Here, we report a world-first bioluminescent indicator for membrane voltage, LOTUS-V. Since it is able to reveal voltage dynamics without external light source, LOTUS-V serves high contrast voltage imaging free from the effect of autofluorescence, suggesting its great versatility in the wide range of bioscience.

Using a common-path interferometric technique, we measure biomechanical and morphological properties of individual red blood cells in SCD patients as a function of cell density, and investigate the correlation of these biophysical properties with drug intake as well as other clinically measured parameters.

Raman spectroscopy is a valuable tool for non-invasive and label-free identification of sample chemical composition. Recently a few miniaturized optical probes emerged driven by the need to address areas of difficult access, such as in endoscopy. However, imaging modality is still out of reach for most of them. Separately, recent advances in wavefront shaping enabled different microscopies to be applied in various complex media including multimode fibers. Here we present the first and thinnest to date Raman fiber imaging probe based on wavefront shaping through a single multimode fiber without use of any additional optics. We image agglomerates of bacteria and pharmaceuticals to demonstrate the capability of our method. This work paves the way towards compact and flexible Raman endoscopy.

We attempted to observe deep regions in biological samples through two-photon excitation microscopy adopting a spatial light modulator (SLM). The SLM is used for correcting spherical aberration (SA) caused by the refractive-index mismatch between the immersion medium and sample. In the observation of fluorescent beads in transparent epoxy resin, the fluorescence intensity from a scan with SA correction was 50 times that from a scan without SA correction. After that, we observed blood vessels in a mouse brain, which became transparent with a clearing agent.

Schizophrenia is a debilitating mental disorder of which the biological underpinning is still unclear. Increasing evidence in neuroscience has indicated that schizophrenia arises from abnormal connections within or between networks, hence called dysconnectvity syndrome. Recently, we established an automatic method to analyze integrity of the white matter tracts over the whole brain based on diffusion MRI data, named tract-based automatic analysis (TBAA), and used this method to study white matter connection in patients with schizophrenia. We found that alteration of tract integrity is hereditary and inherent; it is found in siblings and in patients in the early phase of disease. Moreover, patients with good treatment outcome and those with poor outcome show distinctly different patterns of alterations, suggesting that these two groups of patients might be distinguishable based on the difference in tract alteration. In summary, the altered tracts revealed by TBAA might become potential biomarkers or trait markers for schizophrenia.

The classical limit of the spatial resolution, known as the diffraction limit, has been overcome by the recent development of super-resolution techniques. However, the main application of the technique is limited to fluorescence imaging. In our research, we have developed two techniques to improve the spatial resolution in Raman scattering imaging. We introduced the structured illumination to improve the spatial resolution in line-illumination Raman microscopy. We also utilized the saturation effect of coherent anti-Stokes Raman scattering to improve both spatial and spectral resolution simultaneously.

Osteoarthritis (OA) is very common joint disease in the aging population. Main symptom of OA is accompanied by degenerative changes of articular cartilage. Raman spectroscopy is a label-free technique which enables to analyze molecular composition in degenerative cartilage. We generated an animal OA model surgically induced by knee joint instability and performed Raman spectroscopic analysis for the articular cartilage. In the result, Raman spectral data of the articular cartilage showed drastic changes in comparison between OA and control side. The relative intensity of phosphate band increases in the degenerative cartilage.

Three-dimensional (3D) refractive-index (RI) microscopy is an emerging technique suitable for live-cell imaging due to its label-free and fast 3D imaging capabilities. We have developed a common-path system to acquire 3D RI microscopic images of cells with excellent speed and stability. After obtaining 3D RI distributions of individual leukocytes, we used a 3D finite-difference time-domain tool to study light scattering properties. Backscattering spectra of lymphocytes, monocytes and neutrophils are different from each other. Backscattering spectra of lymphocytes matched well with those of homogeneous spheres as predicted by Mie theory while backscattering spectra of neutrophils are significantly more intense than those of the other two types. This suggests the possibility of classifying the three types of leukocytes based on backscattering.

We describe a method to image objects through scattering media based on single-pixel detection and microstructured illumination. Spatial light modulators are used to project a set of microstructured light patterns onto the sample. The image is retrieved computationally from the photocurrent fluctuations provided by a single-pixel detector. This technique does not require coherent light, raster scanning, time-gated detection or a-priori calibration process. We review several optical setups developed by our research group in the last years with particular emphasis in a new optical system based on a double-pass configuration and in the combination of single-pixel imaging with Fourier filtering.

For transillumination imaging of an animal body, we have attempted to suppress the scattering effect in a turbid medium. It is possible to restore the optical image before scattering using phase-conjugate light. We examined the effect of intensity information as well as the phase information for the restoration of the original light distribution. In an experimental analysis using animal tissue, the contributions of the phase- and the intensity-information to the image restoration through turbid medium were demonstrated.

We have constructed a prototype instrument for holographic fluorescence microscopy (HFM) based on self-interference incoherent digital holography (SIDH) and demonstrate novel imaging capabilities such as differential 3D fluorescence microscopy and optical sectioning by compressive sensing.

Optical scanning holography (OSH) is a scanning-type digital holographic technique. In OSH, a heterodyne interference pattern is generated to raster scan the object. OSH can be operated in the incoherent mode and thus is able to record a fluorescence hologram. In addition, resolution of the OSH is proportional to the density of the interference pattern. Here we use a high-NA microscope objective to generate a dynamic Fresnel zone plate to record a hologram of micro-specimen. The achieved transverse resolution and longitudinal resolution are 0.78μm and 3.1μm, respectively.

We have been developing a simple and practical video microscopy system based on absorption spectra of biological substance to perform spectroscopic observation of living tissues. The diffuse backlighting effect is actively used in the developed system, which is generated by multiple light scattering in the tissue. It is demonstrated that the light specularly reflected from the skin surface can be completely suppressed in the microscopic observation and the biological activity of the capillary vessel systems distributed under the skin can be successfully observed. As a result, we can confirm the effectiveness of the video microscopy system using diffuse backlighting and the applicability of our developed system.

We propose single-shot incoherent digital holography with a common-path configuration and single-shot four-step phase-shifting interferometry and construct a system based on the proposal. Space-division multiplexing and states of the polarizations of the waves are utilized to implement single-shot phase-shifting interferometry. A common-path setup is constructed to capture an incoherent hologram easily with a compact system. An instantaneous and three-dimensional object image is obtained without undesired diffraction waves by phase-shifting interferometry from a single recorded image. The validity of the proposed technique is experimentally investigated for an object with a diameter of 1 mm.

We demonstrated that the high spatial resolution absorption contrast imaging of the crystal of vitamin B9 having absorption at UV wavelengths. The absorption wavelength matches with the wavelength of the emission of the fluorescent thin film of an electron-beam excitation assisted (EXA) optical microscope. The fine crystal structure was imaged beyond the optical diffraction limit. The image contrast corresponded with the thickness of the crystal. The illumination light is absorbed with the vitamin B9 crystal and the intensity of the transmitted light depends on the thickness of the vitamin B9 crystal. The EXA optical microscope is useful for analysis of growth of a crystal, bioimaging, and so on.

The optical heterogeneity of biological tissue imposes a major limitation to acquire detailed structural and functional information deep in the biological specimens using conventional microscopes. To restore optimal imaging performance, we developed an adaptive optical microscope based on direct wavefront sensing technique. This microscope can reliably measure and correct biological samples induced aberration. We demonstrated its performance and application in structural and functional brain imaging in various animal models, including fruit fly, zebrafish and mouse.

Diffraction limit of resolution has been one of the biggest limitations in the optical microscopy. Super-resolution fluorescence microscopy has enabled us to break this limit. However, for the observations of real biological specimens, especially for the imaging of tissues or whole body, the target structures of interest are often embedded deep inside the specimen. Here, we would present our results to extend the target of the super-resolution microscopy deeper into the cells. Confocal microscope optics work effectively to minimize the effect by the aberrations by the cellular components, but at the expense of the signal intensities. Spherical aberrations by the refractive index mismatch between the cellular environment and the immersion liquid can be much larger, but can be reduced by adjusting the correction collar at the objective lens.

We introduce our two research activities related to computational imaging through scattering media. The first topic is holographic imaging with coded diffraction. The second topic is sensing through scattering media based on machine learning. Our approaches can simplify optical setups by means of computational assistances compared with those in conventional systems.

Live-cell imaging using fluorescent molecules is now essential for biological researches. However, images of living cells are accompanied with blur, which becomes stronger according to the depth inside the cells and tissues. This image blur is caused by the disturbance on light that goes through optically inhomogeneous living cells and tissues. Here, we show adaptive optics (AO) imaging of living plant cells. AO has been developed in astronomy to correct the disturbance on light caused by atmospheric turbulence. We developed AO microscope effective for the observation of living plant cells with strong disturbance by chloroplasts, and successfully obtained clear images inside plant cells.

Decoding of information in the brain requires the imaging of large neuronal networks using e.g. two-photon microscopy (TPM). Fast control of the focus in 3D can be achieved with phase shaping of the light beam using acoustooptic deflectors (AODs). However, beam shaping using AODs is not straightforward because of non-stationary of acousto-optic diffraction. Here, we demonstrated a new stable AOD-based phase modulator, which operates at a rate of up to about hundred kHz. It provides opportunity for 3D scanning in TPM with the possibility to correct aberrations independently for every focus position or to achieve refocusing of scattered photons in rapidly decorrelating tissues.

We present methods of fluorescence confocal microscopy that enable unprecedentedly high frame rate of > 10,000 fps. The methods are based on a frequency-division multiplexing technique, which was originally developed in the field of communication engineering. Specifically, we achieved a broad bandwidth (~400 MHz) of detection signals using a dual- AOD method and overcame limitations in frame rate, due to a scanning device, by using a multi-line focusing method, resulting in a significant increase in frame rate. The methods have potential biomedical applications such as observation of sub-millisecond dynamics in biological tissues, in-vivo three-dimensional imaging, and fluorescence imaging flow cytometry.

Dynamic optical coherence elastography (OCE) is expected as new diagnostic technology of near tissue surface. However, few studies about shear wave propagation in inhomogeneous medium have been reported although human tissue is inhomogeneous medium. In this report, estimation of shear wave speeds and strain images of inhomogeneous medium were studied using swept-source optical coherence tomography (SS-OCT) system. Firstly, the shear wave speeds of four-layered chicken sample were measured. Secondly, OCT images of tissue mimicking phantoms, which included thread and aluminum wire were measured and strain distributions were calculated by PIV. Reflection and artifact of strain images were discussed.

Optical microscopy is an indispensable tool for medical and life sciences. Especially, the microscopes utilized with scattering light offer a detailed internal observation of living specimens in real time because of their non-labeling and non-invasive capability. We here focus on two kinds of scattering lights, Raman scattering light and second harmonic generation light. Raman scattering light includes the information of all the molecular vibration modes of the molecules, and can be used to distinguish types and/or state of cell. Second harmonic generation light is derived from electric polarity of proteins in the specimen, and enables to detect their structural change. In this conference, we would like to introduce our challenges to extract biological information from those scattering lights.

Cell image analysis is important for research and discovery in biology and medicine. In this paper, we present our cell tracking methods, which is capable of obtaining fine-grain cell behavior metrics. In order to address difficulties under dense culture conditions, where cell detection cannot be done reliably since cell often touch with blurry intercellular boundaries, we proposed two methods which are global data association and jointly solving cell detection and association. We also show the effectiveness of the proposed methods by applying the method to the biological researches.

Intracellular temperature distribution is an emerging target in biology nowadays. Because thermal diffusion is rapid dynamics in comparison with molecular diffusion, we need a spatiotemporally high-resolution imaging technology to catch this phenomenon. We demonstrate that time-lapse imaging which consists of single-shot 3D volume images acquired at high-speed camera rate is desired for the imaging of intracellular thermal diffusion based on the simulation results of thermal diffusion from a nucleus to cytosol.

A multi-contrast imaging of pathologic posterior eyes is demonstrated by Jones matrix optical coherence tomography (Jones matrix OCT). The Jones matrix OCT provides five tomographies, which includes scattering, local attenuation, birefringence, polarization uniformity, and optical coherence angiography, by a single scan. The hardware configuration, algorithms of the Jones matrix OCT as well as its application to ophthalmology is discussed.

A spectrometer design with a multiple line line-scan camera and beam displacer is presented for ultra-high resolution optical coherence tomography measurements of the human retina at 840 nm. The beam displacer offsets the two orthogonal polarization states on the same line-scan camera, which reduces k-space mapping complexity, as data in both polarization channels can be mapped with the same procedure. Its coherence length is 2.8 μm in tissue (n = 1.38). Birefringence values of 1°/μm and higher were found in a circle with a radius of 2.5° eccentricity centered on the fovea, and in the raphe, pointing at a higher packing density of microtubules and a lower concentration of glia. Birefringence measurements may be more helpful in the modeling of individual structure-function maps than thickness measurements, as they are not affected by glial content.

The nail provides a functional protection to the fingertips and surrounding tissue from external injuries. Nail plate divided into three layers including dorsal, intermediate, and ventral layers. The dorsal layer consists of compact, hard keratins, limiting topical drug delivery through the nail. In this study, we investigate the application of fractional CO₂ laser that produces arrays of microthermal ablation zones (MAZs) to facilitate drug delivery in the nails. Moreover, optical coherence tomography (OCT) is implemented for real-time monitoring of the laser–skin tissue interaction, sparing the patient from invasive surgical sampling procedure. Observations of drug diffusion through the induced MAZ array are achieved by evaluating the time-dependent OCT intensity variance. Subsequently, nails are treated with cream and liquid topical drugs to investigate the feasibility and diffusion efficacy of laser-assisted drug delivery. Our results show that fractional CO₂ laser improves the efficacy of topical drug delivery in the nail plate, and that OCT could potentially be used for in vivo monitoring of the depth of laser penetration as well as real-time observations of drug delivery.

We present an adaptive-optics optical coherence tomography (AO-OCT) system with 3.4-mm beam diameter. A deformable mirror is used for the correction of two radial Zernike orders (defocus, vertical and oblique astigmatism). The aberrations are corrected sequentially with a Shack-Hartmann wave-front sensor and the deformable mirror. This system fills a gap between a standard clinical 1.2-mm beam diameter OCT system and a 6-mm beam diameter AO-OCT system. We also present 8° by 8° en face OCT images from a patient with macular degeneration. This system has a 25 cm by 50 cm footprint, which makes it considerably smaller to conventional 6-mm beam diameter AO-OCT system. Because of its larger field of view and smaller size, it is likely to be useful in the ophthalmic clinics for high-resolution imaging of the human eye retina.

Physiological signals are important for tracking health and emotional states. Imaging photoplethysmography (iPPG) is a set of techniques for remotely recovering cardio-pulmonary signals from video of the human body. Advances in iPPG methods over the past decade combined with the ubiquity of digital cameras presents the possibility for many new, lowcost applications of physiological monitoring. This talk will highlight methods for recovering physiological signals, work characterizing the impact of video parameters and hardware on these measurements, and applications of this technology in human-computer interfaces.

The purpose of this paper is the measurement of spatial-temporal movements by using stereo vision and 3D optical flow algorithms applied at biological samples. Stereo calibration procedures and algorithms for enhance the contrast intensity were applied. The system was implemented for working at the first near infrared windows (NIR-I) at 850 nm due of the penetration depth obtained at this region in biological tissue. Experimental results of 3D tracking of human veins are presented showing the characteristics of the implementation.

Nervous system relies on a continuous and adequate supply of blood flow, bringing the nutrients that it needs and removing the waste products of metabolism. Failure of these mechanisms is found in a number of devastating cerebral diseases, including stroke, vascular dementia, brain injury and trauma. Vasomotion which is the spontaneous low-frequency oscillation derived by the contraction and relaxation of arterioles and appears to be an intrinsic property of the cerebral vasculature, is important for monitoring the cerebral flow, tissue metabolism and health status of brain tissue. In the present study, we investigated a method to visualize the spontaneous low-frequency oscillation of cerebral blood volume based on the sequential RGB images of exposed brain.

High-speed microscopy three-dimensional (3D) microscopy based on trans-illumination is implemented with an amplitude light modulator placed at the Fourier plane of the system. The phase of an incident wave-front is modified and encoded with a defocus parameter to divert the light onto different portion of an image plane depending on their diffraction order and depth positions. The design of the grating pattern for the light modulated is discussed through the simulation and the experiment. 3D imaging capability is demonstrated through the experiment.

Single-molecule localization techniques are effective to resolve fluorescence images with higher resolution. To increase the frame rate, high-density positions of individual fluorescence emitters should be measured. We are studying a Bayesian-based localization method for measuring high density molecular positions with fluorescence coded images. In this paper, a scheme of several color quantum dots aligned with DNA nanostructures are considered. We confirmed that the proposed method could be applied to fluorescence images of quantum dots experimentally and that the positions of the aligned fluorescence emitters at intervals of 80 nm could be measured with little errors in numerical simulations.

We propose three-wavelength phase-shifting interferometry selectively extracting wavelength information from wavelength-multiplexed images with arbitrary phase shifts. Wavelength information is multiplexed on the space and spatial frequency domains and is separated in the polar coordinate plane by utilizing the proposed phase-shifting interferometry. 0th-order diffraction waves and conjugate images are also removed from wavelength-multiplexed images when extracting wavelengths separately. As a result, a full spatial bandwidth of a monochromatic image sensor at each wavelength is available with a small number of images. Images required for three-wavelength three-dimensional imaging with a full spatial bandwidth of a monochromatic image sensor are decreased and speeding up of measurement is expected in comparison with a conventional technique. The validity of the proposed technique is numerically confirmed.

This paper provides overall analytical insights on the common-path incoherent digital holography using dual-focusing lens with diffraction gratings. Especially when one tries to seek an off-axis solution using the suggested configuration, the low temporal and spatial coherence require specific conditions on parameters of the set-up. AA mathematical explanation on the off-axis digital holography is described.

Digital holography is a useful technique for recording and reconstruction of the complex amplitude of an optical field. In this technique, an interference pattern of two waves is detected by an image sensor, and digital holograms are acquired in computer. The wavefront is reconstructed by a numerical calculation. In this study, we present the real-time threedimensional counting and shape measurement of RBCs using flow cytometry with digital holographic microscopy.

In this study, we propose a method to enhance the spatial resolution of digital holographic microscopy with speckle-illumination. In this method, speckle patterns are generated from coherence light passing through ring-slit apertures instead of the most typical circular apertures, to obtain higher numerical aperture. The results show that a reconstructed image with the higher resolution is obtained using ring-slit apertures.

We have proposed a digital holographic microscope using a planar lightwave circuit. Using the system, we report the evaluation of the spatial resolution and measurement of Closterium.

To treat cataract intraocular lenses (IOLs) are used to replace the clouded human eye lens. Due to postoperative healing processes the IOL can displace within the eye, which can lead to deteriorated quality of vision. To test and characterize these effect an IOL can be embedded into a model of the humane eye. One informative measure are wavefront aberrations. In this paper three different setups, the typical double-pass configuration (DP), a single-pass (SP1) where the measured light travels in the same direction as in DP and a single-pass (SP2) with reversed direction, are investigated. All three setups correctly measure the aberrations of the eye, where SP1 is found to be the simplest to set up and align. Because of the lowest complexity it is the proposed method for wavefront measurement in model eyes.

We report here a holographic high speed accessing microscope of sensory-driven synaptic activity across all inputs to single living neurons in the context of the intact cerebral cortex. This system is based on holographic multiple beam generation with spatial light modulator, we have demonstrated performance of the holographic excitation efficiency in several in vitro prototype system. 3D weighted iterative Fourier Transform method using the Ewald sphere in consideration of calculation speed has been adopted; multiple locations can be patterned in 3D with single hologram. Standard deviation of intensities of spots are still large due to the aberration of the system and/or hologram calculation, we successfully excited multiple locations of neurons in living mouse brain to monitor the calcium signals.

Local temperature measurement in deep areas of objects is an important technique in biomedical measurement. We have investigated a non-contact method for measuring temperature inside an object using a point detector for infrared (IR) light. An IR point detector with a pinhole was constructed and the radiant IR light emitted from the local interior of the object is photodetected only at the position of pinhole located in imaging relation. We measured the thermal structure of the filament inside the miniature bulb using the IR point detector, and investigated the temperature dependence at approximately human body temperature using a glass plate positioned in front of the heat source.

Photoacoustic method to detect hidden dental caries is proposed. It was found that high frequency ultrasonic waves are generated from hidden carious part when radiating laser light to occlusal surface of model tooth. By making a map of intensity of these high frequency components, photoacoustic images of hidden caries were successfully obtained. A photoacoustic imaging system using a bundle of hollow optical fiber was fabricated for using clinical application, and clear photoacoustic image of hidden caries was also obtained by this system.

Raman spectroscopy offers information-rich spectra, making it a technique easy to use in areas such as biology, chemistry, and in the field. Human hair spectra has been recorded obtaining interesting information about its composition. Correlating information obtained from these spectra to bone health and determining if Raman spectroscopy could be used as a diagnostic tool of bone health is proposed. Spectra from healthy women were compared to the spectra of women who have suffered a bone fracture, all which were aged 39-60. This technique has potential to become a regular diagnostic tool and further investigation to improve and validate this method are needed.

Raman microspectroscopy is an optical compound identification technique, which is widely used nowadays for different field applications. A crucial part of this technique is the focus given to the sample in the microscope because it depends on which part of the sample it will analyze. In this work, the effects of irradiating a natural hair samples, obtained from women aged 18 to 55, with a monochromatic light of the Raman spectrometer in two different focus is presented. Two different spectra were obtained with a peak in common. Depending on the information wanted, how the sample is focused plays a crucial role, either way the spectra is information-rich and may be used for biomedical applications.

Publisher’s Note: This paper, originally published on 18 April 2017, was withdrawn by author's request and also because the paper was not presented at the conference.

To evaluate the bone quality in the osteoporosis, we generated sciatic nerve resection (NX) mice as an osteoporosis model and analyzed by Raman spectroscopy. Raman spectra were measured in anterior cortical surface of the proximal tibia at 5 points in each bone. After that, the samples were fixed with 70% ethanol. We then performed DXA and μCT measurement. Raman peak intensity ratios were significantly different between NX and Control. Those changes in the Raman peak intensity ratios may reflect loss of bone quality in the osteoporosis model. Raman spectroscopy is a promising technique for measuring the bone quality and bone strength.

In this study, a swept-source optical coherence tomography (OCT) system is developed for in vivo visualization of structural and vascular morphology oral mucosa. For simplification of optical probe fabrication, probe weight, and system setup, the body of the scanning probe is fabricated by a 3D printer to fix the optical components and the mechanical scanning device, and a partially reflective slide is attached at the output end of probe to achieve a common-path configuration. Aside from providing the ability of 3D structural imaging with the developed system, 3D vascular images of oral mucosa can be simultaneously obtained. Then, different locations of oral mucosa are scanned with common-path OCT. The results show that epithelium and lamina propria layers as well as fungiform papilla can be identified and microvascular images can be acquired. With the proposed probe, the system cost and volume can be greatly reduced. Experimental results indicate that such common-path OCT system could be further implemented for oral cancer diagnosis.

In this study, we propose to use gas-filled microbubbles (MBs) simultaneously actuated by the acoustic wave to enhance the imaging contrast of optical coherence tomography (OCT)-based angiography. In the phantom experiments, MBs can result in stronger backscattered intensity, enabling to enhance the contrast of OCT intensity image. Moreover, simultaneous application of low-intensity acoustic wave enables to temporally induce local vibration of particles and MBs in the vessels, resulting in time-variant OCT intensity which can be used for enhancing the contrast of OCT intensitybased angiography. Additionally, different acoustic modes and different acoustic powers to actuate MBs are performed and compared to investigate the feasibility of contrast enhancement. Finally, animal experiments are performed. The findings suggest that acoustic-actuated MBs can effectively enhance the imaging contrast of OCT-based angiography and the imaging depth of OCT angiography is also extended.

A dual illumination system is proposed for cornea and retina imaging using spectral domain optical coherence tomography (SD-OCT). The system is designed to acquire cornea and retina imaging with dual illumination with limited optics and using a single spectrometer. The beam propagation for cornea and retina imaging in dual illumination enables to acquire the images of different segments. This approach will reduce the imaging time for separate corneal and retinal imaging. The in vivo imaging of both the cornea and retina of a health volunteer shows the feasibility of the system for clinical applications

Here we describe the possible application of optical coherence tomography (OCT) to inspect Marssonina coronaria infected apple blotch disease of in situ apple leaves. To fulfill the in situ field inspection requirement, we developed a compact wearable OCT system. For the confirmation of OCT results, simultaneous experiment was performed in realtime using loop-mediated isothermal amplification (LAMP), which is frequently used in agriculture. LAMP method was developed as an alternative approach for the inspection of disease. We performed field inspection for 30 consecutive days, and all the acquired results from both OCT and lamp were compared to confirm the correlation. A clear identification between healthy specimens, apparently healthy but infected specimens, and infected specimens could be obtained through the real-time OCT images, and the correlation between OCT and lamp results was confirmed through the obtained realtime lamp results. Based on this feasibility study, we conclude that the combination of both these diagnosing modalities can be effective for various novel agricultural discoveries.

We have investigated imaging characteristics of full-field OCT (FFF-OCT) using a LED and aa super-continuum (SC) laser with a wavelength-tunable filter. The wavelength selectivity in visible range enables to take spectroscopic tomographic images. It has been considered that the application of the LED-OOCT system might be restricted due to the low spatial coherence and illuminating power. Comparative study of imaging characteristics of the OCT images taken the RGB-visible LED and the SC laser demonstrates superiority of the LED illumination in reconstruction of detail structures.

Adaptive optics is useful not only for the suppression of the blur of image, but also for the reduction of the aberration on the transmitted light. Recent years, methods for optical manipulation of biological tissue under the microscope is becoming available, whereas the live tissue often causes the considerable amount of optical aberration that prevents the clear convergence of the laser beam onto the target cell. This research shows the basic experiments to improve the convergence of the laser beam focused on the tissue in microscope by correcting the optical aberration using adaptive optics.

The content of collagen is up to 30% existing in mammals. It supports the main component of connective tissues such as skin, ligament, and cartilage. Among various types of collagen, type-I collagen is of the most abundance and has been broadly studied due to the importance in bioscience. Second harmonic generation (SHG) microscopy is an effective tool used to study the collagen organization without labeling. In this study, we used circular polarization instead of linear polarization to retrieve three-dimensional (3D) molecular orientation of type-I collagen with only two cross polarized SHG images without acquiring an image stack of varying polarization.

We present the enhancement of targeted treatment on colon cancer cell via microscopic imaging ellipsometry (MIE). All spectroscopic MIE signals on 5μm×5μm area in visible range are captured within the modified Optrel MULTISKOP system. Colon cancer cells are cultured in Bottom-up Millicell EZ SLIDE 4-well structure under the environment (37°C, 10% CO₂). Original single colon cancer cell, single colon cancer cell under untargeted-treatment, and single colon cancer cell under targeted-treatment are studied by specular-reflective mode and off-specular scattering mode in this experiment. Some polarization-related and phase-related MIE images are analyzed to reveal the improvement of targeted-treatment by observing changes in specular and off-specular reflectance and absorption.

A novel of glucose sensing method based on differential Mueller matrix polarimetry is proposed. An analytical model is derived for extracting the optical rotation angle (γ) and degree of depolarization properties (Δ) of glucose sample with scattering affects. The practical feasibility of the proposed method is demonstrated by the experimental results for the sensitivity of the γ and Δ with the glucose samples with 2% phantom particles. The results show that the extracted valued of γ and Δ vary linearly with the glucose concentration over the measured range of 0 to 100 mg/dl with lowest increment of 20 mg/dl. In general, the proposed technique provides a reliable and simple method for low concentration of glucose sensing.

There are sulcus cutis and crista cutis on human skin surface. It is known that these affect the light propagation in human skin. To investigate it experimentally, it is desirable to reproduce sulcus cutis and crista cutis in skin tissue phantom. In this study, we made a prototype of skin tissue phantom having a shape of sulcus cutis and crista cutis, and investigated its optical properties and problems to be solved.

Light propagation into human skin tissue is studied by using Monte Carlo simulation (MCS) with the multi-layered skin tissue model. In this study, we analyzed light propagation in various internal conditions of skin tissue by calculating photon fluence based on Monte Carlo simulation. And we examined a method for quantitative evaluation on the depth and spread of light propagation in skin tissue.

Skin surface texture has an influence on light propagation in tissue and changes the impression of the skin appearance. We use Monte Carlo simulation for estimating spectral reflectance in human skin. However, the simulation was made for parallel layered model having a flat surface. In this study, we investigated to use texture-added skin model in the simulation. We confirmed that a change of intensity distribution was found when the skin surface texture was changed.

Skin measurements based on spectral reflectance are widely studied in the fields of medical care and cosmetics. It has the advantage that several skin properties can be estimated in the non-invasive and non-contacting manner. In this study, we demonstrate the color reproduction of human skin by spectral reflectance using RGB images and the Wiener estimation method.

In this study, we fabricated a dual type fiber-optic radiation sensor (DFORS) system using a spectroscopic technique to measure alpha and beta particles simultaneously and separately. The DFORS is composed of a sensing probe, a plastic optical fiber (POF), a photomultiplier tube (PMT)-amplifier system, and a multichannel analyzer (MCA). As sensing probes, a ZnS(Ag) film and CaF2(Eu) crystal were used for alpha and beta spectroscopy. And, we measured the alpha and beta energy spectra using the proposed DFORS system to discriminate species of the radioisotopes emitting alpha or beta particle. From the experimental results, we demonstrated that the small-sized, flexible, and insertable DFORS system can measure and discriminate the alpha and beta successfully with the spectral information of each radioisotope.

Light propagation in the slab head model that consists of five types of tissues was calculated to estimate the fluorescent intensity emerged from a molecular probe in the brain by a Monte Carlo simulation. The thickness of the scalp, skull and cerebrospinal fluid layer was varied to analyze the influence of the thickness of the superficial tissues on the fluorescent intensity detected on the scalp surface. The fluorescent intensity is exponentially reduced with increasing the depth of the brain surface. The thickness of the cerebrospinal fluid layer more significantly affects the fluorescent intensity than that of the scalp and skull.

In this work gallium (Ga)-Doped ZnO nanorods (GZO NRs) successfully applied for the development of enzyme free glucose. GZO NRs synthesized by using the hydrothermal on ZnO seed layer was subsequently deposited onto the glass substrate. The GZO NRs electrode has peak currents increasing from 620 to 941μA with glucose concentration (6, 8 and 10 mM) in cyclic voltammograms. GZO NRs electrode sensitivity of the sensor to glucose oxidation was 33.4 (μA/mM-cm²). The GZO NRs modified electrode showed a greatly enhanced electrocatalytic property toward glucose oxidation, as well as an excellent anti-interference and a good stability.

For non-invasive measurement of blood glucose level, attenuated total reflection (ATR) absorption spectroscopy system using a QCL as a light source was developed. The results of measurement of glucose solutions showed that the system had a sensitivity that was enough for blood glucose measurement. In-vivo measurement using the proposed system based on QCL showed that there was a correlation between absorptions measured with human lips and blood glucose level.

As new materials have been reported and more knowledge on detailed mechanism of glucose oxidation has been unveiled, the non-enzymatic glucose sensor keeps coming closer to practical applications. Nanostructures with higher surface specific area has great potential applications in sensing devices ZnO nanoords were synthesized in a hydrothermal method using simply available laboratory chemicals. Results showed that as-synthesized Gold Nanoparticle-decorated ZnO Nanorods possessing higher specific surface area, significantly increased the non-enzyme efficiency which in turn improved the sensing performances. The electrode also demonstrated excellent performance in sensing glucose concentration with remarkable sensitivity (46.6 μA/mM-cm²) and good repeatability. This work is expected to open a new avenue to fabricate non-enzymatic electrochemical sensors of glucose involving co-mediating.

A fluorescence measuring method based on glass multi-capillary for detecting trace amounts of proteins is proposed. It promises enhancement of sensitivity due to effects of the adsorption area expansion and the longitudinal excitation. The sensitivity behavior of this method was investigated by using biotin-streptavidin binding. According to experimental examinations, it was found that the sensitivity was improved by a factor of 70 from common glass wells. We also confirmed our measuring system could detect 1 pg/mL of streptavidin. These results suggest that multi-capillary has a potential as a high-sensitive biosensor.

Abnormal corneas with corneal tissue defects like ulceration, melting, laceration, thinning scar, keratoconus etc., poses special challenges for ophthalmologist to measure intraocular pressure (IOP) correctly using air-puff noncontact applanation tonometry. Here, we propose an novel model, Abnormal Applanation IOP Model (AAIOP), to simulate IOP in these abnormal corneas on an air-puff noncontact applanation tonometry system, and the simulated IOP results are correctly fit in those of IOP measured database on human eyes of 91,024 patients (174,666 eyes)¹). Our simulated IOP indicates that every 10 μm of central corneal thickness change results in 0.36 mmHg of IOP change. Using our simulation model, the IOP on abnormal eyes with irregularly-shaped corneas can be correctly expected and reported.

To evaluate the performance of intraocular lenses to treat cataract, an optomechanical eye model was developed. One of the most crucial components is the IOL holder, which should guarantee a physiological representation of the capsular bag and a stable position during measurement sequences. Individual holders are required due to the fact that every IOL has different geometric parameters. A method which allows obtaining the correct dimensions for the holder of a special IOL was developed and tested, by verifying the position of the IOL before and after a measurement sequence. Results of telecentric measurements and MTF measurements show that the IOL position does not change during the displacement sequence induced by the stepper motors of the eye model.

The relationship between probe positions of near-infrared spectroscopy instruments and functional areas in the brain is very important for the brain function measurement. Light propagation in a standard brain was calculated to consider the broadening of the probing region caused by the tissue scattering in the NIRS measurements to determine the relationship between the probe positions and the functional areas. The NIRS signal tends to reflect the brain activation in different functional areas and the primary functional area is possibly different from that indicated by the simple projection of the measurement point.

This paper describes a fiber optics based pH sensor by using wavelength modulated techniques. Fiber Bragg grating (FBG) is functionalized with a stimulus responsive hydrogel which induces a strain on FBG due to mechanical expansion of the gel in response to ambient pH changes. The gel is synthesized from the blends of Poly (vinyl alcohol)/Poly (acrylic acid). The induced strain results in a shift of FBG reflected peak which is monitored by an interrogator. The sensor system shows a good linearity in acidic pH range of 3 to 7 with a sensitivity of 12.16pm/pH. Besides that it shows good repeatability which proves it to be fit for pH sensing applications.

Focused ultrasound (FUS) has been a novel solution for noninvasive treatment in various biomedical applications. FUS enables to temporally and locally increase drug delivery efficiency from the vessels into the surrounding area. However, the temporal effects and the exposure power of FUS are important issues for treatment. In this study, we propose to use high-magnification microscope to investigate the microcirculation of mouse skin after FUS exposures. In the experimental setup, the back skin of mouse is fixed on a window chamber and the window chamber area is exposed to various FUS exposure powers, and the skin is simultaneously imaged by the microscope. Additionally, an imaging process algorithm was developed to acquire vascular images based on the estimation of speckle variance due to flowing red blood cells. Finally, the changes due to various exposure powers are investigated. The results show that FUS enables to result in temporal changes in the vessels size and blood velocity as well as the flow directions.

Optical manipulation techniques proposed so far almost depend on carefully fabricated setups and samples. Similar conditions can be fixed in laboratories, however, it is still a challenging work to manipulate nanoparticles when the environment is not well controlled and is unknown in advance. Nonetheless, coherent light scattered by rough object generates speckles which are random interference patterns with well-defined statistical properties. In the present study, we numerically investigate the motion of a particle in a flow under the illumination of a speckle pattern that is at rest or in motion. Trajectory of the particle is simulated in relation to a flow velocity and a speckle contrast to confirm the feasibility of the present method for performing optical manipulation tasks such as trapping and guiding.