Oblique-viewing endoscope calibration in the diagnostics and treatment in the pelvis minor area

Abstract

Urinary incontinence (UI) is a common condition, especially in women, and affects the quality of life in a physical, social, and economic meaning. Despite improvements in surgical techniques and the implementation of minimally invasive procedures, male and female stress UI still affects their well-being. Treatment limitations have encouraged researchers to investigate new approaches, including those of tissue engineering. The injection of autologous mesenchymal-derived stem cells (AMDC) might rebuild the urethra sphincter function and minimize leakage symptoms. The treatment is carried out with a rigid endoscope. The aim of this study is to present a practical calibration procedure for an oblique-viewing endoscope imaging system. This article presents the results of an examination of the variability of the internal camera’s parameters with the angle of rotation of the endoscope’s cylinder. The research proves that the most variable parameters are the coordinates of the image plane’s principal point. The developed model of variability can be implemented as a simple look-up table in a real-time operating device. In this article, a tool is proposed for the computation of the relative angle of cylinder’s rotation based only on images. All developed methods can be implemented in a robot-assisted system for an AMDC urethra sphincter injection procedure.

An improved camera model for oblique-viewing laparoscopes: high reprojection accuracy independent of telescope rotation

“…2 Holak et al did not observe a circular pattern or any periodic behavior for p 1 and p 2 (Holak et al 2016), but they calibrated the laparoscope at each angle q cal with fixed checkerboard poses within world coordinates, whereas we consistently positioned the checkerboard within image coordinates.…”