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Transient terahertz time-domain spectroscopy (THz-TDS) imaging has emerged as a novel non-ionizing and noninvasive biomedical imaging modality, designed for the detection and characterization of a variety of tissue malignancies due to their high signal-to-noise ratio and submillimeter resolution. We report our design of a pair of aspheric focusing lenses using a commercially available lens-design software that resulted in about 200 × 200-µm2 focal spot size corresponding to the 1-THz frequency. The lenses are made of high-density polyethylene (HDPE) obtained using a lathe fabrication and are integrated into a THz-TDS system that includes low-temperature GaAs photoconductive antennae as both a THz emitter and detector. The system is used to generate high-resolution, two-dimensional (2D) images of formalin-fixed, paraffin-embedded murine pancreas tissue blocks. The performance of these focusing lenses is compared to the older system based on a pair of short-focal-length, hemispherical polytetrafluoroethylene (TeflonTM) lenses and is characterized using THz-domain measurements, resulting in 2D maps of the tissue refractive index and absorption coefficient as imaging markers. For a quantitative evaluation of the lens effect on the image resolution, we formulated a lateral resolution parameter, R2080, defined as the distance required for a 20-80% transition of the imaging marker from the bare paraffin region to the tissue region in the same image frame. The R2080 parameter clearly demonstrates the advantage of the HDPE lenses over TeflonTM lenses. The lens-design approach presented here can be successfully implemented in other THz-TDS setups with known THz emitter and detector specifications.

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The size of the optical zoom system is important in smartphone camera design, especially as it governs the thickness of the smartphone. We present the optical design of a miniaturized 10× periscope zoom lens for smartphones. To achieve the desired level of miniaturization, the conventional zoom lens can be replaced with a periscope zoom lens. In addition to this change in the optical design, the quality of the optical glass, which also affects the performance of the lens, must be considered. With advancements in the optical glass manufacturing process, aspheric lenses are becoming more widely used. In this study, aspheric lenses are incorporated into a design for a 10× optical zoom lens with a lens thickness of less than 6.5 mm and an eight-megapixel image sensor. Furthermore, tolerance analysis is carried out to prove its manufacturability.

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Having the least lenses, the significant feature of the singlet imaging system, helps the development of the portable and cost-effective microscopes. A novel method of monochromatic/color singlet microscopy, which is combined with only one aspheric lens and deep learning computational imaging technology, is proposed in this article. The designed singlet aspheric lens is an approximate linear signal system, which means modulation-transfer-function curves on all field-of-views (5 mm diagonally) are almost coincident with each other. The purpose of the designed linear signal system is to further improve the resolution of our microscope by using deep learning algorithm. As a proof of concept, we designed a singlet microscopy based on our method, which weighs only 400 g. The experimental data and results of the sample USAF-1951 target and bio-sample (the Equisetum-arvense Strobile L.S), prove that the performance of the proposed singlet microscope is competitive to a commercial microscope with the 4X/NA0.1 objective lens. We believe that our idea and method would guide to design more cost-effective and powerful singlet imaging system.

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Resumo Objetivo: A catarata é a principal causa de cegueira reversível no mundo e seu tratamento é baseado em cirurgia, facectomia. A evolução do procedimento tem se baseado em vários pilares, mas é no desenvolvimento de novos tipos de lentes intraoculares que vem mostrando inovações consideráveis. As lentes atuais são capazes, além de tratar a catarata, de corrigir erros refracionais. O objetivo deste estudo foi avaliar a qualidade de vida e de visão pós-facectomia, comparando as lentes multifocais (Restor), tóricas, monofocais esféricas (SN60AT) e monofocais asféricas. Métodos: A pesquisa abrangeu 54 pacientes submetidos a facectomia com implantação de uma das lentes há, pelo menos, 3 meses. Os pacientes responderam questionário de qualidade de vida Cataract TyPE Specification sobre satisfação de visão, dependência de óculos para diversas atividades diárias e presença de fenômenos disfóticos. Para análise dos dados foram utilizados os testes de Kolmogorov-Smirnov, quanto a normalidade e ANOVA com teste de Tukey, quanta parametria. Em comparações não paramétricas, utilizou-se o teste de Mann-Whitney. Em todas as análises foi usado o mesmo nível de significância (p<0,05). Resultados: Numa escala de 0 a 10, a pesquisa mostrou que as lentes SN60AT, esféricas monofocais, foram as que obtiveram menor nível de satisfação entre as 4 lentes, obtendo média de 8,7 (DP= 1,30; IC ± 0,655), seguido das esféricas monofocais (média= 8,3 - DP= 1,83; IC ± 0,927), das esféricas multifocais (Restor) (média = 8,9 - DP = 1,42; IC ± 0,721) e as tóricas (média = 9,1 - DP = 1,67; IC ± 0,844) como a de maior nível de satisfação. Em relação à dependência dos óculos, a lente Restor foi a que mostrou melhor desempenho, com menor dependência dos óculos. Fenômenos disfóticos foram mais frequentes nos pacientes que tiveram implantada a lente SN60AT seguida de lente Restor. Conclusão: Conclui-se que as lentes SN60AT foram as lentes que causaram menor grau de satisfação, tendo os fenômenos disfóticos umas das principais queixas, associada a dependência dos óculos pós-cirurgia. Os pacientes que tiveram as lentes Restor implantadas, apesar dos sintomas disfóticos mais presentes do que as lentes monofocais tóricas e monofocais esféricas, tem o mesmo nível de satisfação, e ainda proporciona maior independência dos óculos.

Abstract Objective: Cataract is the leading cause of reversible blindness in the world and its treatment is based on surgery, facectomy. The evolution of the procedure has been based on several pillars, but it is in the development of new types of intraocular lenses that has been showing considerable innovations. Current lenses are capable, in addition to treating cataracts, of correcting refractive errors. The aim of this study was to evaluate the quality of life and post-facectomy vision, comparing multifocal lenses (Restor), toric, spherical monofocals (SN60AT) and aspheric monofocals. Methods: The study included 54 patients undergoing a facectomy with implantation of one of the lenses for at least 3 months. The patients answered questionnaire quality of life Cataract TyPE Specification on vision satisfaction, glasses dependence for various daily activities and presence of dysphothetic phenomena. For the analysis of the data, the Kolmogorov-Smirnov tests were used, regarding normality and ANOVA with Tukey's test, how much parametric. In non-parametric comparisons, the Mann-Whitney test was used. In all analyzes, the same level of significance was used (p <0.05). Results: On a scale of 0 to 10, the research showed that single-spherical spherical SN60AT lenses were the ones that obtained the lowest level of satisfaction among the four lenses, obtaining an average of 8.7 (SD = 1.30, CI ± 0.655), followed (mean = 8.9 - SD = 1.42, CI ± 0.721) and the toric (mean = 8.3 - SD = 1.83, CI ± 0.927), multifocal spherical (Restor) 9.1 - SD = 1.67, CI ± 0.844) as the highest level of satisfaction. Regarding the dependence of the glasses, the Restor lens showed the best performance, with less dependence on the glasses. Dysphasic phenomena were more frequent in patients who had implanted the SN60AT lens followed by Restor lens. Conclusion: It is concluded that the SN60AT lenses were the lenses that caused less satisfaction, and the dysphothetic phenomena were one of the main complaints, associated with the postoperative glasses dependence. Patients who had restored Restor lenses, despite the more present dysphoric symptoms than spherical monofocal and single-focal lenses, have the same level of satisfaction, and still provide greater independence of the glasses.

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