This PDF file contains the front matter associated with SPIE Proceedings Volume 12159, including the Title Page, Copyright information, and Table of Contents.

Multifocal multiphoton microscopy (MMM) by forming multifocal created with a lenslet array enables high-speed imaging than single-focal multiphoton microscopy. However, most multifocal multiphoton microscopy has a problem of degrading image quality compared to single-focal microscopes. In order to solve this problem, it is necessary to equalize the intensity of the multifocal incident light. The fluorescence signal emitted from the fluorescence material is determined by the intensity of the incident light, but compared to the single-focal multiphoton microscope, the incident light passing through the lenslet array not only causes problems in acquiring fluorescence images but also limits the field of view (FOV). This problem was overcome by using a specially designed beam shaper to equalize the multifocal incident light intensity. Another problem with MMM is that typical biopsy samples are opaque, so light scattering occurs when light is irradiated onto the sample. This is a cause of the noise that degrades image quality by generating crosstalk in which fluorescence signals emitted from each focus deviate from the focal plane and interfere with each other. For the minimization of crosstalk, we set up the algorithm technology to correct the sensitivity non-uniformity between channels of multi-channel photomultiplier tubes (PMT). And to minimize crosstalk between PMT circuits, an independent short-channel photon discriminator was designed to expand the number of focal points of the MMM system. Among the problems of MMM, two techniques were introduced, and it was confirmed that the noise of the fluorescence image was reduced. ¬

A completely novel Surface Plasmon Resonance (SPR) biosensor based on 2 D material Graphene and Transition Metal Dichalcogenides (TMDC) WS2 (Tungsten disulfide) is proposed for the detection of the urine glucose concentration levels. This proposed structure is comprised of the five-layered in the order of the Prism- Au-Graphene-WS2-Biosample.

Bio sample is having the glucose level in the range of 0 -15 mg/dl (for normal person) and 0.625 gm/dL, 1.25 gm/dL, 2.5 gm/dL, 5 gm/dL, and 10 gm/dL (for diabetic person) respectively with the corresponding refractive indices of 1.335,1.336,1.337,1.338,1.341,1.347.

The performance parameters ie. reflectance SPR curves and sensitivity are obtained for the optimized thickness of Gold (Au), Graphene, and WS2 layers, by using the transfer matrix method. Compared with the conventional SPR based biosensor, graphene-WS2 layers can increase the sensitivity of the biosensor. The highest sensitivity of the SPR biosensor with an optimized thickness of 50 -nm Au/0.34-nm Graphene/1.60-nm WS2 is 211 °/RIU which is approximately 40% and 15% higher than the sensitivity of the conventional biosensor and the graphene-based biosensor respectively. Due to its unique optical properties, WS2 remarkably enhances the sensitivity of the proposed sensor in the detection of glucose concentration. Additionally, it is expected that the proposed biosensor has the potential to be fabricated in the scale of nonorange and can be used where the continuous monitoring of glucose is required because of its significant response corresponding to the minute change of 0.001 in the refractive index of the biosample.

Endoscopic biliary drainage including stent are a well-accepted clinical method for treating common bile duct (CBD) stenosis, but the treatment is only successful in the short term with stent exchange at 3 to 6 months. The current study aims to demonstrate a novel endoscopic retrograde cholangiopancreatography (ECRP)-guided laser ablation technique on CBD stenosis by using a balloon catheter-integrated diffusing applicator (BCDA) for uniform treatment of tubular tissue. A 532 nm laser system was employed with BCDA to thermally coagulate the CBD tissue. For performance assessments, photothermal and mechanical responses of the tissue were evaluated in both ex vivo and in vivo mini-pig models in terms of structural and histological variations after the laser treatment. The ex vivo results confirmed the irreversible thermal denaturation in liver tissue without carbonization. The in vivo mini-pig tests confirmed high durability of BCDA during the ERCP procedures and no evidence of CBD perforation. Histological analysis validated a thin circumferential coagulation in the CBD with no or minimal injury to the peripheral organs. The proposed BCDA-assisted treatment may be a feasible endoscopic ablation method for treating disease or disorder in a tubular tissue structure. Further in vivo studies will investigate CBD stenosis-developed animal models to evaluate the chronic response of the laser-treated CBD tissue as well as the recurrence of CBD stenosis.

Xenopus laevis are emerging models to study human diseases and to investigate pharmaceutical effects in vivo due to smaller size and faster developmental rates. It is also an effective organism to observe drug effects on phenotypic characteristics because it can provide many biological systems in a short time and remain optically accessible at the early stages of development. Although morphological evaluation of massive Xenopus data is an essential procedure, it requires labor-intensive and manual inspection under an optical microscope. In this study, we propose a high-throughput, widefield, and time-lapse phenotype screening system modifying the office scanner. We also fabricated the customized PDMS well plate for efficient and stress-free imaging of living Xenopus laevis samples in normal and drug environments. With our manipulated device, we were successfully able to monitor the morphological changes of Xenopus laevis embryos acquired from more than 180 wells throughout 72 hours post fertilization stage. Our home-built software combines best practices of image processing and deep learning for automated accurate segmentation of large Xenopus data. Importantly, phenotypic features are quantitatively extracted to monitor the early-stage morphological abnormalities. In addition, the convolutional neural network (CNN) based algorithm enable to classify phenotype precisely. In conclusion, compared to conventional microscope screening, our platform offers high-throughput, accurate, and fast quantitative phenotype analysis. The suggested platform could become a promising tool in massive and dynamic observation such as developmental studies, drug testing, and phenotype-genotype assays, where statistical knowledge is critical.

This work reports the first demonstration of plasmonic hyperspectral camera by using an active plasmonic tunable filter (APTF) consisting of ultrathin angle-sensitive nanostructures and compact bimorph actuator. APTF clearly exhibits continuous peak shifting from 800 nm to 1000 nm depending on voltages with 1.0 - 3.0 V. Then, fully packaged with compact B/W camera which accomplished the compact plasmonic hyperspectral camera (PHC) with total size of 16 x 16 x 28 mm. Finally, hyperspectral imaging was demonstrated using the PHC so that the featured spectrum of fruits and hand vein was successfully reconstructed.

We have developed an integrated photoacoustic (PA) and ultrasonic (US) endoscopy mini-probe system that can provide coregistered PA and US B-scan images at 20 Hz via the 3.8-mm diameter standard instrument channel of a clinical video endoscope. As the probe was adequately implemented in terms of the dimensions required for a typical gastrointestinal endoscopy mini-probe as well as the integrability of the optical and acoustic elements, we could acquire optical-resolution in vivo PA images from the esophagogastric junction of a swine for the first time. We expect that the developed endoscopic technique could make an important contribution to gastrointestinal endoscopy.

Any spectroscopic method based on exciting a sample through resonant or non-resonant interactions with a light source reaches a detection limit when too few photons interact with the sample. With light scattering techniques for instance, samples that are deemed too transparent cannot be measured. Solutions around this problem include means to increase the cross-section of the interactions (absorption, fluorescence, or scattering) using various probes. While such measurements are widely performed and valid most of the time, this approach can be problematic if the marker is large enough to perturb the system or introduces possible artifacts. Meanwhile, such solutions do not break the fundamental limit that the light source most generally travels through - and interact with - the sample only once.

Here, we propose a technique called Cavity Amplified Scattering Spectroscopy (CASS) that amplifies weak light scattering signals typically by a factor 10³, and thus allows us to study quasi non-scattering objects with no added probe.

We measured the radius of gyration of highly diluted proteins well beyond the limit of current techniques, and the spectrum of internal protein motion was obtained over a 9-decades wide frequency domain. Having no complex sample preparation, and a simple and compact optical setup, CASS represents an attractive complement to other techniques for the study of internal protein dynamics, and can therefore extend the scope of current light scattering techniques.

A briefcase-sized ophthalmic optical coherence tomography (OCT) device was developed. Even with all components, including a PC, monitor, and eye alignment mechanism, this single-body-packaged OCT device has a volume of 36 cm x 23 cm x 7.8 cm and a weight less than 5 kg. Foldable chin and head rests and a protection cover make it conveniently movable. By plugging in a DC adapter, this device gets ready to run, which enables instantaneous installation. A pupil camera facilitates the alignment process and internal and external fixation targets help patients fix their eyes, while OCT images are taken. All the scan processes can be manipulated from the monitor touchscreen. This spectral-domain (SD) OCT system has a super-luminescent diode (SLD) with a center wavelength of 840 nm, which is mounted on our own miniaturized driver board enabling thermoelectric cooling (TEC) and highly stable operation, an ultracompact spectrometer with a maximum speed of 82 kHz (with region-of-interest (ROI) selection), and a reference arm module with a size of 11 cm x 3 cm x 3 cm, having motorized power and pathlength control functions. This device can generate up to 50 B-scan images per second. To characterize this system’s performance, we designed a unique phantom having resolution target patterns immerged in a water tank, to simulate an eye. The measurement based on this phantom indicated that the system has axial and lateral resolutions less than 6 μm and 15 μm, respectively. Also, we could accurately measure the scan range and radius of curvature.

Photobiomodulation (PBM) using organic light-emitting diodes has attracted much attention in biomedical applications. However, therapeutic effects and cytotoxicity of PBM using organic light-emitting diode (OLED) have not been addressed in vitro and in vivo. In this study, the cytotoxicity and skin care effects of OLED lighting modules according to RGB wavelengths were compared with light-emitting diode (LED). Skin care effect of OLED and LED was demonstrated by observing suppression of Nitrogen Oxide production, decrease of melanin synthesis and increase of collagen production.

Correct diagnosis of biliary strictures is often challenging and requires imaging tests that allow physicians to see the bile duct. We developed a 3.38-mm outer diameter integrated PAE-EUS mini-probe, which featured the ability to provide an optical-resolution photoacoustic image as well as the traditional ultrasound image, and acquired the first in vivo PAEEUS images from the bile duct of a swine model by applying our dedicated probe sheath. As a microvasculature change in the walls of the biliary tract is expected to differ between benign and malignant lesions, the demonstrated technique could be a potential solution for the accurate diagnosis of biliary strictures.

Flexible endoscope reprocessing is an important requirement to minimize the risk of cross-infection between patients due to incomplete disinfection of a bacteria biofilm. The present study introduces a novel opto-chemical treatment to disinfect microbial biofilms (both Gram-positive and Gram-negative bacterial biofilms), commonly found in flexible endoscopes. A low concentration disinfectant combined with infrared and blue light irradiations was applied to disinfect the bacterial biofilms in the endoscope. A basket-integrated optical device was designed to deliver uniform and concentric light onto the channel surface of the endoscope. Colony-forming unit assays were performed to quantify the vial cells while scanning electron microscopy (SEM) illustrated an extracellular matrix (ECM) of the bacterial biofilm. The infrared light irradiation heated the surface of the bacterial biofilm to ~ 65°C. The blue light irradiation induced a relative temperature increase of 30°C on the bacterial biofilm. The results showed that the opto-chemical treatment reduced approximately 7.5-log₁₀ of the bacterial biofilm, which was four times higher than that of a standard disinfectant solution (2% glutaraldehyde). In comparison with the control untreated samples with intact ECMs, the SEM images showed significant damage to the bacterial biofilm under the opto-chemical treatment. The combined treatment induced antimicrobial effects in terms of inhibition of protein synthesis, thermal destruction, and oxidative stress, eradicating the bacterial biofilm more than the standard chemical disinfection. The proposed technique could be an alternative approach to disinfect the microbial biofilms and minimize the risk of secondary infection in endoscopy-related medical facilities.

Tracheal stomal stenosis is the most common complication that exists in patients after tracheostomy and prolonged intubation due to inflammatory and fibrotic responses. Various surgical techniques, such as Y-V and two circular incisions, have been attempted to minimize the stenosis. However, the current incision methods still have a risk of infection related to the enlarged stoma. The aim of this study is to develop a novel combined treatment of photobiomodulation (PBM) and phlorotannin (PT) to prevent the stenosis after tracheostomy. The therapeutic effect of the combined treatment was evaluated in tracheal fibroblast and the tracheostomy-developed rodent models. A 405 nm wavelength light was applied for PBM in a continuous-wave mode after treatment with Ecklonia cava-derived PT. MTT assay and western blot analysis showed that 12 J/cm² of PBM and 100 μg/ml of PT were an insignificant cytotoxicity (less than 20%). The combined treatment significantly inhibited cell migration (51.7%) and suppressed the expressions of alpha-smooth muscle actin (38.3%) and type-1 collagen (54.2%) due to the downregulation of SMAD 2/3 and MAPK signalling pathways. In vivo tests confirmed that control group showed obstruction by tissue granulation in the incised tissue seven days after tracheostomy, whereas the combined group still maintained the stoma with minimal fibrosis. The current study demonstrated that PT-combined PBM could minimize the tracheal stomal stenosis in fibrotic conditions as a result of modulated fibrotic responses. Therefore, the combination of PBM and PT can warrant an effective prevention of the tracheal stomal stenosis post-tracheostomy.

A diffusing applicator integrated with a balloon catheter has been developed to treat various types of stenosis [1,2]. To deliver uniform laser light to the tubular tissue, the balloon was inflated by inserting water. However, the residual air trapped in the balloon can cause non-uniform ablation in the tissue due to different thermal boundary conditions between air and water. The current study aims to evaluate optical and thermal effects of the air trap on cylindrical laser treatment on the tubular tissue. A balloon-integrated diffusing applicator was fabricated to deliver 532-nm laser light and to expand an ex vivo liver ductal tissue. The balloon was deflated by using a syringe and then inflated with water. Various numbers of deflations were tested for ex vivo experiments using porcine liver duct. For each deflation condition, the 532 nm laser light was delivered to the tissue at 10 W for 45 s. The liver tissue experienced more coagulation near the air trap region than the water-filled region. In spite of a significant decrease of the air volume in the balloon, at least two deflations were required to entail uniform tissue coagulation in a tubular structure and to avoid the unpredictable optical/thermal effects from the air trap. Further in vivo experiments will be performed to evaluate the effect of the air trap on chronic tissue responses after the cylindrical laser treatment for clinical translations.

Photobiomodulation (PBM) has been investigated for stimulation biological processes including wound healing and pain recovery. Therefore, in this study, the effects of PBM under Blue light (BL), Visible (VIS), and NIR laser irradiations on prostate cancer cells were evaluated to establish safety margins. In in vitro and in vivo studies, BL showed upregulated expression of VEGF, HIF-1α, EGFR, and MMP-9. These results suggested that BL can stimulate cancer cell proliferation, angiogenesis, and hypoxia, leading to aggressive tumor growth. These outcomes can provide a safety margin for the response of PBM-related stimulation after laser treatment.

Tissue analysis needs to determine the pathological properties that occur after wound healing process. Several staining techniques are widely used to understand the morphology of scar tissue, such as staining with hematoxylin and eosin (HE), picrosirius red, and Masson’s Trichome. In spite of the common staining technique, the tissue staining using HE has several limitations, such as labor-intensive, time-consuming, high memory and cost. Due to the limited of view, using the whole slide image is quite challenging to analyze the scar lesion. Hence, we developed a deep learning technique to simultaneously classify and characterize a scar lesion in the whole slide image, based on object instance segmentation. The deep learning trained the patterns from the data representation through neural network and convolution equations. The proposed technique recognized 384 images in less than a minute with 99.9% accuracy. Based on classification, quantitative analysis was performed to confirm the recognition of the scar based on the important features, such as collagen density and directional variance of collagen in scar area. After created the density map and directional variance map of collagen, the differences were almost 50% in normal and scar tissue. Therefore, the proposed deep learning method can be time- and cost-effective to characterize the pathological feature of scar tissue for the objective histological analysis. The analyses are expected to optimize various therapeutic methods to reduce or even eliminate scars on the skin.

Melasma is caused by hyperpigmentation of the skin. The risk factors of melasma include ultra-violet light exposure, hormonal malfunction, and genetic predisposition. However, the precise risk factors of melasma is still unmapped. As melasma occurs regardless of regions and races, treatment planning should consider the optical characteristics of various skin colors to enhance clinical outcomes. The aim of the current study was to evaluate the laser-induced optical breakdown effects during picosecond laser irradiation with micro-lens arrays (MLA) and diffractive optical elements (DOE) on different colors of ex vivo porcine skin tissue. Two different radiant exposures (3.0 and 6.0 J/cm² ) were irradiated 20 times with a 50-μm lateral movement on the black and white skin tissue that matched with photo skin type Ⅵ and Ⅰ. In the black skin tissue, MLA and DOE yielded laser-induced vacuoles in dermis (vacuole depth = 283 ± 114 μm for MLA vs. 140 ± 62 μm for DOE; vacuole size = 67 ± 34 μm for MLA vs. 40 ± 21 μm for DOE). However, the white skin tissue displayed the deeper and larger vacuoles in the dermis (depth = 368 ± 171 μm and size = 134 ± 100 μm for MLA), compared to the black skin tissue. However, DOE generated photo-disruption in the dermis with no laser-induced vacuolization in the white skin tissue. In conclusion, the white skin could lead to deeper laser-induced vacuoles at larger sizes, compared to the black skin after the picosecond laser treatment with MLA and DOE.