Autonomous tissue retraction with a biomechanically informed logic based framework

Autonomy in parts of robot-assisted surgery is essential to reduce surgeons' cognitive load and eventually improve the overall surgical outcome. A key requirement to ensure safety in an Autonomous Robotic Surgical System (ARSS) lies in the generation of interpretable plans that rely on expert knowledge. Moreover, the ARSS must be able to reason on the dynamic and unpredictable anatomical environment, and quickly adapt the surgical plan in case of unexpected situations. In this paper, we present the first cognitive modular framework for the autonomous planning and execution of surgical tasks in deformable anatomical environments. Our framework integrates a logic module for task-level interpretable reasoning, a physics-based simulation that complements data from real sensors, and a situation awareness module for context interpretation. The framework performance is evaluated on simulated soft tissue retraction, a common surgical task to remove the tissue hiding a region of interest. Results show that the framework has the adaptability required to successfully accomplish the task, handling dynamic environmental conditions and possible failures, while guaranteeing the computational efficiency required in a real surgical scenario. The framework is made publicly available.