Development of augmented-reality applications in otolaryngology-head and neck surgery.

OBJECTIVES/HYPOTHESIS: Augmented reality (AR) allows for the addition of transparent virtual images and video to one's view of a physical environment. Our objective was to develop a head-worn, AR system for accurate, intraoperative localization of pathology and normal anatomic landmarks during open head and neck surgery. STUDY DESIGN: Face validity and case study. METHODS: A protocol was developed for the creation of three-dimensional (3D) virtual models based on computed tomography scans. Using the HoloLens AR platform, a novel system of registration and tracking was developed. Accuracy was determined in relation to actual physical landmarks. A face validity study was then performed in which otolaryngologists were asked to evaluate the technology and perform a simulated surgical task using AR image guidance. A case study highlighting the potential usefulness of the technology is also presented. RESULTS: An AR system was developed for intraoperative 3D visualization and localization. The average error in measurement of accuracy was 2.47 ± 0.46 millimeters (1.99, 3.30). The face validity study supports the potential of this system to improve safety and efficiency in open head and neck surgical procedures. CONCLUSIONS: An AR system for accurate localization of pathology and normal anatomic landmarks of the head and neck is feasible with current technology. A face validity study reveals the potential value of the system in intraoperative image guidance. This application of AR, among others in the field of otolaryngology-head and neck surgery, promises to improve surgical efficiency and patient safety in the operating room. LEVEL OF EVIDENCE: 2b Laryngoscope, 129:S1-S11, 2019.

Towards Fully Mobile 3D Face, Body, and Environment Capture Using Only Head-worn Cameras.

We propose a new approach for 3D reconstruction of dynamic indoor and outdoor scenes in everyday environments, leveraging only cameras worn by a user. This approach allows 3D reconstruction of experiences at any location and virtual tours from anywhere. The key innovation of the proposed ego-centric reconstruction system is to capture the wearer's body pose and facial expression from near-body views, e.g. cameras on the user's glasses, and to capture the surrounding environment using outward-facing views. The main challenge of the ego-centric reconstruction, however, is the poor coverage of the near-body views - that is, the user's body and face are observed from vantage points that are convenient for wear but inconvenient for capture. To overcome these challenges, we propose a parametric-model-based approach to user motion estimation. This approach utilizes convolutional neural networks (CNNs) for near-view body pose estimation, and we introduce a CNN-based approach for facial expression estimation that combines audio and video. For each time-point during capture, the intermediate model-based reconstructions from these systems are used to re-target a high-fidelity pre-scanned model of the user. We demonstrate that the proposed self-sufficient, head-worn capture system is capable of reconstructing the wearer's movements and their surrounding environment in both indoor and outdoor situations without any additional views. As a proof of concept, we show how the resulting 3D-plus-time reconstruction can be immersively experienced within a virtual reality system (e.g., the HTC Vive). We expect that the size of the proposed egocentric capture-and-reconstruction system will eventually be reduced to fit within future AR glasses, and will be widely useful for immersive 3D telepresence, virtual tours, and general use-anywhere 3D content creation.

A giant malignant fibrous histiocytoma on the scalp.

Malignant fibrosis histiocytoma (MFH) is one of the most common soft tissue sarcomas of adult life. The most common sites of origin are the proximal extremities, particularly the thigh and buttock. The tumors are multilobular fleshy masses, often apparently circumscribed on gross examination. We report a case of a MFH of the head in a 57-year-old woman. Our case is clinically unusual in that the tumor rapidly grew up to 15 cm in a very short time.

Intradermal nodular fasciitis of the face.

Nodular fasciitis represents reactive myofibroblastic proliferative lesions in the subcutaneous tissue, skeletal muscles, and fascia. Uncommon clinical and pathological variants of nodular fasciitis, such as intravascular, cranial, ossifying, and proliferative fasciitis, have been described. Six cases documenting a dermal location of nodular fasciitis have been reported in the English literature. Some authors have described that the histopathological features of intradermal nodular fasciitis are virtually identical to those of postoperative/posttraumatic spindle cell nodule of the skin. We herein report a 41-year-old Korean woman presenting with a 0.5 cm facial papule in which nodular fasciitis occurred in the dermis.