White light endoscopy,narrow band imaging and chromoendoscopy with magnification in diagnosing colorectal neoplasia

AIM:To evaluate the sensitivity(Sn),specificity(Sp),positive predictive value(PPV) and negative predictive value(NPV) of 3 different techniques:high resolution white light endoscopy(WLE),Narrow Band Imaging(NBI) and Chromoendoscopy(CHR),all with magnification in differentiating adenocarcinomas,adenomatous and hyperplastic colorectal polyps.METHODS:Each polyp was sequentially assessed first by WLE,followed by NBI and finally by CHR.Digital images of each polyp with each modality were taken and stored.Biopsies or polypectomies were then performed followed by blinded histopathological analysis.Each image was blindly graded based on the Kudo's pit pattern(KPP).In the assessment with NBI,the mesh brown capillary network pattern(MBCN) of each polyp was also described.The Sn,Sp,PPV and NPV of differentiating hyperplastic(Type Ⅰ & Ⅱ-KPP,Type Ⅰ-MBCN) adenomatous(Types Ⅲ,Ⅳ-KPP,Type Ⅱ-MBCN) and carcinomatous polyps(Type Ⅴ-KPP,Type Ⅲ-MCBN) was then compared with reference to the final histopathological diagnosis.RESULTS:A total of 50 colorectal polyps(5 adenocarcinomas,38 adenomas,7 hyperplastic) were assessed.CHR and NBI [KPP,MBCN or the combined classification(KPP & MBCN)] were superior to WLE in the prediction of polyp histology(P < 0.001,P=0.002,P=0.001 and P < 0.001,respectively).NBI,using the MBCN pattern or the combined classification showed higher numerical accuracies compared to CHR,but this was not statistically significant(P=0.625,0.250).CONCLUSION:This feasibility study demonstrated that this combined classification with NBI could potentially be useful in routine clinical practice,allowing the endoscopist to predict histology with higher accuracies using a less cumbersome and technically less challenging method.

Polyp detection rates using magnification with narrow band imaging and white light

AIM: To compare the yield of adenomas between narrow band imaging and white light when using high definition/magnification. METHODS: This prospective, non-randomized comparative study was performed at the endoscopy unit of veteran affairs medical center in Phoenix, Arizona. Consecutive patients undergoing first average risk colorectal cancer screening colonoscopy were selected. Two experienced gastroenterologists performed all the procedures that were blinded to each other's findings. Demographic details were recorded. Data are presented as mean ± SEM. Proportional data were compared using the χ2 test and means were compared using the Student's t test. Tandem colonoscopy was performed in a sequential and segmental fashion using one of 3 strategies: white light followed by narrow band imaging [Group A: white light(WL) → narrow band imaging(NBI)]; narrow band imaging followed by white light(Group B: NBI → WL) and, white light followed by white light(Group C: WL → WL). Detection rate of missed polyps and adenomas were evaluated in all three groups. RESULTS: Three hundred patients were studied(100 in each Group). Although the total time for the colonoscopy was similar in the 3 groups(23.8 ± 0.7, 22.2 ± 0.5 and 24.1 ± 0.7 min for Groups A, B and C, respectively), it reached statistical significance between Groups B and C(P < 0.05). The cecal intubation time in Groups B and C was longer than for Group A(6.5 ± 0.4 min and 6.5 ± 0.4 min vs 4.9 ± 0.3 min; P < 0.05). The withdrawal time for Groups A and C was longer than Group B(18.9 ± 0.7 min and 17.6 ± 0.6min vs 15.7 ± 0.4 min; P < 0.05). Overall miss rate for polyps and adenomas detected in three groups during the second look was 18% and 17%, respectively(P = NS). Detection rate for polyps and adenomas after first look with white light was similar irrespective of the light used during the second look(WL → WL: 13.7% for polyps, 12.6% for adenomas; WL → NBI: 14.2% for polyps, 11.3% for adenomas). Miss rate of polyps and adenomas however was significantly higher when NBI was used first(29.3% and 30.3%, respectively; P < 0.05). Most missed adenomas were ≤ 5 mm in size. There was only one advanced neoplasia(defined by size only) missed during the first look. CONCLUSION: Our data suggest that the tandem nature of the procedure rather than the optical techniques was associated with the detection of additional polyps' and adenomas.

Ultra high magnification endoscopy: Is seeing really believing?

Endoscopy is an indispensible diagnostic and thera-peutic instrument for gastrointestinal diseases. Endo-cytoscopy and confocal endomicroscopy are two types of ultra high magnification endoscopy techniques.Standard endoscopy allows for 50 × magnification,whereas endocytoscopy can magnify up to 1400 × and confocal endomicroscopy can magnify up to 1000 ×.These methods open the realm of real time micros copicevaluation of the GI tract, including cellular and subcellular structures. Confocal endomicroscopy has the additional advantage of being able to visualize subsurface structures. The use of high magnification endoscopy inconjunction with standard endoscopy allows for a real-time microscopic assessment of areas with macroscopic abnormalities, providing "virtual biopsies" with valuable information about cellular and subcellular changes. Thiscan minimize the number of biopsies taken at the time of endoscopy. The use of this technology may assistin detecting premalignant or malignant changes at anearlier state, allowing for earlier intervention and treatment. High magnification endoscopy has shown promising results in clinical trials for Barrett's esophagus,esophageal adenocarcinoma, esophageal squamous cell cancer, gastric cancer, celiac disease, colorectalcancer, and inflammatory bowel disease. As the use of high magnification endoscopy techniques increases,the clinical applications will increase as well. Of the two systems, only confocal endomicroscopy is currently commercially available. Like all new technologies there will be an initial learning curve before operators become proficient in obtaining high quality images and discerning abnormal from normal pathology. Validatedcriteria for the diagnosis of the various gastrointestinal diseases will need to be developed for each method. Inthis review, the basic principles of both modalities are discussed, along with their clinical applic ability and limitations.

Variations of OCT measurements corrected for the magnification effect according to axial length and refractive error in children

Purpose:The aim of this paper was to examine the distribution of macular,retinal nerve fiber layer(RNFL)thickness and optic disc parameters of myopic and hyperopic eyes in comparison withemmetropic control eyes and to investigate their variation according to axial length(AL)andspherical equivalent(SE)in healthy children.Methods:This study included 293 pairs of eyes of 293children(145 boys and 148 girks),ranging in age from 6 to 17 years,Subjects were dividedaccording to SE in control(emmetropia,99 children),myopia(100 children)and hyperopia(94children)groups and according to axial AL in 68 short(<22.00 mm,68),medium(from≥22.00 mmto 25.00 mm,189)and long eyes(>25.00 mm,36).Macular parameters,RNFL thickness and opticdisc morphology were assessed by the Cirrus^(TM) HD-OCT.AL was measured using the IOL-Mastersystem.Littmann's formula was used for calculating the corrected AL-related ocular magnification.Results Mean age(±SD)was 10.84±3.05 years;mean(±SD)SE was+0.14±0.51 D(range from8.75 to+8.25 D)and mean AL(±SD)was 23.12±1.49.Average RNFL thickness,averagemacular thickness and macular volume decreased as AL and myopia increased.No correlationsbetween AL/SE and optic disc parameters were found after correcting for magnification effect.Conclusions:AL and refractive error affect measurements of macular and RNFL thickness inhealthy children.To make a correct interpretation of ocT measurements,ocular magnificationeffect should be taken into account by clinicians or OCT manufacturers.

Experimental Modal Damping Identification of a Mechanical Structure Using Video Magnification Technique

Vibration can be introduced in all mechanical fields in our life.Engineers try to avoid its negative effect leading in some cases to deformation in the machines.Many researches are dedicated to study the identification of damping especially in multi degree of freedom systems with particular attention to the source of energy dissipation.They focus on developing new tools or methods which may be used in real problems to obtain accurate results about the amount(or value)and the location of energy dissipation in the structure.The aim of this paper is to present an original procedure aims to experimentally determine the modal damping ratio of a mechanical structure.The proposed procedure consists of extracting the Frequency Response Function of the vibrating system using the video magnification method and then calculate the modal damping ratio using the 3-dB method.These experimental measurements are carried out by giving an external force on a cantilever beam,then the modal damping ratios are extracted using motion magnification.The obtained results show a relative error less than 4.2% between the experimental measurements and the analytical calculation for the Frequency Response Function(FRF)curves.The novelty of the paper is to combine the video magnification technique and the 3dB method in a procedure that aims to experimentally measure the modal damping of a mechanical structure.The proposed procedure in this paper represents the damping identification as a simple and easy engineering application.

In vivo pilot study into superficial microcirculatory characteristics of colorectal adenomas using novel high-resolution magnifying endoscopy with blue laser imaging

BACKGROUND No studies have yet been conducted on changes in microcirculatory hemody-namics of colorectal adenomas in vivo under endoscopy.The microcirculation of the colorectal adenoma could be observed in vivo by a novel high-resolution magnification endoscopy with blue laser imaging(BLI),thus providing a new insight into the microcirculation of early colon tumors.AIM To observe the superficial microcirculation of colorectal adenomas using the novel magnifying colonoscope with BLI and quantitatively analyzed the changes in hemodynamic parameters.METHODS From October 2019 to January 2020,11 patients were screened for colon adenomas with the novel high-resolution magnification endoscope with BLI.Video images were recorded and processed with Adobe Premiere,Adobe Photoshop and Image-pro Plus software.Four microcirculation parameters:Microcirculation vessel density(MVD),mean vessel width(MVW)with width standard deviation(WSD),and blood flow velocity(BFV),were calculated for adenomas and the surrounding normal mucosa.RESULTS A total of 16 adenomas were identified.Compared with the normal surrounding mucosa,the superficial vessel density in the adenomas was decreased(MVD:0.95±0.18 vs 1.17±0.28μm/μm2,P<0.05).MVW(5.11±1.19 vs 4.16±0.76μm,P<0.05)and WSD(11.94±3.44 vs 9.04±3.74,P<0.05)were both increased.BFV slowed in the adenomas(709.74±213.28 vs 1256.51±383.31μm/s,P<0.05).CONCLUSION The novel high-resolution magnification endoscope with BLI can be used for in vivo study of adenoma superficial microcirculation.Superficial vessel density was decreased,more irregular,with slower blood flow.

13.5 nm Schwarzschild microscope with high magnification and high resolution

A Schwarzschild microscope with a numerical aperture of 0.2 and a magnification of 130 in a 100μm field of view(FOV)is designed and is working at 13.5 nm.Meanwhile,a CCD is used as a detector with a pixel size of 13μm×13μm and imaging area of 13 mm×13 mm.The imaging quality with tolerances of system and errors of mirrors are considered.We obtain that the best on-axes object resolution can be up to about 200 nm,the average value is 230 nm,and the resolution is about 360 nm at 80μm FOV.

Shaking table test and cumulative deformation evaluation analysis of a tunnel across the hauling sliding surface

To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical calculations,this study proposed magnification of the Arias intensity(MIa)to characterize the overall local deformation damage of the tunnel lining in terms of the deformation characteristics,frequency domain,and energy.Using the time‐domain analysis method,the plastic effect coefficient(PEC)was proposed to characterize the degree of plastic deformation,and the applicability of the seismic cumulative failure effect(SCFE)was discussed.The results show that the low‐frequency component(f1 and f2≤10 Hz)and the high‐frequency component(f3 and f4>10 Hz)acceleration mainly cause global and local deformation of the tunnel lining.The local deformation caused by the high‐frequency wave has an important effect on the seismic damage of the lining.The physical meaning of PEC is more clearly defined than that of the residual strain,and the SCFE of the tunnel lining can also be defined.The SCFE of the tunnel lining includes the elastic deformation effect stage(<0.15g),the elastic–plastic deformation effect stage(0.15g–0.30g),and the plastic deformation effect stage(0.30g–0.40g).This study can provide valuable theoretical and technical support for the construction of traffic tunnels in high‐intensity earthquake areas.

Narrow-band imaging with magnifying endoscopy is accurate for detecting gastric intestinal metaplasia

AIM:To investigate the predictive value of narrowband imaging with magnifying endoscopy (NBI-ME) for identifying gastric intestinal metaplasia (GIM) in unselected patients. METHODS:We prospectively evaluated consecutive patients undergoing upper endoscopy for various indications, such as epigastric discomfort/pain, anaemia, gastro-oesophageal reflux disease, suspicion of peptic ulcer disease, or chronic liver diseases. Patients underwent NBI-ME, which was performed by three blinded, experienced endoscopists. In addition, five biopsies (2 antrum, 1 angulus, and 2 corpus) were taken and examined by two pathologists unaware of the endoscopic findings to determine the presence or absence of GIM. The correlation between light blue crest (LBC) appearance and histology was measured. Moreover, we quantified the degree of LBC appearance as less than 20% (+), 20%-80% (++) and more than 80% (+++) of an image field, and the semiquantitative evaluation of LBC appearance was correlated with IM percentage from the histological findings. RESULTS:We enrolled 100 (58 F/42 M) patients who were mainly referred for gastro-esophageal reflux disease/dyspepsia (46%), cancer screening/anaemia (34%), chronic liver disease (9%), and suspected celiac disease (6%); the remaining patients were referred for other indications. The prevalence of Helicobacter pylori (H. pylori ) infection detected from the biopsies was 31%, while 67% of the patients used proton pump inhibitors. LBCs were found in the antrum of 33 patients (33%); 20 of the cases were classified as LBC+, 9 as LBC++, and 4 as LBC+++. LBCs were found in the gastric body of 6 patients (6%), with 5 of them also having LBCs in the antrum. The correlation between the appearance of LBCs and histological GIM was good, with a sensitivity of 80% (95%CI:67-92), a specificity of 96% (95%CI:93-99), a positive predictive value of 84% (95%CI:73-96), a negative predictive value of 95% (95%CI:92-98), and an accuracy of 93% (95%CI:90-97). The NBI-ME examination overlooked GIM in 8 cases, but the GIM was less than 5% in 7 of the cases. Moreover, in the 6 false positive cases, the histological examination showed the presence of reactive gastropathy (4 cases) or H. pylori active chronic gastritis (2 cases). The semiquantitative correlation between the rate of LBC appearance and the percentage of GIM was 79% (P < 0.01). CONCLUSION:NBI-ME achieved good sensitivity and specificity in recognising GIM in an unselected population. In routine clinical practice, this technique can reliably target gastric biopsies.

Clinical applicability of gastroscopy with narrow-band imaging for the diagnosis of Helicobacter pylori gastritis, precancerous gastric lesion, and neoplasia

Premalignant gastric lesions such as atrophic gastritis and intestinal metaplasia frequently occur in subjects with long-term Helicobacter pylori(H.pylori)infection.The regular arrangement of collecting venules(RAC)is seen in the normal gastric corpus,whereas mucosal swelling and redness without RAC are observed in H.pylori-infected mucosa.Despite successful H.pylori eradication,the presence of atrophic gastritis and/or gastric intestinal metaplasia(GIM)is a risk factor for gastric cancer.With the development of advanced imaging technologies,recent studies have reported the usefulness of narrow-band imaging(NBI)for endoscopic diagnosis of atrophic gastritis and GIM.Using NBI endoscopy with magnification(M-NBI),atrophic gastritis is presented as irregular coiled microvessels and loss of gastric pits.Typical M-NBI endoscopic findings of GIM are a light blue crest and a white opaque substance.Based on the microvascular patterns,fine network,core vascular,and unclear patterns are useful for predicting gastric dysplasia in polypoid lesions.For diagnosis of early gastric cancer(EGC),a systematic classification using M-NBI endoscopy has been proposed on the basis of the presence of a demarcation line and an irregular microvascular/microsurface pattern.Furthermore,M-NBI endoscopy has been found to be more accurate for determining the horizontal margin of EGC compared to conventional endoscopy.In this review,we present up-to-date results on the clinical usefulness of gastroscopy with NBI for the diagnosis of H.pylori gastritis,precancerous gastric lesion,and neoplasia.

Real-time histology with the endocytoscope

Endoscopic Imaging has progressed tremendously over the last few decades. Novel imaging technologies such as high-resolution and high-magnification white light endoscopy, narrow band imaging, optimal band imaging, auto? ourescence imaging and optical coherence tomography not only aid the endoscopist in detecting malignant or pre-malignant lesions but also assist in predicting histology. Recently, the introduction of Endocytoscopy (EC) and Confocal Endomicroscopy has taken us into a new realm of diagnostic endoscopy. With the ability to magnify up to 1000 ×, cellular structures can be visualized in real-time. This advance in technology could potentially lead to a paradigm shift negating the need to obtain biopsies. EC is, however, still in the early stages of development and further research needs to be carried out before it can be accepted as standard practice. This review will focus on the diagnostic utility of the Endocytoscope.

Design of a flexible piezoelectric microgripper based on combined amplification principles

Aiming to address the problem of the low amplification ratio of traditional microgrippers,a two-stage microgripper based on the principle of combined amplification was designed with a high amplification ratio and large displacement,using a simple and compact structure.The relationship between theoretical input variables and output variables were first calculated by a projection theorem.Secondly,the performance of the microgripper was analyzed by finite element analysis(FEA).Finally,the accuracy of the theoretical calculation and FEA was verified experimentally.The results show that the microgripper has high magnification and can be gripped in parallel,with self-adaptability for many irregular shaped micro objects.The actual magnification was 23.2×,which is greater than similar products.

Cost Optimized Non-Contacting Experimental Modal Analysis Using a Smartphone

The vibrations behavior analysis is an essential step in the mechanical design process.Several methods such as analytical modelling,numerical analysis and experimental measurements can be used for this purpose.However,the numerical or analytical models should be validated through experimental measurements,usually expensive.This paper introduces an inexpensive smartphone as an accurate,non-intrusive vibrations’behavior measurement device.An experimental measurement procedure based on the video processing method is presented.This procedure allows the measurement of the natural frequencies and the mode shapes of a vibrating structure,simply by using a smartphone built-in camera.The experimental results are compared to those obtained using an accurate analytical model,where the natural frequencies error is less than 2.7%and the modal assurance criterion is higher than 0.89.In order to highlight the obtained results,a comparison has been done using a high quality and high frame per second(fps)camera-based measurement of material properties.Since the highest recovered natural frequency and its associated mode shape depend on the frame per second rate of the recorded video,this procedure has great potential in low frequencies problems such as for big structures like buildings and bridges.This validated technique re-introduces the personal smartphone as an accurate inexpensive non-contacting vibration measurement tool.

Study on numerical simulation of nodular graphite iron microstructure formation

In this paper, the mathematical and physical model was developed based on thermodynamics and solidification theory before the eutectoid transformation of nodular graphite iron occurred. The Local Element Substitute and Magnification Method was brought forward and 3-dimensional numerical simulation program based on the model and the new assistant algorithm was developed and used to calculate the samples. Results of calculation have good agreement with experimental data. To display the microstructure formation during solidification of nodular graphite iron, a 2-dimensional numerical simulation program combined with the result of the 3-dimensional numerical simulation of experimental samples was compiled.

Influence of corneal power on circumpapillary retinal nerve fiber layer and optic nerve head measurements by spectral-domain optical coherence tomography

AIM: To evaluate the influence of corneal power on circumpapillary retinal nerve fiber layer(cp RNFL) and optic nerve head(ONH) measurements by spectral-domain optical coherence tomography(SD-OCT).METHODS: Twenty-five eyes of 25 healthy participants(mean age 23.6±3.6y) were imaged by SD-OCT using horizontal raster scans. Disposable soft contact lenses of different powers(from-11 to +5 diopters including 0 diopter) were worn to induce 2-diopter changes in corneal power. Differences in the cp RNFL and ONH measurements per diopter of change in corneal power were analyzed.RESULTS: As corneal power increased by 1 diopter, total and quadrant cp RNFL thicknesses, except for the nasal sector, decreased by-0.19 to-0.32 μm(P<0.01). Furthermore, the disc, cup, and rim areas decreased by-0.017,-0.007, and-0.015 mm2, respectively(P<0.001); the cup and rim volumes decreased by-0.0013 and-0.006 mm^3, respectively(P<0.01); and the vertical and horizontal disc diameters decreased by-0.006 and-0.007 mm, respectively(P<0.001).CONCLUSION: For more precise OCT imaging, the ocular magnification should be corrected by considering both the axial length and corneal power. However, the effect of corneal power changes on cp RNFL thickness and ONH topography are small when compare with those of the axial length.

Whole circumferential endoscopic submucosal dissection of superficial adenocarcinoma in long-segment Barrett's esophagus:A case report

BACKGROUND Esophageal adenocarcinoma(EAC)derived from long-segment Barrett’s esophagus(LSBE)is extremely rare in Asia.LSBE-related EAC is often difficult to diagnose in the horizontal extent.If the tumor has spread throughout the LSBE,whole circumferential endoscopic submucosal dissection(ESD)should be performed,which is difficult to complete safely.Additionally,whole circumferential ESD can bring refractory postoperative stenosis.We hereby report a case of EAC involving the whole circumference of the LSBE,achieving complete endoscopic removal without complications.CASE SUMMARY An 85-year-old man with the chief complaint of dysphagia underwent esophagogastroduodenoscopy.We suspected a flat-type cancerous lesion that extended the whole circumference of the LSBE(C 3.5,M 4.0)using narrow-band imaging magnification endoscopy(NBI-M).We achieved circumferential en bloc resection of the lesion safely with special ESD techniques.Histology of the ESD specimens demonstrated that the superficial EAC extended the whole circumference of the LSBE,and papillary or well-differentiated tubular adenocarcinoma was confined in the lamina propria mucosa showing a vertical negative margin.To prevent post-ESD stenosis,we performed endoscopic local injection of steroids,followed by oral administration of steroids.There was no evidence of esophageal refractory stenosis or tumor recurrence 30 mo after ESD.In summary,we experienced a rare case of LSBE-related EAC.The horizontal tumor extent was accurately diagnosed by NBI-M.Additionally,we achieve whole circumferential ESD safely without postoperative refractory stenosis.CONCLUSION NBI-M,ESD,and steroid therapy enabled the curative resection of superficial full circumferential LSBE-related EAC without refractory postoperative stenosis.

Diameter Measurements of the Upper Parts of Trees Using an Ultra-Telephoto Digital Photography System

We develop a new technique to measure the exact upper diameters of trees that is comparatively simple and inexpensive. We can measure the diameters of entire tree trunks efficiently and with high precision. The system uses a digital camera with a ~15 - 30× telephoto lens to take a photograph that can be used for measuring the diameter of the upper part of a comparatively slender tree trunk. Since this method requires a measuring distance and the height of the target point in the image, a range finder capable of measuring angles was combined with the main digiscoping system. A range finder sensor uses a laser and makes a 360 degree angle of observation possible. The diameter of a target position of the objective tree can be obtained by measuring the digital image using image editing software and calculations from spreadsheet software. We focus on the Japanese cedar species in the southwestern part of Japan. Photographic measurements were obtained prior to thinning. The estimates that we obtained largely agree with the true measurements of all trees. With regard to the estimated accuracy of all measured trees, the maximum error ratio was 7.0% (1.45 cm), with a ~2% - 4% error for most of the estimated results. Although the absolute value of the estimation error was 1.87 cm (5.3%) at the maximum (9.87 m in height and 35.5 cm in diameter), an estimation accuracy of <1 cm was reproduced in almost all measurements except for the extreme hypertrophy portion by butt swelling.

Analysis of Water Mist Suppression with Foam Additive in Wind Generator

The study adopted a 20-foot long container to simulate the situation inside a turbine cabin. Water mist sprays were installed internally and used to perform fire extinguishing tests. Under these different scenarios, several operating factors were adjusted with the results of each adjustment subsequently measured. The operating factors studied included： operating pressures, foam concentrations, cabin opening issues, and obstacles. Each of the factors was compared with the others so as to find out which combinations would be most suitable for a water mist spray system installed inside a wind turbine cabin. The presence of obstructions hinders the direct impact of the mist spray on the fire source and in average an additional 2 to 3 minutes is required to put out the fire. This study found that the effect of the foam-water ratio is linear. Regardless of the scenario, the optimum mixture ratio is 3%. The line graph shows that the most unsuitable aqueous film-forming mixture ratio is 6%. This experiment found that the main fire extinguishing mechanism of water mist spray is the cooling of a large area via water droplets. This system is very effective in bringing down the temperature. The addition of foam in water mist spray, however, impaired the effectiveness of the cooling effect although the fire control mechanism via emulsification markedly reduced the time required to put out the fire. The increase in foam magnification will considerably enhance the fire extinguishing efficiency.

Compact in situ microscope for photoelectron spectroscopy via two-mirror reflection

Photoelectron spectroscopy is a powerful tool in characterizing the electronic structure of materials.To investigate the specific region of interest with high probing efficiency,in this work we propose a compact in situ microscope to assist photoelectron spectroscopy.The configuration of long objective distance of 200 mm with two-mirror reflection has been introduced.Large magnification of 5×to 100×,lateral resolution of 4.08μm,and longitudinal resolution of 4.49μm have been achieved.Meanwhile,the testing result shows larger focal depth of this in situ optical microscope.Similar configurations could also be applied to other electronic microscopes to improve their probing capability.