Method and System for Determining a Safety Criterion during an Autonomous Manipulation of a Surgical Tool by a Robotic System to Treat an Anatomical Structure

A system for an autonomous manipulation of a surgical tool to treat an anatomical structure according to a planned trajectory in a 3D image, said 3D image being registered with a patient tracker, said system comprising:

• a robotic system servo-controlled on movements of the patient tracker, configured to manipulate the surgical tool according to the planned trajectory,
• an X-ray imaging system configured to acquire at least one 2D X-ray image containing the anatomical structure and the surgical tool,
• a localization system adapted to measure relative positions of the patient tracker and of a tracker rigidly fixed to the surgical tool or to a part of the robotic system, and
• a control unit coupled to the robotic system, the X-ray imaging system and the localization system, configured to implement the following method:
• (a) for each at least one 2D X-ray image acquired by the X-ray imaging system:
• i. obtaining synchronous localization measurement of the surgical tool and the patient tracker by the localization system to determine the position of the surgical tool relative to said 3D image,
• ii. registering the 2D X-ray image with the 3D image in a region of interest around the anatomical structure,
• iii. generating a projection onto the 2D X-ray image of a model of the surgical tool in its position relative to the 3D image computed in step (i), said position being called ‘projected localized position’,
• iv. determining a real position of the surgical tool on the 2D X-ray image,
• (b) determining a safety criterion from a similarity information between each real position and each projected localized position of the surgical tool on the at least one 2D X-ray image.