On-patient see-through augmented reality based on visual SLAM.
PURPOSE
An augmented reality system to visualize a 3D preoperative anatomical model on intra-operative patient is proposed. The hardware requirement is commercial tablet-PC equipped with a camera. Thus, no external tracking device nor artificial landmarks on the patient are required.


METHODS
We resort to visual SLAM to provide markerless real-time tablet-PC camera location with respect to the patient. The preoperative model is registered with respect to the patient through 4-6 anchor points. The anchors correspond to anatomical references selected on the tablet-PC screen at the beginning of the procedure.


RESULTS
Accurate and real-time preoperative model alignment (approximately 5-mm mean FRE and TRE) was achieved, even when anchors were not visible in the current field of view. The system has been experimentally validated on human volunteers, in vivo pigs and a phantom.


CONCLUSIONS
The proposed system can be smoothly integrated into the surgical workflow because it: (1) operates in real time, (2) requires minimal additional hardware only a tablet-PC with camera, (3) is robust to occlusion, (4) requires minimal interaction from the medical staff.
['Mahmoud|Nader|N|', 'Grasa|Óscar G|ÓG|', 'Nicolau|Stéphane A|SA|', 'Doignon|Christophe|C|', 'Soler|Luc|L|', 'Marescaux|Jacques|J|', 'Montiel|J M M|JM|']
D059925:Anatomic Landmarks D000818:Animals D034201:Computers, Handheld D006801:Humans D021621:Imaging, Three-Dimensional D008953:Models, Anatomic D019047:Phantoms, Imaging D025321:Surgery, Computer-Assisted D013552:Swine
Augmented reality Visual SLAM Operating room Registration Surface meshes