Optical Verification Research Articles

Biosensor for integrin inhibition of mammalian cell adhesion and migration using micropatterned cell culture substrate and retroreflective optical signaling

Integrins are a family of transmembrane receptors that play a crucial role in cell adhesion and migration. Integrins can uniquely transduce biochemical signals bidirectionally across the membrane and physically link the cell-cell and cell-extracellular matrix (ECM) with ligand bonds. The arginyl-glycyl-aspartic acid (RGD) peptide motif is present in the ECM as a minimal recognition sequence for integrins. To leverage this property in cell-based therapy, RGD variants, such as cyclic-type RGDfK (c(RGDfK)), which share a similar structure with RGD but exhibit a higher affinity for integrins, have been developed. However, because most evaluation methods for newly developed RGD variants focus on affinity strength, tools for cellular effects are required. In this study, we developed a new platform that integrates micropatterned three-dimensional cell culture substrates with a non-spectroscopic optical analysis system to quantitatively analyze the effects of RGD variants on cell adhesion and migration. The specially micropatterned substrate provides a cell adhesive and migration area to provide a restricted analysis area. Owing to the characteristics of retroreflective Janus particles (RJPs), a non-spectroscopic optical analysis system provides long-term stable optical verification properties and a simple optical setup. These techniques were integrated to quantitatively determine the integrin inhibitory effect of various concentrations of RGD variant. To demonstrate the efficacy of the developed cellular level RGD variant testing platform, the model cell line L929 fibroblast and model RGD variant c(RGDfK) were analyzed ranging from 0 to 10 μM. The results showed that the developed system could effectively and quantitatively analyze the effects of RGD variants on cells across various concentrations.

A WSN and vision based smart, energy efficient, scalable, and reliable parking surveillance system with optical verification at edge for resource constrained IoT devices

As urbanization accelerates, the demand for efficient parking surveillance solutions has increased. However, existing solutions often face challenges related to energy consumption, scalability, and reliability. This paper introduces a smart hybrid parking surveillance system integrating wireless sensor networks (WSNs) with vision based solution at the edge for resource constrained IoT devices to address these challenges. The solution leverages WSNs for periodic readings of parking space occupancy and introduces a low power sleep mode in the network for energy efficiency, along with optical verification strategies using computer vision models like R-CNN and Faster R-CNN FPN on ResNet50 and MobileNetv2 backbones for distinguishing between true and false positives in the WSN data for a greater accuracy in parking space occupancy. The system utilizes edge for computing on edge servers resulting in increased responsiveness of the system, reduced data transmission and real time processing of data. The proposed solution is formulated in such a way that it automatically switches between WSN and vision based sensing resulting in less energy consumption and longer lifespan of the system without compromising on accuracy. Through experimental results it is observed that models trained on the MobileNetv2 backbone demonstrated at least twice faster for both processing the images and training compared to those models trained on the ResNet backbone. On the other hand, both Faster R-CNN FPN (input resolution: 1440) and R-CNN (input resolution: 128) models trained on the MobileNetv2 backbone have slightly lower accuracies than the same models trained on the ResNet50 backbone.

Design and fabrication of a Fresnel zone plate with an enhanced depth of focus

A Fresnel zone plate (EFZP) with an extended depth of focus can maintain focused monochromatic light at different distances compared to a general Fresnel zone plate (FZP). The focal distances are determined by dividing the zone plate into multiple areas based on the desired order. The EFZP has potential applications in various research fields such as microscopy, direct laser lithography, and optical coherence tomography. However, manufacturing an EFZP is challenging due to the high precision requirements and difficulties associated with the calculation and simulation processes. In this research, a complete process is presented to design, simulate, and fabricate an EFZP using a Fourier optics design, simulations, and a direct laser lithographic machine. The resulting EFZP has an increased depth of focus of about nine times compared to a general Fresnel zone plate with similar parameters, while maintaining the focal spot diameter. The performance of this EFZP is evaluated through optical verification and mathematical simulation methods.

The study of lithographic variation in resistive random access memory

Reducing the process variation is a significant concern for resistive random access memory (RRAM). Due to its ultra-high integration density, RRAM arrays are prone to lithographic variation during the lithography process, introducing electrical variation among different RRAM devices. In this work, an optical physical verification methodology for the RRAM array is developed, and the effects of different layout parameters on important electrical characteristics are systematically investigated. The results indicate that the RRAM devices can be categorized into three clusters according to their locations and lithography environments. The read resistance is more sensitive to the locations in the array (~30%) than SET/RESET voltage (<10%). The increase in the RRAM device length and the application of the optical proximity correction technique can help to reduce the variation to less than 10%, whereas it reduces RRAM read resistance by 4×, resulting in a higher power and area consumption. As such, we provide design guidelines to minimize the electrical variation of RRAM arrays due to the lithography process.

Optical system design and verification of star sensor applying to satellite internet platform

Optical system design and verification of star sensor applying to satellite internet platform

Structural thermal optical performance (STOP) analysis and experimental verification of an hyperspectral imager for the HYPSO CubeSat

The evaluation of space optical instruments under thermo-elastic loads is a complex and multidisciplinary process that requires integrating thermal, structural, and optical disciplines. This thorough analysis often requires substantial resources, leading small satellite projects to exclude it from their schedules. However, even though the instrument discussed in this paper is compact, its complex design and stringent dimensional stability requirements demand a comprehensive evaluation of its performance under thermal loads. The hyperspectral camera, which comprises 18 lenses, a grating, a slit, and a detector, is especially vulnerable to thermo-elastic distortions, as the deformation of even a single lens could significantly impact its performance. In this paper, we present the experimental validation of the STOP analysis applied to the HYPerspectral Small satellite for ocean Observation (HYPSO) Hypespectral Imager (HSI) model. Both the HSI Structural Thermal Optical Performance (STOP) numerical model and the HSI engineering model were subjected to identical thermal conditions in the simulations and in a Thermal and Vacuum Chamber (TVAC), and subsequently the optical results derived from simulations and the test campaign compared. To characterize the thermal field, an infrared camera and thermocouples were used. Moreover, to assess the thermal performance of the HSI, we measured the Full Width at Half Maximum (FWHM) of the main peaks in the intensity-wavelength spectra when the hyperspectral camera targeted a known spectral lamp. After individually calibrating the STOP models so that the FWHM and index of the intensity peaks are in close alignment with the experimentally measured FWHM and index, the lenses most sensitive for displacements were characterized.

Effect of Input Layer Signal Polarization on the Dynamics of Optical Neural Networks

The polarization encoding-based optical validation and security verification approach is provided in this paper. This technique involves simulating information optically and bonding it to a polarization-encoded mask, such as a biological order or a reaction. The linear polarizers that make up the polarization-encoded mask are positioned at random. The polarization-encoded signal is the name given to this composite signal. In this simulation study, a primary optical neural network adapting a light brain technology is proposed theoretically based on a feed-forward model. Calibration of the nonlinear behavior in such a network is assumed by a semiconductor laser of the Distributed Feedback (DFB) type. Four laser networks are constructed as three influencers, followed by one embedding laser followers. Each of the influencer’s lasers has a different wavelength frequency and polarization (30-60–90) degree, respectively, and then combines the signal with WDM for the last laser. With each value, from the last values, of the polarization effect after this effect, the results indicated that these values would present the greatest weight of spikes and chaotic behavior for the uploaded virtual message.

A Radiotherapy Positioning Method for Both Coarse Guidance and Precise Verification Based on Integration of AR and Optical Surface Imaging

Traditional methods of radiotherapy positioning have shortcomings such as fragile skin-markers, additional doses and lack of information integration. Emerging technologies may provide alternatives for the relevant clinical practice. We proposed a noninvasive radiotherapy positioning method integrating augmented reality (AR) and optical surface, and evaluated its feasibility in clinical workflow. AR and structured light-based surface were integrated to implement the coarse-to-precise positioning through two coherent steps, i) the AR-based coarse guidance. To implement quality assurance, recognition of face and pattern was used for patient authentication, case association and accessory validation in AR scenes. The holographic images reconstructed from simulation computed tomography (CT) images, guided the initial posture correction by virtual-real alignment. ii) optical surface-based precise verification. The point clouds were fused, with the calibration and pose estimation of structured light cameras, and segmented according to the preset regions of interest (ROIs). The global-to-local registration for cross-source point clouds was achieved to calculate couch shifts in 6 degrees-of-freedom (DoF), which were ultimately transmitted to AR scenes. The evaluation based on phantom and human-body (4 volunteers) included, i) quality assurance workflow, ii) errors of both steps and correlation analysis, and iii) receiver operating characteristic (ROC). The maximum errors in phantom evaluation were 3.4±2.5 mm in Vrt and 1.4±1.0° in Pitch for the coarse guidance step, while 1.6±0.9 mm in Vrt and 0.6±0.4° in Pitch for the precise verification step. The Pearson correlation coefficients between precise verification and cone beam CT (CBCT) results were distributed in the interval [0.81, 0.85]. In ROC analysis, the areas under the curve (AUC) were 0.87 and 0.89 for translation and rotation respectively. In human body-based evaluation, the errors of thorax and abdomen (T&A) were significantly greater than those of head and neck (H&N) in Vrt (2.6±1.3 vs. 1.7±1.1, p<0.01), Lng (2.4±1.3 vs. 1.4±0.1, p<0.01) and Rtn (0.8±0.5 vs. 0.6±0.4, p = 0.03) while relatively similar in Lat (1.7±1.0 vs. 1.9±1.1, p = 0.13). The combination of AR and optical surface has utility and feasibility for patient positioning, in terms of both safety and accuracy.

Novel fabrication and designs for hybrid optical elements with wider angle field of view by using integrated direct laser lithographic system

Hybrid optical elements, which are diffraction pattern arrays fabricated on curved refractive optical elements, have the ability to widen the field of view angle, and improve optical performance, by combining refraction and diffraction. As such, they have high potential in next-generation optical devices. However, manufacturing a high resolution diffraction pattern array that fully covers the curve of the refracted optical surface, so that the normal vectors of every pattern are perpendicular to the tangent plane of the refractive lens surface, is challenging. Furthermore, the lack of diffractive pattern designs corresponding to the curvature makes it difficult to replace curved microlens arrays with hybrid optics. In this study, a direct laser lithographic system combined with an auto-focus system and high accuracy rotational system was built to fabricate the diffractive patterns array on a cylindrical lens. This approach provides a method to manufacture hybrid optical elements with wider field of view. In addition, we proposed novel designs of a linear zone plate (LZP) and elliptical zone plate (EZP) on a cylindrical lens that can be used for focusing light beam into lines and points, respectively. These hybrid optics exhibit superior performance in both diffraction efficiency and resolution, 25% better than traditional diffractive optical elements. An array of two types of zone plates were fabricated fully along the curve of the cylindrical lens using the proposed system, giving a 20° angle field of view, which acts like a curved cylindrical lens array and 1D curved microlens array. The performance of these hybrid optical elements were evaluated by optical verification system and simulation.

The role of diet in bowel cleansing for colonoscopy (results of prospective observation study). Prospective observations study

AIM: to evaluate the impact of dietary compliance in bowel cleansing for colonoscopy on the quality of the procedure.PATIENTS AND METHODS: one thousand patients who scheduled for diagnostic colonoscopy were included in the prospective observation study. The quality of bowel preparation was assessed using the Boston scale. Neoplasms were detected and endoscopically evaluated. The optical verification of tumors was used to calculate the indicators of identified adenomas and polyps (ADR and PDR).RESULTS: the quality of bowel cleansing by the Boston Scale was 6 (6; 8) points. One hundred eight (19.8%) patients did not follow the recommended diet. Poor preparation, which did not allow a total colonoscopy was found in 91 (9,1%) cases. The ADR was 37.4%, PDR — 43.4%. Logistic regression analysis showed that the noncompliance for diet recommendation was the only one significantly negative factor associated whit inadequate bowel cleansing.CONCLUSION: the leading factor worsening the quality of bowel cleansing was non-compliance with the prescribed diet before the colonoscopy.

Optical Verification of Physically Unclonable Function Devices Based on Spin‐Orbit Torque Switching

AbstractPhysically unclonable functions (PUFs) are used for various applications such as anticounterfeiting, authentication, and secret key generation. They are generally evaluated through electrical measurements, requiring much time and effort due to the many electrical connections required. This study proposes an optical verification of spin‐orbit torque (SOT) devices for PUF design. SOT devices have gained much attention because they resist degradation and thermal changes and can generate secret keys with high reproducibility. A simple optical method based on the magneto‐optical Kerr effect is introduced to verify the authenticity of the proposed SOT PUF device. Furthermore, this study assesses the feasibility of using a W/CoFeB/MgO/Ta structure as a PUF. The 24‐bit device shows a reliability of 97.8 ± 1.03%, making it a promising candidate for use as a spintronics‐based PUFs.

PO-03-063 A POLYACRYLAMIDE (PAA) GEL PHANTOM FOR STUDYING CATHETER ABLATION

Benchtop studies are often used to evaluate cardiac ablation techniques, and commonly utilize ex-vivo animal tissues. While widely available, ex-vivo animal tissues do not consistently replicate live atrial tissue physical properties, adding variability. Tissue mimicking phantoms have been used in non-cardiac ablation studies, but their mechanical and electrical properties may not mimic cardiac tissue. Furthermore, analysis of ablation lesions ex-vivo has been limited to 2D measurements of lesion cross-sections, precluding lesion volume measurement and limiting accuracy. Polyacrylamide (PAA) gels, which have modifiable elasticity, and similar thermal and electrical properties to live human tissues, have been used to study liver ablation. The addition of bovine serum albumin (BSA) – a protein that coagulates when heated beyond a set temperature – has also been shown to provide optical and MRI contrast in ablated gels. The aim of this study was to develop a reproducible atrial tissue phantom with realistic elasticity, friction, and electrical impedance, enabling in-vitro replication of cardiac ablation lesions and 3D quantification using high resolution MRI scans. Gels were mixed with acrylamide concentrations from 3% to 12% (g/mL) and 2% BSA. Resulting Young's moduli and coefficients of friction were measured with a custom tester. Reference frictional properties of ex-vivo porcine aortic specimens were measured using the same methods. Reference elasticity values were derived from the literature. Gels were ablated in saline with 20-40W of power, for 20-40s, with 10-20g of contact force. Baseline impedances were set to 125Ω by titrating the salinity of the bath. Finally, gels were imaged using a 3D T2-weighted sequence on a 3T MRI scanner. The elasticity and friction of the fabricated gels are reported in Table 1, along with reference values. 10.5-12% acrylamide PAA gel phantoms matched live contractile tissue elasticity, and simulated realistic atrial tissue frictional and electrical properties. Ablations were made optically visible by the coagulation of coagulated BSA (Fig 1a) and appeared hypointense on T2-MRI (Fig 1b), enabling automated 3D analysis by thresholding. Measured lesion dimensions were comparable to those reported in prior literature. PAA gel phantoms enabled in-vitro replication of cardiac lesions with realistic mechanical and electrical properties. The addition of BSA facilitated optical verification of lesions and 3D quantification using MRI.Tabled 1Table 1: Reference and measured physical properties of gel phantoms and ex-vivo aortae as compared to literature valuesPhysical PropertyReferenceMeasured ValueMaterialValueMaterialValueYoung's Modulus (kPa)Ex-vivo porcine left atrium28.0% PAA gel32.6In-vivo human left ventricle20-200.210.5% PAA gel68.1In-vivo skeletal muscle6.2-108.612.0% PAA gel108.0Coefficient of FrictionEx-vivo porcine aorta0.02-0.046Ex-vivo porcine aorta0.058±0.024Agarose gel0.03510.5% PAA gel0.023±0.0014 Open table in a new tab

Improved design method for suppressing optical focal spots and experimental verification

Pupil filtering is an effective method to modulate the 3D point spread function distribution of an optical system. Based on vector Debye-Wolf diffraction integral and a new fusion optimization algorithm, an improved method is described for efficiently designing the most widely-used concentric multi-belt pupil filters. The main advantage of this method is that it actively selects the minimum belt width and the total belt number for facilitating low-cost batch processing. Pupil filters for visible and near-infrared bands have been separately designed for improving the spatial resolution of optical imaging and ultrafast laser processing. The method has been experimentally demonstrated for suppressing the optical focal spot. The proposed method can be readily modified for designing more sophisticated multi-level pupil filters for practical applications in high-resolution imaging and fine laser micromachining.

Innovative integration of augmented reality and optical surface imaging: A coarse-to-precise system for radiotherapy positioning.

Traditional methods of radiotherapy positioning have shortcomings such as fragile skin-markers, additional doses, and lack of information integration. Emerging technologies may provide alternatives for the relevant clinical practice. To propose a noninvasive radiotherapy positioning system integrating augmented reality (AR) and optical surface, and to evaluate its feasibility in clinical workflow. AR and structured light-based surface were integrated to implement the coarse-to-precise positioning through two coherent steps, the AR-based coarse guidance and the optical surface-based precise verification. To implement quality assurance, recognition of face and pattern was used for patient authentication, case association, and accessory validation in AR scenes. The holographic images reconstructed from simulation computed tomography (CT) images, guided the initial posture correction by virtual-real alignment. The point clouds of body surface were fused, with the calibration and pose estimation of structured light cameras, and segmented according to the preset regions of interest (ROIs). The global-to-local registration for cross-source point clouds was achieved to calculate couch shifts in six degrees-of-freedom (DoF), which were ultimately transmitted to AR scenes. The evaluation based on phantom and human-body (4 volunteers) included, (i) quality assurance workflow, (ii) errors of both steps and correlation analysis, (iii) receiver operating characteristic (ROC), (iv) distance characteristics of accuracy, and (v) clinical positioning efficiency. The maximum errors in phantom evaluation were 3.4±2.5mm in Vrt and 1.4±1.0° in Pitch for the coarse guidance step, while 1.6±0.9mm in Vrt and 0.6±0.4° in Pitch for the precise verification step. The Pearson correlation coefficients between precise verification and cone beam CT (CBCT) results were distributed in the interval [0.81, 0.85]. In ROC analysis, the areas under the curve (AUC) were 0.87 and 0.89 for translation and rotation, respectively. In human body-based evaluation, the errors of thorax and abdomen (T&A) were significantly greater than those of head and neck (H&N) in Vrt (2.6±1.1vs. 1.7±0.8, p<0.01), Lng (2.3±1.1vs. 1.4±0.9, p<0.01), and Rtn (0.8±0.4vs. 0.6±0.3, p=0.01) while relatively similar in Lat (1.8±0.9vs. 1.7±0.8, p=0.07). The translation displacement range, after coarse guidance step, required for high accuracy of the optical surface component of the integrated system was 0-42mm, and the average positioning duration of the integrated system was significantly less than that of conventional workflow (355.7±21.7 vs. 387.7±26.6 s, p<0.01). The combination of AR and optical surface has utility and feasibility for patient positioning, in terms of both safety and accuracy.

Peroral Cholangioscopy in the Diagnosis and Treatment of Biliary Strictures

Objective: To determine the role of and indications for peroral cholangioscopy using the SpyGlass system in the differential diagnosis of biliary tract lesions and in case of biliary strictures, based on the literature data analysis and our own experience.Materials and methods: Peroral cholangioscopy is mainly used for the differential diagnosis of biliary tract lesions. During peroral cholangioscopy, we carefully consider gross signs of damage to the bile duct mucosa: abnormal capillary vascular pattern, granulation tissue and other types of proliferation, palpatory characteristics of the wall. Morphology should also be verified during image-guided intraductal forceps biopsy.Results: Peroral endoscopy of the biliary tract significantly increases the effectiveness of differential diagnosis between various types of biliary strictures.Direct examination of the bile duct mucosa with optical forceps biopsy and morphological verification increases the sensitivity and specificity of stricture type determination up to 83.3%–96% and 90.9%–99%, respectively. The diagnostic value of peroral cholangioscopy in the diagnosis of malignant and benign biliary tract lesions exceeds the effectiveness of endoscopic retrograde cholangiopancreatography, even with fluoroscopy-guided verification of ducts.Conclusions: Peroral cholangioscopy with its enormous potential plays an important role in management of patients with various diseases of the bilio-pancreatoduodenal area, including biliary strictures. We formulated key indications for peroral cholangioscopy based on the literature data analysis and our own experience with this technique in patients with bile duct pathology, including nondifferentiated biliary strictures.

Comparison of nice classification for optical diagnosis of colorectal polyps and morphology of removed lesions depending on localisation in colon

Abstract The narrow-band imaging (NBI) International Colorectal Endoscopic (NICE) classification is based on narrow-band pictures of colon polyps viewed through a narrow-band spectrum. The categorisation utilises staining, surface structure, and vascular patterns to differentiate between hyperplastic and adenomatous colon polyps. It is known that accuracy of the NICE classification for colorectal polyps varies depending on the localisation in the colon.The aim of this study was to compare the diagnostic accuracy of the NICE classification and the gold standard — morphological analysis for the determination of the type of colorectal lesions depending on localisation in colon. A prospective study was performed in an outpatient clinic. 1214 colonoscopies were performed by two expert endoscopists and 475 polyps were found in 291 patients. The overall diagnostic accuracy of the NICE classification was 80.3%. Optical verification was better in ascending colon — 93.9%, followed by sigmoid colon — 82.1%. Inferior results were found for the descending colon — 64.0%. The results of this study showed that the NICE classification could be a helpful instrument in daily practice for the ascending and sigmoid colon. For better results, proper training should be considered. The NICE system could have a role in the replacement of morphological analysis if appropriate results of verification could be achieved.

P‐3.14: Development of Thin Film Design based on IGZO‐TFT Displays for Transmittance and Picture Quality Improvement

P‐3.14: Development of Thin Film Design based on IGZO‐TFT Displays for Transmittance and Picture Quality Improvement

Development of a Three-Dimensional Optical Verification Technology without Environmental Pollution for Metal Components with Different Surface Properties.

Nowadays, the optical measuring approach is widely used in the precision machining industry due to high measurement efficiency. In the industry, measuring devices play a crucial role in the field of quality assurance. In practical engineering, the green measurement approach indeed plays an important role in the industry currently. In this study, a state-of-the-art green technique for three-dimensional (3D) optical measurements without environmental pollution is demonstrated, which is an environmentally friendly optical measurement method. This method can perform precise optical measurement without matte coatings. This work dealt with the possibility of measuring four metal components that were not sprayed with anything. The differences in the optical measurement results between with and without matte coatings were investigated and analyzed. It was found that the research result has practical value in the precision machining industry because average size errors of the four measurement objects with different surface properties can be controlled at about 3 µm, 0.1 µm, 0.5 µm, and 9 µm. A technical database with industrial value was established for optical measurements of metal components with different surface properties without matte coatings, which can serve as an alternative to the conventional 3D optical measurement.

K-point longitudinal acoustic phonons are responsible for ultrafast intervalley scattering in monolayer MoSe2

In transition metal dichalcogenides, valley depolarization through intervalley carrier scattering by zone-edge phonons is often unavoidable. Although valley depolarization processes related to various acoustic phonons have been suggested, their optical verification is still vague due to nearly degenerate phonon frequencies on acoustic phonon branches at zone-edge momentums. Here we report an unambiguous phonon momentum determination of the longitudinal acoustic (LA) phonons at the K point, which are responsible for the ultrafast valley depolarization in monolayer MoSe2. Using sub-10-fs-resolution pump-probe spectroscopy, we observed coherent phonons signals at both even and odd-orders of zone-edge LA mode involved in intervalley carrier scattering process. Our phonon-symmetry analysis and first-principles calculations reveal that only the LA phonon at the K point, as opposed to the M point, can produce experimental odd-order LA phonon signals from its nonlinear optical modulation. This work will provide momentum-resolved descriptions of phonon-carrier intervalley scattering processes in valleytronic materials.

Simple and practical methods for utilizing parylene C film based on vertical deposition and laser patterning

We propose two novel methods to effectively utilize parylene C films. First, we demonstrate a vertical deposition method capable of depositing a parylene C film of the same thickness on both sides of a sample. Through this method, we have formed parylene C films with a thickness of 4 μm on both sides of the sample with a thickness deviation of less than 2.5%. Further optical verification indicates that parylene C films formed by this method have a very uniform thickness distribution on each side of the surfaces. Second, we propose a debris-tolerant laser patterning method as a mask-less means to fabricate self-supporting ultrathin parylene C films. This method does not involve any photolithography and entails a simple and rapid process that can be performed using only a few materials with excellent biocompatibility. It is demonstrated that patterned parylene C films exhibit a high degree of surface uniformity and have various geometrical shapes so that they can be used for substrates of highly flexible and/or stretchable devices. Finally, we use both of the proposed methods to fabricate flexible, stretchable, and waterproof-packaged bifacial blue LED modules to illustrate their potential in emerging applications that would benefit from such versatile form factors.