1. Articles from aip.scitation.org

  2. 1-6 of 6
    1. Quantitative angle-insensitive flow measurement using relative standard deviation OCT

      Quantitative angle-insensitive flow measurement using relative standard deviation OCT

      Incorporating different data processing methods, optical coherence tomography (OCT) has the ability for high-resolution angiography and quantitative flow velocity measurements. However, OCT angiography cannot provide quantitative information of flow velocities, and the velocity measurement based on Doppler OCT requires the determination of Doppler angles, which is a challenge in a complex vascular network. In this study, we report on a relative standard deviation OCT (RSD-OCT) method which provides both vascular network mapping and quantitative information for flow velocities within a wide range of Doppler angles. The RSD values are angle-insensitive within a wide range of angles, and a nearly linear ...

      Read Full Article
    2. Development of a combined OCT-Raman probe for the prospective in vivo clinical melanoma skin cancer screening

      Development of a combined OCT-Raman probe for the prospective in vivo clinical melanoma skin cancer screening

      A combined optical coherence tomography (OCT)-Raman probe was designed and built into a spectral domain OCT head, and its performance was evaluated and compared to the most common Raman probe setups, based on a fiber bundle and confocal free space optics. Due to the use of the full field of view of an OCT scanning lens, the combined probe has a superior performance within maximum permissible exposure limits, compared to the other two probes. Skin Raman spectra, recorded in vivo , further prove the feasibility of the OCT-Raman probe for the future in vivo clinical applications in skin cancer screening.

      Read Full Article
    3. Longitudinal shear wave imaging for elasticity mapping using optical coherence elastography

      Longitudinal shear wave imaging for elasticity mapping using optical coherence elastography

      Shear wave measurements for the determination of tissue elastic properties have been used in clinical diagnosis and soft tissue assessment. A shear wave propagates as a transverse wave where vibration is perpendicular to the wave propagation direction. Previous transverse shear wave measurements could detect the shear modulus in the lateral region of the force; however, they could not provide the elastic information in the axial region of the force. In this study, we report the imaging and quantification of longitudinal shear wave propagation using optical coherence tomography to measure the elastic properties along the force direction. The experimental validation and ...

      Read Full Article
    4. Dynamically focused optical coherence tomography for endoscopic applications

      Dynamically focused optical coherence tomography for endoscopic applications

      We report a demonstration of a small liquid-filled polymer lens that may be used to dynamically provide scanning depth focus for endoscopic optical coherence tomography (OCT) applications. The focal depth of the lens is controlled by changing the hydraulic pressure within the lens, enabling dynamic focal depth control without the need for articulated parts. The 1 mm diameter lens is shown to have resolving power of 5 μm, and can enable depth scans of 2.5 mm, making it suitable for use with OCT-enabled optical biopsy applications.

      Read Full Article
    5. Geometric & radiometric vignetting associated with a 72-facet, off-axis, polygon mirror for swept source optical coherence tomography (SS-OCT)

      Geometric & radiometric vignetting associated with a 72-facet, off-axis, polygon mirror for swept source optical coherence tomography (SS-OCT)

      Optical Coherence Tomography (OCT) has a broad range of applications in 2D and volumetric imaging of micron scale structures typically used on inaccessible objects such as the retina of the eye. This report focuses on Swept Source OCT (SS-OCT), favoured for its faster scanning speeds and therefore faster data acquisition (highly favourable when imaging live patients). SS-OCT relies on the scanning of a narrow laser line at speeds typically in excess of 100 kHz. We have employed Zemax TM ray tracing software to simulate one method of splitting the spectrum of a broadband, near-infrared source, into its component wavelengths by ...

      Read Full Article
    6. Volumetric Doppler angle correction for ultrahigh-resolution optical coherence Doppler tomography

      Volumetric Doppler angle correction for ultrahigh-resolution optical coherence Doppler tomography

      Ultrahigh-resolution optical coherence Doppler tomography (μODT) demonstrates great potential for quantitative blood flow imaging owing to its large field of view and capillary resolution. However, μODT only detects the axial flow velocity and requires Doppler angle correction to retrieve the absolute velocity. Although methods for Doppler angle tracking of single or few large vessels have been reported, a method that enables angle correction of the entire 3D microvascular networks remains a challenge. Here, we present a method based on eigenvalue analysis of 3D Hessian matrix to retrieve the orientation of each tubular vessel. As the algorithm is voxel based, it ...

      Read Full Article
    1-6 of 6
  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