Noninvasive blood glucose monitoring has been a long-standing dream in diabetes management. The use of Raman spectroscopy, with its molecular specificity, investigated this regard over the past decade. Previous studies reported on sensing based indirect evidence such as statistical correlation to reference concentration. However, these claims fail demonstrate peaks, which raised questions regarding effectiveness spectroscopy for sensing. Here, we first direct observation peaks from vivo...

Photoacoustic microscopy (PAM) is used to visualize blood vessels and monitor their time-dependent changes. Photoplethysmography (PPG) measures hemodynamic time-series changes such as heart rate. However, PPG's limited visual access the dynamic of has prohibited further understanding hemodynamics. Here, we propose a novel, fully integrated PAM photoplethysmography (PAM-PPG) system understand features in detail. Using PAM-PPG system, simultaneously acquire vascular images (by PAM) volume PPG)...

Postprandial hyperglycemia, blood glucose spikes, induces endothelial dysfunction, increasing cardiovascular risks. Endothelial dysfunction leads to vasoconstriction, and observation of this phenomenon is important for understanding acute hyperglycemia. However, high-resolution imaging microvessels during hyperglycemia has not been fully developed. Here, we demonstrate that photoacoustic microscopy can noninvasively monitor morphological changes in vessels live animals' extremities when...

In this letter, we present a modification of Vertical Bell Laboratories Layered Space-Time (V-BLAST), and propose an effective transmit power allocation (TPA) scheme for the modified system. The proposed TPA minimizes uncoded bit-error rate (BER) averaged over all detection stages, requires small feedback overhead. Simulation results show that V-BLAST system with provides significant reduction in BER compared conventional When minimum mean-square error nulling is adopted, found to achieve...

We present the formation of a singular (diabolical) point in k-space from periodic metal-dielectric waveguide array. The singularity originates balance between alternating normal and anomalous coupling. numerically demonstrate strong diffraction anomaly (conical-like diffraction) near point. also show evolution pattern with band deformation. resultant peculiar propagation dynamics surface plasmon polaritons could provide new toolset for manipulating light on nano-scale.

We report high performance reflective color filters based on one-dimensional metal-dielectric multilayer. Wide viewing angle of ±50°, far beyond that with conventional all-dielectric multilayers, is achieved while maintaining approximately 100% peak reflectance and reproducibility. Reflectance 40% in white mode gamut 47% to the United States National Television Systems Committee (NTSC) standard demonstrated. The proposed filter integrated into 3.5-in. display shows 30% increase brightness...

Raman spectroscopy is commonly used in analytical chemistry for identification of molecules based on the analysis spectral lines spectrum corresponding to molecular vibrations. For solids and gases, usually high resolution required. many other applications, however, a less critical, while compactness reduced system cost are increasingly important. Several studies have already shown applicability low (LRRS) systems wide variety fields, such as situ monitoring process control, on-site...

Stratum corneum is the outer most part of skin for barrier function. Disorder in stratum related with many diseases including acne, atopic dermatitis and psoriasis. In developed countries, about 20% population has disorder function corneum. Adhesive tape stripping a method to disrupt studying this study, we obtained NIR (Near-Infrared) spectrum human after stripping. Changes spectra disruption were investigated through principal component analysis (PCA) spectrum. PCA revealed that peaks -NH...

Electrical methods are among the primarily studied non-invasive glucose measurement techniques; however, various factors affect accuracy of sensors used. Of these, temperature is a critical factor; hence, effects on electrical properties blood components investigated in this study. Furthermore, changes according to level corrected by considering properties. An impedance sensor developed and used measure whole 10 healthy participants at temperatures levels. Subsequently, conductivities plasma...

Biological production of citramalate has garnered attention due to its wide application for food additives and pharmaceuticals, although improvement yield is known be challenging. When glucose used as the sole carbon source, loss through decarboxylation steps providing acetyl-CoA from pyruvate inevitable. To avoid this, we engineered a strain co-utilize cost-effective acetate while preventing enhancing production. The pathway diverged independently supply precursors required synthesis...

Recently the world population with diabetes has increased significantly, and market demand for noninvasive blood glucose monitoring accordingly. Our previous study demonstrated capability to detect through direct observation of Raman fingerprint peaks from in vivo skin but using a benchtop device. From perspective commercialization, miniaturized devices are expected make more impact on than bulky devices. In this study, as an effort commercialization sensing technology, we investigate...

Abstract Optical throughput and optical path length are key parameters to obtain high signal noise ratio sensor sensitivity for the detection of skin tissue components based on short wavelength infrared (SWIR) spectroscopy. These should be taken into account at stage system design. We aim develop a method estimate efficiency effective water newly designed SWIR spectroscopy measurement using Monte-Carlo photon migration simulation. To length, we investigated characteristics simulation...

Bio-impedance analysis provides non-invasive estimation of body composition. Recently, applications based on bio-impedance measurement in skin tissue such as cancer diagnosis and composition monitoring have been studied. For scanning the electrical properties along depth, relationship between electrode topologies depth sensitivity should be clarified. This work reports a systematic designing line to measure layer at specific using finite element method (FEM). Four electrodes consisting two...

In this paper, we introduce a floating plasmonic absorber having multiple resonances in the 8 ~ 14 μm spectral range and broadband absorption characteristics by adjusting Drude relaxation rate of metal. This resonator capable capturing light with large optical cross-section area is able to substantially enhance performance micro-bolometer (response time, noise equivalent temperature difference, pixel size so on) due significantly reduced thermal mass conductance. Firstly, adjust rate, mean...

We present an efficient lossless coding method for skin spectral data. In contrast to the conventional prefix-based methods, proposed algorithm utilizes unique property of data which changes monotonically with wavelength. The compression ratio alone is similar those previous ones in average. However, when our hybridized a one, increases two times. This study provides highly way storing especially continuous big bio-signal measured from wearable devices.

Advanced glycation end products (AGE) are produced by non-enzymatic reaction between glucose and biomolecules including proteins. AGE accumulation is known to cause alternations of structure function in proteins be related with an increased risk diabetic complications, cardiovascular diseases, aging processes. Conventionally, has been estimated measuring auto fluorescence level using ultraviolet (UV) light excitation. In this study, we investigated alternative approach estimate thus vivo...

We introduce recent research activities on optical MEMS (micro-electro-mechanical systems) and nanophotonics in Samsung Electronics. Several key devices for commercial applications such as lenses, shutters, switches, absorbers are discussed. The developed based various tuning mechanisms by electro active polymer, electrostatic, micro-electro-fluidic actuation. Also, we discuss applicability of nanophotonic components to infrared imaging applications.

We suggest a method to monitor dehydration status using the change of albumin concentration measured from short wavelength infrared (SWIR) in-vivo spectrum. Absorption spectra were on swine skin Fourier transform spectroscopy based system, while and rehydration subject induced by intravenous infusion mannitol saline solutions, respectively. The effective water path length amount absorption regressed Then, was acquired normalizing length. Experimental results showed that increases during...

We present the formation of a singularity in <i>k</i>-space from periodic metal-dielectric nanostructure. The originates balance between alternating normal and anomalous coupling. By employing formalism Dirac dynamics for relativistic quantum particles, we theoretically describe propagation surface plasmon polaritons demonstrate strong diffraction anomaly (conical-like diffraction) near singular point.

For noninvasive glucose sensing, we investigate the relationship between Raman spectrometer specification, especially collection efficiency, and prediction performance in computer simulation. The simulation for synthetic spectrum generation was designed to include signals at specific concentrations, Monte-Carlo used simulate a multi-layer model of skin tissue. We quantified tendency decrease efficiency deterioration performance. This study can be important analysis specification required...

Abstract Optical throughput and optical path length are key parameters to obtain high signal noise ratio sensor sensitivity for the detection of skin tissue components based on short wavelength infrared (SWIR) spectroscopy. These should be taken into account at stage system design. We aim develop a method estimate efficiency effective water newly designed SWIR spectroscopy measurement using Monte-Carlo photon migration simulation. To length, we investigated characteristics simulation...

Although diffuse reflectance measurement has convenience in obtaining spectra from skin, it extremely low light efficiency compared with other configurations as the skin forward scattering characteristics. To increase amount of photon illumination and enhance SNR, we suggest a honeycombed optical interface multi-fibers based probe for skin. Experimental results human swine measurements show spectral noise range 13~16 µAU effective water path length 1.8~2.2 mm. With this interface, 5~6 times...