On-chip hullámfront érzékelés és processzálás parallel implementációja = Parallel implementation of on-chip wavefront sensing and processing

Turbulens közeg által okozott dinamikus aberrációk méréséhez hullámfront szenzorokra van szükség, melyekben találkozik a fejlett fényérzékelő tömbök technológiája és a nagysebességű valós idejű feldolgozás, amit párhuzamos, szenzor közeli eszközökkel lehet teljesíteni. Három módszert vizsgáltunk: 1. Analóg és digitális processzálással is rendelkező, celluláris architektúrát használó, párhuzamos processzálásra képes - programozható szenzorhoz (Eye-Ris) illesztettünk egy lencse mátrixot (Shack-Hartmann szenzor, SH). Erre eszközre korrelációs hullámfront mérő algoritmust készítettünk. Ugyan az eszközön elérhető felbontás nem túl nagy, de magán a chip-en párhuzamosan futó algoritmus következtében igen nagy sebesség érhető el. 2. A speciális, nagysebességű és felbontású CMOS szenzort (SH) egy nagy teljesítményű FPGA eszközzel egészítettük ki, ami a szenzor kontrol funkcióján kívül a szükséges processzálásokat is elvégzi nagy párhuzamossággal. Az eszköz hullámfront korrigáló egysége egy nagysebességű LCOS mikro-megjelenítő, aminek a kontrol funkcióit is a beépített FPGA látja el. Ílymódon sokkal nagyobb sebesség érhető el, mint más hasonló, ma hozzáférhető eszközzel. 3. A térbeli fázistolás-interferometrián alapuló (FINCH) eljárás lényege, hogy a hullámfrontról egyszerre több önmagával képzett, nulla úthossz különbségű interferogrammot veszünk fel különböző fázistolásokkal (0, pi/2, pi, 3pi/2). Ekkor a hullámfront fázisa egyszerűen (elemi algebrai műveletekkel) meghatározható. | To measure and compensate dynamic aberrations caused by turbulent media wavefront sensors using high end area scan technology and high speed, parallel, close-to-sensor, real time processing are applied. We have developed three methods: 1. We applied a new, mixed mode cellular array sensor-computer device, which combines analog and digital parallel processing capabilities with on chip sensors (Eye-Ris). We attached to the sensory elements a lens array (Shack-Hartmann sensor, SH) and developed an appropriate, parallel, on chip correlation based wavefront sensor algorithm. Although the achievable resolution is constrained, but due to its analog, parallel processing capabilities very high speed was accessible. 2. A high speed, high resolution CMOS sensor (SH) is combined with a FPGA, which in addition to the sensor control function can fulfill the required processing with high parallelism. This device has a wavefront corrector unit, an LCOS micro display, which in accordance with the measured wavefront distortions can compensate it at a very high speed. This device outperforms any contemporary counterparts in resolution, speed, noise and price. 3. A fast wavefront sensor method based on spatial phase shifting interferometry (FINCH), applying measurements of several zero path length difference interferograms with different phase shifts (0, p/2, p, 3p/2). From these smaller resolution interferograms the wavefront can be reconstructed using only elementary algebra

In-line hologram segmentation for volumetric samples

We propose a fast, noniterative method to segment an in-line hologram of a volumetric sample into in-line subholograms according to its constituent objects. In contrast to the phase retrieval or twin image elimination algorithms, we do not aim or require to reconstruct the complex wave field of all the objects, which would be a more complex task, but only provide a good estimate about the contribution of the particular objects to the original hologram quickly. The introduced hologram segmentation algorithm exploits the special inner structure of the in-line holograms and applies only the estimated supports and reconstruction distances of the corresponding objects as parameters. The performance of the proposed method is demonstrated and analyzed experimentally both on synthetic and measured holograms. We discussed how the proposed algorithm can be efficiently applied for object reconstruction and phase retrieval tasks

Programozható optoelektronikus tömbprocesszorok (POAC) és alkalmazásaik = Programmable opto-electric array processors (POAC) and their applications

Kidolgoztunk és megépítettünk egy hordozható programozható opto-elektronikus analogikus CNN számítógépet (Laptop-POAC), amelyet céltárgyak felismerésére és követésére alkalmaztunk. A POAC (programmabble optical analogic array computer) magprocesszora egy új típusu optikai korrelátor, amelyben bakteriorhodopsin (BR) filmet alkalmaztunk dinamikus (újraírható, többszörösen olvasható, törölhető) holografikus anyagként. Ez az optikai CNN implementáció egyesíti az optikai számítógépek nagy sebességét, rendkívűl nagy práhuzamosságát (milliós nagyságrendű csatornaszám) és a nagymértű templatek alkalmazhatóságát a CNN eszköszök rugalmas programozhatóságával. Különös jellemzője ennek az optikai tömbprocesszornak az, hogy a programozó templateket vagy egy kétdimenziós akuszto-optikai eltérítővel (ez esetben 64x64 pixel méretű templateket használtunk), vagy egy VCSEL lézer mátrixszal valósíthatjuk meg. A bemenő képeket 600x800 pixel felbontású folyadékkristályos mikromegjelenítővel vittük be. Meghatároztuk a jelenleg beszerezhető kulcselemekkel elérhető maximális felbontás és a sebesség korlátait. Ezáltal kimutatttuk, hogy a kispárhuzamosságú elektronikus adatátvitel (továbbá a létező CCD, CMOS és vizuális CNN chipek felbontás/sebesség) korlátai miatt 2D-s optika utófeldolgozásra van szükség és lehetőség. Új és hatékony céltárgy felismerő és több tárgy kvázi-egyidejű követésére alkalmas algoritmust dolgoztunk ki. Mérésekkel bizonyítottuk a berendezés és az algoritmusok hatékonyságát. | A portable programmable opto-electronic analogic CNN computer (Laptop-POAC) has been built and used to recognize and track targets. Its kernel processor is a novel type of high performance optical correlator based on the use of bacteriorhodopsin (BR) as a dynamic holographic material. This optical CNN implementation combines the optical computer's high speed, high parallelism (1 000 000 channel) and large applicable template sizes with flexible programmability of the CNN devices. A unique feature of this optical array computer is that programming templates can be applied either by a 2D acousto-optical deflector (up to 64x64 pixel size templates) incoherently or by VCSEL arrays. Input images are fed-in by a LCD-SLM of 600x800 pixel resolution. Evaluation of trade-off between speed and resolution is given. Novel and effective target recognition and multiple-target-tracking algorithms have been developed for the POAC. Tracking experiments are demonstrated. In the present model a video-speed CCD camera is recording the correlograms, however, later a CNN-UM chip and a high-speed CMOS camera will be applied for combined optical/electro-optical post-processing. An optical CNN template- and algorithm-library has been developed to solve a great variety of image processing tasks. It seems to be an important future work to expand this library

Special multicolor illumination and numerical tilt correction in volumetric digital holographic microscopy

We introduce a color imaging method in our digital holographic microscope system (DHM). This DHM can create color images of freely floating, or moving objects inside a large volume by simultaneously capturing three holograms using three different illumination wavelengths. In this DHM a new light source assembly is applied, where we use single mode fibers according to the corresponding wavelengths that are tightly and randomly arranged into a small array in a single FC/PC connector. This design has significant advantages over the earlier approaches, where all the used illuminations are coupled in the same fiber. It avoids the coupling losses and provides a cost effective, compact solution for multicolor coherent illumination. We explain how to determine and correct the different fiber end positions caused tilt aberration during the hologram reconstruction process. To demonstrate the performance of the device, color hologram reconstructions are presented that can achieve at least 1 μm lateral resolution

Arteriolar biomechanics in a rat polycystic ovary syndrome model - effects of parallel vitamin D3 treatment.

To clarify the effects of dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS) on arteriolar biomechanics in a rat model and the possible modulatory role of vitamin D3. METHODS AND RESULTS: The PCOS model was induced in female Wistar rats by ten-weeks DHT treatment. Arteriolar biomechanics was tested in arterioles by pressure arteriography in control as well as DHT- and DHT with vitamin D3-treated animals in contracted and passive conditions. Increased wall stress and distensibility as well as increased vascular lumen were detected after DHT treatment. Concomitant vitamin D3 treatment lowered the mechanical load of the arterioles and restored the vascular diameter. CONCLUSION: The hyperandrogenic state resulted in more rigid, less flexible arteriolar walls with increased vascular lumen compared with controls. DHT treatment caused eutrophic remodelling of gracilis arteriole. These prehypertensive alterations caused by chronic DHT treatment were mostly reversed by concomitant vitamin D3 administration

Results of a systematic review and meta-analysis of early studies on ivermectin in SARS-CoV-2 infection

Ivermectin, an antiparasitic drug, has been repurposed for COVID-19 treatment during the SARS-CoV-2 pandemic. Although its antiviral efficacy was confirmed early in vitro and in preclinical studies, its clinical efficacy remained ambiguous. Our purpose was to assess the efficacy of ivermectin in terms of time to viral clearance based on the meta-analysis of available clinical trials at the closing date of the data search period, one year after the start of the pandemic. This meta-analysis was reported by following the PRISMA guidelines and by using the PICO format for formulating the question. The study protocol was registered on PROSPERO. Embase, MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials (CENTRAL), bioRvix, and medRvix were searched for human studies of patients receiving ivermectin therapy with control groups. No language or publication status restrictions were applied. The search ended on 1/31/2021 exactly one year after WHO declared the public health emergency on novel coronavirus. The meta-analysis of three trials involving 382 patients revealed that the mean time to viral clearance was 5.74 days shorter in case of ivermectin treatment compared to the control groups [WMD = -5.74, 95% CI (-11.1, -0.39), p = 0.036]. Ivermectin has significantly reduced the time to viral clearance in mild to moderate COVID-19 diseases compared to control groups. However, more eligible studies are needed for analysis to increase the quality of evidence of ivermectin use in COVID-19

Effects of vitamin D3 derivate calcitriol on pharmacological reactivity of aortic rings in a rodent PCOS model

BACKGROUND: The aim of this study was to examine the effects of the hyperandrogenic state in dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS), the vascular responses to different vasoactive agents, and the modulatory role of vitamin D3. METHODS: APCOS model was induced by DHT application in 20 female Wistar rats. Ten of the DHT treated rats simultaneously received calcitriol treatment. After 10 weeks, myographs were used to test the reactivity of isolated thoracic aortic rings to norepinephrine and acetylcholine. Thereafter, the vascular rings were incubated with the NO-synthase blocker (nitro-L-arginine methyl ester) or the cyclooxygenase inhibitor (indomethacin) for 20 min, and the effects of norepinephrine and acetylcholine were re-evaluated. RESULTS: Norepinephrine-induced vasoconstriction was enhanced after DHT treatment, but this effect was attenuated by calcitriol administration. Vasorelaxation of DHT-treated thoracic aortic rings was impaired, but this could be partly reversed by calcitriol application. Impaired NO-dependent vasorelaxation in DHT-treated animals was mostly reversed by concomitant calcitriol administration, but this effect was diminished by prostanoid-dependent vasoconstriction. CONCLUSIONS: These studies show that the enhanced sensitivity to vasoconstrictors and impaired NO-dependent vasorelaxation in hyperandrogenic PCOS rats could be partially reversed by calcitriol treatment

Effects of vitamin D3 derivative--calcitriol on pharmacological reactivity of aortic rings in a rodent PCOS model.

Abstract BACKGROUND: The aim of this study was to examine the effects of the hyperandrogenic state in dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS), the vascular responses to different vasoactive agents, and the modulatory role of vitamin D3. METHODS: APCOS model was induced by DHT application in 20 female Wistar rats. Ten of the DHT treated rats simultaneously received calcitriol treatment. After 10 weeks, myographs were used to test the reactivity of isolated thoracic aortic rings to norepinephrine and acetylcholine. Thereafter, the vascular rings were incubated with the NO-synthase blocker (nitro-L-arginine methyl ester) or the cyclooxygenase inhibitor (indomethacin) for 20 min, and the effects of norepinephrine and acetylcholine were re-evaluated. RESULTS: Norepinephrine-induced vasoconstriction was enhanced after DHT treatment, but this effect was attenuated by calcitriol administration. Vasorelaxation of DHT-treated thoracic aortic rings was impaired, but this could be partly reversed by calcitriol application. Impaired NO-dependent vasorelaxation in DHT-treated animals was mostly reversed by concomitant calcitriol administration, but this effect was diminished by prostanoid-dependent vasoconstriction. CONCLUSIONS: These studies show that the enhanced sensitivity to vasoconstrictors and impaired NO-dependent vasorelaxation in hyperandrogenic PCOS rats could be partially reversed by calcitriol treatment