File:Humerus Clausus - Navigation chirurgicale par vision monoculaire (MédiHAL 4190125).webm

English: The Humerus Clausus project is a Franco-Swiss partnership that aims to develop tools to assist the surgeon in the various phases of diagnosis, surgical planning, surgical navigation, and during the follow-up of the patient's rehabilitation in a context associated with orthopaedic shoulder surgery. The main contribution of this thesis is to meet the needs of surgical navigation for the care of certain pathologies of the scapulohumeral link. A real-time tracking system based on monocular vision is proposed. An original locator is developed from a set of flat markers rigidly fixed on a host object whose geometry can be arbitrary. The proposed calibration approach allows finding the relative position of the planar markers based on a set of images of this object observed from different points of view. At the end of this calibration step, the spatial position of the object is accessible regardless of its orientation towards the camera. This tracking system is robust to the problems inherent in individual plane markers, notably by avoiding the problem of pose ambiguity. In a configuration adapted to the operating room, the measurement uncertainties of this locator are sub-millimetre in position and of the order of one-tenth of a degree in rotation. The adaptation of the device to the operating room led to the development of various calibration procedures allowing the recovery of geometric primitives necessary for the specificities of surgical instruments (registration of 3D surfaces, aiming axis). This adaptation also led to the creation of a host object geometry in the form of a double-dodecahedron, which reduces the measurement uncertainties of the tool, particularly in terms of orientation. The device was tested in anatomy laboratory sessions during the placement of intramedullary nails of the humerus and during the placement of the glenoid part of an inverted prosthesis following the recommendations of surgical planning. These test results demonstrated the performance of the proposed tracking system.