For real-time processing (which involves fast Fourier transform) and display, resampling or numerical calibration is required to convert the time-uniform OCT fringe data to a K-space uniform set prior to Fourier transform. Therefore, the OCT fringe signal that is typically digitized with a uniform time interval results in a nonuniform sample distribution in K-space. Normally, a sinusoidal drive waveform is used to drive a fiber-optic Fabry-Perot tunable filter (FFP-TF) for wavelength sweeping and the response of the FFP-TP is nonlinear and hysteretic. Uninterrupted real-time imaging with a rapidly sweeping FDML requires high-speed analog-to-digital conversion, data processing, display and storage. Since its first demonstration at the wavelength of 1.3 μm, Fourier-domain mode-locked laser (FDML) has become the most convenient and powerful source for SS-OCT with an excellent combination of imaging speed, instantaneous coherence length, and spectral width among the frequency-swept laser sources. above 1 μm) where commercial high-speed CCD or CMOS line cameras of an adequate number of pixels for spectral-domain OCT are still lacking and/or costly. Between these two approaches, swept-source OCT (SS-OCT) is generally chosen when imaging highly scattering epithelial tissues such as the esophagus, colon and aorta etc., at longer wavelengths (i.e. a grating) and a CW broadband light source (spectral-domain OCT) or in time with a frequency scanning light source (swept-source OCT). Two approaches have been developed to deploy the Fourier-domain techniques: encoding the spectral information either in space with a dispersive component (e.g. The recently developed Fourier-domain OCT technology (FD-OCT) has led to substantial improvements on A-scan rate and detection sensitivity over the conventional time-domain technologies. Real-time imaging of biological tissues using such a system was demonstrated with a measured axial resolution of 9.3 μm and detection sensitivity greater than 120dB. We successfully implemented the Rt-UKSS method in an SS-OCT system based on a Fourier-domain mode-locked laser (FDML) of a 40-kHz scanning rate. The Rt-UKSS method is adaptive and applicable to a generic SS-OCT system of a wide range of A-scan rates without special adjustment. Different from the numerical calibration algorithm commonly used in an SS-OCT system, the method reported here does not require over-sampling, thus greatly reducing the demand for digitization, data processing and storage speed. The clock was synchronized with the zero-crossing time of an interferometric calibration signal and used as triggers for a high-speed data acquisition system in a point-by-point fashion, hence enabling uniform data sampling in K-space. An external clock uniform in K-space was generated. To sum up, although Mach Clock does seem to be a really nice application for users that want more than what the default OS X clock has to offer, its high CPU consumption bug does not recommend it as a safe app to have installed on your Mac.We developed a universal, real-time uniform K-space sampling (Rt-UKSS) method for high-speed swept-source optical coherence tomography (SS-OCT). Unfortunately, even though it does not crash and there are no errors while running, Mach Clock eats up a lot of your system resources, too much considering the fact that it was created for such a simple task as keeping track of the current time. If you don’t want to completely disable the clock window, you can rapidly minimize it by double clicking Mach Clock’s docklet. When the clock window is disabled, the Mach Clock’s dock icon will continue to update in real-time, allowing you to keep an eye on the current time in style. In addition, you can quickly toggle the clock window, thus making it a dock only utility. Moreover, Mach Clock’s clocks can be configured to have digital and analog faces, each of this types of faces featuring multiple themes that make it very easy to customize the clocks, both in the dock and in the monitoring window.įrom the Preferences window, you can easily set Mach Clock to display the AM / PM marks, to show the seconds or not and choose the type of face it uses. Mach Clock will enable you to see the current time either via its real-time updated dock icon or with the help of its main window, where the clocks are displayed. The Mach Clock application has been designed from scratch to help you keep track of the time in up to five cities at a time.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |