Augmented Reality of the Middle Ear Combining Otoendoscopy and Temporal Bone Computed Tomography. Issue 8 (September 2018)

• Record Type: Journal Article
• Authors: Marroquin, Roberto; Lalande, Alain; Hussain, Raabid; Guigou, Caroline; Grayeli, Alexis Bozorg
• Is Part Of: Otology & neurotology. Volume 39:Issue 8(2018)
• Publication Date: 2018-09
• Subjects: Augmented reality -- Labyrinthine windows -- Middle ear -- Minimally invasive surgery -- Otoendoscopy -- Transtympanic surgery; Otology -- Periodicals; Ear -- Diseases -- Periodicals; Skull base -- Surgery -- Periodicals; 617.8005
• DOI: 10.1097/MAO.0000000000001922
• Languages: English
• ISSNs: 1531-7129

Abstract

Abstract : Hypothesis: Augmented reality (AR) may enhance otologic procedures by providing sub-millimetric accuracy and allowing the unification of information in a single screen. Background: Several issues related to otologic procedures can be addressed through an AR system by providing sub-millimetric precision, supplying a global view of the middle ear cleft, and advantageously unifying the information in a single screen. The AR system is obtained by combining otoendoscopy with temporal bone computer tomography (CT). Methods: Four human temporal bone specimens were explored by high-resolution CT-scan and dynamic otoendoscopy with video recordings. The initialization of the system consisted of a semi-automatic registration between the otoendoscopic video and the 3D CT-scan reconstruction of the middle ear. Endoscope movements were estimated by several computer vision techniques (feature detectors/descriptors and optical flow) and used to warp the CT-scan to keep the correspondence with the otoendoscopic video. Results: The system maintained synchronization between the CT-scan image and the otoendoscopic video in all experiments during slow and rapid (5–10 mm/s) endoscope movements. Among tested algorithms, two feature-based methods, scale-invariant feature transform (SIFT); and speeded up robust features (SURF), provided sub-millimeter mean tracking errors (0.38 ± 0.53 mm and 0.20 ± 0.16 mm, respectively) and an adequate image refresh rate (11 and 17 frames per second, respectively) after 2 minutes of procedure with continuous endoscope movements. Conclusion: A precise augmented reality combining video and 3D CT-scan data can be applied to otoendoscopy without the use of conventional neuronavigation tracking thanks to computer vision algorithms. Abstract : Supplemental Digital Content is available in the text