1. Articles from Jian Ren

    1-10 of 10
    1. Intravascular Polarimetry in Patients With Coronary Artery Disease

      Intravascular Polarimetry in Patients With Coronary Artery Disease

      Objectives The aims of this first-in-human pilot study of intravascular polarimetry were to investigate polarization properties of coronary plaques in patients and to examine the relationship of these features with established structural characteristics available to conventional optical frequency domain imaging (OFDI) and with clinical presentation. Background Polarization-sensitive OFDI measures birefringence and depolarization of tissue together with conventional cross-sectional optical frequency domain images of subsurface microstructure. Methods Thirty patients undergoing polarization-sensitive OFDI (acute coronary syndrome, n = 12; stable angina pectoris, n = 18) participated in this study. Three hundred forty-two cross-sectional images evenly distributed along all imaged coronary arteries were classified into ...

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    2. Demonstration of Triband Multi-Focal Imaging with Optical Coherence Tomography

      Demonstration of Triband Multi-Focal Imaging with Optical Coherence Tomography

      We demonstrate an extended depth of focus optical coherence tomography (OCT) system based on the use of chromatic aberration to create displaced focal planes in the sample. The system uses a wavelength-swept source tuning over three spectral bands and three separate interferometers, each of which interfaces to a single illumination/collection fiber. The resulting three imaged volumes are merged in post-processing to generate an image with a larger depth of focus than is obtained from each band individually. The improvements are demonstrated in structural imaging of a porous phantom and a lipid-cleared murine brain, and by angiographic imaging of human ...

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    3. Northeast Symposium on Biomedical Optics to be Held October 24th, 2018

      Northeast Symposium on Biomedical Optics to be Held October 24th, 2018

      On behalf of the Center for Biomedical OCT Research and Translation (CBORT) at the Wellman Center for Photomedicine, Massachusetts General Hospital, we would like to invite you to participate in the Northeast Symposium on Biomedical Optics 2018 and present your interesting work. This one-day symposium will be held on October 24th, 2018 on the MIT campus in Cambridge, MA. Lunch and coffee will be provided, and a Best Poster Award will be presented at the closing reception with food and drink. Registration is completely FREE. If you would like to participate, please register at the following link, where you will ...

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    4. Radiometric model for coaxial single- and multimode optical emission from double-clad fiber

      Radiometric model for coaxial single- and multimode optical emission from double-clad fiber

      Double-clad fibers (DCFs) are versatile waveguides supporting a single-mode core surrounded by a multimode inner cladding. DCFs are increasingly used for multimodal biomedical applications, such as imaging or therapy, for which the core is typically used for coherent illumination and the inner cladding, to support a concurrent modality. Proper optimization is, however, critical to ensure high optical performance and requires accurate modeling of coaxial single- and multimode output beams. In this paper, we present an approach based on geometrical optics and radiometry, which provides a simple and efficient modeling tool for designing and optimizing DCF-based systems. A radiometric definition of ...

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    5. Imaging of the Rotator Cuff With Optical Coherence Tomography

      Imaging of the Rotator Cuff With Optical Coherence Tomography

      This study evaluated the utility of optical coherence tomography (OCT) in imaging porcine and human rotator cuff (RTC) tissue, analyzed its effectiveness in identifying clinical pathology, and correlated these findings with histologic examination. Twelve human cadaveric and 6 porcine shoulders were evaluated. Six-millimeter–wide bone sections were harvested from the proximal humerus of each specimen, with each containing the entire enthesis of the respective RTC tendon, as well as 2 cm of tendon medial to the enthesis. Only the supraspinatus tendon was evaluated in the human specimens, whereas the enthesis of multiple RTC tendons were evaluated in the porcine model ...

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    6. Image reconstruction by position and motion tracking

      Image reconstruction by position and motion tracking

      A system, method, and apparatus provide the ability to reconstruct an image from an object. A hand-held image acquisition device is configured to acquire local image information from a physical object. A tracking system obtains displacement information for the hand-held acquisition device while the device is acquiring the local image information. An image reconstruction system computes the inverse of the displacement information and combines the inverse with the local image information to transform the local image information into a reconstructed local image information. A display device displays the reconstructed local image information.

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    7. Congratulations to Jian Ren from Caltech a Winner of a 2012 Student Travel Grant Award

      Congratulations to Jian Ren from  Caltech a Winner of a 2012 Student Travel Grant Award
      Jian Ren from the California Institute of Technology is one of four winners of the OCT News 2012 student travel grant awards (see prior announcement Here). Below is a summary of his work. Glaucoma is one type of ophthalmic diseases, where ocular hypertension damages optical nerve, making it the second leading cause of blindness worldwide. One major cause of Open Angle Glaucoma is the poor outflow of aqueous humor through the Trabecular Meshwork (TM). Potential treatments include the micro-bypass stents, which are implanted in the TM and shunt fluid directly to the Schlemm’s Canal (SC) to reduce intraocular pressure ...
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    8. Feature Of The Week 5/1/11: Caltech Researchers Develop an OCT Needle Probe for Investigating Open Angle Glaucoma

      Feature Of The Week 5/1/11: Caltech Researchers Develop an OCT Needle Probe for Investigating Open Angle Glaucoma
      Feature Of The Week 5/1/11: One major cause of Open Angle Glaucoma is the poor outflow of aqueous humor through the Trabecular Meshwork (TM). Potential treatments include the micro-bypass stents, which are implanted in the TM and shunt fluid directly to the Schlemm’s Canal (SC) to reduce intraocular pressure. Implanting the stent with the appropriate orientation near a major collector channel (CC) might maximize outflow of aqueous humor.As scleral tissue and the TM are not transparent to visible light, OCT using infrared light may be useful in visualizing and locating collector channels, hence could assist the ...
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    9. Ex vivo Optical Coherence Tomography Imaging of Collector Channels with a Scanning Endoscopic Probe

      Ex vivo Optical Coherence Tomography Imaging of Collector Channels with a Scanning Endoscopic Probe
      Abstract Purpose: To achieve high-fidelity optical coherence tomography (OCT) imaging of ex vivo collector channels (CCs) exiting Schlemm's canal (SC) using a paired angled rotating scanning endoscopic probe. Methods: An endoscopic probe was developed to guide an OCT laser beam onto human cadaver eye tissue samples to detect CCs. The prototype probe consisted of two gradient-index (GRIN) lenses, which were housed in two stainless steel needles respectively. The probe scanned the laser beam across a fan shape area by rotating the two GRIN lenses. We built a swept source based OCT system to provide the depth scans. Human cadaver ...
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    10. Manual-scanning optical coherence tomography probe based on position tracking

      Manual-scanning optical coherence tomography probe based on position tracking
      A method based on position tracking to reconstruct images for a manual-scanning optical coherence tomography (OCT) probe is proposed and implemented. The method employs several feature points on a hand-held probe and a camera to track the device’s pose. The continuous device poses tracking, and the collected OCT depth scans can then be combined to render OCT images. The tracking accuracy of the system was characterized to be about 6 um along two axes and 19 um along the third. A phantom target was used to validate the method. In addition, we report OCT images of a 54-stage Xenopus ...
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    1-10 of 10
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  2. Topics in the News

    1. (10 articles) Jian Ren
    2. (5 articles) California Institute of Technology
    3. (5 articles) Changhuei Yang
    4. (4 articles) Harvard University
    5. (4 articles) Massachusetts General Hospital
    6. (4 articles) Jigang Wu
    7. (3 articles) Henrick K. Gille
    8. (3 articles) Brett E. Bouma
    9. (2 articles) Massachusetts Institute of Technology
    10. (1 articles) University of Athens
    11. (1 articles) Columbia University
    12. (1 articles) Cardiovascular Research Foundation
    13. (1 articles) Gary S. Mintz
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    Manual-scanning optical coherence tomography probe based on position tracking Ex vivo Optical Coherence Tomography Imaging of Collector Channels with a Scanning Endoscopic Probe Feature Of The Week 5/1/11: Caltech Researchers Develop an OCT Needle Probe for Investigating Open Angle Glaucoma Congratulations to Jian Ren from  Caltech a Winner of a 2012 Student Travel Grant Award Image reconstruction by position and motion tracking Imaging of the Rotator Cuff With Optical Coherence Tomography Radiometric model for coaxial single- and multimode optical emission from double-clad fiber Northeast Symposium on Biomedical Optics to be Held October 24th, 2018 Demonstration of Triband Multi-Focal Imaging with Optical Coherence Tomography Intravascular Polarimetry in Patients With Coronary Artery Disease Intravascular Imaging-Guided Percutaneous Coronary Intervention: A Universal Approach for Optimization of Stent Implantation Clinical Usefulness of a Novel Optical Coherence Tomography Procedure, “Low Molecular Weight Dextran Infusion Followed by Catheter PUSH (D-PUSH)”