Development and testing of an endoscopic pseudo-viewpoint alternating system

Purpose:    An endoscopic system is needed that presents informative images irrespective of the surgical situation and the number of degrees of freedom in endoscopic manipulation. This goal may be achieved with a virtual reality view for a region of interest from an arbitrary viewpoint. An endoscopic pseudo-viewpoint alternation system for this purpose was developed and tested. Method:    Surgical experts and trainees from an endoscopic surgery training course at the minimally invasive surgery training center of Kyushu University were enrolled in a trial of a virtual reality system. The initial viewpoint was positioned to approximate the horizontal view often seen in laparoscopic surgery, with ^20∘ between the optical axis of the endoscope and the task surface. A right-to-left suturing task with right hand, based on a task from the endoscopic surgery training course, was selected for testing. We compared task outcomes with and without use of a new virtual reality-viewing system.Result:    There was a 0.37 mm reduction in total error (p=0.02) with use of the proposed system. Error reduction was composed of 0.1 mm reduction on the y-axis and 0.27 mm reduction on the x-axis. Experts benefited more than novices from use of the proposed system. Most subjects worked at a pseudo-viewpoint of around 34^∘.Discussion:    Suturing performance improved with the new virtual reality endoscopic display system. Viewpoint alternation resulted in an overview that improved depth perception and allowed subjects to better aim the marker. This suggests the proposed method offers users better visualization and control in endoscopic surgery.