Tendon-Actuated Concentric Tube Endonasal Robot (TACTER)

2025-04-28

AI Summary

In endoscopic endonasal approaches (EEA) to skull base surgery, rigid instruments face severe limitations in confined anatomical spaces and risk injuring the internal carotid artery and cranial nerves. To address this, we propose TACTER—a tendon-driven concentric-tube intranasal robot. Its key innovation is the first realization of “follow-the-leader” navigation within the natural nasal cavity, enabled by synergistic actuation between an asymmetrically slotted NiTi outer tube and a 3D-printed bidirectional inner tube—supporting independent bending of both tubes and coupled axial translation of the inner tube. We develop a Cosserat rod-based mechanical model integrating dual-robot tension and relative displacement, achieving submillimeter prediction accuracy. In human cadaveric head experiments, TACTER successfully executed fully autonomous navigation from the naris to the sphenoid sinus and performed critical structure avoidance across the full EEA operative workspace.

Technology Category

• Intelligent Robots: Localization, Mapping, and Navigation
• Natural Language Processing: Safety and Robustness
• Planning, Routing, and Scheduling: Model-Based Reasoning

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

Endoscopic endonasal approaches (EEA) have become more prevalent for minimally invasive skull base and sinus surgeries. However, rigid scopes and tools significantly decrease the surgeon's ability to operate in tight anatomical spaces and avoid critical structures such as the internal carotid artery and cranial nerves. This paper proposes a novel tendon-actuated concentric tube endonasal robot (TACTER) design in which two tendon-actuated robots are concentric to each other, resulting in an outer and inner robot that can bend independently. The outer robot is a unidirectionally asymmetric notch (UAN) nickel-titanium robot, and the inner robot is a 3D-printed bidirectional robot, with a nickel-titanium bending member. In addition, the inner robot can translate axially within the outer robot, allowing the tool to traverse through structures while bending, thereby executing follow-the-leader motion. A Cosserat-rod based mechanical model is proposed that uses tendon tension of both tendon-actuated robots and the relative translation between the robots as inputs and predicts the TACTER tip position for varying input parameters. The model is validated with experiments, and a human cadaver experiment is presented to demonstrate maneuverability from the nostril to the sphenoid sinus. This work presents the first tendon-actuated concentric tube (TACT) dexterous robotic tool capable of performing follow-the-leader motion within natural nasal orifices to cover workspaces typically required for a successful EEA.

Problem

• Enhances maneuverability in tight nasal spaces during surgery
• Avoids critical structures like carotid artery and nerves
• Enables follow-the-leader motion for endoscopic tools

Innovation

• Tendon-actuated concentric tube robot design
• Independent bending outer and inner robots
• Follow-the-leader motion in nasal orifices