Lack of mutual occlusion capability between computer-rendered and real objects is one of fundamental problems for
most existing optical see-through head-mounted displays (OST-HMD). Without the proper occlusion management, the
virtual view through an OST-HMD appears “ghost-like”, floating in the real world. To address this challenge, we have
developed an innovative optical scheme that uniquely combines the eyepiece and see-through relay optics to achieve an
occlusion-capable OST-HMD system with a very compelling form factor and high optical performances. The proposed
display system was based on emerging freeform optical design technologies and was designed for highly efficient liquid
crystal on silicon (LCoS) type spatial light modulator (SLM) and bright Organic LED (OLED) microdisplay. The
proposed display technology was capable of working in both indoor and outdoor environments. Our current design
offered a 1280x1024 color resolution based on 0.8" microdisplay and SLM. The MTF values for the majority of the
fields at the cutoff frequency of 40lps/mm, which is determined by the pixel size of the microdisplay, are better than
15%. The design achieved a diagonal FOV of 40 degrees, 31.7 degrees horizontally and 25.6 degrees vertically, an exit
pupil diameter of 8mm (non-vignetted), and an eye clearance of 18mm. The optics weights about 20 grams per eye. Our
proposed occlusion capable OST-HMD system can easily find myriads of applications in various military and
commercial sectors such as military training, gaming and entertainment.
Ratiometric fluorescence-imaging technique is commonly used to measure extracellular pH in tumors and surrounding tissue within a dorsal skin-fold window chamber. Using a pH-sensitive fluorophore such as carboxy SNARF-1 one can measure pH distributions with high precision. However, it is often observed that the measured pH is lower than expected, with a bias that varies from one image to another. A comprehensive analysis of possible error sources is presented. These error sources include photon noise, estimator bias, instrument errors, temperature, and calibration errors from biological factors.
Window chambers are support structures implanted in the dorsal skin fold of a rodent model. Optical imaging of window chambers has been used in many basic cancer and vascular biology studies. We have recently shown that this technique can be extended to MRI by using plastic rather than metal window chambers. Here we describe a system for simultaneous optical and MR imaging of the window chambers. It provides many possibilities for independent cross validation of the measurements of one modality from the other. In the system, a GRIN lens images the tissue to the distal end of a coherent imaging fiber bundle, which relays this image to a camera system located outside the magnet room. Both trans- and epi-illumination are provided to this system. Light sources are located outside the magnet room
and the light is delivered through fiber optics. A group of fibers are used to deliver white light from under the window chamber for standard transmission imaging, while another single fiber delivers the laser light from the top to induce fluorescence. An appropriate bandpass emission filter is inserted between the lenses at the camera end for fluorescence imaging. Results of simultaneously optical and MR imaging of tumor and vessel are presented.
Conference Committee Involvement (8)
Optical Metrology and Inspection for Industrial Applications X
15 October 2023 | Beijing, China
Optical Metrology and Inspection for Industrial Applications IX
5 December 2022 | Online Only, China
Optical Metrology and Inspection for Industrial Applications VIII
11 October 2021 | Nantong, JS, China
Optical Metrology and Inspection for Industrial Applications VII
12 October 2020 | Online Only, China
Optical Metrology and Inspection for Industrial Applications VI
21 October 2019 | Hangzhou, China
Optical Metrology and Inspection for Industrial Applications V
11 October 2018 | Beijing, China
Optical Metrology and Inspection for Industrial Applications IV
12 October 2016 | Beijing, China
Optical Metrology and Inspection for Industrial Applications III
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