase-shift method for three-dimensional shape measurement

• Published in: DEN open 2025-04, Vol.5 (1), p.e381-e381
• Main Authors: Sakamoto, Taku, Oda, Ichiro, Okamura, Takuma, Cho, Hourin, Toyoshima, Naoya, Nonaka, Satoru, Suzuki, Haruhisa, Nakamura, Tatsuya, Watanabe, Daichi, Matsuo, Keigo, Hanano, Kazunari, Takeyama, Tetsuhide, Yoshinaga, Shigetaka, Saito, Yutaka
• Format: Article
• Language: English
• Subjects: Techniques and Innovation
• ISSN: 2692-4609; 2692-4609
• DOI: 10.1002/deo2.381

Accurate measurement of the size of lesions or distances between any two points during endoscopic examination of the gastrointestinal tract is difficult owing to the fisheye lens used in endoscopy. To overcome this issue, we developed a phase-shift method to measure three-dimensional (3D) data on a curved surface, which we present herein. Our system allows the creation of 3D shapes on a curved surface by the phase-shift method using a stripe pattern projected from a small projecting device to an object. For evaluation, 88 measurement points were inserted in porcine stomach tissue, attached to a half-pipe jig, with an inner radius of 21 mm. The accuracy and precision of the measurement data for our shape measurement system were compared with the data obtained using an Olympus STM6 measurement microscope. The accuracy of the path length of a simulated protruded lesion was evaluated using a plaster model of the curved stomach and graph paper. The difference in height measures between the measurement microscope and measurement system data was 0.24 mm for the 88 measurement points on the curved surface of the porcine stomach. The error in the path length measurement for a lesion on an underlying curved surface was