Journal articles: 'White Light Interferometry (WLI)'

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Deng, Lin Juan, Yu Xia Fu, Xiao Yu Cai, Yuan Li, Li Hua Lei, and Dong Zhao. "Study on Phase Shifting Algorithm and System of White Light Interference." Advanced Materials Research 889-890 (February 2014): 749–54. http://dx.doi.org/10.4028/www.scientific.net/amr.889-890.749.

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The white-light interferometry (WLI) has been widely used in 3D topography measurement. This paper introduces a white light phase shifting method for interferometry with the combination of Hariharan phase shifting and WLI. A micro/nanolevel mechanic system was designed and built for the experiments. To verify system accuracy and feasibility, a 100nm step height standard was measured by the designed system and the metrological nanomeasurement machine (NMM). Results of 102.7nm and 102.5nm are obtained respectively. En value of 0.14 is calculated, demonstrating the reliability of result measured by the system. Based on classic nanoquantity traceability system, the measurement results can effectively traced back to the definition of nanometer magnitude, which can improve the accuracy of measurement.

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Li, Shengyuan, Haifeng Lv, Yachuan Kuang, Nianchun Deng, Changsen Sun, and Xuefeng Zhao. "Force-monitoring ring based on white-light interferometry for bridge cable force monitoring and its temperature compensation." Advances in Structural Engineering 22, no. 6 (December 4, 2018): 1444–52. http://dx.doi.org/10.1177/1369433218815620.

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This article proposes a novel white-light interference (WLI) force-monitoring ring for bridge cable force monitoring and temperature compensation. The WLI force-monitoring ring employs a sensing optical fiber wrapped around the outer surface of an elastomer to measure the expansion caused by applied load and temperature. By installing WLI force-monitoring ring between the anchor plate and the spherical plate of the cable, cable force can be captured by the sensing optical fiber and thus measured after temperature compensation. Based on white-light interferometry, two force-monitoring rings with resolution of 0.25 µ are designed. To find a route to temperature compensation, laboratory experiments are carried to study the effects of temperature on WLI force-monitoring ring both in free and forced states. Theoretical analysis and calibration experiments are implemented to verify the effectiveness of the proposed WLI force-testing ring, and the experiment results expose that the temperature-induced strain can be compensated using a WLI force-monitoring ring in free state. As a comparison, similar work is made for four fiber Bragg grating sensors attached to the elastomer evenly near the sensing optical fiber. The comparison results verify that the WLI method achieves better linear relation and repeatability than fiber Bragg grating. The WLI force-monitoring ring provides a high-precision and low-cost method for bridge cable force monitoring.

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Ishiji, Kotaro, Seiji Kawado, Yasuharu Hirai, and Shinji Nagamachi. "Warpage Structure of 4H-SiC after Implantation and Annealing Processes." Materials Science Forum 858 (May 2016): 544–48. http://dx.doi.org/10.4028/www.scientific.net/msf.858.544.

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The warpage structure of 4°-off-axis (0001) 4H-SiC samples after implantation and annealing processes was investigated using white light interferometry (WLI) and X-ray rocking curve (XRC) measurements. The WLI images showed that the surface warpage of the 300 °C-implanted/annealed SiC sample was small and almost the same as that of the un-implanted SiC sample, but the 30 and 150 °C-implanted/annealed SiC samples had a typically saddle-like warpage. The XRCs of the 0008-reflection were measured using monochromatic X-rays with different energies to change the X-ray penetration depth. The subtracted XRCs were reconstructed, and then the depth-dependence of the curvature radius of the 0008-reflection was evaluated. The results indicated that the saddle-like warpage of the 30 and 150 °C-implanted/annealed samples relaxed with increasing depth.

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Lv, Haifeng, Xianglong Kong, Jie Ren, Xuefeng Zhao, and Changsen Sun. "Research on Real-Time Monitoring of Strain Behavior of Concrete under Freezing-Thawing Cycle by White Light Interferometer." Advances in Materials Science and Engineering 2022 (January 25, 2022): 1–7. http://dx.doi.org/10.1155/2022/8049092.

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To study the degenerative process of concrete subjected to freezing-thawing (F-T) cycles in real-time, the strain behavior of concrete cylinder was monitored by a fiber optic F-T testing method based on the white light interferometer (WLI) technique. The principle of the WLI technique was described in detail and the design of the fiber optic testing method. Two mixed proportions of concrete immersed in 3.5% NaCl solution were tested in a freeze-thaw testing machine. The theory and method of temperature compensation were stated in detail. The results indicated that the variation of strain decreases in the cooling stage and increases in the heating stage in a F-T cycle. The residual strain was generated in the test.

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Wang, Xiaofan, Jiliang Mo, Huajiang Ouyang, Zaiyu Xiang, Wei Chen, and Zhongrong Zhou. "Simultaneous energy harvesting and tribological property improvement." Friction 9, no. 5 (February 27, 2021): 1275–91. http://dx.doi.org/10.1007/s40544-020-0467-z.

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AbstractIn this study, piezoelectric elements were added to a reciprocating friction test bench to harvest friction-induced vibration energy. Parameters such as vibration acceleration, noise, and voltage signals of the system were measured and analyzed. The results show that the piezoelectric elements can not only collect vibration energy but also suppress friction-induced vibration noise (FIVN). Additionally, the wear of the friction interface was examined via optical microscopy (OM), scanning electron microscopy (SEM), and white-light interferometry (WLI). The results show that the surface wear state improved because of the reduction of FIVN. In order to analyze the experimental results in detail and explain them reasonably, the experimental phenomena were simulated numerically. Moreover, a simplified two-degree-of-freedom numerical model including the original system and the piezoelectric system was established to qualitatively describe the effects, dynamics, and tribological behaviors of the added piezoelectric elements to the original system.

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Aizawa, Tatsuhiko, Tomomi Shiratori, Yoshihiro Kira, and Tadahiko Inohara. "Simultaneous Nano-Texturing onto a CVD-Diamond Coated Piercing Punch with Femtosecond Laser Trimming." Applied Sciences 10, no. 8 (April 13, 2020): 2674. http://dx.doi.org/10.3390/app10082674.

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In this study, a CVD (Chemical Vapor Deposition)-diamond coated tungsten carbide cobalt (WC (Co)) punch was trimmed to adjust its surface roughness and to significantly reduce its edge curvature for fine piercing by femtosecond laser processing. Through this laser trimming, the surface quality of the diamond coating and the punch edge profile were improved to less than 0.5 μm at the maximum roughness and 2 μm in the edge width, respectively. In parallel with this improvement of surface quality, the side surface of the diamond coating was modified to include nano-textures via the LIPSS (Laser Induced Periodic Surface Structuring) process. Through the fine piercing process, this nanotexture was transcribed onto the pierced hole surface together with fine shearing of the hole by piercing. WLI (White-Light Interferometry) and SEM (Scanning Electron Microscopy) were utilized to describe this transcription of nanotextures during the piercing process. These semiregular nanotextures with an LIPSS period of 300 nm on the pierced hole surface induced a blue colored surface plasmon.

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Gunasekera, Deshani H. A. T., SzeLee Kuek, Denis Hasanaj, Yinfeng He, Christopher Tuck, Anna K. Croft, and Ricky D. Wildman. "Three dimensional ink-jet printing of biomaterials using ionic liquids and co-solvents." Faraday Discussions 190 (2016): 509–23. http://dx.doi.org/10.1039/c5fd00219b.

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1-Ethyl-3-methylimidazolium acetate ([C₂C₁Im][OAc]) and 1-butyl-3-methylimidazolium acetate ([C₄C₁Im][OAc]) have been used as solvents for the dissolution and ink-jet printing of cellulose from 1.0 to 4.8 wt%, mixed with the co-solvents 1-butanol and DMSO. 1-Butanol and DMSO were used as rheological modifiers to ensure consistent printing, with DMSO in the range of 41–47 wt% producing samples within the printable range of a DIMATIX print-head used (printability parameter < 10) at 55 °C, whilst maintaining cellulose solubility. Regeneration of cellulose from printed samples using water was demonstrated, with the resulting structural changes to the cellulose sample assessed by scanning electron microscopy (SEM) and white light interferometry (WLI). These results indicate the potential of biorenewable materials to be used in the 3D additive manufacture process to generate single-component and composite materials.

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Li, Gui Yu, Jian Feng Li, and Jie Sun. "Influences of Processing Parameters on Hole Shape Accuracy in Drilling Carbon Fiber Reinforced Composite." Advanced Materials Research 325 (August 2011): 375–80. http://dx.doi.org/10.4028/www.scientific.net/amr.325.375.

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Drilling parameters have great influences on hole accuracy and defect production. In this study, single factor test is applied to obtain the relationship between the torque deviation and the spindle speed n at different feeds per revolution fr. White Light Interferometer (WLI) is applied to measure the hole shape. Based on the frequency domain analysis of torque deviation, the cause of hole shape deviation is investigated. Relationship between the hole shape accuracy and drilling parameters is established, which can be used to predict the hole shape by analyzing the torque deviation. Moreover, the reasonable processing parameters can be selected to obtain drilling hole with ideal shape and satisfying production efficiency.

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Guo, Qi, Xiu Jie Jia, Shuo Li, Yan Yan Nie, and Shun Xin Ge. "Research on the Decoating Effect and Microstructure of Surface Damage of High-Pressure Waterjet." Applied Mechanics and Materials 541-542 (March 2014): 180–84. http://dx.doi.org/10.4028/www.scientific.net/amm.541-542.180.

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The high-pressure water jet is utilized to perform impact test on coated surfaces with different hardness. The decoating effect is measured and the surface roughness change can be tested by White-light Interferometer (WLI). Also the microstructure of surface damage after impact test is analyzed. The result shows that when utilizing high-pressure water jet to clean the coating, it’s a better choice to start at the place where the coating is broken. The gap will be enlarged rapidly and the decoating velocity will increase linearly. Otherwise, the impact of water jet will cause surface damages and generate holes of particular shape. This kind of hole is flat in the middle, then forming a sunken district and apophysis successively along the radius outwards.

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Buchheit, Olivier, Claire Arnoult, Fatima Eddoumy, Doriane Del Frari, Jean Di Martino, and David Ruch. "COMBINING WLI AND SEM TECHNIQUES TO OBTAIN A 4D SURFACE IMAGE OF A ppHDMSO/AlCeO3 NANOCOMPOSITE." Image Analysis & Stereology 29, no. 1 (May 3, 2011): 27. http://dx.doi.org/10.5566/ias.v29.p27-34.

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Compositional images from a SEM (scanning electron microscope) are sometimes complemented by quantitative topographical data from devices such as an AFM (atomic force microscope) or WLI (white light interferometer). Indeed, even if a SEM could provide both kinds of information (composition and topography), the topographical data are incomplete because the SEM does not allow measuring the vertical dimension (i.e., perpendicular to the measurement plane). Thus these two kinds of information are usually measured using two different techniques, and at different locations on the sample. Mean values of surface composition are then linked to mean values of topography, and as a consequence this approach does not allow precisely linking a local topographical peak to its corresponding composition. The present work deals with a SEM/WLI combination methodology, based on the characterization, at the same location, of a nanocomposite (nanoparticles of AlCeO3 dispersed in a plasma-polymerized hexamethyldisiloxane ppHMDSO matrix and deposited by atmospheric plasma on a glass substrate) developed for improving anticorrosion properties. SEM images allow the supposition that the protuberances (peaks) observed on the surface of a specimen are linked to the nanoparticles dispersed in the polymer coating, but this link is not fully convincing. Thanks to a precise localization method, SEM compositional data and WLI topographical data are here measured at the same location. The recombination of both signals to form a 4D image (3D geometry and 1D composition) allows linking protuberances to nanoparticles aggregates without ambiguity. This composite image appears to be an interesting new tool (at the scale of observation, i.e., hundreds of micrometers) for the study of nanostructured coatings.

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Zhao, Qing Liang, Ekkard Brinksmeier, Otmann Riemer, and Kai Rickens. "ELID Assisted Precision Conditioning of Coarse-Grained Diamond Grinding Wheel." Key Engineering Materials 364-366 (December 2007): 578–83. http://dx.doi.org/10.4028/www.scientific.net/kem.364-366.578.

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In order to realize ductile machining of optical glasses using mono-layer nickel electroplated coarse-grained diamond grinding wheel, a novel conditioning technique features using a copper bonded diamond grinding wheels of 15m grain size dressed by ELID (electrolytic inprocess dressing) to condition the 46m grain sized diamond wheel has been developed. During the conditioning process, a force transducer was used to monitor the conditioning force, a coaxial optical distance measurement system was used to in-situ monitor the modified wheel surface status. White-light interferometry (WLI), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the conditioned wheel surface status as well as the ground optical glass surface topography correspondingly. The experimental result indicates that a minimized wheel radial run-out error of less than 2μm as well as the top-flattened diamond grains of constant wheel peripheral envelop profile were generated on a 5-axis ultra-precision machine tool. The grinding experiment proved that the well conditioned 46μm coarse-grained diamond wheel can be used in realizing the ductile grinding of optical glass BK7, which indicates that the newly developed conditioning technique is feasible and applicable to introduce the coarse-grained diamond wheels into precision machining of brittle and hard-to-machine materials.

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Nicolas-Silvente, Ana Isabel, Eugenio Velasco-Ortega, Ivan Ortiz-Garcia, Loreto Monsalve-Guil, Javier Gil, and Alvaro Jimenez-Guerra. "Influence of the Titanium Implant Surface Treatment on the Surface Roughness and Chemical Composition." Materials 13, no. 2 (January 9, 2020): 314. http://dx.doi.org/10.3390/ma13020314.

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The implant surface features affect the osseointegration process. Different surface treatment methods have been applied to improve the surface topography and properties. Trace of different elements may appear on the implant surface, which can modify surface properties and may affect the body’s response. The aim was to evaluate the roughness based on the surface treatment received and the amount and type of trace elements found. Ninety implants (nine different surface treatment) were evaluated. Roughness parameters were measured using white-light-interferometry (WLI). The arithmetical mean for Ra, Rq, Rt, and Rz of each implant system was calculated, and Fisher’s exact test was applied, obtaining Ra values between 0.79 and 2.89 µm. Surface chemical composition was evaluated using X-ray photoelectron spectroscopy (XPS) at two times: as received by the manufacturer (AR) and after sputter-cleaning (SC). Traces of several elements were found in all groups, decreasing in favor of the Ti concentration after the sputter-cleaning. Within the limitations of this study, we can conclude that the surface treatment influences the roughness and the average percentage of the trace elements on the implant surface. The cleaning process at the implant surface should be improved by the manufacturer before assembling the implant.

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Khan, Pearlin Amaan, Aravind Kumar Thoutam, Vasanth Gopal, Aswin Gurumallesh, Shrikant Joshi, Arunkumar Palaniappan, Nicolaie Markocsan, and Geetha Manivasagam. "Influence of Graphene Nanoplatelets on the Performance of Axial Suspension Plasma-Sprayed Hydroxyapatite Coatings." Bioengineering 10, no. 1 (December 29, 2022): 44. http://dx.doi.org/10.3390/bioengineering10010044.

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Axial suspension plasma spraying (ASPS) is an alternative technique to atmospheric plasma spraying (APS), which uses a suspension of much finer powders (<5-micron particle size) as the feedstock. It can produce more refined microstructures than APS for biomedical implants. This paper highlights the influence of incorporated graphene nanoplatelets (GNPs) on the behavior of ASPS hydroxyapatite (HAp) coatings. The characterization of the ASPS coatings (HAp + varying GNP contents) was carried out using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), confocal Raman microscopy (CRM), white light interferometry (WLI), and contact angle measurements. The evaluation of the mechanical properties such as the hardness, roughness, adhesion strength, and porosity was carried out, along with a fretting wear performance. Additionally, the biocompatibility of the Hap + GNP coatings was evaluated using cytotoxicity testing which revealed a decrease in the cell viability from 92.7% to 85.4%, with an increase in the GNP wt.%. The visualization of the cell’s components was carried out using SEM and Laser Scanning Microscopy. Furthermore, the changes in the genetic expression of the various cellular markers were assessed to analyze the epigenetic changes in human mesenchymal stem cells. The gene expression changes suggested that GNPs upregulated the proliferation marker and downregulated the pluripotent markers by a minimum of three folds.

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Joerger, Arn, Stefan Reichert, Christoph Wittig, Navid Sistanizadeh Aghdam, and Albert Albers. "An Approach for the Transfer of Real Surfaces in Finite Element Simulations." Lubricants 9, no. 8 (August 5, 2021): 77. http://dx.doi.org/10.3390/lubricants9080077.

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Virtual simulations are a relevant element in product engineering processes and facilitate engineers to test different concepts during early phases of the development. However, in tribological product engineering, simulations are hardly used because input data such as material behavior are often missing. Besides the material behavior, the surface roughness of the contacting elements is relevant for tribological systems. To expand the capabilities of the virtual engineering of tribological components such as bearings or brakes, the hereby presented approach allows for the depiction of real rough surfaces in finite element simulations. Rough surfaces are scanned by a white-light interferometer (WLI) and further processed by removing the outliers and replacing non-measured samples. Next, a spline generation creates a solid body, which is imported to CAD software and afterwards meshed with triangle and quadrilateral elements in different sizes. The results comprise the evaluation of six differently manufactured (turned, coated, and pressed) real surfaces. The surfaces are compared by the deviations of the roughness values after measuring with the WLI and after meshing them. Furthermore, the elements’ aspect ratios and skewness describe the mesh quality. The results show that the transfer is dependent upon deep cliffs and large Sz values in comparison to the lateral expansion.

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NIEMCZEWSKA-WÓJCIK, Magdalena. "COINCIDENCE OF THE TECHNOLOGY AND THE SURFACE TOPOGRAPHY OF SPHERICAL ELEMENTS OCCURING DURING MACHINING PROCESS OF HIGH PRECISION." Tribologia 270, no. 6 (December 31, 2016): 83–94. http://dx.doi.org/10.5604/01.3001.0010.6909.

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The paper presents issues concerning the surface layer and the changes in surface topography with respect to spherical elements at the subsequent stages of manufacturing process. Special attention was paid to the forming of surface topography in precision machining processes (preliminary grinding, precision grinding, lapping with polishing). The subjects of research and analysis were spherical elements made of a biomaterial, i.e. titanium alloy (Ti-6.5Al-1.3Si-2Zr). The surfaces of the studied components shaped during the subsequent operations of abrasive machining processes were measured using a coordinate measurement machine (CMM) and a white light interferometer (WLI). Based on the obtained results, the changes in the surface topography of metallic spherical elements brought about during the subsequent operations of precision machining processes were assessed. In addition to this, functional properties of these surfaces were identified.

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Peng, Yonghong, Shuai Zhang, Fanghua Zhu, Wa Li, Yong Yi, Kai Du, and Qiang Yin. "Fabrication and Characterization of Fluorinated Polyimides (PI) Films with Improved Hydrophobic Property." Nano 13, no. 07 (July 2018): 1850080. http://dx.doi.org/10.1142/s1793292018500807.

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There is a demand for composite films with excellent hydrophobic properties in inertial confinement fusion (ICF) physics experiments. In this paper, we prepared fluorinated polyimide hydrophobic films using spinning and plasma etching methods. The experimental results indicate that the water contact angle for the perfluorodecyltrichlorosilane (PFTS) treatment polyimide (PI) film is 112.0[Formula: see text], which is larger than the pure PI film [Formula: see text]. The rap oil contact angle is 84.2[Formula: see text], which is also much larger than the contact angle of PI film [Formula: see text]. Moreover, the surface roughness of the prepared films was measured by white light interferometry (WLI). The surface roughness (Ra) of pure PI is 9.79[Formula: see text]nm, but with the application of FSiO2 particles, the Ra of the films increases to 65.05[Formula: see text]nm. After plasma treatment, the Ra of the PI/FSiO2 composite film increases to 186.71[Formula: see text]nm because plasma treatment can scratch the film surface and increase its roughness. However, treating the PI/FSiO2 composite film with the plasma and PFTS, the Ra is only 88.90[Formula: see text]nm. This decrease in Ra is due to the PFTS, which is able to reduce the surface roughness. The development of composite films, compared to pure PI films, could prove to be an extremely valuable material in ICF experiments.

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Pu, Jian, Dongsheng Wu, Yali Zhang, Xiaogang Zhang, and Zhongmin Jin. "An Experimental Study on the Fretting Corrosion Behaviours of Three Material Pairs at Modular Interfaces for Hip Joint Implants." Lubricants 9, no. 2 (January 21, 2021): 12. http://dx.doi.org/10.3390/lubricants9020012.

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The fretting corrosion behaviours of Al2O3 ceramic/Ti6Al4V alloy, 316 L stainless/Ti6Al4V alloy, and CoCrMo alloy/Ti6Al4V alloy pairs were studied in an in-house developed fretting-corrosion tester. The fretting behaviours were characterized by the Ft-D-N and Ft/Fn curves. The morphology of the worn surface was analyzed by energy dispersive X-ray spectrometry (EDX), a scanning electron microscope (SEM), and a white light interferometer (WLI). The fretting regimes were found to vary from slip regime (SR) to mixed fretting regime (MFR), with an increase in loads for the Al2O3/Ti6Al4V and 316 L/Ti6Al4V pairs, while for the CoCrMo/Ti6Al4V pair the fretting always remained in SR. The damage mechanism of the Al2O3/Ti6Al4V pair was mainly abrasive wear and corrosive wear, while for the 316 L/Ti6Al4V pair and CoCrMo/Ti6Al4V pair, the wear mechanism was mainly adhesive wear and corrosive wear with slight abrasive wear. The electrochemical impedance spectrum results show that the material transfer layer formed on the surface of the material can protect the material from corrosion for the 316 L/Ti6Al4V and CoCrMo/Ti6Al4V pairs.

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Punset, Miquel, Javi Vilarrasa, José Nart, José María Manero, Begoña Bosch, Roberto Padrós, Roman A. Perez, and Javier Gil. "Citric Acid Passivation of Titanium Dental Implants for Minimizing Bacterial Colonization Impact." Coatings 11, no. 2 (February 12, 2021): 214. http://dx.doi.org/10.3390/coatings11020214.

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Surface topography and physical-chemical properties usually play a key-role in both osseointegration improvement and bacterial colonization reduction over the surface of dental implants. The aim of this study is to compare the chemical and bacteriological behavior of two different acid passivation surface treatments on titanium c.p. grade 3 used for dental implant manufacturing. Surface roughness was evaluated using White Light Interferometry (WLI) in order to determine different roughness parameters such as average roughness (Sa), the spacing parameter (Sm) and the hybrid parameter of surface index area (SIA). Contact angle (CA) and surface free energy (SFE) were evaluated in order to establish the surface wettability of the different groups of samples. Titanium ion-release from the different samples was also been analyzed in Hank’s solution medium at 37 °C by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) at different immersion times. Bacterial viability adhesion assays were done using S. sanguinis (CECT 480, Spain) as a bacterial strain model of primary colonizer in oral biofilm formation. The bacteria attachment and morphology on Ti surfaces were determined using a live/dead staining method after 4 h of incubation and further analyzed by scanning electron microscope (SEM). Acid passivation surface treatments produced a statistically-significant (p < 0.05) roughness increase in all the evaluated parameters (Sa, Sm, SAI). The treatment with citric acid decreased the static contact angle (CA) and caused an increase in surface free energy (SFE) with a high polarization and oxidizing character. These physical-chemical surface characteristics obtained by means of citric acid passivation caused the bactericidal behavior as it has been proved in bacterial studies.

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Fook, Pablo, Daniel Berger, Oltmann Riemer, and Bernhard Karpuschewski. "Structuring of Bioceramics by Micro-Grinding for Dental Implant Applications." Micromachines 10, no. 5 (May 9, 2019): 312. http://dx.doi.org/10.3390/mi10050312.

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Metallic implants were the only option for both medical and dental applications for decades. However, it has been reported that patients with metal implants can show allergic reactions. Consequently, technical ceramics have become an accessible material alternative due to their combination of biocompatibility and mechanical properties. Despite the recent developments in ductile mode machining, the micro-grinding of bioceramics can cause insufficient surface and subsurface integrity due to the inherent hardness and brittleness of these materials. This work aims to determine the influence on the surface and subsurface damage (SSD) of zirconia-based ceramics ground with diamond wheels of 10 mm diameter with a diamond grain size (dg) of 75 μm within eight grinding operations using a variation of the machining parameters, i.e., peripheral speed (vc), feed speed (vf), and depth of cut (ae). In this regard, dental thread structures were machined on fully sintered zirconia (ZrO2), alumina toughened zirconia (ATZ), and zirconia toughened alumina (ZTA) bioceramics. The ground workpieces were analysed through a scanning electron microscope (SEM), X-ray diffraction (XRD), and white light interferometry (WLI) to evaluate the microstructure, residual stresses, and surface roughness, respectively. Moreover, the grinding processes were monitored through forces measurement. Based on the machining parameters tested, the results showed that low peripheral speed (vc) and low depth of cut (ae) were the main conditions investigated to achieve the optimum surface integrity and the desired low grinding forces. Finally, the methodology proposed to investigate the surface integrity of the ground workpieces was helpful to understand the zirconia-based ceramics response under micro-grinding processes, as well as to set further machining parameters for dental implant threads.

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Niemczewska-Wójcik, Magdalena, Jerzy Sładek, Małgorzata Tabaka, and Artur Wójcik. "Product Quality Assessment – Measurement and Analysis of Surface Topography." Metrology and Measurement Systems 21, no. 2 (June 1, 2014): 271–80. http://dx.doi.org/10.2478/mms-2014-0023.

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Abstract This paper concerns the issues of measurement techniques, analysis and assessment of the machined surface geometric structure. The aim of this work was to show the application of surface analysis in diagnosing the causes of discrepancies occurring in the manufacturing process, which may result from ill-matched (poorly fitting) process parameters. An appropriate system of control and interpretation of results may allow early reaction to unfavorable trends (for example blunting of the tool) and prevention of undesirable defects. The subject of research was a waste basket used in the construction of retaining sewer systems. In this paper, the quality of the waste basket as well as its manufacturing process were analyzed and assessed. The research was carried out with the use of three measurement stands, i.e. optical microscopy (OM), scanning electron microscopy (SEM) and white light interferometer (WLI). The surface analysis proved to be important from the viewpoint of outlining the production process as well as improving the product quality. The software used for topographical analysis appeared to be significant for the success of the analysis, providing notable economic effects, namely the lack of defects.

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Padrós, Roberto, Luís Giner, Mariano Herrero-Climent, Carlos Falcao-Costa, José-Vicente Ríos-Santos, and Francisco Javier Gil. "Influence of the CAD-CAM Systems on the Marginal Accuracy and Mechanical Properties of Dental Restorations." International Journal of Environmental Research and Public Health 17, no. 12 (June 15, 2020): 4276. http://dx.doi.org/10.3390/ijerph17124276.

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The aim of this study was to compare the quality of different computer-assisted-design and computer assisted manufacturing systems (CAD-CAM) generated by only one scanner, focusing on vertical fit discrepancies and the mechanical properties. A master model was obtained from a real clinical situation: the replacement of an absent (pontic) tooth, with the construction of a fixed partial denture on natural abutments with three elements. Nine scans were performed by each tested and 36 copies were designed using a dental CAD-CAM software (Exocad). The frameworks were manufactured using three-axis and five-axis, with the same batch of the chrome-cobalt (CrCo) alloy. The frameworks were not cemented. A focus ion beam-high resolution scanning electron microscope (FIB-HRSEM) allowed us to obtain the vertical gap measurements in five points for each specimen. Roughness parameters were measured using white light interferometry (WLI). The samples were mechanically characterized by means of flexural tests. A servo-hydraulic testing machine was used with a cross-head rate of 1 mm/min. One-way ANOVA statistical analysis was performed to determine whether the vertical discrepancies and mechanical properties were significantly different between each group (significance level p < 0.05). The overall mean marginal gap values ranged: from 92.38 ± 19.24 µm to 19.46 ± 10.20 µm, for the samples produced by three-axis and five-axis machines, respectively. Roughness was lower in the five-axis machine than the three-axis one, and as a consequence, the surface quality was better when the five-axis machine was used. These results revealed a statistically significant difference (p < 0.005) in the mean marginal gap between the CAD-CAM systems studied. The flexural strength for these restorations range from 6500 to 7000 N, and does not present any statistical differences’ significance between two CAD-CAM systems studied. This contribution suggests that the number of axes improves vertical fit and surface quality due to the lower roughness. These claims show some discrepancies with other studies.

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Prajapati, Deepak K., and Mayank Tiwari. "The correlation between friction coefficient and areal topography parameters for AISI 304 steel sliding against AISI 52100 steel." Friction 9, no. 1 (July 29, 2020): 41–60. http://dx.doi.org/10.1007/s40544-019-0323-1.

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Abstract Dry wear experiments provide an insight detail on how severely contacting surfaces change under unlubricated sliding condition. The theory of dry sliding wear is used for understanding mixed-lubrication regime in which asperity interactions play a significant role in controlling of the friction coefficient (f). The purpose of this work is to study the tribological behavior of AISI 304 steel in contact with AISI 52100 steel during wear. Both materials are used in rolling element bearings commanly. Experiments are carried out using a pin-on-disc tribometer under dry friction condition. The areal (three dimensional, 3D) topography parameters are measured using a 3D white light interferometer (WLI) with a 10× objective. After wear tests, wear mechanisms are analyzed utilizing scanning electron microscope (SEM). Factorial design with custom response surface design (C-RSD) is used to study the mutual effect of load and speed on response variables such as f and topography parameters. It is observed that the root mean square roughness (Sq) decreases with an increase in sliding time. Within the range of sliding time, Sq decreases with an increase in the normal load. Within the range of sliding speed and normal load, it is found that Sq, mean summit curvature (Ssc), and root mean square slope (Sdq) are positively correlated with f. Whereas, negative correlation is found between f and correlation length (Sal), mean summit radius (R), and core roughness depth (Sk).

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Padrós, Roberto, Miquel Punset, Meritxell Molmeneu, Aritza Brizuela Velasco, Mariano Herrero-Climent, Elisa Rupérez, and Francisco Javier Gil. "Mechanical Properties of CoCr Dental-Prosthesis Restorations Made by Three Manufacturing Processes. Influence of the Microstructure and Topography." Metals 10, no. 6 (June 14, 2020): 788. http://dx.doi.org/10.3390/met10060788.

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The aim of this study is to compare the mechanical properties of three different dental restorations’ manufacturing processes (CADCAM milling, casting and laser sintering) generated by only one laboratory scanner focusing on marginal fit analysis and their mechanical properties. A chrome-cobalt (Cr-Co) alloy from the same batch was used for three different methods to make an implant abutment. This simulates a maxillary right first molar that was fixed in a hemi-maxillary stone model. Five scans were performed by each tested framework. Nine frameworks were manufactured for each manufacture procedure. Field-Emission Scanning Electron Microscope (FE-SEM) direct vision was used to marginal gap measurement in five critical points for each specimen. In order to fix the samples in the microscope chamber, the restorations were submitted at a compression load of 50 N. The samples always have the same orientation and conditions. The resolution of the microscope is 4 nm and it is equipped by J image software. The microstructure of the samples was also determined with the FE-SEM equipped with EDS-microanalysis. Roughness parameters were measured using White Light Interferometry (WLI). The arithmetical mean for the Ra and Rq of each sample was calculated. The samples were mechanically characterized by means of microhardness and flexural testing. Servo-hydraulic testing machine was used with cross-head rate of 1 mm/min. Two-way ANOVA statistical analysis was performed to determine whether the marginal discrepancies and mechanical properties were significantly different between each group (significance level p < 0.05). The overall mean marginal gap values were: from 50.53 ± 10.30 µm for the samples produced by CADCAM to 85.76 ± 22.56 µm for the samples produced by the casting method. Laser sintering presents a marginal gap of 60.95 ± 20.66 µm. The results revealed a statistically significant difference (p-value < 0.005) in the mean marginal gap between the CADCAM systems studied. The higher flexure load to fracture for these restorations were for CADCAM restoration and the lower was for the casting samples. For these restorations, CADCAM Restoration yielded a higher flexure load to fracture and Casting ones yielded the lower. Porosity and microstructure play a very important role in the mechanical properties.

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Kosior, Łukasz, Damian Radziewicz, Iwona Zborowska-Lindert, Andrzej Stafiniak, Mikołaj Badura, and Beata Ściana. "Epitaxial regrowth of InP/InGaAs heterostructure on patterned, nonplanar substrates." Materials Science-Poland 34, no. 4 (December 1, 2016): 872–80. http://dx.doi.org/10.1515/msp-2016-0103.

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AbstractThe main goal of the studies on epitaxial regrowth process of InP on patterned substrates is to gain knowledge about growth rates and interface quality on various areas to improve the fabrication technology for future applications. Prepared samples were measured at every step of the process by scanning electron microscope (SEM), optical microscope with dark field and phase contrast modes, atomic force microscope (AFM) and also using optical profilometer WLI (White Light Interferometer). Fabrication steps were divided into three main groups. First was the epitaxial growth of 5 µm thick InP layer. Next was patterning, which was made by applying a mask film on the epilayer. Shapes of the mesas after wet chemical etching with photoresist as a mask as well as the shapes of mesas slopes were irregular on the whole substrate area. These problems were solved by the use of silicon nitride mask. The mesas shapes and their slopes became then regular, independently of etching depth. Second fabrication step was etching of selected area. Couple of solutions were examined, but in details HCl:H3PO4 mixture in various proportions, which gave the best results in mesas shapes and orientations relative to the substrate. After that, the etching mask material was removed from the epilayer using a buffered hydrofluoric acid (BHF). The last step was epitaxial regrowth. To see how the epitaxial growth process was performed on different areas of patterned substrate it was suggested using a “sandwich”, which consisted of 50 layers of indium phosphide and indium gallium arsenide. This idea helped to understand the phenomena occurring during the epitaxial growth on that kind of substrate. The highest growth rate occurred on the top of the mesas and the lowest on their slopes. Described experiments are introduction to the studies on epitaxial growth of buried heterostructure (BH).

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Tomie, Akira, Osamu Dohi, Nobuaki Yagi, Hiroaki Kitae, Atsushi Majima, Yusuke Horii, Tomoko Kitaichi, et al. "Blue Laser Imaging-Bright Improves Endoscopic Recognition of Superficial Esophageal Squamous Cell Carcinoma." Gastroenterology Research and Practice 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/6140854.

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Background/Aims. The aim of this study was to evaluate the endoscopic recognition of esophageal squamous cell carcinoma (ESCC) using four different methods (Olympus white light imaging (O-WLI), Fujifilm white light imaging (F-WLI), narrow band imaging (NBI), and blue laser imaging- (BLI-) bright).Methods.We retrospectively analyzed 25 superficial ESCCs that had been examined using the four different methods. Subjective evaluation was provided by three endoscopists as a ranking score (RS) of each image based on the ease of detection of the cancerous area. For the objective evaluation we calculated the color difference scores (CDS) between the cancerous and noncancerous areas with each of the four methods.Results. There was no difference between the mean RS of O-WLI and F-WLI. The mean RS of NBI was significantly higher than that of O-WLI and that of BLI-bright was significantly higher than that of F-WLI. Moreover, the mean RS of BLI-bright was significantly higher than that of NBI. Furthermore, in the objective evaluation, the mean CDS of BLI-bright was significantly higher than that of O-WLI, F-WLI, and NBI.Conclusion. The recognition of superficial ESCC using BLI-bright was more efficacious than the other methods tested both subjectively and objectively.

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Sugimoto, Mitsushige, Yusuke Kawai, Yoshika Akimoto, Mariko Hamada, Eri Iwata, Masaki Murata, Hitomi Mizuno, et al. "Third-Generation High-Vision Ultrathin Endoscopy Using Texture and Color Enhancement Imaging and Narrow-Band Imaging to Evaluate Barrett’s Esophagus." Diagnostics 12, no. 12 (December 13, 2022): 3149. http://dx.doi.org/10.3390/diagnostics12123149.

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It remains unclear whether texture- and color-enhancement imaging (TXI) and narrow-band imaging (NBI) provide an advantage over white-light imaging (WLI) in Barrett’s esophagus. We compared endoscopic findings and color differences between WLI and image-enhanced endoscopy (IEE) using a third-generation ultrathin endoscope. We retrospectively enrolled 40 patients who evaluated Barrett’s esophagus using WLI, TXI, and NBI. Color differences determined using the International Commission on Illumination 1976 (L∗, a∗, b∗) color space among Barrett’s epithelium, esophageal, and gastric mucosa were compared among the endoscopic findings. As the secondary outcome, we assessed the subjective visibility score among three kinds of endoscopic findings. The prevalence of Barrett’s esophagus and gastroesophageal reflux disease (GERD) in WLI was 82.5% and 47.5%, respectively, and similar among WLI, TXI, and NBI. Color differences between Barrett’s epithelium and esophageal or gastric mucosa on NBI were significantly greater than on WLI (all p < 0.05). However, the color difference between Barrett’s epithelium and esophageal mucosa was significantly greater on NBI than TXI (p < 0.001), and the visibility score of Barrett’s epithelium detection was significantly greater on TXI than NBI (p = 0.022), and WLI (p = 0.016). High-vision, third-generation ultrathin endoscopy using NBI and TXI is useful for evaluating Barrett’s epithelium and GERD compared with WLI alone.

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Ang, Tiing Leong, James Weiquan Li, Yu Jen Wong, Yi-Lyn Jessica Tan, Kwong Ming Fock, Malcolm Teck Kiang Tan, Andrew Boon Eu Kwek, Eng Kiong Teo, Daphne Shih-Wen Ang, and Lai Mun Wang. "A prospective randomized study of colonoscopy using blue laser imaging and white light imaging in detection and differentiation of colonic polyps." Endoscopy International Open 07, no. 10 (October 2019): E1207—E1213. http://dx.doi.org/10.1055/a-0982-3111.

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Abstract Background and study aims Published data on blue laser imaging (BLI) for detection and differentiation of colonic polyps are limited compared to narrow band imaging (NBI). This study investigated whether BLI can increase the detection rate of colonic polyps and adenomas when compared to white light imaging (WLI), and examined use of NICE (NBI International Colorectal Endoscopic) and JNET (Japan NBI Expert Team) classifications with BLI. Patients and methods Patients aged 50 years and above referred for colonoscopy were randomized to BLI or WLI on withdrawal. Detected polyps were characterized using NICE and JNET classifications under BLI mode and correlated with histology. Primary outcome was adenoma detection rate. Secondary outcomes were utility of NICE and JNET classifications to predict histology using BLI. Results A total of 182 patients were randomized to BLI (92) or WLI (90). Comparing BLI with WLI, the polyp detection rate was 59.8 % vs 40.0 %, P = 0.008, and the adenoma detection rate was 46.2 % vs 27.8 %, P = 0.010. NICE 1 and JNET 1 diagnosed hyperplastic polyps with sensitivity of 87.18 % and specificity of 84.35 %. NICE 2 diagnosed low- (LGD) or high-grade dysplasia (HGD) with sensitivity of 92.31 % and specificity of 77.45 %. JNET 2A diagnosed LGD with sensitivity of 91.95 %, and specificity of 74.53 %. Four cases of focal HGD all had JNET 2A morphology. Conclusion BLI increased adenoma detection rate compared to WLI. NICE and JNET classifications can be applied when using BLI for endoscopic diagnosis of HP and LGD but histological confirmation remains crucial.

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Paggi, Silvia, Giuseppe Mogavero, Arnaldo Amato, Emanuele Rondonotti, Alida Andrealli, Gianni Imperiali, Nicoletta Lenoci, et al. "Linked color imaging reduces the miss rate of neoplastic lesions in the right colon: a randomized tandem colonoscopy study." Endoscopy 50, no. 04 (March 14, 2018): 396–402. http://dx.doi.org/10.1055/a-0580-7405.

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Abstract Background Linked color imaging (LCI) is a newly developed image-enhancing endoscopy technology that provides bright endoscopic images and increases color contrast. We investigated whether LCI improves the detection of neoplastic lesions in the right colon when compared with high definition white-light imaging (WLI). Methods Consecutive patients undergoing colonoscopy were randomized (1:1) after cecal intubation into right colon inspection at first pass by LCI or by WLI. At the hepatic flexure, the scope was reintroduced to the cecum under LCI and a second right colon inspection was performed under WLI in previously LCI-scoped patients (LCI–WLI group) and vice versa (WLI–LCI group). Lesions detected on first- and second-pass examinations were used to calculate detection and miss rates, respectively. The primary outcome was the right colon adenoma miss rate. Results Of the 600 patients enrolled, 142 had at least one adenoma in the right colon, with similar right colon adenoma detection rates (r-ADR) in the two groups (22.7 % in LCI–WLI and 24.7 % in WLI–LCI). At per-polyp analysis, double inspection of the right colon in the LCI–WLI and WLI–LCI groups resulted in an 11.8 % and 30.6 % adenoma miss rate, respectively (P < 0.001). No significant difference in miss rate was found for advanced adenomas or sessile serrated lesions. At per-patient analysis, at least one adenoma was identified in the second pass only (incremental ADR) in 2 of 300 patients (0.7 %) in the LCI – WLI group and in 13 of 300 patients (4.3 %) in the WLI – LCI group (P = 0.01). Conclusions LCI could reduce the miss rate of neoplastic lesions in the right colon.

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Khurelbaatar, Tsevelnorov, Yoshimasa Miura, Hiroyuki Osawa, Yuji Ino, Takahito Takezawa, Chihiro Iwashita, Yoshie Nomoto, et al. "Improved detection of early gastric cancer with linked color imaging using an ultrathin endoscope: a video-based analysis." Endoscopy International Open 10, no. 05 (May 2022): E644—E652. http://dx.doi.org/10.1055/a-1793-9414.

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Abstract Background and study aims Ultrathin endoscopy causes a minimal gag reflex and has minimal effects on cardiopulmonary function. Linked color imaging (LCI) is useful for detection of malignancies in the digestive tract. The aim of this study was to clarify whether LCI with ultrathin endoscopy facilitates detection of early gastric cancer (EGC) despite its lower resolution compared with high-resolution white light imaging (WLI) with standard endoscopy. Patients and methods This was a retrospective analysis with prospectively collected video, including consecutive 166 cases of EGC or gastric atrophy alone. Ninety seconds of screening video was collected using standard and ultrathin endoscopes with both WLI and LCI for each case. Three expert endoscopists assessed each video and the sensitivity of detecting EGC calculated. Color difference calculations were performed. Results Sensitivities using ultrathin WLI, ultrathin LCI, standard WLI, and standard LCI for the identification of cancer were 66.0 %, 80.3 %, 69.9 %, and 84.0 %, respectively. The color difference between malignant lesions and surrounding mucosa with ultrathin LCI and standard LCI were significantly higher than using ultrathin WLI or standard WLI, supported subjectively by the visibility score. Ultrathin LCI color difference and visibility score were significantly higher than standard WLI. Conclusions LCI with a low-resolution ultrathin endoscope is superior to WLI with a high-resolution standard endoscope for gastric cancer screening. This suggests that the high color contrast between EGC and the surrounding mucosa is more important than high-resolution images.

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Ogawa, H., and A. Hirabayashi. "Sampling Theory in White-Light Interferometry." Sampling Theory in Signal and Image Processing 1, no. 2 (May 2002): 87–116. http://dx.doi.org/10.1007/bf03549372.

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Diddams, Scott, and Jean-Claude Diels. "Dispersion measurements with white-light interferometry." Journal of the Optical Society of America B 13, no. 6 (June 1, 1996): 1120. http://dx.doi.org/10.1364/josab.13.001120.

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Dong Yifan, 董一帆, 万新军 Wan Xinjun, 孟涵 Meng Han, and 解树平 Xie Shuping. "Fast and Stable White Light Interferometry." Laser & Optoelectronics Progress 54, no. 5 (2017): 051203. http://dx.doi.org/10.3788/lop54.051203.

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Farr, Keith B. "Beamsplitter cube for white light interferometry." Optical Engineering 31, no. 10 (1992): 2191. http://dx.doi.org/10.1117/12.59886.

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Kawada, Kenro, Miwako Arima, Ryoji Miyahara, Mika Tsunomiya, Masakazu Kikuchi, Fumiko Yamamoto, Akihiro Hoshino, Yasuaki Nakajima, Yusuke Kinugasa, and Tatsuyuki Kawano. "Effect of adding magnifying BLI, magnifying NBI, and iodine staining to white light imaging in diagnosis of early esophageal cancer." Endoscopy International Open 09, no. 12 (December 2021): E1877—E1885. http://dx.doi.org/10.1055/a-1583-9196.

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Abstract Background and study aims We investigated the effect of adding magnifying blue laser imaging (BLI), magnifying narrow-band imaging (NBI), and iodine staining to white light imaging in diagnosis of early esophageal squamous cell carcinoma (EESCC) in high-risk patients. Patients and methods Between May 2013 and March 2016, two parallel prospective cohorts of patients received either primary WLI followed by NBI-magnifying endoscopy (ME) or primary WLI followed by BLI-ME, were studied. At the end of screening, both groups underwent iodine staining. The percentage of patients with newly detected esophageal malignant lesions in each group and the diagnostic ability of image-enhanced endoscopy (IEE)-ME were evaluated. Results There are 258 patients assigned to the NBI-ME group and 254 patients assigned to the BLI-ME group. The percentage of patients with one or more malignant lesions detected in the WLI + NBI-ME examination was similar in the WLI + BLI-ME examination (15 of 258 patients or 5.81 % vs. 14 of 254 patients or 5.51 %). However, four of 19 lesions in the NBI-ME group and six of 21 lesions in the BLI-ME group were overlooked and were detected by iodine staining. NBI-ME and BLI-ME showed similar accuracy in differentiation of cancerous lesions from non-cancerous lesions in diagnosis of EESCC (NBI/BLI: sensitivity, 87.5/89.5; specificity, 78.9/76.6; accuracy, 80.8/79.5; positive predictive value, 53.8/53.1; negative predictive value, 95.7/96.1). Conclusions Both NBI and BLI were useful for detection of EESCC. However, because some lesions were overlooked by even NBI and BLI, high-risk patients may benefit from use of iodine staining during endoscopic screening of EESCC (UMIN000023596).

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Nishizawa, Toshihiro, Osamu Toyoshima, Shuntaro Yoshida, Chie Uekura, Ken Kurokawa, Munkhbayar Munkhjargal, Miho Obata, et al. "TXI (Texture and Color Enhancement Imaging) for Serrated Colorectal Lesions." Journal of Clinical Medicine 11, no. 1 (December 27, 2021): 119. http://dx.doi.org/10.3390/jcm11010119.

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Background and aim: Olympus Corporation released the texture and color enhancement imaging (TXI) technology as a novel image-enhancing endoscopic technique. We investigated the effectiveness of TXI in the imaging of serrated colorectal polyps, including sessile serrated lesions (SSLs). Methods: Serrated colorectal polyps were observed using white light imaging (WLI), TXI, narrow-band imaging (NBI), and chromoendoscopy with and without magnification. Serrated polyps were histologically confirmed. TXI was compared with WLI, NBI, and chromoendoscopy for the visibility of the lesions without magnification and for that of the vessel and surface patterns with magnification. Three expert endoscopists evaluated the visibility scores, which were classified from 1 to 4. Results: Twenty-nine consecutive serrated polyps were evaluated. In the visibility score without magnification, TXI was significantly superior to WLI but inferior to chromoendoscopy in the imaging of serrated polyps and the sub-analysis of SSLs. In the visibility score for vessel patterns with magnification, TXI was significantly superior to WLI and chromoendoscopy in the imaging of serrated polyps and the sub-analysis of SSLs. In the visibility score for surface patterns with magnification, TXI was significantly superior to WLI but inferior to NBI in serrated polyps and in the sub-analysis of SSLs and hyperplastic polyps. Conclusions: TXI provided higher visibility than did WLI for serrated, colorectal polyps, including SSLs.

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Kanmura, Shuji, Hitomi Hamamoto, Akihito Tanaka, Shiho Arima, Fumisato Sasaki, Shiroh Tanoue, Yuichiro Nasu, Shinichi Hashimoto, Michiyo Higashi, and Akio Ido. "Diagnostic utility of linked color imaging in the evaluation of colonic mucosal inflammation in ulcerative colitis: a pilot study." Endoscopy International Open 07, no. 08 (July 24, 2019): E937—E943. http://dx.doi.org/10.1055/a-0810-0398.

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Abstract Background and aims Recent studies recommend histological mucosal healing of intestinal tissue as a treatment goal in ulcerative colitis (UC). Linked-color imaging (LCI) is a new endoscopy system that enhances the color differences of the gastrointestinal mucosa. We investigated the efficacy of LCI in the evaluation of intestinal activity, including the histological activity in UC. Method A total of 21 UC patients who were evaluated by the LASEREO system (FUJIFILM Co., Tokyo, Japan) were enrolled from August to December in 2016. All of the target points were observed by conventional white-light imaging (WLI) and LCI and biopsied from the region of interest in each view. We quantified the color tones of 73 biopsied points on WLI and LCI using the L*a*b* color value (WLI-L, WLI-a, WLI-b, and LCI-L, LCI-a, LCI-b). We then investigated the relationships among the L*a*b* color values, endoscopic findings, and histological healing. Results The average LCI-a and LCI-b values of patients with high mucosal activity disease were significantly higher than in those with mucosal healing (P < 0.01), and only LCI-a was significantly correlated with the score for histological healing. With regard to the other color values (LCI-L and all WLI values), there were no statistically significant differences in terms of average color value and correlation between patients with high mucosal activity and those with mucosal healing. In addition, the difference in the average color values with LCI and WLI was 7.1 and 3.1, respectively. Conclusion LCI is more useful than WLI for the visualization and evaluation of mucosal inflammation in UC.

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Kikuchi, Daisuke, Hiroyuki Odagiri, Yoshio Hoshihara, Yorinari Ochiai, Yugo Suzuki, Junnosuke Hayasaka, Masami Tanaka, et al. "Definition of Mucosal Breaks in the Era of Magnifying Endoscopy with Narrow-Band Imaging." Gastroenterology Research and Practice 2022 (May 13, 2022): 1–6. http://dx.doi.org/10.1155/2022/3952962.

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Background. Gastroesophageal reflux disease is diagnosed endoscopically based on the presence of mucosal breaks. However, mucosal breaks can be judged differently depending on the endoscopist, even in the same image. We investigated how narrow-band imaging (NBI) and magnified endoscopy affect the judgment of mucosal breaks. Methods. A total of 43 consecutive patients were enrolled who had suspected mucosal breaks on white-light images (WLI) and underwent nonmagnified NBI (N-NBI) and magnified NBI (M-NBI) by a single endoscopist. From WLI, N-NBI, and M-NBI, 129 image files were created. Eight endoscopists reviewed the image files and judged the presence of mucosal breaks. Results. The 8 endoscopists determined mucosal breaks were present in 79.4 ± 9.5% (67.4%–93.0%) on WLI, and 76.7 ± 12.7% (53.5%–90.7%) on N-NBI. However, the percentage of mucosal breaks on M-NBI was significantly lower at 48.8 ± 17.0% (18.6%–65.1%) ( p < 0.05 ). Intraclass correlation between observers was 0.864 (95% CI 0.793–0.918) for WLI and 0.863 (95% CI 0.791–0.917) for N-NBI but was lower for M-NBI at 0.758 (95% CI 0.631–0.854). Conclusion. Rates of detection and agreement for mucosal breaks on WLI and N-NBI were high among endoscopists. However, these rates were lower on M-NBI.

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Dobashi, Akira, Shingo Ono, Hiroto Furuhashi, Toshiki Futakuchi, Naoto Tamai, Takashi Yamauchi, Machi Suka, and Kazuki Sumiyama. "Texture and Color Enhancement Imaging Increases Color Changes and Improves Visibility for Squamous Cell Carcinoma Suspicious Lesions in the Pharynx and Esophagus." Diagnostics 11, no. 11 (October 23, 2021): 1971. http://dx.doi.org/10.3390/diagnostics11111971.

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Texture and color enhancement imaging (TXI) has been developed as an image-enhanced endoscopy technology. TXI mode2 enhances texture and brightness, and TXI mode1 also enhances color. This study aims to assess the color differences in squamous cell carcinoma (SCC) suspicious lesions in the pharynx and esophagus using white light imaging (WLI), TXI mode1, TXI mode2, and narrow-band imaging (NBI). A total of 59 SCC suspicious lesions from 30 patients were analyzed. The color differences (ΔE) between the lesion and the surrounding mucosa were calculated for each modality. The color value was assessed using the Commission Internationale d’Eclairage L*a*b* color space. The visibility of the lesion in each modality was evaluated and compared to that in the WLI by six endoscopists. The mean ΔE values in the WLI, TXI mode1, TXI mode2, and NBI were 11.6; 18.6; 14.3; and 17.2, respectively, and the ΔE values of TXI mode1, TXI mode2, and NBI were significantly higher than those of the WLI (p < 0.001). No lesions had worse visibility, and 62.5% (37/59) had improved visibility, as assessed by more than half of the endoscopists in TXI mode1. TXI mode1 can enhance color changes and improve the visibility of SCC suspicious lesions in the pharynx and esophagus, compared to WLI.

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Yamaguchi, Daisuke, Shinya Kodashima, Mitsuhiro Fujishiro, Satoshi Ono, Keiko Niimi, Satoshi Mochizuki, Yosuke Tsuji, et al. "Evaluation of image-enhanced endoscopic technology using advanced diagnostic endoscopy for the detection of early gastric cancer: a pilot study." Endoscopy International Open 05, no. 09 (September 2017): E825—E833. http://dx.doi.org/10.1055/s-0043-113632.

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Abstract Background and study aims Image-enhanced endoscopy (IEE) plays an important role in early detection and detailed examination of early gastric cancer (EGC). The current study aimed to clarify the efficacy of IEE using advanced diagnostic endoscopy for EGC detection without magnification. Patients and methods We performed endoscopic examinations without magnification in patients referred to our hospital with a diagnosis of upper gastrointestinal tumor detected through routine screening endoscopy. In this study, we used three IEE technologies: narrow-band imaging; blue laser imaging; and i-scan optical enhancement. The detection rates for EGC between IEE and white-light imaging (WLI) were compared. Results Between July 2013 and June 2014, 156 patients were enrolled. Among upper gastrointestinal tumors, we analyzed endoscopic examination results of 119 lesions that were histologically diagnosed as EGC in 109 patients. The EGC detection rate in the IEE plus WLI groups was 77.3 %. Although the EGC detection rate in the IEE group was higher than that in the WLI group (80.0 % vs. 70.3 %), there was no significant difference between these two modalities. An important detection factor using IEE was tumor circumference, where the rate of detection in the anterior wall and lesser curvature was significantly higher than that in the posterior wall and greater curvature (P = 0.046). An important detection factor using WLI was color variation, where the rate of occurrence of a reddened or pale tumor was significantly higher than that of normal colored tumors (P = 0.030). Conclusions The detection rate of EGC without magnification was similar between the IEE group and the WLI group. Important detection factors differed between IEE and WLI; therefore, the IEE and WLI modalities have different characteristics regarding EGC detection. Consequently, we propose to use both IEE and WLI in the evaluation of EGC.

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Lee, Yun, Jong Moon, Hyun Choi, Tae Lee, Moon Choi, Sang-Woo Cha, Young Cho, and Sang-Heum Park. "Direct peroral cholangioscopy for diagnosis of bile duct lesions using an I-SCAN ultraslim endoscope: a pilot study." Endoscopy 49, no. 07 (May 31, 2017): 675–81. http://dx.doi.org/10.1055/s-0043-106179.

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Abstract Background and study aims I-SCAN is a computed virtual chromoendoscopy (CVC) system designed to enhance surface and vascular patterns. In this study, we evaluated the usefulness of direct peroral cholangioscopy (POC) using I-SCAN compared with a conventional white-light image (WLI) to diagnose bile duct lesions. Patients and methods Patients with mucosal lesions in the bile duct detected during direct POC were enrolled prospectively. The quality of endoscopic visualization and the visual diagnosis were assessed using I-SCAN and WLI modes, respectively, during direct POC. Results A total of 20 patients (9 malignant and 11 benign lesions) underwent I-SCAN to evaluate lesions in the bile duct using direct POC. The quality of endoscopic visualization using direct POC with I-SCAN was significantly higher than that of WLI for surface structure (P = 0.04), surface microvascular architecture (P = 0.01), and margins (P = 0.02). Overall diagnostic accuracy of the visual diagnosis was not different between I-SCAN and WLI (90.0 % vs. 75.0 %; P = 0.20). Conclusion Direct POC using CVC by I-SCAN seems to be helpful for evaluating mucosal lesions of the bile duct, without the interference from bile.Clinical trial registration: UMIN000021009

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Wang, Jun, Chuncui Ye, Kejian Wu, and Sujuan Fei. "The Effect of Linked Color Imaging for Adenoma Detection. A Meta-analysis of Randomized Controlled Studies." Journal of Gastrointestinal and Liver Diseases 31, no. 1 (March 19, 2022): 67–73. http://dx.doi.org/10.15403/jgld-4027.

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Background and Aims: The effect of linked color imaging (LCI) compared with white light imaging (WLI) is conflicting. The aim of this meta-analysis is to compare the efficacy of LCI versus WLI for the adenoma detection. Methods: PubMed, Embase, Google Scholar and Cochrane Library were searched up to the end of Aug 18, 2021. All randomized controlled trials (RCTs) comparing LCI with WLI were included. Dichotomous data were pooled to obtain the relative risk (RR) with a 95% confidence interval (CI), whereas continuous data were pooled using a mean difference (MD) with 95%CI. Results: A total of 10 RCTs involving 5,510 patients were included. The use of LCI was associated with a statistically significant improvement in adenoma detection rate (ADR), polyp detection rate (PDR), mean adenomas per patient (MAP) and mean polyp per patient (MPP) when compared to WLI (ADR: RR=1.15, 95%CI: 1.07-1.23, p=0.0001, PDR: RR=1.15, 95%CI: 1.08-1.22, p<0.0001; MAP: MD=0.18, 95%CI: 0.09- 0.28, p=0.0002; MPP: MD=0.13, 95%CI: 0.01, 0.25, p=0.03). When stratified by size, LCI group had a higher detection rate of small adenomas (<10 mm) than the WLI group. Besides, LCI showed a significant decrease in adenoma miss rate (AMR) when compared to WLI. There were no statistically significant differences between the two groups in advanced ADR (AADR), sessile serrated lesion detection rate (SDR), cecal intubation rate, insertion time, and withdrawal time. Conclusions: The pooled evidence suggests that LCI can significantly improve the detection of ADR, especially for small adenomas (<10 mm). Moreover, the AMR were significantly lower using LCI compared with WLI.

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Kanzaki, Hiromitsu, Ryuta Takenaka, Yoshiro Kawahara, Daisuke Kawai, Yuka Obayashi, Yuki Baba, Hiroyuki Sakae, et al. "Linked color imaging (LCI), a novel image-enhanced endoscopy technology, emphasizes the color of early gastric cancer." Endoscopy International Open 05, no. 10 (October 2017): E1005—E1013. http://dx.doi.org/10.1055/s-0043-117881.

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Abstract Background and study aims Linked color imaging (LCI) and blue laser imaging (BLI) are novel image-enhanced endoscopy technologies with strong, unique color enhancement. We investigated the efficacy of LCI and BLI-bright compared to conventional white light imaging (WLI) by measuring the color difference between early gastric cancer lesions and the surrounding mucosa. Patients and methods Images of early gastric cancer scheduled for endoscopic submucosal dissection were captured by LCI, BLI-bright, and WLI under the same conditions. Color values of the lesion and surrounding mucosa were defined as the average of the color value in each region of interest. Color differences between the lesion and surrounding mucosa (ΔE) were examined in each mode. The color value was assessed using the CIE L*a*b* color space (CIE: Commission Internationale d’Eclairage). Results We collected images of 43 lesions from 42 patients. Average ΔE values with LCI, BLI-bright, and WLI were 11.02, 5.04, and 5.99, respectively. The ΔE was significantly higher with LCI than with WLI (P < 0.001). Limited to cases of small ΔE with WLI, the ΔE was approximately 3 times higher with LCI than with WLI (7.18 vs. 2.25). The ΔE with LCI was larger when the surrounding mucosa had severe intestinal metaplasia (P = 0.04). The average color value of a lesion and the surrounding mucosa differed. This value did not have a sufficient cut-off point between the lesion and surrounding mucosa to distinguish them, even with LCI. Conclusion LCI had a larger ΔE than WLI. It may allow easy recognition and early detection of gastric cancer, even for inexperienced endoscopists.

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Fujimoto, Ai, Yutaka Saito, Seiirhicro Abe, Shu Hoteya, Kosuke Nomura, Hiroshi Yasuda, Yasumasa Matsuo, et al. "Haemostasis treatment using dual red imaging during endoscopic submucosal dissection: a multicentre, open-label, randomised controlled trial." BMJ Open Gastroenterology 6, no. 1 (March 2019): e000275. http://dx.doi.org/10.1136/bmjgast-2019-000275.

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IntroductionPatients scheduled to undergo oesophageal, gastric and colorectal endoscopic submucosal dissection (ESD) are to be investigated to verify the efficacy of dual red imaging (DRI) for establishing haemostasis during ESD.Methods and analysisThe trial is designed as a multicentre, open-label randomised, parallel-group, controlled intervention study. Registered patients will be randomly assigned to DRI and white light imaging (WLI) groups. In the DRI group, the mucosal incision and submucosal dissection will be performed by WLI, and haemostasis will be managed by DRI when bleeding occurs. In the WLI group, the mucosal incision and submucosal dissection are to be performed by WLI and the haemostasis management is to be performed by WLI. The primary endpoint is the time from the recognition of bleeding up to the achievement of complete haemostasis (haemostasis time). The secondary endpoints are the operation time, the proportion of cases in which perforation occurs, and the psychological stress experienced by the endoscopist during haemostasis treatment.Ethics and disseminationThis trial was approved by the Keio University Review Board for Clinical Trials (5 December 2016).DiscussionThis will be the first multicentre collaborative research using DRI for haemostasis treatment during ESD. When the safety and simplicity of DRI as a treatment for haemostasis during ESD can be proven, the ESD procedure can be simplified and disseminated more widely in clinical practice.Trial registration numberUMIN000025134

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Tsai, Cho-Lun, Arvind Mukundan, Chen-Shuan Chung, Yi-Hsun Chen, Yao-Kuang Wang, Tsung-Hsien Chen, Yu-Sheng Tseng, Chien-Wei Huang, I.-Chen Wu, and Hsiang-Chen Wang. "Hyperspectral Imaging Combined with Artificial Intelligence in the Early Detection of Esophageal Cancer." Cancers 13, no. 18 (September 13, 2021): 4593. http://dx.doi.org/10.3390/cancers13184593.

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This study uses hyperspectral imaging (HSI) and a deep learning diagnosis model that can identify the stage of esophageal cancer and mark the locations. This model simulates the spectrum data from the image using an algorithm developed in this study which is combined with deep learning for the classification and diagnosis of esophageal cancer using a single-shot multibox detector (SSD)-based identification system. Some 155 white-light endoscopic images and 153 narrow-band endoscopic images of esophageal cancer were used to evaluate the prediction model. The algorithm took 19 s to predict the results of 308 test images and the accuracy of the test results of the WLI and NBI esophageal cancer was 88 and 91%, respectively, when using the spectral data. Compared with RGB images, the accuracy of the WLI was 83% and the NBI was 86%. In this study, the accuracy of the WLI and NBI was increased by 5%, confirming that the prediction accuracy of the HSI detection method is significantly improved.

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Fujimoto, Daisaku, Naoki Muguruma, Koichi Okamoto, Yasuteru Fujino, Kaizo Kagemoto, Yasuyuki Okada, Yoshifumi Takaoka, et al. "Linked color imaging enhances endoscopic detection of sessile serrated adenoma/polyps." Endoscopy International Open 06, no. 03 (March 2018): E322—E334. http://dx.doi.org/10.1055/s-0043-124469.

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Abstract Background and study aims Although new image-enhanced endoscopy (IEE) technologies such as blue laser imaging (BLI), BLI-bright, and linked color imaging (LCI) have been developed, their utility for the detection of sessile serrated adenoma/polyps (SSA/Ps) is still unclear. This study aimed to evaluate the utility of BLI, BLI-bright, and LCI for SSA/P detection in still image examinations and in a prospective randomized controlled trial (RCT). Patients and methods A group of 6 expert and non-expert endoscopists read 200 endoscopic still images containing SSA/P lesions using white light image (WLI), BLI, BLI-bright, and LCI. Color differences were calculated using the color space method. A prospective RCT of tandem colonoscopy with WLI and LCI was performed. Patients with SSA/P and those with a history of SSA/P that had been endoscopically removed were enrolled and randomly allocated to WLI-LCI or LCI-WLI groups. Additional endoscopic detection rates for SSA/P were compared between the 2 groups. Results LCI showed the highest SSA/P detection rate among the 4 modes for both expert and non-expert endoscopists. The detection rate with LCI for the 6 expert endoscopists (mean 98.3 ± standard deviation 2.0 %) was significantly higher than that with WLI (86.7 ± 6.0 %, P < 0.01). Likewise, the detection rate with LCI for the 6 non-expert endoscopists (92.3 ± 2.9 %) was significantly higher than that with WLI (72.7 ± 11.5 %, P < 0.01). The color difference of SSA/P with LCI was the highest among the 4 modes, and was significantly higher than with WLI (median 15.9, (interquartile range 13.7 – 20.6) vs. 10.2, (7.6 – 14.2); P < 0.0001). In the RCT, a total of 44 patients (WLI-LCI 22 vs. LCI-WLI 22) underwent colonoscopy. The additional detection rate for SSA/P in the second inspection in the WLI-LCI group (21.6 %, 8/37) was significantly higher than in the LCI-WLI group (3.2 %, 1/31; P = 0.02). The small, flat, non-mucus and isochromatic SSA/Ps in the transverse colon were detected more frequently in the second inspection with LCI. Conclusions LCI was the most sensitive mode for SSA/P detection among WLI, BLI, BLI-bright, and LCI in the still image examinations. Our RCT strongly suggests that LCI is superior to conventional WLI for SSA/P detection during colonoscopy. UMIN000017599.

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Jiang Yi, 江毅. "Progress in Fiber Optic White-Light Interferometry." Chinese Journal of Lasers 37, no. 6 (2010): 1413–20. http://dx.doi.org/10.3788/cjl20103706.1413.

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Hamprecht, Fred A. "Bayesian surface estimation for white light interferometry." Optical Engineering 44, no. 1 (January 1, 2005): 015601. http://dx.doi.org/10.1117/1.1829651.

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Kim, Jeong-Gon. "Absolute Temperature Measurement using White Light Interferometry." Journal of the Optical Society of Korea 4, no. 2 (September 1, 2000): 89–93. http://dx.doi.org/10.3807/josk.2000.4.2.089.

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Shavrin, Igor, Lauri Lipiäinen, Kimmo Kokkonen, Steffen Novotny, Matti Kaivola, and Hanne Ludvigsen. "Stroboscopic white-light interferometry of vibrating microstructures." Optics Express 21, no. 14 (July 8, 2013): 16901. http://dx.doi.org/10.1364/oe.21.016901.

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Ferreira, L. A., J. L. Santos, and F. Farahi. "Polarization insensitive fibre-optic white-light interferometry." Optics Communications 114, no. 5-6 (February 1995): 386–92. http://dx.doi.org/10.1016/0030-4018(94)00599-p.

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Journal articles on the topic 'White Light Interferometry (WLI)'

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