Research on Metaverse Technology-enabled Innovation Ecosystem

Traditional innovation systems are facing new dilemmas and challenges, and there is an urgent need for digital technologies to reduce investment risks and fuel technology transformation at scale. The metaverse, as an integrator of multiple emerging technologies, brings new opportunities for the development of innovation systems as it provides a trusted platform for innovative companies and organizations. The metaverse initially started as a game experiment that generated a new form of innovation in a virtual world with a plethora of opportunities and capabilities. However, research on the issue of innovation entrepreneurship in the metaverse and the conceptual framework its core technologies in this process is limited. In this paper,we construct the conceptual framework of the metaverse technologyenabled innovation ecosystem, and summarize the three phases of the metaverse innovation ecosystem towards maturity

Contrast Enhanced Subsurface Fingerprint Detection Using High-Speed Optical Coherence Tomography

Spectral-domain optical coherence tomography (SD-OCT) has been demonstrated to be a viable tool in forensic science for fingerprint detection, yet it still suffers from certain practical issues, e.g., the limited scanning speed and low image contrast. In this letter, we report a high-speed SD-OCT together with an image contrast enhancement mechanism for reliable subsurface fingerprint detection. The constructed SD-OCT system achieves a scanning rate up to 60k A-lines/s, and thus, both 3D volumetric images, reaching up to 20 mm × 20 mm × 1.2 mm, and en face internal fingerprint furrow pattern images could be obtained. Based upon the analyses of the papillary layer anatomical structures, the contrast enhancement technique not only suppresses image artifacts, but also is effective in detecting fingerprint spoofing. Experiments on healthy subjects have also been conducted to verify the system imaging capability and the effectiveness of the contrast-enhancement technique.NRF (Natl Research Foundation, S’pore)ASTAR (Agency for Sci., Tech. and Research, S’pore)MOE (Min. of Education, S’pore)NMRC (Natl Medical Research Council, S’pore)Accepted versio

Polarization management to mitigate misalignment-induced fringe fading in fiber-based optical coherence tomography

In fiber-based optical coherence tomography (OCT), the interference fringes suffer from the fading effect due to misalignment of the light polarization states between the reference and sample arms, resulting in sensitivity degradation and image intensity variation. We theoretically and experimentally analyzed the relation between the misalignment and the fading coefficient. Assuming that the variation of the light polarization in single-mode fiber (SMF) was a random process, we statistically quantified the fading effect. Furthermore, in OCT configuration based on the Michelson interferometer, we reported an interesting observation that the polarization states of light traveling a round-trip in SMF are not evenly distributed on the Poincare sphere. Based on this observation, we demonstrated the existence of an optimal output polarization state of the reference arm to mitigate the fading effect. We demonstrated that in an optimal setup, the statistical average signal-to-noise ratio could be 3.5 dB higher than a setup without proper polarization management.NRF (Natl Research Foundation, S’pore)MOE (Min. of Education, S’pore)NMRC (Natl Medical Research Council, S’pore)Published versio

Single input state polarization-sensitive optical coherence tomography with high resolution and polarization distortion correction

Abstract: In single input state polarization-sensitive optical coherence tomography (PS-OCT) with high resolution, the imperfections of quarter-wave plate (QWP) and the sensitivity roll-off mismatch between the two detection channels cause unpredictable polarization distortion. We present a correction method based on the Jones matrix modeling of the system. In a single input PS-OCT system working at 840 nm with an axial resolution of ~2.3 μm, the method yielded better estimation of retardation and optic axis orientation with significantly reduced noise level, especially in weakly birefringent samples. Numerical simulations and quantitative imaging of a sample of known birefringence were performed to validate the performance. We further demonstrate the advantages of our approach with birefringence imaging of swine retina, rat aortic wall, and rat esophageal mucosa for potential clinical applications.NRF (Natl Research Foundation, S’pore)ASTAR (Agency for Sci., Tech. and Research, S’pore)MOE (Min. of Education, S’pore)Published versio

Visualizing Micro-anatomical Structures of the Posterior Cornea with Micro-optical Coherence Tomography

Abstract Diagnosis of corneal disease and challenges in corneal transplantation require comprehensive understanding of corneal anatomy, particularly that of the posterior cornea. Micro-optical coherence tomography (µOCT) is a potentially suitable tool to meet this need, owing to its ultrahigh isotropic spatial resolution, high image acquisition rate and depth priority scanning mode. In this study, we explored the ability of µOCT to visualize micro-anatomical structures of the posterior cornea ex vivo and in vivo using small and large animals. µOCT clearly delineated cornea layers and revealed micro-anatomical structures, including not only polygonal endothelial cells, stellate keratocytes, collagen fibres and corneal nerve fibres but also new structures such as the dome-shaped basolateral side of endothelial cells and lattice structures at the interface between endothelium and Descemet’s membrane. Based on these observations, a short post-harvest longitudinal study was conducted on rat cornea to test the feasibility of using µOCT to monitor the quality of endothelial cells. This study successfully reveals a series of morphological features and pathological changes in the posterior cornea at the cellular level in situ and in real time with µOCT. These findings enrich knowledge of corneal anatomy and suggest that µOCT may be a promising imaging tool in corneal transplantation

Cellular resolution corneal imaging with extended imaging range

Current optical coherence tomography (OCT) technology, which is used for imaging the eye’s anterior segment, has been established as a clinical gold standard for the diagnosis of corneal diseases. However, the cellular resolution level information that is critical for many clinical applications is still not available. The major technical challenges toward cellular resolution OCT imaging are the limited ranging depth and depth of focus (DOF). In this work, we present a novel ultrahigh resolution OCT system that achieves an isotropic spatial resolution of <2 µm in tissue. The proposed system could approximately double the ranging depth and extend the DOF using the dual-spectrometer design and the forward-model based digital refocusing method, respectively. We demonstrate that the novel system is capable of visualizing the full thickness of the pig cornea over the ranging depth of 3.5 mm and the border of the corneal endothelial cells 8 times Rayleigh range away from the focal plane. This technology has the potential to realize cellular resolution corneal imaging in vivo.NRF (Natl Research Foundation, S’pore)ASTAR (Agency for Sci., Tech. and Research, S’pore)MOE (Min. of Education, S’pore)Published versio

Endomicroscopic optical coherence tomography for cellular resolution imaging of gastrointestinal tracts

Our ability to detect neoplastic changes in gastrointestinal (GI) tracts is limited by the lack of an endomicroscopic imaging tool that provides cellular-level structural details of GI mucosa over a large tissue area. In this article, we report a fiber-optic-based micro-optical coherence tomography (μOCT) system and demonstrate its capability to acquire cellular-level details of GI tissue through circumferential scanning. The system achieves an axial resolution of 2.48 μm in air and a transverse resolution of 4.8 μm with a depth-of-focus (DOF) of ~150 μm. To mitigate the issue of limited DOF, we used a rigid sheath to maintain a circular lumen and center the distal-end optics. The sensitivity is tested to be 98.8 dB with an illumination power of 15.6 mW on the sample. With fresh swine colon tissues imaged ex vivo, detailed structures such as crypt lumens and goblet cells can be clearly resolved, demonstrating that this fiber-optic μOCT system is capable of visualizing cellular-level morphological features. We also demonstrate that time-lapsed frame averaging and imaging speckle reduction are essential for clearly visualizing cellular-level details. Further development of a clinically viable μOCT endomicroscope is likely to improve the diagnostic outcome of GI cancers.NRF (Natl Research Foundation, S’pore)MOE (Min. of Education, S’pore)NMRC (Natl Medical Research Council, S’pore)Accepted versio