1. Articles in category: Gastroenterology

    481-504 of 531 « 1 2 ... 18 19 20 21 22 23 »
    1. Serial Endoscopy in Azoxymethane Treated Mice Using Ultra-High Resolution Optical Coherence Tomography

      Serial Endoscopy in Azoxymethane Treated Mice Using Ultra-High Resolution Optical Coherence Tomography

      Purpose: Optical coherence tomography (OCT) is a minimally invasive, depth-resolved imaging tool that can be implemented in a small diameter endoscope for imaging mouse models of colorectal cancer (CRC). In this study, we utilized ultrahigh resolution (UHR) OCT to serially image the lower colon of azoxymethane (AOM) treated A/J mouse models of CRC in order to monitor the progression of neoplastic transformations and determine if OCT is capable of identifying early disease. Experimental Design: Thirteen AOM treated A/J and two control A/J mice were surveyed at four timepoints (8, 14, 22, and 26 weeks post AOM treatment ...

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    2. Illuminating optical system for endoscope

      An endoscope illuminating optical system having a gradient index lens capable of illuminating by a sufficient light amount and by a wider angle is provided. The endoscope illuminating optical system is constituted to illuminate an observed region by light guided by a light guide 1, by way of a gradient index lens 2, and the gradient index lens 2 satisfies Condition Equations (2) and (3) below: (AR).sup.2.ltoreq.0.6 (2) 0.5k+0.35.ltoreq.AL/.pi..ltoreq.0.5k+0.65 (3) where, R designates an effective radius of the gradient index lens, L designates a ...
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    3. Ultrahigh-Resolution Endoscopic Optical Coherence Tomography for In Vivo Mouse Colonoscopy (Thesis)

      Ultrahigh-Resolution Endoscopic Optical Coherence Tomography for In Vivo Mouse Colonoscopy (Thesis)
      In vivo monitoring of mouse models of colon cancer promises to reduce the cost of research by improving sacrifice timing and allowing serial studies that observe the progression of disease and drug efficacy in a relatively small set of animals. Optical coherence tomography (OCT) is an optical analog of ultrasound imaging, capable of minimally-invasive mapping of light scatter intensity up to 2 mm deep in tissue. In this work, factors limiting resolution in OCT were examined and devices were created and applied to mouse colon imaging that extended the state-of-the-art in endoscopic ultrahigh-resolution OCT. First, axial chromatic aberration of the ...
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    4. Image-distorting endoscopes and methods of making and using such endoscope

      An endoscope having restricted dimensions and comprising at least one image gatherer, at least one image distorter and at least one image sensor shaped to fit within said limited dimensions, and wherein said image distorter is operable to distort an image received from said image gatherer so that the image is sensible at said shaped image sensor.
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    5. Optiscan and Carl Zeiss Sign a Collaboration Deal

      3 July 2007 Optiscan and Carl Zeiss Group sign collaboration deal • • • • • Optiscan’s first rigid endo-microscope deal Carl Zeiss Group secure exclusive use of Optiscan technology for clinical rigid endo-microscope applications in their core market segments A$20 million of milestone payments and product sales anticipated over the initial 5 years Carl Zeiss Group to fund market development and sales of “ZEISS” branded instruments produced by Optiscan Optiscan retains rights to separately commer
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    6. Optical Coherence Tomography of Airway and Pleural Disorders

      Optical methods for obtaining images in airway passages for early detection of endobronchial lung and pleural cancer are needed. Optical coherence tomography (OCT) is a non-invasive or minimally invasive diagnostic technique that can provide information about tissue abnormalities. OCT can produce images of abnormalities both at and below the surface of the airways without damaging the tissue surface This technique uses a harmless device to emit infrared (not visible) light that can produce images of the specimen under investigation without causing damage or alterations
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    7. Optical system and optical apparatus capable of switching between optical coherence tomography observation and optical coherence microscopy observation

      An optical system and optical apparatus prevent degradation of the S/N ratio due to switching between OCT and OCM observation modes and attain a high S/N ratio in both the observation modes. The optical system includes a light source 1 and a light-branching member 2 for branching light from the light source 1 into a reference light path and a signal light path. An objective 3 is placed in the signal light path. A light-scanning system 5 scans light in the signal light path with respect to a sample 4 placed in the signal light path. A beam ...
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      Mentions: Olympus
    8. Scanning mirror unit and beam scanning probe

      A scanning mirror unit for scanning a beam comprises: at least one cantilever which is formed by bonding an elastic material and a piezoelectric material together and supported by a base at its one end; and a movable mirror which is supported at least by a free end of the cantilever at its peripheral part. When voltage is applied to the piezoelectric material, the free end of the cantilever moves in a prescribed direction to press and move the peripheral part of the movable mirror while leaving a central part of the movable mirror at substantially the same position to ...
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      Mentions: Pentax
    9. Comprehensive esophageal microscopy by using optical frequency–domain imaging (with video)

      Comprehensive esophageal microscopy by using optical frequency–domain imaging (with video)
      Background Optical coherence tomography (OCT) has been used for high-resolution endoscopic imaging and diagnosis of specialized intestinal metaplasia, dysplasia, and intramucosal carcinoma of the esophagus. However, the relatively slow image-acquisition rate of the present OCT systems inhibits wide-field imaging and limits the clinical utility of OCT for diagnostic imaging in patients with Barrett's esophagus. Objective This study describes a new optical imaging technology, optical frequency-domain imaging (OFDI), derived from OCT, that enables comprehensive imaging of large esophageal segments with microscopic resolution. Design A prototype OFDI system was developed for endoscopic imaging. The system was used in combination with a ...
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    10. OCT for Early Detection and Staging of Endobronchial Lung and Pleural Cancer, Airway Injury, and Prostate Cancer

      Optical coherence tomography (OCT) is a non-invasive diagnostic technique that can provide information about tissue abnormalities. This technique uses a near-infrared diode to emit light that can produce images of the specimen under investigation without causing damage or alterations. The research' want to compare the OCT results with that obtained from conventional histologic examination and to show that the OCT results may be almost as accurate as the standard Pathology results. Optical coherence tomography (OCT) is a new technique being developed that can be used for visualizing human tissue. OCT offers a means of providing information on the characteristics and ...
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    11. Optical imaging apparatus

      An optical imaging apparatus has an optical scanning probe configured to irradiate low-coherence light onto a subject and to perform photo-reception of light scattered at the subject, and an observation device adapted to construct a cross-section image of the subject based on information from the light received through the optical scanning probe. The optical scanning probe is detachably connected to the observation device.
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      Mentions: Olympus
    12. Optical scanning observation apparatus

      Before performing observation with an optical scanning probe using a low-coherence light source and the like, a shutter is inserted in a reference light side optical path to create a state wherein interference light does not occur, in which state a reference member is set to a focal position of a converging optical system such that the output of a light detector is maximal by moving the reference member by a driving device at an observation light optical path side of an optical scanning probe, following which the shutter is opened, and the position of a mirror at the reference ...
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      Mentions: Olympus
    13. Optical Technique Provides Improved 'Virtual Biopsies' Of Internal Surfaces

      Optical Technique Provides Improved 'Virtual Biopsies' Of Internal Surfaces
      A new optical imaging technique, developed at the Wellman Center for Photomedicine at Massachusetts General Hospital (MGH), can provide three-dimensional microscopic views of the inner surfaces of blood vessels and gastrointestinal organs. In their report in the journal Nature Medicine, receiving early online release today, the MGH-Wellman researchers describe using optical frequency-domain imaging (OFDI) to visualize broad areas of the esophagus and coronary arteries of living pigs. The technique is an advance over optical coherence tomography (OCT) -- another noninvasive MGH-developed technology that details much smaller areas -- and could be useful for identifying precancerous lesions and dangerous deposits of plaque in ...
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    14. Robotic endoscope with wireless interface

      An endoscope apparatus and method of operating the same. The endoscope apparatus comprises an endoscope portion and a control and display unit. The endoscope portion preferably comprises: (i) a sensor disposed at a distal end of the endoscope portion and providing endoscope data; (ii) one or more electronically controlled actuators (e.g., electroactive polymer actuators) controlling the operation of the endoscope portion based on received control signals; (iii) a first wireless transceiver coupled to the sensor and the one or more electronically controlled actuators, transmitting received endoscope data from the sensor and forwarding received control signals to the one or ...
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    15. Endoscopic optical coherence tomography and laser-induced fluorescence spectroscopy in a murine colon cancer model

      Background and Objectives The diagnostic feasibility of optical coherence tomography (OCT) and laser-induced fluorescence (LIF) have been evaluated for human colorectal cancer. This study applies these technologies to a murine model of colorectal adenoma. Study Design/Materials and Methods The lower colon of 10 ApcMin and two C57BL/6J mice was surveyed over five 4-week intervals using a prototype 2.0 mm diameter OCT-LIF endoscope-based system. Four categories were histologically classified: control C57BL/6J, adenomatous, non-diseased regions of adenomatous, and non-diseased ApcMin. OCT images were compared to histology. Spectra from the four categories were compared via the Student's t-test ...

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    16. Anatomical optical coherence tomography in the human upper airway (Thesis)

      Anatomical optical coherence tomography in the human upper airway (Thesis)
      This thesis describes the development, clinical validation and initial application of a technique for taking measurements of the shape and dimensions of the human upper airway, called anatomical optical coherence tomography (aOCT). The technique uses a transparent catheter containing a rotating optical probe which is introduced transnasally and positioned in the airway and oesophagus. Optical coherence tomography is used to take calibrated cross-sectional images of the airway lumen as the probe rotates. The probe can also be advanced or withdrawn within the catheter during scanning to build up three-dimensional information. The catheter remains stationary so that the subject is not ...
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    17. Imaging apparatus

      An compact imaging apparatus having an OCT function is provided. An image formed of the illuminating-light reflected from a examination area is displayed on a monitor. A signal-light for obtaining an optical tomographic image is guided in a fiber through an insertion portion and projected onto a living tissue measurement area by an illuminating lens. The measurement area is scanned with the signal-light by a Piezo actuator moving the output face of the fiber. An OCT obtaining-portion obtains and displays on a monitor an optical tomographic image by using the interference caused by the signal-light reflected from the measurement area ...
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    18. Optical Coherence Tomography to Identify Intramucosal Carcinoma and High-Grade Dysplasia in Barrett’s Esophagus

      Optical Coherence Tomography to Identify Intramucosal Carcinoma and High-Grade Dysplasia in Barrett’s Esophagus
      Background & Aims: Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett’s esophagus. Methods: Biopsy-correlated OCT images were acquired from patients with Barrett’s esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A ...
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    19. Accuracy of endoscopic optical coherence tomography in the detection of dysplasia in Barrett's esophagus: a prospective, double-blinded study

      Accuracy of endoscopic optical coherence tomography in the detection of dysplasia in Barrett's esophagus: a prospective, double-blinded study

      Background Endoscopic optical coherence tomography (EOCT) is a high-resolution, cross-sectional tissue-imaging technique that provides microscopic morphologic information. EOCT should detect dysplasia in Barrett's epithelium, but this has not been established in a prospective blinded study. This study evaluated the accuracy of EOCT for the diagnosis and the exclusion of dysplasia in patients with Barrett's esophagus. Methods A 2.4-mm diameter EOCT probe was modified for use with a cap-fitted, two-channel endoscope. Pairs of EOCT image streams and jumbo biopsy specimens were obtained. Endoscopy/EOCT procedures were performed by 4 endoscopists who separately reviewed the EOCT digital images for ...

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    20. Methods for forming an optical window for an intracorporeal device and for joining parts

      Optical windows for intracorporeal devices, intracorporeal devices comprising a window and a method for forming a window for an intracorporeal device are provided. The method comprises placing within a mold an assembly comprising a mandrel located within a pair of parts separated by a collar of window material, heating the window preform effective to cause the window material to soften, and applying force to urge together the pair of parts to deform the window material so as to form a window. The intracorporeal devices, such as imaging devices, include guidewires, catheters, endoscopes. In addition, the method is suitable for joining ...
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    21. Medical scanning system and related method of scanning

      The present invention is directed to a scanning system that uses uniform rotary motion of an optical reflector to create reciprocal linear scanning. The system converts uniform rotation into uniform longitudinal scanning. The system thereby creates mechanical reciprocal linear scanning free of reciprocally moving mechanical parts common in conventional scanning systems. In a preferred embodiment of the invention, the scanning system is incorporated within an imaging catheter for medical scanning. The optical reflector is rotatable and includes a spiral reflecting portion. The spiral reflecting portion may be a single uniform reflecting surface or may include several reflection surfaces arranged in ...
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    22. Optical Coherence Tomography of the Gastrointestinal Tract (OCT)

      Optical coherence tomography (OCT) is a non-invasive imaging technique that uses light to create pictures of living tissues and has been successfully used to generate high resolution cross-sectional images of tissue in the human eye and skin. OCT systems are now commercially available for eye and skin use, and several clinical reports on the use of OCT in the gastrointestinal tract have been published as well. The purpose of this study is to develop a high-speed noninvasive OCT probe which can be placed through an endoscope for the early diagnosis of pre-cancerous and cancerous lesions in the gastrointestinal tract. This ...
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    481-504 of 531 « 1 2 ... 18 19 20 21 22 23 »
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