1. Articles from Garret T. Bonnema

    1-10 of 10
    1. Swept source optical coherence tomography (OCT) method and system

      Swept source optical coherence tomography (OCT) method and system

      A method and apparatus are provided for a swept source optical coherence tomography (OCT) system utilizing a fast scanning mechanism in the sample arm and a slowly swept light source. The position data is collected rapidly while the wavelength of the source is swept slowly. The system reduces the sweep speed requirements of the light source enabling higher power, greater imaging range, and linear sweeps of the source frequency. The OCT components (or most of them) may be implemented within a hand held imaging probe. In operation, a triangulation scan may be used to orient the imaging probe with respect ...

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      Mentions: D4D Technologies
    2. Novel focused OCT-LIF endoscope

      Novel focused OCT-LIF endoscope
      Combined optical coherence tomography (OCT) and laser-induced fluorescence (LIF) endoscopy has shown higher sensitivity and specificity for distinguishing normal tissue from adenoma when compared to either modality alone. Endoscope optical design is complicated by the large wavelength difference between the two systems. A new high-resolution endoscope 2 mm in diameter is presented that can create focused beams from the ultraviolet to near-infrared. A reflective design ball lens operates achromatically over a large wavelength range, and employs TIR at two faces and reflection at a third internal mirrored face. The 1:1 imaging system obtains theoretically diffraction-limited spots for both the ...
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    3. Swept Source Optical Coherence Tomography (OCT) Method And System

      Swept Source Optical Coherence Tomography (OCT) Method And System
      A method and apparatus are provided for a swept source optical coherence tomography (OCT) system utilizing a fast scanning mechanism in the sample arm and a slowly swept light source. The position data is collected rapidly while the wavelength of the source is swept slowly. The system reduces the sweep speed requirements of the light source enabling higher power, greater imaging range, and linear sweeps of the source frequency. The OCT components (or most of them) may be implemented within a hand held imaging probe. In operation, a triangulation scan may be used to orient the imaging probe with respect ...
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      Mentions: D4D Technologies
    4. New scheme for polarimetric glucose sensing without polarizers

      New scheme for polarimetric glucose sensing without polarizers
      Polarimetric glucose sensing is a promising method for noninvasive estimation of blood glucose concentration. Published methods of polarimetric glucose sensing generally rely on measuring the rotation of light as it traverses the aqueous humor of the eye. In this article, an interferometer is described that can detect polarization changes due to glucose without the use of polarization control or polarization analyzing elements. Without polarizers, this system is sensitive to optical activity, inherent to glucose, but minimally sensitive to linear retardance, inherent to the cornea. The underlying principle of the system was experimentally verified using spectral domain optical coherence tomography. A ...
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    5. A concentric three element radial scanning optical coherence tomography endoscope

      We have developed a 2.1 mm outer diameter optical coherence tomography endoscope that provides radial scans of luminal structures. The endoscope consists of three elements: (1) a stationary central core containing the fibers and focusing elements, (2) a rotating intermediate tube with a distal rod prism, and (3) a stationary sterilized glass cover. This design enables radial and spiral scanning and allows adjustment of the axial focal distance. Additionally, this design is capable of focusing light from multiple fibers into tissue. The performance of the endoscope was demonstrated in a study of tissue engineered blood vessels imaged at various ...
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    6. Laparoscopic optical coherence tomography imaging of human ovarian cancer

      Objectives Ovarian cancer is the fourth leading cause of cancer-related death among women in the US largely due to late detection secondary to unreliable symptomology and screening tools without adequate resolution. Optical coherence tomography (OCT) is a recently emerging imaging modality with promise in ovarian cancer diagnostics, providing non-destructive subsurface imaging at imaging depths up to 2 mm with near-histological grade resolution (10–20 μm). In this study, we developed the first ever laparoscopic OCT (LOCT) device, evaluated the safety and feasibility of LOCT, and characterized the microstructural features of human ovaries in vivo. Methods A custom LOCT device was ...
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    7. An automatic algorithm for detecting stent endothelialization from volumetric optical coherence tomography datasets

      Recent research has suggested that endothelialization of vascular stents is crucial to reducing the risk of late stent thrombosis. With a resolution of approximately 10 µm, optical coherence tomography (OCT) may be an appropriate imaging modality for visualizing the vascular response to a stent and measuring the percentage of struts covered with an anti-thrombogenic cellular lining. We developed an image analysis program to locate covered and uncovered stent struts in OCT images of tissue-engineered blood vessels. The struts were found by exploiting the highly reflective and shadowing characteristics of the metallic stent material. Coverage was evaluated by comparing the luminal ...
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    8. Imaging Tissue Engineered Blood Vessel Mimics with Optical Coherence Tomography (Thesis)

      Imaging Tissue Engineered Blood Vessel Mimics with Optical Coherence Tomography (Thesis)
      Optical coherence tomography (OCT) is a technology that enables 2D cross-sectional images of tissue microstructure. This interferometric technique provides resolutions of approximately 10-20 um with a penetration depth of 1-2 mm in highly scattering tissues. With the use of fiber optics, OCT systems have been developed for intravascular imaging with a demonstrated improvement in both resolution and dynamic range compared to commercial intravascular ultrasound systems. OCT studies of normal, atherosclerotic, and stented arteries indicate the ability of OCT to visualize arterial structures. These results suggest OCT may be a valuable tool for studying luminal structures in tissue engineered constructs. In ...
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    9. Imaging stented tissue engineered blood vessel mimics

      An ideal vascular stent design promotes a thin anti-thrombogenic cellular lining while avoiding restenosis. To assess the utility of their designs, stent manufactures often use destructive techniques such as scanning electron microscopy to measure the percentage of the stent covered with a cellular ... [Proc. SPIE Int. Soc. Opt. Eng. 6858, 68580F (2008)] published Wed Feb 6, 2008.
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    10. Laparoscopic optical coherence tomographic imaging of human ovarian cancer

      Ovarian cancer is the fourth leading cause of cancer-related death among women in the United States. If diagnosed at an early stage, the 5-year survival rate is 94%, but drops to 68% for regional disease and 29% for distant metastasis; only 19% of all cases are diagnosed at the early, localized stag ... [Proc. SPIE Int. Soc. Opt. Eng. 6851, 685107 (2008)] published Tue Feb 5, 2008.
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    1-10 of 10
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  2. Topics in the News

    1. (8 articles) University of Arizona
    2. (2 articles) University of Connecticut
    3. (2 articles) D4D Technologies
    4. (1 articles) Northwestern University
    5. (1 articles) University College London
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    Imaging Tissue Engineered Blood Vessel Mimics with Optical Coherence Tomography (Thesis) New scheme for polarimetric glucose sensing without polarizers Swept Source Optical Coherence Tomography (OCT) Method And System Novel focused OCT-LIF endoscope Swept source optical coherence tomography (OCT) method and system Influence of scan direction on subfoveal choroidal vascularity index using optical coherence tomography Subthreshold Nanosecond Laser for Non-resolving Central Serous Chorioretinopathy: A Double-masked Sham-controlled Randomised Trial Optical Coherence Tomography Angiography (OCTA) to Assess Cardiac Output and Cerebral Perfusion at the Time of Children's Cardiac Surgery Recent advances in optical coherence tomography for anterior segment imaging in small animals and their clinical implications Intraoperative optical coherence tomography-guided donor corneal tissue assessment and preparation Peripapillary and fovea avascular zone optical coherence tomography angiography parameters in exfoliation glaucoma versus primary open-angle glaucoma versus healthy eyes Comparison of the proposed DCNN model with standard CNN architectures for retinal diseases classification