Design and evaluation of an intuitive distal-flexible endoscope for constrained surgical environments

Minimally invasive surgery is increasingly applied to complex procedures; however, conventional endoscopes are limited by restricted maneuverability and unintuitive control, often leading to frequent endoscope adjustments and suboptimal visualization in anatomically constrained spaces.

We developed a distal-flexible endoscopic system with an intuitive control strategy inspired by human cervical-trunk coordination. The system enables decoupled rotational and translational movements and incorporates head-motion-based control using a HoloLens interface to facilitate natural endoscope navigation. The system was evaluated through benchtop accuracy tests, a simulated surgical task, and in vivo experiments.

The prototype system demonstrated high positioning accuracy and precise motion control, with sub-millimeter translational and low angular errors. Compared with a conventional semi-rigid endoscope, it significantly reduced external workspace occupation while maintaining full visualization of key thoracic anatomical structures in both phantom and animal studies. In the simulated surgical task, the system reduced operative time (5.8 vs. 4.6 min, p = 0.042) and operator workload (lower NASA-TLX scores across all subscales). In vivo experiments further showed shorter operative time (40.2 vs. 51.0 min, p = 0.046) and fewer endoscope repositionings (4.8 vs. 12.8, p = 0.004), with comparable safety outcomes.

The prototype endoscopic system improves procedural efficiency and reduces operator workload while maintaining comparable safety outcomes, providing preliminary evidence of its clinical feasibility. This approach may offer a promising solution for intuitive and efficient visualization in minimally invasive surgical procedures.