1. Articles from paul M. McNamara

    1-9 of 9
    1. Feasibility study of phase-sensitive imaging based on multiple reference optical coherence tomography

      Feasibility study of phase-sensitive imaging based on multiple reference optical coherence tomography

      Multiple reference optical coherence tomography (MR-OCT) is a recently developed, low-cost and compact time-domain OCT solution for primary care and consumer level applications. A combination of a voice coil actuator and a partial mirror (PM) extends the scan range for imaging depths of approximately 1 mm in biological samples. Our previous research on MR-OCT is based only on intensity information obtained from the depth-resolved interference signal. In this Letter, we extract the phase information from the MR-OCT signal and, hence, provide an additional contrast modality. The phase sensitivity of the system is measured to be approximately 0.2 and 1 ...

      Read Full Article
    2. Simultaneous en-face imaging of multiple layers with multiple reference optical coherence tomography

      Simultaneous en-face imaging of multiple layers with multiple reference optical coherence tomography

      A technique based on multiple reference optical coherence tomography (MR-OCT) is proposed for simultaneous imaging at multiple depths. The technique has been validated by imaging a reference sample and a fingerprint in-vivo. The principle of scanning multiple selected layers is shown by imaging a partial fingerprint with 200×200×200 voxels of 3×3×0.5  mm size and obtaining an arbitrary amount of layers merely by digital processing. The spacing among the layers can be adjusted arbitrarily, and the SNR roll-off is shown for three different spacings. At a mirror scan frequency of 1 kHz and an A-line rate ...

      Read Full Article
    3. Development of a first-generation miniature multiple reference optical coherence tomography imaging device

      Development of a first-generation miniature multiple reference optical coherence tomography imaging device

      Multiple reference optical coherence tomography (MR-OCT) is a technology ideally suited to low-cost, compact OCT imaging. This modality is an extension of time-domain OCT with the addition of a partial mirror in front of the reference mirror. This enables extended, simultaneous depth scanning with the relatively short scan range of a miniature voice coil motor on which the scanning mirror is mounted. This work details early stage development of the first iteration of a miniature MR-OCT device. This iteration utilizes a fiber-coupled input from an off-board superluminescent diode. The dimensions of the module are 40×57  mm40×57  mm ...

      Read Full Article
    4. The how and why of a $10 optical coherence tomography system

      The how and why of a $10 optical coherence tomography system

      Optical Coherence Tomography (OCT) is the fastest growing medical imaging modality with more than $1Bln worth of scans ordered and over $400M worth of equipment shipped in 2010, just nine years after its commercialization. It is at various stages of acceptance and approvals for eye care, coronary care and skin cancer care and is spreading rapidly to other medical specialties. Indeed, it is the leading success of translation of biophotonics science into clinical practice. Significant effort is being made to provide sufficient evidence for efficacy across a broad range of applications, but more needs to be done to radically reduce ...

      Read Full Article
    5. Evaluation of a polarization sensitive multiple reference optical coherence tomography system

      Evaluation of a polarization sensitive multiple reference optical coherence tomography system

      Multiple reference optical coherence tomography (MR-OCT) is a new compact optical sensor platform based on a small form factor recirculating reference arm scanning optical delay, which promises a robust, cost-effective semisolid state design for integration with next generation mobile devices. The miniature re-circulating optical delay is based on a voice coil motor (VCM) actuator and a partial mirror. Imaging capability of MR-OCT has been recently demonstrated using a non-polarizing bulk optics design and an unbalanced detection system with a sensitivity of up to 98 dB at an axial rate of 1200 A-scans per second. In this study, we implemented a ...

      Read Full Article
    6. Development of a miniature multiple reference optical coherence tomography imaging device

      Development of a miniature multiple reference optical coherence tomography imaging device

      Multiple reference optical coherence tomography (MR-OCT) is a new technology ideally suited to low-cost, compact OCT imaging. This modality is an extension of time-domain OCT with the addition of a partial mirror in front of the reference mirror. This enables extended, simultaneous depth scanning with the relatively short sweep of a miniature voice coil motor on which the scanning mirror is mounted. Applications of this technology include biometric security, ophthalmology, personal health monitoring and non-destructive testing. This work details early-stage development of the first iteration of a miniature MR-OCT device. This device utilizes a fiber-coupled input from an off-board superluminescent ...

      Read Full Article
    7. Assessment of curing behavior of light-activated dental composites using intensity correlation based multiple reference optical coherence tomography

      Assessment of curing behavior of light-activated dental composites using intensity correlation based multiple reference optical coherence tomography

      Background and Objectives Monitoring the curing kinetics of light-activated resin is a key area of research. These resins are used in restorative applications and particularly in dental applications. They can undergo volumetric shrinkage due to poor control of the depth dependent curing process, modulated by the intensity and duration of the curing light source. This often results in the formation of marginal gaps, causing pain and damage to the restoration site. In this study, we demonstrate the capabilities of a correlation method applied using a multiple references optical coherence tomography (MR-OCT) architecture to monitor the curing of the resin. Study ...

      Read Full Article
    8. Feature Of The Week 1/6/14: In Vivo Full-Field En Face Optical Coherence Tomography

      Feature Of The Week 1/6/14: In Vivo Full-Field En Face Optical Coherence Tomography

      The correlation mapping processing algorithm was developed by our group and utilises the time varying speckle effect produced from moving scatterers to provide contrast against static tissue. The technique has previously been applied to images acquired with frequency-domain OCT systems and hence in a cross-sectional geometry. In this work, a full-field optical coherence tomography system has been developed for the purpose of performing non-scanning en face flow imaging. The light source is centred at 840 nm with a bandwidth of 50 nm resulting in an axial resolution of 8 µm in air. Microscope objectives with a numerical aperture of 0 ...

      Read Full Article
    9. In vivo full-field en face correlation mapping optical coherence tomography

      In vivo full-field en face correlation mapping optical coherence tomography

      A full-field optical coherence tomography (OCT) system has been developed for the purpose of performing nonscanning en face flow imaging. The light source is centered at 840 nm with a bandwidth of 50 nm resulting in an axial resolution of 8 μ m in air. Microscope objectives with a numerical aperture of 0.1 were incorporated giving a transverse resolution of 5 μ m. A magnification of 5.65 was measured, resulting in a field of view of 1260 × 945     μ m . Pairs of interference fringe images are captured with opposing phase and a two-step phase image reconstruction method is applied to reconstruct ...

      Read Full Article
    1-9 of 9
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Topics in the News

    1. (9 articles) National University of Ireland, Galway
    2. (9 articles) Martin J. Leahy
    3. (8 articles) Paul M. McNamara
    4. (7 articles) Compact Imaging, Inc
    5. (5 articles) Roshan Dsouza
    6. (5 articles) Hrebesh M. Subhash
    7. (1 articles) Don Bogue
    8. (1 articles) Technical University of Denmark (DTU)
    9. (1 articles) Medical University of Vienna
    10. (1 articles) Université Pierre et Marie Curie
    11. (1 articles) University of Kent
    12. (1 articles) Semmelweis University
    13. (1 articles) Adrian G. Podoleanu
    14. (1 articles) George M. Dobre
    15. (1 articles) Thorlabs
    16. (1 articles) Superlum
    17. (1 articles) Santec
  3. Popular Articles

  4. Picture Gallery

    In vivo full-field en face correlation mapping optical coherence tomography Feature Of The Week 1/6/14: In Vivo Full-Field En Face Optical Coherence Tomography Assessment of curing behavior of light-activated dental composites using intensity correlation based multiple reference optical coherence tomography Development of a miniature multiple reference optical coherence tomography imaging device Evaluation of a polarization sensitive multiple reference optical coherence tomography system The how and why of a $10 optical coherence tomography system Development of a first-generation miniature multiple reference optical coherence tomography imaging device Simultaneous en-face imaging of multiple layers with multiple reference optical coherence tomography Feasibility study of phase-sensitive imaging based on multiple reference optical coherence tomography 2nd Canterbury Conference on Optical Coherence Tomography Optical Coherence Tomography Angiography to Better understand Glaucoma Clinical relevance of retinal structure in children with laser-treated retinopathy of prematurity versus controls – using optical coherence tomography