Depth resolved detection of lipid using spectroscopic optical coherence tomography

Optical frequency domain imaging (OFDI) can identify key components related to plaque vulnerability but can suffer from artifacts that could prevent accurate identification of lipid rich regions. In this paper, we present a model of depth resolved spectral analysis of OFDI data for improved detection of lipid. A quadratic Discriminant analysis model was developed based on phantom compositions known chemical mixtures and applied to a tissue phantom of a lipid-rich plaque. We demonstrate that a combined spectral and attenuation model can be used to predict the presence of lipid in OFDI images

Feasibility of the Assessment of Cholesterol Crystals in Human Macrophages Using Micro Optical Coherence Tomography

The presence of cholesterol crystals is a hallmark of atherosclerosis, but until recently, such crystals have been considered to be passive components of necrotic plaque cores. Recent studies have demonstrated that phagocytosis of cholesterol crystals by macrophages may actively precipitate plaque progression via an inflammatory pathway, emphasizing the need for methods to study the interaction between macrophages and crystalline cholesterol. In this study, we demonstrate the feasibility of detecting cholesterol in macrophages in situ using Micro-Optical Coherence Tomography (µOCT), an imaging modality we have recently developed with 1-µm resolution. Macrophages containing cholesterol crystals frequently demonstrated highly scattering constituents in their cytoplasm on µOCT imaging, and µOCT was able to evaluate cholesterol crystals in cultured macrophage cells. Our results suggest that µOCT may be useful for the detection and characterization of inflammatory activity associated with cholesterol crystals in the coronary artery

Issues with digital electric measurements in modern medium and low voltage systems

Mimo ogromnych postępów w modelowaniu półprzewodnikowych przekształtników energii, jak również kompletnych układów napędowych, ostateczną weryfikację wyników modelowania stanowi pomiar w układzie rzeczywistym. Równolegle z rozwojem technik napędowych rozwijana jest technika pomiarowa, mająca na celu identyfikację i weryfikację algorytmów sterowania oraz ocenę sprawności rozwiązań układów napędowych. Pomiar w warunkach przemysłowych jest najczęściej przedsięwzięciem jednorazowym. Wykonanie takiego pomiaru wiąże się przeważnie z koniecznością dwukrotnego krótkotrwałego przerwania procesu technologicznego w celu zainstalowania i zdemontowania oprzyrządowania. Problemy pomiarów są więc wielorakiego rodzaju: organizacyjne, bezpieczeństwa sprzętu i personelu, dostępu do obwodów elektrycznych i sterujących badanego obiektu, doboru właściwych czujników pomiarowych i elementów kondycjonowania sygnałów, oceny maksymalnych wartości sygnałów w celu optymalnego doboru zakresów kanałów pomiarowych i na koniec interpretacji uzyskanych wyników. Zebrane w rejestracji przemysłowej wyniki pomiaru wymagają właściwej interpretacji. O ile problemy, np. aliasingu są dość łatwe do rozwiązania, to wyznaczenie mocy pobieranej przez układ napędowy oraz pomiar momentu mechanicznego maszyny stanowi poważne wyzwanie. W artykule opisano specyfikę przygotowania typowych pomiarów w warunkach przemysłowych. Opisano tor pomiaru napięcia i prądu przy uwzględnieniu dostępnych przyrządów pomiarowych i zasad bezpiecznego użytkowania tych przyrządów. Ponadto zaprezentowano technikę instalowania czujników pomiarowych ze szczególnym uwzględnieniem możliwości ich zamontowania. Na zakończenie przedstawiono przykładowy opis metod analizy uzyskanych wyników pomiarowych.Despite significant progress in modelling of semiconductor energy converters and complete motive systems, measurement in real time systems serves as the ultimate verification of modelling results. Along with a gradual improvement of motive systems, measurement techniques, which allow for identifying and verifying steering algorithms, and assessing the efficiency of motive systems, are being improved as well. For the industrial purposes, one-off measurements are most common. Such measurements require two short interruptions of production process - while installing and dismantling the measurement sets. Measurement involves various challenges, such as management, safety procedures for measurement devices and staff, access to electronic and steering networks, proper selection of measurement sensors and signal conditioning items, assessment of maximum signal values for optimum choice of measurement channel range, and last but not least proper interpretation of the obtained results. While e.g. aliasing issues are relatively easy to solve, transmission of power by the motive system or torque measurement are serious challenges. This paper discusses particularities of typical real time measurements for industrial purposes. It describes voltage and electric current waveforms taking into account the accessibility of measurement devices and safety procedures. In addition, it presents the manner of installing measurement devices. In the final part of the paper, we show examples of how to analyze the measurement outcomes

The influence of drive unit on measurement error of ultrasonic sensor in multi - rotor flying robot

The article describes the impact of the drive units on the data obtained from ultrasonic sensors. These sensors are mounted on the multi-rotor flying robot. In experiments, previously designed ultrasonic sensor was used. On purpose of this study special testbed, consisted of a dynamometer and manipulator from KUKA company was created. In the research the influence of the location of the drive unit on the aforementioned sensor was measured. For this purpose, the sensor was placed in front, behind and in the line of the rotating propeller. The obtained results allowed to identify places where there are the least interference from the drive units that affect the ultrasonic sensor. Thanks to this, the results of measurements of the obstacles distance from a flying robot were improved

An adequate mathematical model of four-rotor flying robot in the context of control simulations

In this paper a model of the dynamics of four-rotor flying robot is described in details. Control design must be preceded by the modeling and subsequent analysis of the robot behavior in simulator. It is therefore necessary to develop the mathematical model as accurate as it is possible. The paper contains a detailed derivation of the mathematical model in the context of physics laws affecting the quadrocopter. The novelty of presented notation is an extention of Coriolis forces in linear acceleration and the gyroscopic effect on angular acceleration. In the validation phase, the mathematical model was verified with the use of proposed control algorithms. Simulation studies have demonstrated the adequacy of a MATLAB model to properly reflect the real quadrocopter dynamics. This would allow for its use in the simulator and afterwards to implement and verify of control laws on the real fourrotor flying robot

Imaging the Human Prostate Gland Using 1-µm-Resolution Optical Coherence Tomography

Context.-The accuracy of needle biopsy for the detection of prostate cancer is limited by well-known sampling errors. Thus, there is an unmet need for a microscopic screening tool that can screen large regions of the prostate comprehensively for cancer. Previous prostate imaging by optical coherence tomography (OCT) has had insufficient resolution for imaging cellular features related to prostate cancer. We have recently developed micro-optical coherence tomography (µ OCT) that generates depth-resolved tissue images at a high frame rate with an isotropic resolution of 1 µ m. Objective.-To demonstrate that optical images obtained with µ OCT provide cellular-level contrast in prostate specimens that will enable differentiation and diagnosis of prostate pathologies. Design.-Fresh prostate specimens obtained from surgical resections were scanned with µ OCT ex vivo. Histologic features in the µ OCT images were correlated to the corresponding conventional histology. Results.-Findings indicate that µ OCT is capable of resolving many of the architectural and cellular features associated with benign and neoplastic prostate. Conclusions.-Because µ OCT can be implemented in a small-diameter flexible probe, this study suggests that high-resolution µ OCT imaging may be a useful tool for needle-based virtual biopsy of the prostate gland