Instrument guidance system for sinus surgery

A method for guiding a surgical instrument during sinus surgery on a patient, said method comprising the steps of:

• a. receiving pre-operative 3D patient image data;
• b. marking a plurality of points in a plurality of slice images of the 3D patient image data to define a planned drainage pathway, wherein at least one of said plurality of points comprises a starting point and an end point;
• c. using an endoscope to obtain a real-time intra-operative image of an operating field including the patient;
• d. determining a position of the surgical instrument relative to the marked planned drainage pathway and relative to the endoscope;
• e. computing a virtual image corresponding to the real-time intra-operative image comprising a first visualization element representing the planned drainage pathway illustrated as a tube shaped object, a second visualization element representing the determined position of the surgical instrument relative to the planned drainage pathway, the second visualization element comprising:
• i. a plurality of circles spaced along the tube shaped object, the position of the plurality of circles being based on the position of the surgical instrument relative to the planned drainage pathway;
• and
• ii. wherein the centers of each of the plurality of circles are placed on the tube shaped object illustrating the planned drainage pathway so that the plane of each of the plurality of circles is oriented to be perpendicular to the central axis of the planned drainage pathway;
• f. superimposing the virtual image over the real-time intraoperative image to generate an augmented reality image including each of the first and the second visualization elements;
• and
• g. displaying the augmented reality image to help guide the surgical instrument along the planned drainage pathway.