Three-dimensional integral imaging based capture and display system using digital programmable Fresnel lenslet arrays

Ankara : The Department of Electrical and Electronics Engineering and the Graduate School of Engineering and Science of Bilkent University, 2012.Thesis (Ph. D.) -- Bilkent University, 2012.Includes bibliographical refences.A Fresnel lenslet array pattern is written on a phase-only LCoS spatial light modulator device (SLM) to replace the regular analog lenslet array in a conventional integral imaging system. We theoretically analyze the capture part of the proposed system based on Fresnel wave propagation formulation. Due to pixelation and quantization of the lenslet array pattern, higher diffraction orders and multiple focal points emerge. Because of the multiple focal planes introduced by the discrete lenslets, multiple image planes are observed. The use of discrete lenslet arrays also causes some other artefacts on the recorded elemental images. The results reduce to those available in the literature when the effects introduced by the discrete nature of the lenslets are omitted. We performed simulations of the capture part. It is possible to obtain the elemental images with an acceptable visual quality. We also constructed an optical integral imaging system with both capture and display parts using the proposed discrete Fresnel lenslet array written on a SLM. Optical results, when self-luminous objects, such as an LED array, are used indicate that the proposed system yields satisfactory results. The resulting system consisting of digital lenslet arrays offers a flexible integral imaging system. Thus, to increase the visual performance of the system, previously available analog solutions can now be implemented digitally by using electro-optical devices. We also propose a method and present applications of this method that converts a diffraction pattern into an elemental image set in order to display them on a display-only integral imaging setup. We generate elemental images based on diffraction calculations as an alternative to commonly used ray tracing methods. Ray tracing methods do not accommodate the interference and diffraction phenomena. Our proposed method enables us to obtain elemental images from a holographic recording of a 3D object/scene. The diffraction pattern can be either numerically generated or digitally acquired from optical input. The method shows the connection between a hologram (diffraction pattern) of a 3D object and an elemental image set of the same 3D object. We obtained optical reconstructions with a display-only integral imaging setup where we used a digital lenslet array. We also obtained numerical reconstructions, again by using the diffraction calculations, for comparison. The digital and optical reconstruction results are in good agreement. Finally, we showed a method to obtain an orthoscopic image of a 3D object. We converted an elemental image set that gives real pseudoscopic reconstruction into another elemental image set that gives real orthoscopic reconstruction. Again, we used wave propagation simulations for this purpose. We also demonstrated numerical and optical reconstructions from the obtained elemental image sets for comparison. The results are satisfactory given the physical limitations of the display system.Yöntem, Ali ÖzgürPh.D

Demonstrating a multi-primary high dynamic range display system for vision experiments.

We describe the design, construction, calibration, and characterization of a multi-primary high dynamic range (MPHDR) display system for use in vision research. The MPHDR display is the first system to our knowledge to allowfor spatially controllable, high dynamic range stimulus generation using multiple primaries.We demonstrate the high luminance, high dynamic range, and wide color gamut output of the MPHDR display. During characterization, the MPHDR display achieved a maximum luminance of 3200 cd=m2, a maximum contrast range of 3; 240; 000 V 1, and an expanded color gamut tailored to dedicated vision research tasks that spans beyond traditional sRGB displays. We discuss how the MPHDR display could be optimized for psychophysical experiments with photoreceptor isolating stimuli achieved through the method of silent substitution. We present an example case of a range of metameric pairs of melanopsin isolating stimuli across different luminance levels, from an available melanopsin contrast of117%at 75 cd=m2 to a melanopsin contrast of23%at 2000 cd=m2

Evaluation of nutritional status in pediatric intensive care unit patients: The results of a multicenter, prospective study in Turkey

IntroductionMalnutrition is defined as a pathological condition arising from deficient or imbalanced intake of nutritional elements. Factors such as increasing metabolic demands during the disease course in the hospitalized patients and inadequate calorie intake increase the risk of malnutrition. The aim of the present study is to evaluate nutritional status of patients admitted to pediatric intensive care units (PICU) in Turkey, examine the effect of nutrition on the treatment process and draw attention to the need for regulating nutritional support of patients while continuing existing therapies.Material and MethodIn this prospective multicenter study, the data was collected over a period of one month from PICUs participating in the PICU Nutrition Study Group in Turkey. Anthropometric data of the patients, calorie intake, 90-day mortality, need for mechanical ventilation, length of hospital stay and length of stay in intensive care unit were recorded and the relationship between these parameters was examined.ResultsOf the 614 patients included in the study, malnutrition was detected in 45.4% of the patients. Enteral feeding was initiated in 40.6% (n = 249) of the patients at day one upon admission to the intensive care unit. In the first 48 h, 86.82% (n = 533) of the patients achieved the target calorie intake, and 81.65% (n = 307) of the 376 patients remaining in the intensive care unit achieved the target calorie intake at the end of one week. The risk of mortality decreased with increasing upper mid-arm circumference and triceps skin fold thickness Z-score (OR = 0.871/0.894; p = 0.027/0.024). The risk of mortality was 2.723 times higher in patients who did not achieve the target calorie intake at first 48 h (p = 0.006) and the risk was 3.829 times higher in patients who did not achieve the target calorie intake at the end of one week (p = 0.001). The risk of mortality decreased with increasing triceps skin fold thickness Z-score (OR = 0.894; p = 0.024).ConclusionTimely and appropriate nutritional support in critically ill patients favorably affects the clinical course. The results of the present study suggest that mortality rate is higher in patients who fail to achieve the target calorie intake at first 48 h and day seven of admission to the intensive care unit. The risk of mortality decreases with increasing triceps skin fold thickness Z-score

Demonstrating a multi-primary high dynamic range display system for vision experiments.

We describe the design, construction, calibration, and characterization of a multi-primary high dynamic range (MPHDR) display system for use in vision research. The MPHDR display is the first system to our knowledge to allowfor spatially controllable, high dynamic range stimulus generation using multiple primaries.We demonstrate the high luminance, high dynamic range, and wide color gamut output of the MPHDR display. During characterization, the MPHDR display achieved a maximum luminance of 3200 cd=m2, a maximum contrast range of 3; 240; 000 V 1, and an expanded color gamut tailored to dedicated vision research tasks that spans beyond traditional sRGB displays. We discuss how the MPHDR display could be optimized for psychophysical experiments with photoreceptor isolating stimuli achieved through the method of silent substitution. We present an example case of a range of metameric pairs of melanopsin isolating stimuli across different luminance levels, from an available melanopsin contrast of117%at 75 cd=m2 to a melanopsin contrast of23%at 2000 cd=m2

Demonstrating a multi-primary high dynamic range display system for vision experiments

We describe the design, construction, calibration, and characterization of a multi-primary high dynamic range (MPHDR) display system for use in vision research. The MPHDR display is the first system to our knowledge to allow for spatially controllable, high dynamic range stimulus generation using multiple primaries. We demonstrate the high luminance, high dynamic range, and wide color gamut output of the MPHDR display. During characterization, the MPHDR display achieved a maximum luminance of 3200 cd/m^2, a maximum contrast range of 3,240,000:1, and an expanded color gamut tailored to dedicated vision research tasks that spans beyond traditional sRGB displays. We discuss how the MPHDR display could be optimized for psychophysical experiments with photoreceptor isolating stimuli achieved through the method of silent substitution. We present an example case of a range of metameric pairs of melanopsin isolating stimuli across different luminance levels, from an available melanopsin contrast of 117% at 75 cd/m^2 to a melanopsin contrast of 23% at 2000 cd/m^2

The evaluation of the clinical effect of HBS1L-MYB RS4895441 gene polymorphisms in thalassemia major and intermedia patients

Giriş: Beta talasemiler en sık gözlenen otozomal resesif hastalıklardan biridir.Beta talasemilerde klinik özelliklerson derece değişkendir.Hastalık ciddiyetini belirleyen ana faktörler, hastalığa neden olan mutasyonun kendisi(HBB gen mutasyonu) ve α/γ globulin zinciri üretme kapasitesidir. Bu çalışmada HbF düzeyindeki değişikliklerleilişkili olduğu gösterilmiş 6q23.3 üzerindeki HBS1L-MYB interjenik bölgesindeki değişikliklerin kliniğe etkisininaraştırılması amaçlanmıştır.Gereç ve Yöntem: Talasemi majör ve intermedia tanısıyla izlenen 87 hasta çalışmaya alındı. Tanı yaşı, ilktransfüzyon yaşı, tanı dönemindeki kan sayımı verileri, HbF düzeyleri, splenektomi durumu, yıllık eritrosittransfüzyon miktarı (ml/kg/yıl), transfüzyonel demir yükü (mg/kg/gün), çalışma anındaki ferritin değerlerikaydedildi.HBS1L-MYB rs4895441 gen polimorfizmi PCR-RFLP yöntemi ile çalışıldı. Beta globin gen mutasyonu,αglobin gen mutasyonu, HBS1L-MYB rs4895441 gen polimorfizminin kliniğe etkisi ve talasemi intermedia kliniğinitahmin ettirici etkisi incelendi.Bulgular: HBS1L-MYB rs4895441 lokusunda en az bir G aleli taşıyan hastalarda ortalama tanı yaşı daha geç veHbF düzeyleri daha yüksek saptandı. İyileştirici alellerin talasemi intermediayı tahmin ettirici etkisinideğerlendirmek için yapılan lojistik regresyon analizinde HBS1L-MYB rs4895441polimorfizminin Tİ ile ilişkiliolduğu saptandı.Sonuç: Gelecekteki tüm genom dizileme çalışmalarının, hastalık ciddiyetini değiştiren polimorfizmleri daha iyitanımlaması muhtemel olsa da; bu çalışmanın sonuçları, HBS1L-MYB rs4895441 polimorfizminin daha geç tanıyaşı ve talasemi intermedia kliniğini öngörmede yardımcı olabileceğini göstermiştir.Introduction: Beta thalassemia is one of the most common autosomal recessive diseases. The clinical features of beta thalassemia are highly variable. The main factors that determine the severity of the disease are the mutation itself (HBB gene mutation) and the α/γ globulin chain production capacity. The aim of this study was to investigate the effect of changes in the HBS1L-MYB intergenic area on 6q23.3 which wasshown to be associated with changes in HbF level. Materials and Method: 87 thalassemia major and intermedia patients were enrolled in the study. Age of diagnosis, first transfusion age, blood count data at the time of diagnosis, HbF level, history of splenectomy, amount of erythrocyte transfusion (ml/kg/year), transfusional iron load (mg/kg/day), and ferritin level were examined. HBS1L-MYB rs4895441 gene polymorphism was studied by PCR-RFLP method. Beta globulin gene mutation, α globulin gene mutation, the effect of HBS1L-MYB rs4895441 gene polymorphism on the manifestation of the disease and the predicting the thalassemia intermedia manifestation were investigated. Results: Patients with at least one G allele in the HBS1L-MYB rs4895441 locus had a higher meanage of diagnosis and higher HbF levels. HBS1L-MYB rs4895441 polymorphism was found to be related to TI in the logistic regression analysis performed in order to assess the healing alleles in predicting thalassemia intermedia. Conclusion: Although it is likely that the future genome sequencing studies will beter describe the polymorphisms that alter these verity of disease, this study has shown that the HBS1L-MYB rs 4895441 polymorphism is related with higher age of diagnosis and may help in predicting thalassemia intermedia clinic

Talasemi Majör ve İntermedia Hastalarında Hbs1l-Myb Rs4895441 Gen Polimorfizminin Kliniğe Etkisinin Değerlendirilmesi

Introduction: Beta thalassemia is one of the most common autosomal recessive diseases. the clinical features of beta thalassemia are highly variable. the main factors that determine the severity of the disease are the mutation itself (HBB gene mutation) and the ?/? globulin chain production capacity. the aim of this study was to investigate the effect of changes in the HBS1L-MYB intergenic area on 6q23.3 which wasshown to be associated with changes in HbF level. Materials and Method: 87 thalassemia major and intermedia patients were enrolled in the study. Age of diagnosis, first transfusion age, blood count data at the time of diagnosis, HbF level, history of splenectomy, amount of erythrocyte transfusion (ml/kg/year), transfusional iron load (mg/kg/day), and ferritin level were examined. HBS1L-MYB rs4895441 gene polymorphism was studied by PCR-RFLP method. Beta globulin gene mutation, ? globulin gene mutation, the effect of HBS1L-MYB rs4895441 gene polymorphism on the manifestation of the disease and the predicting the thalassemia intermedia manifestation were investigated. Results: Patients with at least one G allele in the HBS1L-MYB rs4895441 locus had a higher meanage of diagnosis and higher HbF levels. HBS1L-MYB rs4895441 polymorphism was found to be related to TI in the logistic regression analysis performed in order to assess the healing alleles in predicting thalassemia intermedia. Conclusion: Although it is likely that the future genome sequencing studies will beter describe the polymorphisms that alter these verity of disease, this study has shown that the HBS1L-MYB rs 4895441 polymorphism is related with higher age of diagnosis and may help in predicting thalassemia intermedia clinic.Giriş: Beta talasemiler en sık gözlenen otozomal resesif hastalıklardan biridir.Beta talasemilerde klinik özellikler son derece değişkendir.Hastalık ciddiyetini belirleyen ana faktörler, hastalığa neden olan mutasyonun kendisi (HBB gen mutasyonu) ve ?/? globulin zinciri üretme kapasitesidir. Bu çalışmada HbF düzeyindeki değişikliklerle ilişkili olduğu gösterilmiş 6q23.3 üzerindeki HBS1L-MYB interjenik bölgesindeki değişikliklerin kliniğe etkisinin araştırılması amaçlanmıştır. Gereç ve Yöntem: Talasemi majör ve intermedia tanısıyla izlenen 87 hasta çalışmaya alındı. Tanı yaşı, ilk transfüzyon yaşı, tanı dönemindeki kan sayımı verileri, HbF düzeyleri, splenektomi durumu, yıllık eritrosit transfüzyon miktarı (ml/kg/yıl), transfüzyonel demir yükü (mg/kg/gün), çalışma anındaki ferritin değerleri kaydedildi.HBS1L-MYB rs4895441 gen polimorfizmi PCR-RFLP yöntemi ile çalışıldı. Beta globin gen mutasyonu, ?globin gen mutasyonu, HBS1L-MYB rs4895441 gen polimorfizminin kliniğe etkisi ve talasemi intermedia kliniğini tahmin ettirici etkisi incelendi. Bulgular: HBS1L-MYB rs4895441 lokusunda en az bir G aleli taşıyan hastalarda ortalama tanı yaşı daha geç ve HbF düzeyleri daha yüksek saptandı. İyileştirici alellerin talasemi intermediayı tahmin ettirici etkisini değerlendirmek için yapılan lojistik regresyon analizinde HBS1L-MYB rs4895441polimorfizminin Tİ ile ilişkili olduğu saptandı. Sonuç: Gelecekteki tüm genom dizileme çalışmalarının, hastalık ciddiyetini değiştiren polimorfizmleri daha iyi tanımlaması muhtemel olsa da; bu çalışmanın sonuçları, HBS1L-MYB rs4895441 polimorfizminin daha geç tanı yaşı ve talasemi intermedia kliniğini öngörmede yardımcı olabileceğini göstermiştir