1,234 research outputs found

    First-order Design of a Reflective Viewfinder for Adaptive Optics Ophthalmoscopy

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    Adaptive optics (AO) ophthalmoscopes with small fields of view have limited clinical utility. We propose to address this problem in reflective instruments by incorporating a viewfinder pupil relay designed by considering pupil and image centering and conjugation. Diverting light from an existing pupil optical relay to the viewfinder relay allows switching field of view size. Design methods that meet all four centering and conjugation conditions using either a single concave mirror or with two concave mirrors forming an off-axis afocal telescope are presented. Two different methods for calculating the focal length and orientation of the concave mirrors in the afocal viewfinder relay are introduced. Finally, a 2.2 × viewfinder mode is demonstrated in an AO scanning light ophthalmoscope

    Rotary target V-block

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    A device used in the optical alignment of machinery to maintain a measuring scale in the proper position for optical readings to be taken is described. The device consists of a block containing a notch in the shape of an inverted ""v'' and a rotatable plug positioned over the centerline of notch. The block is placed on the object to be aligned, the notch allows the block to be securely placed upon flat or curved surfaces. A weighted measuring scale is inserted through plug so that it contacts the object to be aligned. The scale and plug combination can be rotated so that the scale faces an optical aligning instrument. The instrument is then used in conjunction with the scale to measure the distance of the machinery from a reference plane

    The Application of Airtraq (fibreoptic intubation device) to Otolaryngology

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    The anaesthetic laryngoscope Airtraq is designed for the difficult airway. This disposable laryngoscope requires minimal cervical manipulation and unlike other common anaesthetic larynmgoscopes contains a channel for the guidance of an endotracheal tube. This could also be used for diagnosis and biopsy under a general anaesthetic or potentially under a local anaesthetic in an outpatient setting for biopsies or the removal of hypopharyngeal foreign bodies via flexible biopsy forceps obviating the need for a general anaesthetic. Thus Airtraq could be included in the armoury of pre-existing direct laryngoscopes because of its virtue of minimal airway manipulation

    Staffordshire University

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    Construction of ATS Cloud Console Final Report

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    ATS cloud console for rapid analysis of cloud image sequence

    Computational Re-Photography

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    Rephotographers aim to recapture an existing photograph from the same viewpoint. A historical photograph paired with a well-aligned modern rephotograph can serve as a remarkable visualization of the passage of time. However, the task of rephotography is tedious and often imprecise, because reproducing the viewpoint of the original photograph is challenging. The rephotographer must disambiguate between the six degrees of freedom of 3D translation and rotation, and the confounding similarity between the effects of camera zoom and dolly. We present a real-time estimation and visualization technique for rephotography that helps users reach a desired viewpoint during capture. The input to our technique is a reference image taken from the desired viewpoint. The user moves through the scene with a camera and follows our visualization to reach the desired viewpoint. We employ computer vision techniques to compute the relative viewpoint difference. We guide 3D movement using two 2D arrows. We demonstrate the success of our technique by rephotographing historical images and conducting user studies

    Skylab Earth Resource Experiment Package critical design review

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    An outline of the conference for reviewing the design of the EREP is presented. Systems design for review include: tape recorder, support equipment, view finder/tracking, support hardware, and control and display panel

    Design, Implementation and Operation of a Sparse Aperture Imaging Satellite Testbed

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    In order to better understand the technological difficulties involved in designing and building a sparse aperture array, the challenge of building a white light Golay-3 telescope was undertaken. The MIT Adaptive Reconnaissance Golay-3 Optical Satellite (ARGOS) project exploits wide-angle Fizeau interferometer technology with an emphasis on modularity in the optics and spacecraft subsystems. Unique design procedures encompassing the nature of coherent wavefront sensing, control and combining as well as various system engineering aspects to achieve cost effectiveness, are developed. To demonstrate a complete spacecraft in a 1-g environment, the ARGOS system is mounted on a frictionless air-bearing, and has the ability to track fast orbiting satellites like the ISS or the planets. Wavefront sensing techniques are explored to mitigate initial misalignment and to feed back real-time aberrations into the optical control loop. This paper presents the results and the lessons learned from the conceive, design, implement and operate phases of ARGOS. A preliminary assessment shows that the beam combining problem is the most challenging aspect of sparse optical arrays. The need for optical control is paramount due to tight beam combining tolerances. The wavefront sensing/control requirements appear to be a major technology and cost driver
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