Optical Coherence Tomography is a natural candidate for imaging biological structures just under tissue surface. Human thoracic aorta from aneurysms reveal elastin disorders and smooth muscle cell alterations when visualizing the media layer of the aortic wall, which is only some tens of microns in depth from surface. The resulting images require a suitable processing to enhance interesting disorder features and to use them as indicators for wall degradation, converting OCT into a hallmark for diagnosis of risk of aneurysm under intraoperative conditions. This work proposes gradient-based digital image processing approaches to conclude this risk. These techniques are believed to ...
We developed an ultrahigh speed, handheld swept source optical coherence tomography (SS-OCT) ophthalmic instrument using a 2D MEMS mirror. A vertical cavity surface-emitting laser (VCSEL) operating at 1060 nm center wavelength yielded a 350 kHz axial scan rate and 10 µm axial resolution in tissue. The long coherence length of the VCSEL enabled a 3.08 mm imaging range with minimal sensitivity roll-off in tissue. Two different designs with identical optical components were tested to evaluate handheld OCT ergonomics. An iris camera aided in alignment of the OCT beam through the pupil and a manual fixation light selected the imaging ...
We present a novel optical coherence tomography (OCT)-based technique for rapid volumetric imaging of red blood cell (RBC) flux in capillary networks. Previously we reported that OCT can capture individual RBC passage within a capillary, where the OCT intensity signal at a voxel fluctuates when an RBC passes the voxel. Based on this finding, we defined a metric of statistical intensity variation (SIV) and validated that the mean SIV is proportional to the RBC flux [RBC/s] through simulations and measurements. From rapidly scanned volume data, we used Hessian matrix analysis to vectorize a segment path of each capillary ...
We developed an ultrahigh speed endoscopic swept source optical coherence tomography (OCT) system for clinical gastroenterology using a vertical-cavity surface-emitting laser (VCSEL) and micromotor based imaging catheter, which provided an imaging speed of 600 kHz axial scan rate and 8 μm axial resolution in tissue. The micromotor catheter was 3.2 mm in diameter and could be introduced through the 3.7 mm accessory port of an endoscope. Imaging was performed at 400 frames per second with an 8 μm spot size using a pullback to generate volumetric data over 16 mm with a pixel spacing of 5 μm in ...
The electric field induced optical changes (EIOC) measured by the optical coherence tomography (OCT) reflect the local electro-kinetic properties of the tissue. In this study we developed a method to use the phase of the complex OCT images to map EIOC in tissue samples. Switching the polarity of the electric field induced significant reversible changes in the phase of the complex OCT images. Since the resulting phase was degraded by the noise an advanced signal processing algorithm was developed to obtain the EIOC images. The developed algorithm made it possible to get structural phase images from a standard commercial OCT ...
Optical coherence tomography (OCT) is a contact-free non-destructive high-resolution imaging technique based on low-coherence interferometry. This study investigates the application of spectral-domain OCT as an in-line quality control tool for monitoring pharmaceutical film-coated tablets. OCT images of several commercially-available film-coated tablets of different shapes, formulations and coating thicknesses were captured off-line using two OCT systems with centre wavelengths of 830 nm and 1325 nm. Based on the off-line image evaluation, another OCT system operating at a shorter wavelength was selected to study the feasibility of OCT as an in-line monitoring method. Since in spectral-domain OCT motion artefacts can occur as ...
An agile optical imaging system for optical coherence tomography imaging using a tunable source comprising a wavelength tunable VCL laser is disclosed. The tunable source has long coherence length and is capable of high sweep repetition rate, as well as changing the sweep trajectory, sweep speed, sweep repetition rate, sweep linearity, and emission wavelength range on the fly to support multiple modes of OCT imaging. The imaging system also offers new enhanced dynamic range imaging capability for accommodating bright reflections. Multiscale imaging capability allows measurement over orders of magnitude dimensional scales. The imaging system and methods for generating the waveforms ...
Thorlabs. Optical Components, Tunable Sources, and Systems. Thorlabs is an optical company with headquarters in Newton, New Jersey, and offices in the US, UK, Germany, Japan, and Sweden. The president and founder is Alex Cable. It designs & manufactures products in the areas of fibre optics, laser diodes, optical instrumentation & polarization. Thorlabs bought Covega, and optical components supplyer, in 2009.
In pairing the FN1 microscope with Thorlabs' OCT technology, we are able to complement our traditional widefield and confocal imaging systems by providing a similar but more macro view.Stanley A. Schwartz in Nikon Instruments and Thorlabs Together Bring OCT Imaging to the FN1 'Physiostation' Microscope
Covega comes to the Thorlabs family with a new suite of optical technologies that Thorlabs looks forward to offering to its diverse customer base. We are committed to ensuring continued access to the broad array of products that Covega currently manufacturers.Alex E. Cable in Thorlabs Acquires Covega