Doppler Optical Coherence Tomography (DOCT) is a biomedical imaging technique that allows simultaneous structural
imaging and flow monitoring inside biological tissues and materials with spatial resolution in the micrometer scale. It
has recently been applied to the characterization of microfluidic systems. Structural and flow imaging of novel
microfluidics platforms for cytotoxicologic applications were obtained with a real-time, Near Infrared Spectral Domain
DOCT system. Characteristics such as flow homogeneity in the chamber, which is one of the most important parameters
for cell culture, are investigated. OCT and DOCT images were used to monitor flow inside a specific platform that is
based on microchannel division for a better flow homogeneity. In particular, the evolution of flow profile at the
transition between the microchannel structure and the chamber is studied.
Most of the time, arterial stenoses caused by atherosclerosis, hardening of the artery walls, or buildup of fatty deposits
prevent the blood from flowing normally. Blood flow characteristics in the vicinity of a stenosis are therefore very
important since the restriction may accelerate fatty deposits and thus quickly clog the artery. Doppler Optical Coherence
Tomography (DOCT) is a biomedical technique that allows simultaneous structural imaging and flow monitoring inside
biological tissues and materials with spatial resolution at least one order of magnitude better than ultrasound. This study
deals with the application of a Near Infrared DOCT system for imaging and monitoring of liquid flow inside a stenosis phantom inserted in a glass tube. For the measurement of the Doppler frequency, we use a numerical method based on the detection of the zero-crossing points of the OCT signal.
Broadband sources (BBSs) are commonly used in a wide range of applications in optical communication systems and biophotonics. They are particularly useful tools for Optical Coherence Tomography (OCT), which is a biomedical imaging technique that uses low-coherence light sources. In order to obtain high image quality, we have developed a novel, spectrally-flat S+C+L band source with > 120 nm bandwidth and more than 4 mW output power based on two cascaded semiconductor optical amplifiers (SOA) mixed with an Erbium-doped fiber (EDF) amplifier.
Bandwidth and output power improvements are achieved by modifying the former configuration and mixing the EDF with the first SOA before amplification in the second SOA. This configuration results in bandwidth and output power enhancements of up to 146 nm and 8 mW, respectively.
The source was then tested in an OCT system. It gives a 10 &mgr;m FWHM, low sidelobe OCT autocorrelation trace. Images and OCT autocorrelation traces were compared for the two aforementioned (which two; you mentioned one?) configurations. Images of miscellaneous samples made with the BBS show an image aspect and sharpness that is comparable with more expensive sources such as Ti:Sapphire lasers.
Optical coherence tomography (OCT) is a powerful, noninvasive biomedical technique that uses low-coherence light sources to obtain in-depth scans of biological tissues. We report results obtained with three different sources emitting at 1570, 1330, and 810 nm, respectively. Attenuation and backscattering measurements are obtained with these sources for several in vitro biological tissues. From these measurements, we use a graphical method to make comparisons of the penetration depth and backscattering intensity of each wavelength for the studied samples. The influence of the coherence length of each source is also taken into account in order to make a more relevant comparison.
Optical Coherence Tomography is a powerful, noninvasive biomedical technique that uses low coherence light sources to obtain in-depth scans of biological tissues. In this study, we report results obtained with three different sources: a 60 nm bandwidth superluminescent diode with a 1570 nm emission wavelength, a high power broadband fiber source (up to 100 nm bandwidth around 1330 nm wavelength), and a Ti:Sapphire ultrashort-pulsed laser (810 nm emission wavelength and 100 nm maximum bandwidth). Along with enhancement of some details and discontinuities in heterogeneous tissues, characterization of samples using these three wavelengths allows for a more complete description of tissue optical properties, such as attenuation, backscattering, or penetration depth. We will present results obtained in vitro on several samples of biological tissues.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.