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Biomedical Optics Express

Robert F Cooper, William S Tuten, Alfredo Dubra, David H Brainard, Jessica I W Morgan
[This corrects the article on p. 5098 in vol. 8, PMID: 29188106.].
April 1, 2018: Biomedical Optics Express
Robert A Byers, Raman Maiti, Simon G Danby, Elaine J Pang, Bethany Mitchell, Matt J Carré, Roger Lewis, Michael J Cork, Stephen J Matcher
Measurement of sub-clinical atopic dermatitis (AD) is important for determining how long therapies should be continued after clinical clearance of visible AD lesions. An important biomarker of sub-clinical AD is epidermal hypertrophy, the structural measures of which often make optical coherence tomography (OCT) challenging due to the lack of a clearly delineated dermal-epidermal junction in AD patients. Alternatively, angiographic OCT measurements of vascular depth and morphology may represent a robust biomarker for quantifying the severity of clinical and sub-clinical AD...
April 1, 2018: Biomedical Optics Express
Bingying Chen, Xiaoshuai Huang, Dongzhou Gou, Jianzhi Zeng, Guoqing Chen, Meijun Pang, Yanhui Hu, Zhe Zhao, Yunfeng Zhang, Zhuan Zhou, Haitao Wu, Heping Cheng, Zhigang Zhang, Chris Xu, Yulong Li, Liangyi Chen, Aimin Wang
Owing to its tissue-penetration ability, multi-photon fluorescence microscopy allows for the high-resolution, non-invasive imaging of deep tissue in vivo ; the recently developed three-photon microscopy (3PM) has extended the depth of high-resolution, non-invasive functional imaging of mouse brains to beyond 1.0 mm. However, the low repetition rate of femtosecond lasers that are normally used in 3PM limits the temporal resolution of point-scanning three-photon microscopy. To increase the volumetric imaging speed of 3PM, we propose a combination of an axially elongated needle-like Bessel-beam with three-photon excitation (3PE) to image biological samples with an extended depth of focus...
April 1, 2018: Biomedical Optics Express
Muhammad Anisuzzaman Talukder, Curtis R Menyuk, Yordan Kostov
Distinguishing between whole cells and cell debris is important in microscopy, e.g., in screening of pulmonary patients for infectious tuberculosis. We propose and theoretically demonstrate that whole cells and cell debris can be distinguished from the far-field pattern of surface plasmon coupled emission (SPCE) of a fluorescently-labeled sample placed on a thin metal layer. If fluorescently-labeled whole cells are placed on the metal film, SPCE takes place simultaneously at two or more different angles and creates two or more distinct rings in the far field...
April 1, 2018: Biomedical Optics Express
Rongwen Lu, Masashi Tanimoto, Minoru Koyama, Na Ji
Understanding how neural circuits control behavior requires monitoring a large population of neurons with high spatial resolution and volume rate. Here we report an axicon-based Bessel beam module with continuously adjustable depth of focus (CADoF), that turns frame rate into volume rate by extending the excitation focus in the axial direction while maintaining high lateral resolutions. Cost-effective and compact, this CADoF Bessel module can be easily integrated into existing two-photon fluorescence microscopes...
April 1, 2018: Biomedical Optics Express
Katharina Rifai, Matthias Hornauer, Ramona Buechinger, Roland Schoen, Maria Barraza-Bernal, Selam Habtegiorgis, Carsten Glasenapp, Siegfried Wahl, Timo Mappes
Ocular UV doses accumulate all-day, not only during periods of direct sun exposure. The UV protection efficiency of three clear lenses was evaluated experimentally, validated by simulation, and compared to non-UV protection: a first spectacle lens with a tailored UV absorber, a second spectacle lens, minimizing UV back reflections, as well as a third spectacle lens, combining both. A tailored UV-absorber efficiently reduced overall UV irradiance to 7 %, whereas reduction of back-reflections still left UV irradiance at 42 %...
April 1, 2018: Biomedical Optics Express
Hyeong Soo Nam, Woo Jae Kang, Min Woo Lee, Joon Woo Song, Jin Won Kim, Wang-Yuhl Oh, Hongki Yoo
The pathophysiological progression of chronic diseases, including atherosclerosis and cancer, is closely related to compositional changes in biological tissues containing endogenous fluorophores such as collagen, elastin, and NADH, which exhibit strong autofluorescence under ultraviolet excitation. Fluorescence lifetime imaging (FLIm) provides robust detection of the compositional changes by measuring fluorescence lifetime, which is an inherent property of a fluorophore. In this paper, we present a dual-modality system combining a multispectral analog-mean-delay (AMD) FLIm and a high-speed swept-source optical coherence tomography (OCT) to simultaneously visualize the cross-sectional morphology and biochemical compositional information of a biological tissue...
April 1, 2018: Biomedical Optics Express
Xuanyu Li, Zhaojun Zhu, Weina Zhao, Yu Sun, Dong Wen, Yunyan Xie, Xiangyu Liu, Haijing Niu, Ying Han
Multiscale entropy (MSE) analysis is a novel entropy-based analysis method for quantifying the complexity of dynamic neural signals and physiological systems across multiple temporal scales. This approach may assist in elucidating the pathophysiologic mechanisms of amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD). Using resting-state fNIRS imaging, we recorded spontaneous brain activity from 31 healthy controls (HC), 27 patients with aMCI, and 24 patients with AD. The quantitative analysis of MSE revealed that reduced brain signal complexity in AD patients in several networks, namely, the default, frontoparietal, ventral and dorsal attention networks...
April 1, 2018: Biomedical Optics Express
Esther E Freeman, Aggrey Semeere, Hany Osman, Gary Peterson, Milind Rajadhyaksha, Salvador González, Jeffery N Martin, R Rox Anderson, Guillermo J Tearney, Dongkyun Kang
We report development of a low-cost smartphone confocal microscope and its first demonstration of in vivo human skin imaging. The smartphone confocal microscope uses a slit aperture and diffraction grating to conduct two-dimensional confocal imaging without using any beam scanning devices. Lateral and axial resolutions of the smartphone confocal microscope were measured as 2 and 5 µm, respectively. In vivo confocal images of human skin revealed characteristic cellular structures, including spinous and basal keratinocytes and papillary dermis...
April 1, 2018: Biomedical Optics Express
Jernej Laloš, Peter Gregorčič, Matija Jezeršek
We present an optical study of elastic wave propagation inside skin phantoms consisting of agar gel as induced by an Er:YAG (wavelength of 2.94 μm) laser pulse. A laser-beam-deflection probe is used to measure ultrasonic propagation and a high-speed camera is used to record displacements in ablation-induced elastic transients. These measurements are further analyzed with a custom developed image recognition algorithm utilizing the methods of particle image velocimetry and spline interpolation to determine point trajectories, material displacement and strain during the passing of the transients...
April 1, 2018: Biomedical Optics Express
Matthias Salas, Marco Augustin, Franz Felberer, Andreas Wartak, Marie Laslandes, Laurin Ginner, Michael Niederleithner, Jason Ensher, Michael P Minneman, Rainer A Leitgeb, Wolfgang Drexler, Xavier Levecq, Ursula Schmidt-Erfurth, Michael Pircher
Imaging of the human retina with high resolution is an essential step towards improved diagnosis and treatment control. In this paper, we introduce a compact, clinically user-friendly instrument based on swept source optical coherence tomography (SS-OCT). A key feature of the system is the realization of two different operation modes. The first operation mode is similar to conventional OCT imaging and provides large field of view (FoV) images (up to 45° × 30°) of the human retina and choroid with standard resolution...
April 1, 2018: Biomedical Optics Express
Yunpeng Dai, Xueli Chen, Jipeng Yin, Guodong Wang, Bo Wang, Yonghua Zhan, Yongzhan Nie, Kaichun Wu, Jimin Liang
Dynamic optical data from a series of sampling intervals can be used for quantitative analysis to obtain meaningful kinetic parameters of probe in vivo . The sampling schemes may affect the quantification results of dynamic fluorescence imaging. Here, we investigate the influence of different sampling schemes on the quantification of binding potential ( BP ) with theoretically simulated and experimentally measured data. Three groups of sampling schemes are investigated including the sampling starting point, sampling sparsity, and sampling uniformity...
April 1, 2018: Biomedical Optics Express
Alexey Lihachev, Ilze Lihacova, Emilija V Plorina, Marta Lange, Alexander Derjabo, Janis Spigulis
A clinical trial on the autofluorescence imaging of skin lesions comprising 16 dermatologically confirmed pigmented nevi, 15 seborrheic keratosis, 2 dysplastic nevi, histologically confirmed 17 basal cell carcinomas and 1 melanoma was performed. The autofluorescence spatial properties of the skin lesions were acquired by smartphone RGB camera under 405 nm LED excitation. The diagnostic criterion is based on the calculation of the mean autofluorescence intensity of the examined lesion in the spectral range of 515 nm-700 nm...
April 1, 2018: Biomedical Optics Express
Simon Peter Mekhail, Nilupaer Abudukeyoumu, Jonathan Ward, Gordon Arbuthnott, Síle Nic Chormaic
In order to observe deep regions of the brain, we propose the use of a fiber bundle for microendoscopy. Fiber bundles allow for the excitation and collection of fluorescence as well as wide field imaging while remaining largely impervious to image distortions brought on by bending. Furthermore, their thin diameter, from 200-500 µ m, means their impact on living tissue, though not absent, is minimal. Although wide field imaging with a bundle allows for a high temporal resolution since no scanning is involved, the largest criticism of bundle imaging is the drastically lowered spatial resolution...
April 1, 2018: Biomedical Optics Express
Thomas Pauwelyn, Richard Stahl, Lakyn Mayo, Xuan Zheng, Andy Lambrechts, Stefan Janssens, Liesbet Lagae, Veerle Reumers, Dries Braeken
The high rate of drug attrition caused by cardiotoxicity is a major challenge for drug development. Here, we developed a reflective lens-free imaging (RLFI) approach to non-invasively record in vitro cell deformation in cardiac monolayers with high temporal (169 fps) and non-reconstructed spatial resolution (352 µm) over a field-of-view of maximally 57 mm2 . The method is compatible with opaque surfaces and silicon-based devices. Further, we demonstrated that the system can detect the impairment of both contractility and fast excitation waves in cardiac monolayers...
April 1, 2018: Biomedical Optics Express
Juan Heredia-Juesas, Jeffrey E Thatcher, Yang Lu, John J Squiers, Darlene King, Wensheng Fan, J Michael DiMaio, Jose A Martinez-Lorenzo
The process of burn debridement is a challenging technique requiring significant skills to identify the regions that need excision and their appropriate excision depths. In order to assist surgeons, a machine learning tool is being developed to provide a quantitative assessment of burn-injured tissue. This paper presents three non-invasive optical imaging techniques capable of distinguishing four kinds of tissue-healthy skin, viable wound bed, shallow burn, and deep burn-during serial burn debridement in a porcine model...
April 1, 2018: Biomedical Optics Express
Yuanzhi Zhang, Huayi Hou, Yang Zhang, Yikun Wang, Ling Zhu, Meili Dong, Yong Liu
In order to reduce the influence of scattering and absorption on tissue fluorescence spectra, after tissue fluorescence and diffuse reflectance in different tissue optical properties were simulated by the Monte Carlo method, a tissue intrinsic fluorescence recovering algorithm making use of diffuse reflectance spectrum was developed. The empirical parameters in the tissue intrinsic fluorescence recovering algorithm were coded as a particle in the solution domain, the classification performance was defined as the fitness, and then a particle swarm optimization (PSO) algorithm was established for empirical parameters optimization...
April 1, 2018: Biomedical Optics Express
Yao-Xiong Huang, Lin Li, Liu Yang, Yi Zhang
Here we report a technique of laser chromosome welding that uses a violet pulse laser micro-beam for welding. The technique can integrate any size of a desired chromosome fragment into recipient chromosomes by combining with other techniques of laser chromosome manipulation such as chromosome cutting, moving, and stretching. We demonstrated that our method could perform chromosomal modifications with high precision, speed and ease of use in the absence of restriction enzymes, DNA ligases and DNA polymerases...
April 1, 2018: Biomedical Optics Express
William J Shain, Nicholas A Vickers, Jiang Li, Xue Han, Thomas Bifano, Jerome Mertz
High-speed volumetric imaging represents a challenge in microscopy applications. We demonstrate a technique for acquiring volumetric images based on the extended depth of field microscopy with a fast focal scan and modulated illumination. By combining two frames with different illumination ramps, we can perform local depth ranging of the sample at speeds of up to half the camera frame rate. Our technique is light efficient, provides diffraction-limited resolution, enables axial localization that is largely independent of sample size, and can be operated with any standard widefield microscope based on fluorescence or darkfield contrast as a simple add-on...
April 1, 2018: Biomedical Optics Express
Manoj Kumar Dasa, Christos Markos, Michael Maria, Christian R Petersen, Peter M Moselund, Ole Bang
We propose a cost-effective high-pulse energy supercontinuum (SC) source based on a telecom range diode laser-based amplifier and a few meters of standard single-mode optical fiber, with a pulse energy density as high as ~25 nJ/nm in the 1650-1850 nm regime (factor >3 times higher than any SC source ever used in this wavelength range). We demonstrate how such an SC source combined with a tunable filter allows high-resolution spectroscopic photoacoustic imaging and the spectroscopy of lipids in the first overtone transition band of C-H bonds (1650-1850 nm)...
April 1, 2018: Biomedical Optics Express
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