Minimally Invasive Endotracheal Inside-Out Flexible Needle Driving System Towards Microendoscope-Guided Robotic Tracheostomy

Open tracheostomy (OT) is considered the traditional way and golden standard for treating airway obstruction patients. However, OT has many unavoidable drawbacks, including strict performing scenarios, significant scarring, and the risk of surgeon infection. Percutaneous dilation tracheostomy (PDT) emerges, with advantages including a lower cost, smaller scarring, and better protection of surgeons from inflecting by aerosol. However, the outside-in puncture manner of PDT has a risk of piercing the post-tracheal wall and the esophagus with uncontrolled force. Additionally, locating tracheal rings and determining the puncture site externally can be challenging for certain patients, such as those who are obese or have undergone neck surgery, while this procedure typically relies on palpation and the surgeon's expertise. Hence, to improve the safety and simplicity of tracheostomy, a minimally-invasive endotracheal inside-out flexible needle-driving system towards microendoscope-guided robotic tracheostomy (MERT) has been proposed in this paper. Guided by an optical coherence tomography (OCT) probe and a microendoscope, the robot inserts into the trachea and performs an inside-out puncture using a flexible needle. The robot can work through a standard endotracheal tube (ETT), and the puncture direction of the flexible needle is variable. Kinematics and statics models of the flexible needle have been derived, and the minimum position errors generated in the kinematics and statics validation experiments are $0.57 \pm 0.21 \mathbf{~ m m}$ and $0.27 \pm 0.21 \mathbf{~ m m}$. Finally, a porcine trachea puncture experiment is carried out, and the feasibility of the proposed system is verified.