Biomedical Optics

Second-harmonic generation (SHG) and two-photon excitation fluorescence (TPEF) are relatively new and promising tools for the detailed imaging of biological samples and processes at the microscopic level. By exploiting these nonlinear phenomena phototoxicity and photobleaching effects on the specimens are reduced dramatically. The main target of this work was the development of a compact inexpensive and reliable experimental apparatus for nonlinear microscopy measurements. Femtosecond laser pulses were utilized for excitation. We achieved high-resolution imaging and mapping of Caenorhabditis elegans (C. elegans) neurons and muscular structures of the pharynx, at the microscopic level by performing SHG and TPEF measurements. By detecting nonlinear phenomena such as SHG and TPEF it is feasible to extract valuable information concerning the structure and the function of nematode neurons.

The use of transcranial low-level laser (light) therapy (tLLLT) to treat stroke and traumatic brain injury (TBI) is attracting increasing attention. We previously showed that LLLT using an 810-nm laser 4 h after controlled cortical impact (CCI)-TBI in mice could significantly improve the neurological severity score, decrease lesion volume, and reduce Fluoro-Jade staining for degenerating neurons. We obtained some evidence for neurogenesis in the region of the lesion. We now tested the hypothesis that tLLLT can improve performance on the Morris water maze (MWM, learning, and memory) and increase neurogenesis in the hippocampus and subventricular zone (SVZ) after CCI-TBI in mice. One and (to a greater extent) three daily laser treatments commencing 4-h post-TBI improved neurological performance as measured by wire grip and motion test especially at 3 and 4 weeks post-TBI. Improvements in visible and hidden platform latency and probe tests in MWM were seen at 4 weeks. Caspase-3 express...

We determine temperature effect on the absorption and reduced scattering coefficients (a and s Ј) of human forearm skin. Optical and thermal simulation data suggest that a and s Ј are determined within a temperature-controlled depth of Ϸ2 mm. Cutaneous s Ј change linearly with temperature. Change in a was complex and irreversible above body normal temperatures. Light penetration depth (␦) in skin increased on cooling, with considerable person-toperson variations. We attribute the effect of temperature on s Ј to change in refractive index mismatch, and its effect on a to perfusion changes. The reversible temperature effect on s Ј was maintained during more than 90 min. contact between skin and the measuring probe, where temperature was modulated between 38 and 22°C for multiple cycles While temperature modulated s Ј instantaneously and reversibly, a exhibited slower response time and consistent drift. There was a statistically significant upward drift in a and a mostly downward drift in s Ј over the contact period. The drift in temperature-induced fractional change in s Ј was less statistically significant than the drift in s Ј. ⌬ s Ј values determined under temperature modulation conditions may have less nonspecific drift than s Ј which may have significance for noninvasive determination of analytes in human tissue.

We describe a novel technical approach with enhanced fluorescence detection capabilities in twophoton microscopy that achieves deep tissue imaging, while maintaining micron resolution. Compared to conventional two-photon microscopy, greater imaging depth is achieved by more efficient harvesting of fluorescence photons propagating in multiple-scattering media. The system maintains the conventional two-photon microscopy scheme for excitation. However, for fluorescence collection the detection system harvests fluorescence photons directly from a wide area of the turbid sample. The detection scheme relies on a wide area detector, minimal optical components and an emission path bathed in a refractive-index-matching fluid that minimizes emission photon losses. This detection scheme proved to be very efficient, allowing us to obtain high resolution images at depths up to 3 mm. This technique was applied to in vivo imaging of the murine small intestine (SI) and colon. The challenge is to image normal and diseased tissue in the whole live animal, while maintaining high resolution imaging at millimeter depth. In Lgr5-GFP mice, we have been successful in imaging Lgr5-eGFP positive stem cells, present in SI and colon crypt bases.

We report on rapid identification of single bacteria using a low-cost, compact, Raman spectroscope. We demonstrate that a 60-s procedure is sufficient to acquire a comprehensive Raman spectrum in the range of 600 to 3300 cm⁻¹. This time includes localization of small bacteria aggregates, alignment on a single individual, and spontaneous Raman scattering signal collection. Fast localization of small bacteria aggregates, typically composed of less than a dozen individuals, is achieved by lensfree imaging over a large field of view of 24 mm². The lensfree image also allows precise alignment of a single bacteria with the probing beam without the need for a standard microscope. Raman scattered light from a 34-mW continuous laser at 532 nm was fed to a customized spectrometer (prototype Tornado Spectral Systems). Owing to the high light throughput of this spectrometer, integration times as low as 10 s were found acceptable. We have recorded a total of 1200 spectra over seven bacterial spe...

Polarization-sensitive optical coherence tomography ͑PS-OCT͒ and near-infrared ͑NIR͒ imaging are promising new technologies under development for monitoring early carious lesions. Fluorosis is a growing problem in the United States, and the more prevalent mild fluorosis can be visually mistaken for early enamel demineralization. Unfortunately, there is little quantitative information available regarding the differences in optical properties of sound enamel, enamel developmental defects, and caries. Thirty extracted human teeth with various degrees of suspected fluorosis were imaged using PS-OCT and NIR. An InGaAs camera and a NIR diode laser were used to measure the optical attenuation through transverse tooth sections ͑ϳ200 m͒. A digital microradiography system was used to quantify the enamel defect severity by measurement of the relative mineral loss for comparison with optical scattering measurements. Developmental defects were clearly visible in the polarizationresolved OCT images, demonstrating that PS-OCT can be used to nondestructively measure the depth and possible severity of the defects. Enamel defects on whole teeth that could be imaged with high contrast with visible light were transparent in the NIR. This study suggests that PS-OCT and NIR methods may potentially be used as tools to assess the severity and extent of enamel defects.

Oxygenation measurements are widely used in patient care. However, most clinically available instruments currently consist of contact probes that only provide global monitoring of the patient (e.g., pulse oximetry probes) or local monitoring of small areas (e.g., spectroscopy-based probes). Visualization of oxygenation over large areas of tissue, without a priori knowledge of the location of defects, has the potential to improve patient management in many surgical and critical care applications. In this study, we present a clinically compatible multispectral spatial frequency domain imaging (SFDI) system optimized for surgical oxygenation imaging. This system was used to image tissue oxygenation over a large area (16×12 cm) and was validated during preclinical studies by comparing results obtained with an FDA-approved clinical oxygenation probe. Skin flap, bowel, and liver vascular occlusion experiments were performed on Yorkshire pigs and demonstrated that over the course of the experiment, relative changes in oxygen saturation measured using SFDI had an accuracy within 10% of those made using the FDA-approved device. Finally, the new SFDI system was translated to the clinic in a first-in-human pilot study that imaged skin flap oxygenation during reconstructive breast surgery. Overall, this study lays the foundation for clinical translation of endogenous contrast imaging using SFDI.

Coronary calcified plaque (CP) is both an important marker of atherosclerosis and major determinant of the success of coronary stenting. Intracoronary optical coherence tomography (OCT) with high spatial resolution can provide detailed volumetric characterization of CP. We present a semiautomatic method for segmentation and quantification of CP in OCT images. Following segmentation of the lumen, guide wire, and arterial wall, the CP was localized by edge detection and traced using a combined intensity and gradient-based level-set model. From the segmentation regions, quantification of the depth, area, angle fill fraction, and thickness of the CP was demonstrated. Validation by comparing the automatic results to expert manual segmentation of 106 in vivo images from eight patients showed an accuracy of 78 ± 9%. For a variety of CP measurements, the bias was insignificant (except for depth measurement) and the agreement was adequate when the CP has a clear outer border and no guide-wire overlap. These results suggest that the proposed method can be used for automated CP analysis in OCT, thereby facilitating our understanding of coronary artery calcification in the process of atherosclerosis and helping guide complex interventional strategies in coronary arteries with superficial calcification.

Videokeratometers and Scheimpflug cameras permit accurate estimation of corneal surfaces. From height data it is possible to adjust analytical surfaces that will be later used for aberration calculation. Zernike polynomials are often used as adjusting polynomials, but they have shown to be not precise when describing highly irregular surfaces. We propose a combined zonal and modal method that allows an accurate reconstruction of corneal surfaces from height data, diminishing the influence of smooth areas over irregular zones and vice versa. The surface fitting error is decreased in the considered cases, mainly in the central region, which is more important optically. Therefore, the method can be established as an accurate resampling technique.

Optics has played a key role in the rapidly developing field of molecular imaging. The spectroscopic nature and high-resolution imaging capabilities of light provide a means for probing biological morphology and function at the cellular and molecular levels. While

Our aim is to apply image analysis on photosensitizer fluorescence and compare the relationship between histopathology and endoscopic fluorescence imaging. The correlation between hypericin fluorescence and histopathology of diseased tissue was explored in a clinical study involving 58 fluorescence cystoscopic images from 23 patients. Based on quantification of fluorescence colorimetric parameters extracted from the image analysis, diagnostic functions were developed to pathologically classify the bladder cancer. Our preliminary results show that the differences in fluorescence intensity ratios among the three different grades of bladder cancer are statistically significant. The results also show a decrease in macroscopic fluorescence intensity that correlated with higher cancer grades. By combining both the red-to-green and red-to-blue fluorescence intensity ratios into a 2-D scatter plot and defining diagnostic linear discrimination functions on the data points, this technique is able to yield an average sensitivity and specificity of around 68.6% and 86.1%, respectively, for pathological cancer grading of the three different grades of bladder cancer in our study. We conclude that our proposed approach in applying colorimetric intensity ratio analysis on hypericin fluorescence shows potential to optically grade bladder cancer in situ.

Medical laser applications based on widespread research and development is a very dynamic and increasingly popular field from an ecological as well as an economic point of view. Conferences and personal communication are necessary to identify specific requests and potential unmet needs in this multi-and interdisciplinary discipline. Precise gathering of all information on innovative, new, or renewed techniques is necessary to design medical devices for introduction into clinical applications and finally to become established for routine treatment or diagnosis. Five examples of successfully addressed clinical requests are described to show the long-term endurance in developing light-based innovative clinical concepts and devices. Starting from laboratory medicine, a noninvasive approach to detect signals related to iron deficiency is shown. Based upon photosensitization, fluorescence-guided resection had been discovered, opening the door for photodynamic approaches for the treatment of brain cancer. Thermal laser application in the nasal cavity obtained clinical acceptance by the introduction of new laser wavelengths in clinical consciousness. Varicose veins can be treated by innovative endoluminal treatment methods, thus reducing side effects and saving time. Techniques and developments are presented with potential for diagnosis and treatment to improve the clinical situation for the benefit of the patient.

A low-cost, fast, and noninvasive method for early diagnosis of malignant lesions of oral mucosa based on diffuse reflectance spectral signatures is presented. In this technique, output of a tungsten halogen lamp is guided to the tissue through the central fiber of a reflection probe whose surrounding six fibers collects tissue reflectance. Ex vivo diffuse reflectance spectra in the 400 to 600-nm region is measured from surgically removed oral cavity lesions using a miniature fiber optic spectrometer connected to a computer. Reflectance spectral intensity is higher in malignant tissues and shows dips at 542 and 577 nm owing to absorption from oxygenated hemoglobin ͑HbO 2 ͒. Measurements carried out, within an hour of surgical excision, on malignant lesion and adjoining uninvolved mucosa show that these absorption features are more prominent in neoplastic tissues owing to increased microvasculature and blood content. It is observed that reflectance intensity ratio of hemoglobin bands, R540/R575, from malignant sites are always lower than that from normal sites and vary according to the histological grade of malignancy. The diffuse reflectance intensity ratio R540/R575 of the hemoglobin bands appears to be a useful tool to discriminate between malignant lesions and normal mucosa of the oral cavity in a clinical setting.

... Molly J. Rossow, Rodolfo Gatto, Enrico D'Amico, William W. Mantulin and Enrico Gratton Physics Department, University of Illinois Urbana Champaign, 1110 West Green Street, Urban, IL 61801 [email protected] ... 6. References 1. Elson, EL and D. Madge (1974). ...

We have employed near-infrared optical methods to measure noninvasively the dynamics of muscle blood flow and oxygen saturation (S t O 2 ) during cuff occlusion and plantar flexion exercise. Relative muscle oxygen consumption (rVO 2 ) was also computed from these data. Diffuse correlation spectroscopy provides information about blood flow, and diffuse reflectance spectroscopy provides information about blood oxygenation. Ten healthy subjects and one patient with peripheral arterial disease (PAD) were studied during 3-min arterial cuff occlusion of arm and leg, and during 1-min plantar flexion exercise. Signals from different layers (cutaneous tissues and muscles) during cuff occlusion were differentiated, revealing strong hemodynamic responses from muscle layers. During exercise in healthy legs, the observed ϳ4.7 fold increase in relative blood flow (rBF) was significantly lower than the corresponding increase in rVO 2 (ϳ7 fold). The magnitudes of rBF and rVO 2 during exercise in the PAD patient were ϳ1/2 of the healthy controls, and the S t O 2 recovery time was twice that of the controls. The hybrid instrument improves upon current technologies for measuring muscle responses by simultaneously measuring rBF and S t O 2 . The instrument thus provides a method for evaluation of microcirculation and muscle metabolism in patients with vascular diseases.

We report on the modification of mechanical properties of breast cancer cells when they get in contact with other neighboring cells of the same type. Optical tweezers vertical indentation was employed to investigate cell mechanics in isolated and contact conditions, by setting up stiffness as a marker. Two human breast cancer cell lines with different aggressiveness [MCF-7 (luminal breast cancer) and MDA-MB-231 (basal-like breast cancer)] and one normal immortalized breast cell line HBL-100 (normal and myoepithelial) were selected. We found that neighboring cells significantly alter cell stiffness: MDA-MB-231 becomes stiffer when in contact, while HBL-100 and MCF-7 exhibit softer character. Cell stiffness was probed at three cellular subregions: central (above nucleus), intermediate (cytoplasm), and near the leading edge. In an isolated condition, all cells showed a significant regional variation in stiffness: higher at the center and fading toward the leading edge. However, the regional variation becomes statistically insignificant when the cells were in contact with other neighboring cells. The proposed approach will contribute to understand the intriguing temporal sequential alterations in cancer cells during interaction with their surrounding microenvironment.

The corneo-scleral limbus contains several biological components, which are important constituents for understanding, diagnosing and managing several ocular pathologies, such as glaucoma and corneal abnormalities. An anterior segment optical coherence tomography (AS-OCT) system integrated with optical microangiography (OMAG) is used in this study to non-invasively visualize the three-dimensional microstructural and microvascular properties of the limbal region. Advantages include first the ability to correct optical distortion of microstructural images enabling quantification of relationships in the anterior chamber angle. Second, microvascular images enable the visualization of the microcirculation in the limbal area without the use of exogenous contrast agents. Third, by combining the microstructural and microvascular information, the aqueous outflow pathway can be identified. The proposed AS-OCT can serve as a useful tool for ophthalmological research to determine normal and pathologic changes in the outflow system. As a clinical tool it has the potential to detect early aqueous outflow system abnormalities that lead to the pressure elevation in glaucoma. Recent surgical innovations and their implementations also rely on an assessment of outflow system structure and function, which can be revealed by AS-OCT.

ALGUNAS ESPECTROSCOPIAS OPTICAS EXISTEN DESDE HACE MAS DE DIEZ DECADAS; SIN EMBARGO, EN RECIENTES ANOS ESTAS TECNICAS SE HAN APLICADO EN DISTINTAS AREAS DEL CONOCIMIENTO. POR OTRO LADO, LA MEDICINA Y LA BIOLOGIA SON DOS AREAS DE INVESTIGACION DONDE LA OPTICA PUEDE FACILITAR EL ESTUDIO Y CARACTERIZACION DE TEJIDOS Y MOLECULAS BIOLOGICAS CON EL FIN DE MEJORAR EL DIAGNOSTICO CLINICO. LAS ESPECTROSCOPIAS OPTICAS PUEDEN AYUDAR EN EL ESTUDIO Y DETECCION DE ALGUNAS ENFERMEDADES DE MANERA MAS RAPIDA QUE LAS TECNICAS ESTANDAR DE LABORATORIO. EN ESTE TRABAJO, MOSTRAMOS ALGUNAS APLICACIONES DE LA ESPECTROSCOPIA RAMAN Y DEL ANALISIS MULTIVARIANTE EN ALGUNOS PROBLEMAS ESPECIFICOS DEL AREA BIOMEDICA, POR EJEMPLO: DETECCION DE CANCER DE MAMA, DIAGNOSTICO DE LA TOXOPLASMOSIS E IDENTIFICACION DE ISOTIPOS (IGG E IGM). Abstract ALTHOUGH SOME OPTICAL SPECTROSCOPY METHODS WERE INTRODUCED MORE THAN TEN DECADES AGO, THEY ARE STILL FINDING NEW APPLICATIONS IN MANY AREAS OF CIENCE. SPECIFICALLY, MEDICIN AND...

We present the optical measurement techniques used in human skin phantom studies. Their accuracy and the sources of errors in microscopic parameters’ estimation of the produced phantoms are described. We have produced optical phantoms for the purpose of simulating human skin tissue at the wavelength of 930 nm. Optical coherence tomography was used to measure the thickness and surface roughness and to detect the internal inhomogeneities. A more detailed study of phantom surface roughness was carried out with the optical profilometer. Reflectance, transmittance, and collimated transmittance of phantoms were measured using an integrating-sphere spectrometer setup. The scattering and absorption coefficients were calculated with the inverse adding-doubling method. The reduced scattering coefficient at 930 nm was found to be 1.57±0.14  mm(−1) and the absorption was 0.22±0.03  mm(−1) . The retrieved optical properties of phantoms are in agreement with the data found in the literature for r...

This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.

Hyperspectral imaging (HSI) is an emerging imaging modality for medical applications, especially in disease diagnosis and image-guided surgery. HSI acquires a three-dimensional dataset called hypercube, with two spatial dimensions and one spectral dimension. Spatially resolved spectral imaging obtained by HSI provides diagnostic information about the tissue physiology, morphology, and composition. This review paper presents an overview of the literature on medical hyperspectral imaging technology and its applications. The aim of the survey is threefold: an introduction for those new to the field, an overview for those working in the field, and a reference for those searching for literature on a specific application. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Monte Carlo (MC) simulations are often at the heart of the testing procedure in biomedical optics. One of the critical points in MC simulations is to define the new photon direction after each scattering event. One of the most popular solutions is to use the Henyey-Greenstein phase function or some linear combinations of it. In this note, we demonstrate that randomly generating the angle defining the new direction of a photon after a collision, by means of the Henyey-Greenstein phase function, is not equivalent to generating the cosine of this angle, as is classically done. In practice, it is demonstrated that for a nearly isotropic medium (asymmetry parameter g ∼ 0) this discrepancy is not large, however for an anisotropic medium as is typically found in vivo (e.g. g = 0.98) the two methods give completely different results.

Water is the most important biological liquid. On the basis of literature data we present a simple approximation of water refractive index in dependence on temperature and wavelength in the spectral range from 200 to 1 000 nm. The approximation is important for different applications in biomedical optics and optics of tissues.

High speed and ultra-high capacity optical communications have emerged as the essential techniques for backbone global information transmission networks. As the bit rate of the transmission system gets higher and higher 40 Gb/s to 100 Gb/s the modeling of proposed modulation techniques is very important so as to avoid costly practical demonstration. The search for a universal modeling platform for such systems is urgent. Matlab Simulink has become the universal mathematical and modeling tools in most universities and research laboratories around the world. This paper thus describes the modeling techniques for advanced photonic transmission systems and Simulink is proven to be very effective platform for development of photonic communications systems due its comprehensive blocksets. The simulation is based mainly on the physical phenomena and understanding of its concepts of communications and photonics. Simulink models are given as examples of various sub-systems of the photonic transmission systems. Some simulated transmission performances are demonstrated as examples of final results obtained from Simulink models of the transmission systems.

A new, freely available third party MATLAB toolbox for the simulation and reconstruction of photoacoustic wave fields is described. The toolbox, named k-Wave, is designed to make realistic photoacoustic modeling simple and fast. The forward simulations are based on a k-space pseudo-spectral time domain solution to coupled first-order acoustic equations for homogeneous or heterogeneous media in one, two, and three dimensions. The simulation functions can additionally be used as a flexible time reversal image reconstruction algorithm for an arbitrarily shaped measurement surface. A one-step image reconstruction algorithm for a planar detector geometry based on the fast Fourier transform ͑FFT͒ is also included. The architecture and use of the toolbox are described, and several novel modeling examples are given. First, the use of data interpolation is shown to considerably improve time reversal reconstructions when the measurement surface has only a sparse array of detector points. Second, by comparison with one-step, FFT-based reconstruction, time reversal is shown to be sufficiently general that it can also be used for finitesized planar measurement surfaces. Last, the optimization of computational speed is demonstrated through parallel execution using a graphics processing unit.

We have developed a novel nitroimidazole indocyanine dye conjugate for tumor-targeted hypoxia fluorescence tomography. The hypoxia probe has been evaluated in vitro using tumor cell lines and in vivo with tumor targeting in mice. The in vitro cell studies were performed to assess fluorescence labeling differences between hypoxia and normoxia conditions. When treated with the hypoxia probe, a fluorescence emission ratio of 2.5-fold was found between the cells incubated under hypoxia compared to the cells in normoxia condition. Hypoxia specificity was also confirmed by comparing the cells treated with indocyanine dye alone. In vivo tumor targeting in mice showed that the fluorescence signals measured at the tumor site were twice those at the normal site after 150 min post-injection of the hypoxia probe. On the other hand, the fluorescence signals measured after injection of indocyanine dye were the same at tumor and normal sites. In vivo fluorescence tomography images of mice injected with the hypoxia probe showed that the probe remained for more than 5 to 7 h in the tumors, however, the images of mice injected with indocyanine only dye confirmed that the unbound dye washed out in less than 3 h. These findings are supported with fluorescence images of histological sections of tumor samples using a Li-COR scanner and immunohistochemistry technique for tumor hypoxia.

pH is a tightly regulated indicator of metabolic activity. In mammalian systems, an imbalance of pH regulation may result from or result in serious illness. In this paper, we report photoacoustic microscopy (PAM) of a commercially available pH-sensitive fluorescent dye (SNARF-5F carboxylic acid) in tissue phantoms. We demonstrated that PAM is capable of pH imaging in absolute values at tissue depths of up to 2.0 mm, greater than possible with other forms of optical microscopy. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

Surface plasmon resonance based sensor for detection of different human blood groups in near infrared region is proposed. The plasmonic structure is based on fused silica or chalcogenide sulfide glass Ge 20 Ga 5 Sb 10 S 65, commonly known as 2S2G. Experimental results describing the wavelength-dependent refractive index variation in multiple samples of different blood groups are considered for theoretical calculations. The angular interrogation method is considered. The sensor's performance is closely analyzed ...

Spatial profiles of the optical fluence distribution in live tissues can be used for noninvasive measurements of tissue optical properties. Axial profiles of the optical fluence distribution can be, in turn, measured from the spatial profiles of the laser induced optoacoustic pressure. Short (nansecond) laser pulses and ultrawideband ultrasonic transducers enable these measurements.

Form Approved OMB No. 0704-0188 ^ihlif™P2.2"7^1 for this collection of Information Is estimated to average 1 hour per response, including the time for reviewing instructions, searching data sources 2? ". " 9 ? m 5 ning thB d 2 te n » eded j and competing and reviewing the collection of Information. Send comments regarding this burden estimate or any other aspect of this collection of information. Including suggestions for reducing this burden to Washington Headquarters Service, Directorate for Information Operations and Reports, ^ collection 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget Paperwork Reduction Project (0704-0188) Washington, DC 20503.

We present the prediction of malaria infection in human plasma using Raman spectroscopy. Raman spectra of malaria-infected samples are compared with those of healthy and dengue virus infected ones for disease recognition. Raman spectra were acquired using a laser at 532 nm as an excitation source and 10 distinct spectral signatures that statistically differentiated malaria from healthy and dengue-infected cases were found. A multivariate regression model has been developed that utilized Raman spectra of 20 malariainfected, 10 non-malarial with fever, 10 healthy, and 6 dengue-infected samples to optically predict the malaria infection. The model yields the correlation coefficient r 2 value of 0.981 between the predicted values and clinically known results of trainee samples, and the root mean square error in cross validation was found to be 0.09; both these parameters validated the model. The model was further blindly tested for 30 unknown suspected samples and found to be 86% accurate compared with the clinical results, with the inaccuracy due to three samples which were predicted in the gray region. Standard deviation and root mean square error in prediction for unknown samples were found to be 0.150 and 0.149, which are accepted for the clinical validation of the model. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

The importance of dermatological noninvasive imaging techniques has increased over the last decades, aiming at diagnosing nonmelanoma skin cancer (NMSC). Technological progress has led to the development of various analytical tools, enabling the in vivo/in vitro examination of lesional human skin with the aim to increase diagnostic accuracy and decrease morbidity and mortality. The structure of the skin layers, their chemical composition, and the distribution of their compounds permits the noninvasive photodiagnosis of skin diseases, such as skin cancers, especially for early stages of malignant tumors. An important role in the dermatological diagnosis and disease monitoring has been shown for promising spectroscopic and imaging techniques, such as fluorescence, diffuse reflectance, Raman and near-infrared spectroscopy, optical coherence tomography, and confocal laserscanning microscopy. We review the use of these spectroscopic techniques as noninvasive tools for the photodiagnosis of NMSC.

A number of noninvasive fiber optic optical technologies are under development for real-time diagnosis of neoplasia. We investigate how the light scattering properties of cervical cells are affected by changes in nuclear morphology, DNA content, and chromatin texture, which occur during neoplastic progression. We used a Cyto-Savant computer-assisted image analysis system to acquire quantitative nuclear features measurements from 122 Feulgen-thionin-stained histopathologic sections of cervical tissue. A subset of the measured nuclear features was incorporated into a finite-difference time-domain (FDTD) model of cellular light scattering. The magnitude and angular distribution of scattered light was calculated for cervical cells as a function of pathologic grade. The nuclear atypia strongly affected light scattering properties. The increased size and elevated DNA content of nuclei in high-grade lesions caused the most significant changes in scattering intensity. The spatial dimensions of chromatin texture features and the amplitude of refractive index fluctuations within the nucleus impacted both the angular distribution of scattering angles and the total amount of scattered light. Cellular scattering is sensitive to changes in nuclear morphology that accompany neoplastic progression. Understanding the quantitative relationships between nuclear features and scattering properties will aid in the development of noninvasive optical technologies for detection of precancerous conditions.

We compared the ability of 1.5 T magnetic resonance imaging (MRI), computed tomography (CT), and computed radiography (CR) to evaluate noncartilaginous structures of the equine metacarpophalangeal joint (MCP), and the association of imaging changes with gross cartilage damage in the context of osteoarthritis. Four CR projections, helical single-slice CT, and MRI (T1-weighted gradient recalled echo [GRE], T2 Ã -weighted GRE with fast imaging employing steady-state acquisition [FIESTA], T2weighted fast spin echo with fat saturation, and spoiled gradient recalled echo with fat saturation [SPGR-FS]) were performed on 20 racehorse cadaver forelimbs. Osteophytosis, synovial effusion, subchondral bone lysis and sclerosis, supracondylar lysis, joint fragments, bone marrow lesions, and collateral desmopathy were assessed with each modality. Interexaminer agreement was inferior to intraexaminer agreement and was generally moderate (i.e., 0.4ojo0.6). Subchondral bone sclerosis scores using CT or MRI were correlated significantly with the reference quantitative CT technique used to assess bone mineral density (Po0.0001). Scores for subchondral lysis and osteophytosis were higher with MRI or CT vs. CR (Po0.0001). Although differences between modalities were noted, osteophytosis, subchondral sclerosis, and lysis as well as synovial effusion were all associated with the degree of cartilage damage and should be further evaluated as potential criteria to be included in a whole-organ scoring system. This study highlights the capacity of MRI to evaluate noncartilaginous changes in the osteoarthritic equine MCP joint. r

study focuses on the preparation of thermoplastic polyurethane (TPU) nanocomposite using Vietnamese montmorillonite (MMT) as the reinforced phase. The MMT was previously modified by intercalating polyethylene oxide (PEO) and polyvinyl alcohol (PVA) molecules between the clay layers. X-ray diffraction (XRD) results of organoclays revealed that galleries of MMT were increased to 18. A and 2 A after their intercalation with PEO and PVA, respectively. Thermoplastic polyurethane (TPU) nanocomposites composed of 1, 3, 5, and 7%wt organoclays were synthesized. The result of XRD and transmission electron microscopic (TEM) analyses implied that the PEO modified MMT was well dispersed, at 3%wt, in polyurethane matrix. Fourier Transform Infrared Spectroscopic (FTIR) has confirmed this result by showing the hydrogenous interaction between the urethane linkage and OH group on the surface of silicate layer. Thermogravimetric (TG) showed that the organoclay samples also presented improved thermal ...

Three dimensional (3D) ophthalmic imaging using optical coherence tomography (OCT) has revolutionized assessment of the eye, the retina in particular. Recent technological improvements have made the acquisition of 3D-OCT datasets feasible. However, while volumetric data can improve disease diagnosis and follow-up, novel image analysis techniques are now necessary in order to process the dense 3D-OCT dataset. Fundamental software improvements include methods for correcting subject eye motion, segmenting structures or volumes of interest, extracting relevant data post hoc and signal averaging to improve delineation of retinal layers. In addition, innovative methods for image display, such as C-mode sectioning, provide a unique viewing perspective and may improve interpretation of OCT images of pathologic structures. While all of these methods are being developed, most remain in an immature state. This review describes the current status of 3D-OCT scanning and interpretation, and discusses the need for standardization of clinical protocols as well as the potential benefits of 3D-OCT scanning that could come when software methods for fully exploiting these rich data sets are available clinically. The implications of new image analysis approaches include improved reproducibility of measurements garnered from 3D-OCT, which may then help improve disease discrimination and progression detection. In addition, 3D-OCT offers the potential for preoperative surgical planning and intraoperative surgical guidance.

We review fluorescence lifetime techniques including timeresolved laser-induced fluorescence spectroscopy ͑TR-LIFS͒ and fluorescence lifetime imaging microscopy ͑FLIM͒ instrumentation and associated methodologies that allow for characterization and diagnosis of atherosclerotic plaques. Emphasis is placed on the translational research potential of TR-LIFS and FLIM and on determining whether intrinsic fluorescence signals can be used to provide useful contrast for the diagnosis of high-risk atherosclerotic plaque. Our results demonstrate that these techniques allow for the discrimination of important biochemical features involved in atherosclerotic plaque instability and rupture and show their potential for future intravascular applications.

Horse milk has long been a popular gourmet food with an exceptionally delicious flavor and subtle nuances found in no ordinary dairy product in central Asia. Equine milk has important nutritional and therapeutic properties that can benefit the diet of the elderly, convalescent or newborn. Horse milk seems with regard to composition on milk of people. It has a sweet taste because it contains a lot of lactases. Beside that the taste is very gentle and a little watery in comparison with cow milk. Horse milk contains less casein than cow milk as a result of which it is better digestible. In this study, we investigated the composition, equine milk proteins, milk allergy and Homology between mammal species with horse.

We performed epi-mode pump-probe imaging of melanin in excised human pigmented lesions and both hemoglobin and melanin in live xenograft mouse melanoma models to depths greater than 100 µm. Eumelanin and pheomelanin images, which have been previously demonstrated to differentiate melanoma from benign lesions, were acquired at the dermal-epidermal junction with cellular resolution and modest optical powers (down to 15 mW). We imaged dermal microvasculature with the same wavelengths, allowing simultaneous acquisition of melanin, hemoglobin and multiphoton autofluorescence images. Molecular pumpprobe imaging of melanocytes, skin structure and microvessels allows comprehensive, non-invasive characterization of pigmented lesions.