Transorbital Neuro Surgery (TNS) offers a novel treatment towards the lesion inside skull pursuing minimal invasiveness. Most conventional TNS tools are rigid and straight, limiting the dexterity and accessibility in passing a small port. Bendable and steerable surgical tools provides an alternative for this issue. In this work, we proposed a dual-segment slender surgical robot arm for TNS, which is a Co-Axial Slender Tubular robot (CAST), and modelled it using novel approaches. Another contribution is tendon-mortise shaped slits along the axial direction, enhancing the overall stiffness. The bending of CAST is actuated by pushing/pulling distance, and the maximum diameter is only 1.7mm with high dexterity after mounting on a rigid robot arm. Experiments demonstrates that the proposed the slit design doubles the stiffness properties compared to traditional rectangle slit designs. The path-following task shows that the position error was maximally 3mm in open-looped control. Test on a skull model demonstrates that the whole system could successfully perform electrocoagulation procedure inside the depth of skull in a robotized manner effectively.

Severe chronic pulmonary endarterectomy needs a dissector to delicately remove proliferative intima located in the depth of the pulmonary artery. This work proposed a novel endoscopic robotized steerable dissector for this surgery, enabling easier access to curved deep artery branches. The handheld surgical dissector also provides suction and visualization for surgeons to enhance effectiveness. The steerable section is a cable-driven hinged structure, and through an antagonistic mechanism regulating the cable tension, the overall stiffness is adjusted to adapt various surroundings. The mapping between actuation space and shape configuration and tip force estimation model are respectively established for further closed-loop control scheme, achieving adaptive positioning and safe surgery. Experiments first demonstrate the feasibility of the proposed models and ex vitro trials validated the usage and effectiveness of the robotized dissector.