A Shape and Stiffness Adjustable Laryngoscope for Transoral Robotic Surgery

Laryngoscopes are essential tools in transoral robotic surgery (TORS) for visualizing and accessing the larynx. However, the rigidity and non-adjustable design of conventional laryngoscopes limit their ability to reach certain lesion areas, increasing patient invasiveness. This study presents a novel shape and stiffness adjustable laryngoscope to address these challenges. The proposed laryngoscope features a spring-tendon layout that allows for stable bending through tendon actuation by a single motor. A lockable mechanism enhances stiffness, enabling the instrument to be securely positioned at various bending angles. We evaluated the performance of the spring-tendon layout in reducing the hysteresis error by 26%, while the lockable mechanism significantly improves the stiffness of the manipulator under a large load of 20 N by an average of 481% and up to 1462%. Experimental results from a physical prototype demonstrate the robustness of the proposed design in withstanding disturbances of varying magnitudes applied from different locations, and validate the prototype's ability to expose areas of the throat that are inaccessible with a traditional laryngoscope. The bendable, lockable laryngoscope significantly improves access, stability, and visualization in TORS, providing enhanced capabilities for surgeons performing complex procedures. This innovative design provides a promising solution to the current limitations in laryngoscopy, potentially enhancing the precision and minimally invasive nature of TORS, and ultimately leading to improved patient outcomes.