Channelled spectrum liquid refractometer

We describe an experimental demonstration of a novel technique for liquid refractometry. A channeled spectrum is produced from an optical beam generated by a diode laser operating below threshold by intercepting half of the beam with a liquid cell. The spectrum is analyzed using a grating and a linear CCD array and provides information on the refractive index of the liquid. The experimental results show that accuracies of better than 0.3% in the index may be obtained with the present method

Novel software package to facilitate operation of any spectral (Fourier) OCT system

We present a novel software method (master-slave) to facilitate operation of any SDOCT system. This method relaxes constraints on dispersion compensation and k-domain re-sampling in SDOCT methods without requiring any changes in the hardware used

Arrhythmia Caused by a Drosophila Tropomyosin Mutation Is Revealed Using a Novel Optical Coherence Tomography Instrument

Background: Dilated cardiomyopathy (DCM) is a severe cardiac condition that causes high mortality. Many genes have been confirmed to be involved in this disease. An ideal system with which to uncover disease mechanisms would be one that can measure the changes in a wide range of cardiac activities associated with mutations in specific, diversely functional cardiac genes. Such a system needs a genetically manipulable model organism that allows in vivo measurement of cardiac phenotypes and a detecting instrument capable of recording multiple phenotype parameters. Methodology and Principal Findings: With a simple heart, a transparent body surface at larval stages and available genetic tools we chose Drosophila melanogaster as our model organism and developed for it a dual en-face/Doppler optical coherence tomography (OCT) instrument capable of recording multiple aspects of heart activity, including heart contraction cycle dynamics, ostia dynamics, heartbeat rate and rhythm, speed of heart wall movement and light reflectivity of cardiomyocytes in situ. We applied this OCT instrument to a model of Tropomyosin-associated DCM established in adult Drosophila. We show that DCM pre-exists in the larval stage and is accompanied by an arrhythmia previously unidentified in this model. We also detect reduced mobility and light reflectivity of cardiomyocytes in mutants. Conclusion: These results demonstrate the capability of our OCT instrument to characterize in detail cardiac activity i

Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

Route to OCT from OFS at University of Kent

A review is presented of several technical solutions developed by the Applied Optics Group (AOG) in the field of low coherence interferometry applied to optical fiber sensors (OFS) that subsequently allowed AOG to quickly progress in the field of optical coherence tomography (OCT). © 2011 University of Electronic Science and Technology of China and Springer-Verlag Berlin Heidelberg

Variante simple de mode-locking avec applications dans la mesure du temps de réponse des dispositifs opto-électroniques

An experimental study is developed on the mode-locking regime obtained by the modulation of the coupled cavity length. We further show how a simple installation useful for the measure of the photodetectors response — time and fibre optics dispersion may be easily realized.On présente une étude expérimentale sur une variante de mode-locking qui consiste dans la modulation de la longueur de la cavité couplée à la cavité laser. On indique aussi comment on peut construire rapidement, en utilisant cette méthode de mode-locking, une installation simple qui peut servir à la mesure des temps de réponse de certains photodétecteurs et de la dispersion des fibres optiques

Variante simple de mode-locking avec applications dans la mesure du temps de réponse des dispositifs opto-électroniques

On présente une étude expérimentale sur une variante de mode-locking qui consiste dans la modulation de la longueur de la cavité couplée à la cavité laser. On indique aussi comment on peut construire rapidement, en utilisant cette méthode de mode-locking, une installation simple qui peut servir à la mesure des temps de réponse de certains photodétecteurs et de la dispersion des fibres optiques

Criteria in the simultaneous presentation of the images provided by a stand alone OCT/SLO system

A new instrument for simultaneous display of an en-face optical coherence tomography (OCT) image and of a confocal image (similar with that produced by the scanning laser ophthalmoscope (SLO)) for the retina in vivo is demonstrated. The system is based on a fiberised OCT configuration, where a separate bulk optical confocal receiver is introduced between the transversal galvanometer scanner and the OCT fiber arm. Criteria for presenting the two images are discussed. These address the resulting impact on the quality of each image as result of differences in the two imaging techniques, low coherence interferometry and confocal imaging. The transversal and depth pixel size are governed by different principles and consequently are generally different. Additionally, the OCT image is disturbed by Doppler shifts introduced by the transversal scanning and speckle