Microscopic 3D plant imaging with high-resolution optical coherence tomography

Mechanical wall stress and wall shear stress are associated with atherosclerosis development in non-calcified coronary segments

Background and aims: Atherosclerotic plaque onset and progression are known to be affected by local biomechanical factors. While the role of wall shear stress (WSS) has been studied, the impact of another biomechanical factor, namely mechanical wall stress (MWS), remains poorly understood. In this study, we investigated the association of MWS...

Application of OCT and IVUS to investigate the combined effect of plaque structural stress and wall shear stress on plaque progression in human coronary arteries

Introduction: Atherosclerosis, the major source of cardiovascular diseases, is one of the leading causes of death. During atherosclerosis the arterial wall is affected by a complex process of lipid driven inflammation that leads to thickening of the arterial wall resulting in a so called plaque. Because of plaque growth, the lumen of the artery...

A single-chip micro-opto-electro-mechanical system for optical coherence tomography imaging

Image reconstruction algorithms for optical tomography

Disease model systems, such as the zebrafish, play an important role in understanding the onset of diseases like cancer and monitor the efficacy of new drugs. In the past, non-invasive methods for screening, diagnostics and treatment monitoring were intrinsically from the outside. In the past decades, there has been a strong drive to look inside...

High-resolution deep-tissue quantitative optical tomography

Optical imaging is one of the primary tools in biological and medical research. Over the years many different optical imaging modalities have been developed that have driven the imaging performance in terms of image resolution, contrast, imaging time, and maximum allowed sample size. The goal of this work is to develop techniques for 3D optical...

A MEMS Actuator System for an Integrated 3-D Optical Coherent Tomography Scanner

In this paper, we present an electrothermal biaxial MEMS actuator system, which provides x-A nd y-direction scanning for a fully integrated 3-D optical coherence tomography (OCT) scanner. An angular scanning range of 8° (corresponding to a 7-mm linear scanning range in both directions) is achieved, with an average power consumption of 150 mW....

Accurate estimation of the attenuation coefficient from axial point spread function corrected OCT scans of a single layer phantom

The attenuation coefficient (AC) is a property related to the microstructure of tissue on a wavelength scale that can be estimated from optical coherence tomography (OCT) data. Since the OCT signal sensitivity is affected by the finite spectrometer/detector resolution called roll-off and the shape of the focused beam in the sample arm,...

In-vitro detection of small isolated cartilage defects: Intravascular ultrasound vs. optical coherence tomography

This experimental work focused on the sensor selection for the development of a needle-like instrument to treat small isolated cartilage defects with hydrogels. The aim was to identify the most accurate and sensitive imaging method to determine the location and size of defects compared to a gold standard (µCT). Only intravascular ultrasound...

Optimization-based adaptive optics for optical coherence tomography

Optical coherence tomography (OCT) is a technique for non-invasive imaging based on low coherence interferometry. Its main application is found in ophthalmology, where it is used for 3D in vivo imaging of the cornea and the retina. OCT has evolved over the past decade as one of the most important ancillary tests in ophthalmic practice, providing...

Wavefront control with a multi-actuator adaptive Lens in imaging applications

The use of adaptive lenses instead of deformable mirrors can simplify the implementation of an adaptive optics system. The recently introduced Multi-actuator Adaptive Lens (MAL) can be used in closed loop with a wavefront sensor to correct for time-variant wavefront aberrations. The MAL can guarantee a level of correction and a response time...

Automatic estimation of retinal nerve fiber bundle orientation in SD-OCT images using a structure-oriented smoothing filter

Optical coherence tomography (OCT) yields high-resolution, three-dimensional images of the retina. A better understanding of retinal nerve fiber bundle (RNFB) trajectories in combination with visual field data may be used for future diagnosis and monitoring of glaucoma. However, manual tracing of these bundles is a tedious task. In this work,...