Biomedical subjects

David D Sampson

Publications and source records attributed to David D Sampson.

4 recordsLinked to original sources

PubMed2003

Bifocal optical coherenc refractometry of turbid media.

We propose and demonstrate a novel technique, which we term bifocal optical coherence refractometry, for the rapid determination of the refractive index of a turbid medium. The technique is based on the simultaneous creation of two closely spaced confocal gates in a sample. The optical path-length difference between the gates is measured by means of low-coherence interferometry and used to determine the refractive index. We present experimental results for the refractive indices of milk solutions and of human skin in vivo. As the axial scan rate determines the acquisition time, which is potentially of the order of tens of milliseconds, the technique has potential for in vivo refractive-index measurements of turbid biological media under dynamic conditions.

Animals↗

PubMed2003

Delay and dispersion characteristics of a frequency-domain optical delay line for scanning interferometry.

The reflective frequency-domain optical delay line employing a diffraction grating, a lens, and a tiltable mirror has emerged as a device particularly suitable for interferometry and optical coherence tomography. The device is comprehensively described, both theoretically and experimentally, in the context of interferometry. The variations of phase and group delay produced by the device as well as its dispersive properties are described and demonstrated experimentally.

Interferometry↗

PubMed2002

High-speed, high-sensitivity, gated surface profiling with closed-loop optical coherence topography.

We describe and experimentally demonstrate a novel (to our knowledge) surface profiling technique, for which we propose the term closed-loop optical coherence topography. This technique is a scanning beam, servo-locked variation of low-coherence interferometry. It allows for the sub-wavelength-resolution tracking of a weakly scattering macroscopic-scale surface, with the surface profile being directly output by the controlling electronics. The absence of significant real-time computational overhead makes the technique well suited to high-speed tracking. The use of a micrometer-scale coherence gate efficiently suppresses signals arising from structures not associated with the surface. These features make the technique particularly well suited to real-time surface profiling of in vivo, macroscopic biological surfaces.

Animals↗

PubMed2002

High-speed gated surface profiling with closed-loop optical coherence topography.

The here presented work describes a surface profiling technique, for which the term closed-loop optical coherence topography (CLOCT) was proposed [1]. This technique is a scanning beam, servo-locked variation of low-coherence interferometry. It allows for the sub-wavelength-resolution tracking of a weakly scattering macroscopic-scale surface with the absence of significant real-time computational overhead and is thus particularly well suited to real-time surface profiling of in vivo, macroscopic biological surfaces.

Corneal Topography↗