System, apparatus and methods for intraoperative registration and tracking

A method of tracking and registration for a spine surgery;

• said method comprising:
• providing volumetric image data obtained from a preoperative scan of at least a portion of a spine including preselected vertebrae of the spine;
• processing the volumetric image data, including extracting surface data characterizing bone surfaces of the preselected vertebrae;
• extracting partial surface data that can be captured by ultrasound from the extracted surface data characterizing bone surfaces of the preselected vertebrae;
• sweeping, from locations external of a body in which the spine is located, at least the preselected vertebrae and processing data obtained therefrom to provide ultrasound volumetric image data;
• correlating the ultrasound volumetric image data and the extracted partial surface data and identifying ultrasound surface data characterizing the bone surfaces of the preselected vertebrae that correspond to the surface data extracted from the volumetric image data from the preoperative scan and coarsely registering the identified ultrasound surface data with the surface data extracted from the volumetric image data for each vertebra of the preselected vertebrae by calculating rotation matrices and translation vectors that transform the surface data extracted from the volumetric image data to correlate with the ultrasound surface data;
• making a least one incision to provide access to the preselected vertebrae;
• obtaining post-incision image data for each of said preselected vertebrae;
• for each of said preselected vertebrae, performing a registration refinement comprising processing said post-incision image data obtained after incision, calculating refinement of said rotation matrices and translation vectors, based on said post-incision image data obtained;
• applying said rotation matrices and translation vectors and generating and displaying at least one model of an instrument, screw or device overlaid on an image generated from said volumetric image data obtained from said preoperative scan.