Design and Analysis of a Dual-Stiffness Flexible Continuum for Endotracheal Intubation Robot

During complex endotracheal intubation surgery, avoiding the fragile structure of the complex endotracheal is the key to endotracheal intubation surgery, which requires high flexibility of the endotracheal intubation actuator. This paper proposes a flexible actuator based on dual-stiffness design, which is applied to the end of the endotracheal intubation robot, aiming to improve the flexibility and obstacle avoidance performance during the operation and reduce the control difficulty. The actuator consists of two sections of notch flexible structures, which use different notch gaps and different lengths to achieve self-decoupling performance and to adapt to the complex endotracheal structure. This paper first explains the design principle of the dual-stiffness flexible continuum, and conducts mechanical modeling and kinematic analysis of the notch unit and the overall continuum based on the Timoshenko beam theory. Subsequently, the obstacle avoidance performance and forward vision function of the dual-stiffness continuum are simulated and verified using SOFA and COMSOL. The simulation results show that the dual-stiffness continuum can not only improve the actuator's adaptability, but also achieve precise obstacle avoidance motion in an obstacle environment. Finally, the dynamic performance of the continuum is demonstrated through simulation, verifying the practical application potential of this design in endotracheal intubation.