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Journal of Biomedical Optics

Norihiro Honda, Katsunori Ishii, Yoshinaga Kajimoto, Toshihiko Kuroiwa, Kunio Awazu
The optical properties of human brain tumor tissues, including glioblastoma, meningioma, oligodendroglioma, and metastasis, that were classified into "strong," "vague," and "unobservable" fluorescence by a neurosurgeon were measured and compared. The optical properties of the tissues were measured with a double integrating sphere and the inverse Monte Carlo technique from 350 to 1000 nm. Using reasons of ex-vivo measurement, the optical properties at around 420 nm were potentially affected by the hemoglobin content in tissues...
July 2018: Journal of Biomedical Optics
Subhasri Chatterjee, Tomas Ysehak Abay, Justin Paul Phillips, Panayiotis A Kyriacou
Photoplethysmography (PPG) is an optical noninvasive technique with the potential for assessing tissue perfusion. The relative time-change in the concentration of oxyhemoglobin and deoxyhemoglobin in the blood can be derived from DC part of the PPG signal. However, the absolute concentration cannot be determined due to the inadequate data on PPG optical paths. The optical path and differential pathlength factor (DPF) for PPG at red (660 nm) and infrared (880 nm) wavelengths were investigated using a heterogeneous Monte Carlo model of the human forearm...
July 2018: Journal of Biomedical Optics
Patrick Delafontaine-Martel, Joel Lefebvre, Pier-Luc Tardif, Bernard I Lévy, Philippe Pouliot, Frédéric Lesage
Given known correlations between vascular health and cognitive impairment, the development of tools to image microvasculature in the whole brain could help investigate these correlations. We explore the feasibility of using an automated serial two-photon microscope to image fluorescent gelatin-filled whole rodent brains in three-dimensions (3-D) with the goal of carrying group studies. Vascular density (VD) was computed using automatic segmentation combined with coregistration techniques to build a group-level vascular metric in the whole brain...
July 2018: Journal of Biomedical Optics
Zahra Turani, Emad Fatemizadeh, Qiuyun Xu, Steven Daveluy, Darius Mehregan, Mohammad Reza Nasiri Avanaki
We propose an algorithm to compensate for the refractive index error in the optical coherence tomography (OCT) images of multilayer tissues, such as skin. The performance of the proposed method has been evaluated on one- and two-layer solid phantoms, as well as the skin of rat paw.
July 2018: Journal of Biomedical Optics
Nikola Krstajić, Bethany Mills, Ian Murray, Adam Marshall, Dominic Norberg, Thomas H Craven, Philip Emanuel, Tushar R Choudhary, Gareth O S Williams, Emma Scholefield, Ahsan R Akram, Andrew Davie, Nik Hirani, Annya Bruce, Anne Moore, Mark Bradley, Kevin Dhaliwal
A highly sensitive, modular three-color fluorescence endomicroscopy imaging platform spanning the visible to near-infrared (NIR) range is demonstrated. Light-emitting diodes (LEDs) were sequentially pulsed along with the camera acquisition to provide up to 20 frames per second (fps) three-color imaging performance or 60 fps single color imaging. The system was characterized for bacterial and cellular molecular imaging in ex vivo human lung tissue and for bacterial and indocyanine green imaging in ex vivo perfused sheep lungs...
July 2018: Journal of Biomedical Optics
Salvatore Smirni, Michael P MacDonald, Catherine P Robertson, Paul M McNamara, Sean O'Gorman, Martin J Leahy, Faisel Khan
Correlation mapping optical coherence tomography (cmOCT) is a powerful technique for the imaging of skin microvessels structure, based on the discrimination of the static and dynamic regions of the tissue. Although the suitability of cmOCT to visualize the microcirculation has been proved in humans and animal models, less evidence has been provided about its application to examine functional dynamics. Therefore, the goal of this research was validating the cmOCT method for the investigation into microvascular function and vasomotion...
July 2018: Journal of Biomedical Optics
Jesus Sambrano, Alexandre Chigaev, Kapil S Nichani, Yelena Smagley, Larry A Sklar, Jessica P Houston
Förster resonance energy transfer (FRET) continues to be a useful tool to study movement and interaction between proteins within living cells. When FRET as an optical technique is measured with flow cytometry, conformational changes of proteins can be rapidly measured cell-by-cell for the benefit of screening and profiling. We exploit FRET to study the extent of activation of α4β1 integrin dimers expressed on the surface of leukocytes. The stalk-like transmembrane heterodimers when not active lay bent and upon activation extend outward...
July 2018: Journal of Biomedical Optics
Lu An, Benjamin T Cox
Independent component analysis (ICA) is an unmixing method based on a linear model. It has previously been applied in in vivo multiwavelength photoacoustic imaging studies to unmix the components representing individual chromophores by assuming that they are statistically independent. Numerically simulated and experimentally acquired two-dimensional images of tissue-mimicking phantoms are used to investigate the conditions required for ICA to give accurate estimates of the relative chromophore concentrations...
July 2018: Journal of Biomedical Optics
Jesse Korber, Connor Barth, Summer Gibbs
Surgical nerve damage due to difficulty with identification remains a major risk for postsurgical complications and decreased quality of life. Fluorescence-guided surgery offers a means to specifically highlight tissues of interest such as nerves and a number of fluorescence-guided surgical systems are in clinical trial or are approved for clinical use. However, no clinically approved nerve-specific fluorophores exist. In addition, many preclinical nerve-specific fluorophores tend to accumulate in adipose tissue due to the molecular composition similarities between the two tissues, making it challenging to generate a specific nerve signal...
July 2018: Journal of Biomedical Optics
Ravikiran Attota
In recent years, the use of through-focus (TF) or volumetric type of optical imaging has gained momentum in several areas such as biological imaging, microscopy, adaptive optics, material processing, optical data storage, and optical inspection. We provide a review of basic TF optical methods highlighting their design, major unique characteristics, and application space.
July 2018: Journal of Biomedical Optics
Zhifang Li, Qinggong Tang, Timm Dickfeld, Yu Chen
Atrial fibrillation (AF) is the most common cardiac arrhythmia and has high patient morbidity. One of the root causes of AF is initiating triggers from atrial myocardium extending into the pulmonary veins. Visualizing the muscular bundles of myocardial extension is essential to guide the catheter radio-frequency ablation and confirm the curative tissue necrosis thereafter. We applied optical coherence tomography (OCT) for direct visualization of cardial muscle extension in myocardium pulmonary junction. Two perspectives (cross-sectional and en face images) are presented for imaging myocardial extensions...
July 2018: Journal of Biomedical Optics
Stefan Andersson-Engels, Peter Andersen
A guest editorial to introduce the Special Section on Selected Topics in Biophotonics: Optogenetics and Label-Free Optical Spectroscopy.
July 2018: Journal of Biomedical Optics
Zuzana Orságová Králová, Andrej Oriňak, Renáta Oriňaková, Ondrej Petruš, Ján Macko, Jozef Radoňak, Lucia Sukovská Lakyová, Zuzana Jurašeková, Roger Smith, Magdaléna Strečková, Karol Koval
Surface-enhanced Raman spectroscopy (SERS) of blood plasma on an electrochemically prepared silver surface has been studied as a label-free, noninvasive diagnostic test for colorectal cancer. Indium tin oxide glass substrates were modified with 0.01  mol dm  -  3 silver nitrate using the pulsed double-potentiostatic method. The prepared silver substrates were tested with Rhodamine 6G as a model analyte and the surface with the highest signal enhancement was selected. This silver dendritic surface was used as a diagnostic substrate for SERS measurements of human blood plasma...
July 2018: Journal of Biomedical Optics
Hsun-Chia Hsu, Lei Li, Junjie Yao, Terence T W Wong, Junhui Shi, Ruimin Chen, Qifa Zhou, Lihong Wang
Optical-resolution photoacoustic microscopy (OR-PAM) has demonstrated fast, label-free volumetric imaging of optical-absorption contrast within the quasiballistic regime of photon scattering. However, the limited numerical aperture of the ultrasonic transducer restricts the detectability of the photoacoustic waves, thus resulting in incomplete reconstructed features. To tackle the limited-view problem, we added an oblique illumination beam to the original coaxial optical-acoustic scheme to provide a complementary detection view...
July 2018: Journal of Biomedical Optics
Adam Eshein, Andrew Radosevich, Bradley Gould, Wenli Wu, Vani Konda, Leslie Yang, Ann Koons, Seth Feder, Vesta Valuckaite, Hemant Roy, Vadim Backman, The-Quyen Nguyen
While there are a plethora of in vivo fiber-optic spectroscopic techniques that have demonstrated the ability to detect a number of diseases in research trials with highly trained personnel familiar with the operation of experimental optical technologies, very few techniques show the same level of success in large multicenter trials. To meet the stringent requirements for a viable optical spectroscopy system to be used in a clinical setting, we developed components including an automated calibration tool, optical contact sensor for signal acquisition, and a methodology for real-time in vivo probe calibration correction...
July 2018: Journal of Biomedical Optics
Jaroslava Joniová, Veronika Kažiková, Emmanuel Gerelli, Gregor Bánó, Georges Wagnières
Models mimicking the endogenous production of protoporphyrin IX (PpIX), as well as its fluorescence, are of high interest for applied and fundamental studies in the fields of cancer detection by fluorescence imaging, photodynamic therapy (PDT), and photobiomodulation (PBM). Here, we present and describe optical properties of the yeast-based models able to produce PpIX endogenously after the administration of 5-aminolevulinic acid (ALA) and/or 2,2'-bipyridyl. As their optical properties have an important impact on the spatial distribution of the fluence rate in these liquid models, their absorption and reduced scattering coefficients were determined to be between 400 and 808 nm for two yeast solutions previously described by our group...
July 2018: Journal of Biomedical Optics
Christopher Wilson, Joshua D Kennedy, Pierce Irby, Nathaniel Fried
Thulium fiber laser lithotripsy using smaller optical fibers may enable development of miniature ureteroscopes. Two ureteroscope distal tip prototypes were built and characterized. The first design was 4.5-French (Fr) [1.5-mm outer diameter (OD)], five channel tip, housing 200-μm inner diameter (ID) dedicated central channel for insertion of 100-μm core fibers and four surrounding channels, each with 1.5 Fr (510-μm ID) for instrumentation, irrigation, imaging, and illumination, respectively. The second design was 6...
July 2018: Journal of Biomedical Optics
Andrea Anzalone, Jenu V Chacko, Rebecca A Nishi, Courtney Dumont, Dominique Smith, Lonnie D Shea, Michelle A Digman, Brian J Cummings, Aileen J Anderson
Spinal cord injury (SCI) causes permanent paralysis below the damaged area. SCI is linked to neuronal death, demyelination, and limited ability of neuronal fibers to regenerate. Regeneration capacity is limited by the presence of many inhibitory factors in the spinal cord environment. The use of poly(lactide-co-glycolide) (PLG) bridges has demonstrated the ability to sustain long-term regeneration after SCI in a cervical hemisection mouse model. Critically, imaging of regenerating fibers and the myelination status of these neuronal filaments is a severe limitation to progress in SCI research...
June 2018: Journal of Biomedical Optics
Jun Liao, Shaowei Jiang, Zibang Zhang, Kaikai Guo, Zichao Bian, Yutong Jiang, Jingang Zhong, Guoan Zheng
Digital pathology via whole-slide imaging (WSI) systems has recently been approved for the primary diagnostic use in the US. Acquiring whole-slide images with spectral information at each pixel permits the use of multiplexed antibody labeling and allow for the measurement of cellularly resolved chemical information. Here, we report the development of a high-throughput terapixel hyperspectral WSI system using prism-based slit-array dispersion. We demonstrate a slit-array detection scheme for absorption-based measurements and a slit-array projection scheme for fluorescence-based measurements...
June 2018: Journal of Biomedical Optics
Gang Sun, Xiaoyan Liu, Ling Gao, Pu Zhang, Siyuan Wang, Yandan Zhou
Examination of the retinal circulation in patients with retinal diseases is a clinical routine for ophthalmologists. In the present work, an automatic method is proposed for measuring the global retinal circulation in fluorescein angiography (FA). First, the perfusion region in FA images is segmented using a multiscale line detector. Then, the time evolution of the perfusion area is modeled using damped least-squares regression. Based on the perfusion area profile, some circulation parameters are defined to describe quantitatively the global retinal circulation...
June 2018: Journal of Biomedical Optics
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