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Endoscopes are an important component for the development of minimally invasive surgeries. Their size is one of the most critical aspects, because smaller and less rigid endoscopes enable higher agility, facilitate larger accessibility, and induce less stress on the surrounding tissue. In all existing endoscopes, the size of the optics poses a major limitation in miniaturization of the imaging system. Not only is making small optics difficult, but their performance also degrades with downscaling. Meta-optics have recently emerged as a promising candidate to drastically miniaturize optics while achieving similar functionalities with significantly reduced size. Herein, we report an inverse-designed meta-optic, which combined with a coherent fiber bundle enables a 33% reduction in the rigid tip length over traditional gradient-index (GRIN) lenses. We use the meta-optic fiber endoscope (MOFIE) to demonstrate real-time video capture in full visible color, the spatial resolution of which is primarily limited by the fiber itself. Our work shows the potential of meta-optics for integration and miniaturization of biomedical devices towards minimally invasive surgery.

 

Telecystoscopy can lower the barrier to access critical urologic diagnostics for patients around the world. A major challenge for robotic control of flexible cystoscopes and intuitive teleoperation is the pose estimation of the scope tip. We propose a novel real-time camera localization method using video recordings from a prior cystoscopy and 3D bladder reconstruction to estimate cystoscope pose within the bladder during follow-up telecystoscopy. We map prior video frames into a low-dimensional space as a dictionary so that a new image can be likewise mapped to efficiently retrieve its nearest neighbor among the dictionary images. The cystoscope pose is then estimated by the correspondence among the new image, its nearest dictionary image, and the prior model from 3D reconstruction. We demonstrate performance of our methods using bladder phantoms with varying fidelity and a servo-controlled cystoscope to simulate the use case of bladder surveillance through telecystoscopy. The servo-controlled cystoscope with 3 degrees of freedom (angulation, roll, and insertion axes) was developed for collecting cystoscope videos from bladder phantoms. Cystoscope videos were acquired in a 2.5D bladder phantom (bladder-shape cross-section plus height) with a panorama of a urothelium attached to the inner surface. Scans of the 2.5D phantom were performed in separate arc trajectories each of which is generated by actuation on the angulation with a fixed roll and insertion length. We further included variance in moving speed, imaging distance and existence of bladder tumors. Cystoscope videos were also acquired in a water-filled 3D silicone bladder phantom with hand-painted vasculature. Scans of the 3D phantom were performed in separate circle trajectories each of which is generated by actuation on the roll axis under a fixed angulation and insertion length. These videos were used to create 3D reconstructions, dictionary sets, and test data sets for evaluating the computational efficiency and accuracy of our proposed method in comparison with a method based on global Scale-Invariant Feature Transform (SIFT) features, named SIFT-only. Our method can retrieve the nearest dictionary image for 94–100% of test frames in under 55[Formula: see text]ms per image, whereas the SIFT-only method can only find the image match for 56–100% of test frames in 6000–40000[Formula: see text]ms per image depending on size of the dictionary set and richness of SIFT features in the images. Our method, with a speed of around 20 Hz for the retrieval stage, is a promising tool for real-time image-based scope localization in robotic cystoscopy when prior cystoscopy images are available. 

Untreated dental decay is the most prevalent dental problem in the world, affecting up to 2.4 billion people and leading to significant economic and social burden. Early detection can greatly mitigate irreversible effects of dental decay, avoiding the need for expensive restorative treatment that forever disrupts the enamel protective layer of teeth. However, two key challenges exist that make early decay management difficult: unreliable detection, and lack of quantitative monitoring during treatment. New optically-based imaging through the enamel provides the dentist a safe means to detect, locate, and monitor the healing process. This work explores the use of an Augmented Reality (AR) headset to improve the workflow of early decay therapy and monitoring. The proposed workflow includes two novel AR-enabled features: 1) in-situ visualization of pre-operative optically-based dental images and 2) augmented guidance for repetitive imaging during therapy monitoring. The workflow is designed to minimize distraction, mitigate hand-eye coordination problems, and help guide monitoring of early decay during therapy in both clinical and mobile environments. The results from quantitative evaluations as well as a formative qualitative user study uncover the potentials of our system and indicates that AR can serve as a promising tool in tooth decay management. 

Background and Objective A safer alternative method to radiographic imaging is needed. We present a multispectral near‐infrared scanning fiber endoscope (nirSFE) for dental imaging which is designed to be the smallest imaging probe with near‐infrared (NIR) imaging (1200–2000 nm). Materials and Methods The prototype nirSFE is designed for wide‐field forward viewing of scanned laser illumination at 1310, 1460, or 1550 nm. Artificial lesions with varying sizes and locations were prepared on proximal surfaces of extracted human teeth to examine capability and limitation of this new dental imaging modality. Nineteen artificial interproximal lesions and several natural occlusal lesions on extracted teeth were imaged with nirSFE, OCT, and microCT. Results Our nirSFE system has a flexible shaft as well as a probe tip with diameter of 1.6 mm and a rigid length of 9 mm. The small form factor and multispectral NIR imaging capability enables multiple viewing angles and reliable detection of lesions that can extend into the dentin. Among nineteen artificial interproximal lesions, the nirSFE reflectance imaging operating at 1460‐nm and OCT operating at 1310‐nm scanned illumination exhibited high sensitivity for interproximal lesions that were closer to occlusal surface. Diagnosis from a non‐blinded trained user by looking at real‐time occlusal‐side nirSFE videos indicate true positive rate of 78.9%. There were no false positives. Conclusions This study demonstrates that nirSFE may be used for detecting occlusal lesions and interproximal lesions located less than 4 mm under the occlusal surface. Major advantages of this imaging system include multiple viewing angles due to flexibility and small form factor, as well as the ability to capture real‐time video. The multispectral nirSFE has the potential to be employed as a low‐cost dental camera for detecting dental lesions without exposure to ionizing radiation. 

Personal health and wellness technologies can improve people’s care at home, connect everyday activities to clinical settings, and allow more efficient use of clinical resources. Recently, the Human-Computer Interaction community has begun to develop tools to improve oral care. In this research, we investigate dental practices and information needs through surveys and interviews with a range of patients and oral health providers. We find that personal users want to track their progress—or lack thereof—between dental visits for feedback, so they can adjust their home care routines, or so they can seek an escalation in care if they identify a problem. Among providers and clinical health workers, there exists an opportunity for better screening and diagnostic tools to identify dental caries at early stages. Providers in rural areas desire better tools to communicate problem areas to patients and their caregivers to bridge oral health care disparities in areas with limited access to care. Our results can guide the development of dental technologies that can address currently unmet needs of patients and providers.