Optical Magnification Research Articles

Endoscopic Treatment of Neurosurgical Pathologies: Experience and Future Prospects in the Neurosurgery Department at Mohammed 6 University Hospital, Marrakech

Endoscopy is a new procedure in neurosurgery that uses optical magnification and video-assisted endoscopes to guide the hand to hard-to-reach locations. Despite extensive trials and meta-analyses, no definitive results have been published on its benefits. Neuroendoscopy has expanded beyond ventricular operations to treat various neurosurgical conditions, including cyst fenestration, tumor biopsy, tumor excision, and metastatic disease evaluation. It is beneficial for patients with hydrocephalus, intraventricular cysts, and concurrent hydrocephalus. Intracranial cysts are ideal for neuro-endoscopic therapy, and it can treat cystic craniopharyngiomas, dysontogenic tumors, gliomas, and metastases. Endoscopic tumor biopsy is a reliable technique for ventricle brain tumors. our study treated 480 hydrocephalus patients using endoscopic third ventriculostomy, accounting for 50.5% of cases. The most common cause was Sylvius aqueduct stenosis. Endoscopy was beneficial for treating colloidal cysts, arachnoid cysts, pituitary adenoma, and craniopharyngioma. It also served as a complement to microsurgery in 55 cases. Neuroendoscopy improved sciatic pain in 15 patients who underwent lumbar discectomy, with only minor issues due to the surgical scar. Neuroendoscopic surgery is expected to advance significantly in the future, with advancements in camera and optical technology, surgical instrument design, navigation systems, multiport surgery, and improved microsurgery.

Technical Strategies and Learning Curve in Robotic-assisted Peripheral Nerve Surgery.

Robotic-assisted peripheral nerve surgery (RASPN) has emerged as a promising advancement in microsurgery, offering enhanced precision and tremor reduction for nerve coaptations. This study investigated the largest published patient collective in RASPN and provided specific technical aspects, operative setups, and a learning curve. Data collection involved creating a prospective database that recorded surgical details such as surgery type, duration, nerve coaptation time, and number of stitches. The experienced surgeon first underwent a 12-hour training program utilizing the Symani robot system in combination with optical magnification tools before using the system clinically. The study included 19 patients who underwent robot-assisted peripheral nerve reconstruction. The cohort included six men (31.6%) and 13 women (68.4%), with an average age of 53.8 ± 18.4 years. The procedures included nerve transfers, targeted muscle reinnervation, neurotized free flaps, and autologous nerve grafts. Learning curve analysis revealed no significant reduction in time per stitch over the initial nine coaptations (4.9 ± 0.5 min) compared with the last 10 coaptations (5.5 ± 1.5 min). The learning curve for RASPN was compared with early experiences with other surgical robots, emphasizing the importance of surgical proficiency and assistant training. Obstacles such as instrument grip strength and blood clot formation were highlighted, and suggestions for future advancements were proposed. RASPN presents an exciting opportunity to enhance precision; however, ongoing research and optimization are necessary to fully harness its benefits.

Advances in Modern Microsurgery.

Background/Objectives: Microsurgery employs techniques requiring optical magnification and specialized instruments to operate on small anatomical structures, including small vessels. These methods are integral to plastic surgery, enabling procedures such as free tissue transfer, nerve reconstruction, replantation, and lymphatic surgery. This paper explores the historical development, advancements, and current applications of microsurgery in plastic surgery. Methods: The databases MEDLINE (via PubMed) and Web of Science were selectively searched with the term "(((microsurgery) OR (advances)) OR (robotic)) OR (AI)) AND (((lymphatic surgery) OR (peripheral nerve surgery)) OR (allotransplantation))" and manually checked for relevance. Additionally, a supplementary search among the references of all publications included was performed. Articles were included that were published in English or German up to June 2024. Results: Modern microsurgical techniques have revolutionized plastic surgery, enabling precise tissue transfers, improved nerve reconstruction, and effective lymphedema treatments. The evolution of robotic-assisted surgery, with systems like da Vinci and MUSA, has enhanced precision and reduced operative times. Innovations in imaging, such as magnetic resonance (MR) lymphography and near-infrared fluorescence, have significantly improved surgical planning and outcomes. Conclusions: The continuous advancements in microsurgery, including supermicrosurgical techniques and robotic assistance, have significantly enhanced the capabilities and outcomes of plastic surgery. Future developments in AI and robotics promise further improvements in precision and efficiency, while new imaging modalities and surgical techniques expand the scope and success of microsurgical interventions.

(Invited) Optical Probes for Resonance-Enhanced Gold Growth on Nanooptical Substrates

We investigate light-stimulated growth of gold metal lines to technically mimic the growth of long-range axonal connections for neuromorphic computing architectures. Photocatalytic gold growth from an aqueous gold chloride precursor solution (HAuCl4) on a photoactive titanium dioxide layer is used. It is known that local gold growth may be obtained by UV illumination through a shadow mask [1]. To obtain a wavelength and angle dependent growth of metal lines – and thus stimulus-dependent resistances – we suggest to employ a nanooptical template. Inspired by the typical number of 2 to 10 connections to a node found, e.g., in the neuronal system of the biological species Hydra, we decided on the implementation of a hexagonal design. The edges are formed by periodic grating nanostructures with 10 to 20 periods and a grating pitch of 170 nm to 210 nm for excitation in the UV. In order to investigate the resonant optical enhancement, we employ optical probes. It is well known that colloidal quantum dots show enhanced fluorescence emission on photonic crystal surfaces due to resonant excitation and resonant outcoupling [2]. In our initial experiments for investigation of the resonant enhancement, we use 4,4’-Bis(2,2-diphenylvinyl)-1,1’-biphenyl (DBVBi) as the emitter material. Its absorption maximum matches the excitation laser at 355 nm and fluorescence in the visible spectrum around 455 nm may be monitored with our camera and spectrometer setup.The nanostructure master was fabricated by electron-beam lithography (Kelvin Nanotechnology Ltd.) according to our design. We transfer the nanostructure pattern onto 1.1 mm thick soda-lime glass substrates by UV-nanoimprint lithography. Subsequently, a 100 nm titanium dioxide layer is deposited. The 150 nm emissive DBVBi layer is then added by thermal evaporation. The samples are characterized optically with a camera setup and magnifying optics on an in-plane rotatable xy-stage. We use a Cobolt Zouk 355 nm 10 mW laser to excite the emissive layer. The output power of the laser is set to 2 mW and its output beam is widened with a collimating lens setup to a diameter of approximately 1.5 mm². The widened beam is essential to obtain a homogeneous excitation. We observe the successful resonant excitation by the higher emission intensity of DPVBi in specific regions of the nanostructure at specific excitation angles. Already for 10 periods of the grating structure resonance effects are observed. A stronger enhancement is obtained for 20 periods. Further, the enhancement depends on the grating pitch as connections with nanograting pitches below 190 nm are no longer visible. They do not meet the criteria for resonant excitation.This method of using optical probes on the nanooptical template works well for initial characterization of the resonance enhancement at different excitation angles. Now the setup is ready for performing gold growth under different excitation conditions. Without the additional emissive layer, the waveguide thickness change needs to be compensated with an increased titanium dioxide layer thickness. For online monitoring of the resonant enhancement during growth optical probes may be employed below the photoactive titanium dioxide layer. It is expected that the resonance enhancement is reduced with the addition of gold due to the increased absorption and thus reduced quality factor as was previously studied in the context of nanostructured OLEDs [3].We acknowledge funding by the DFG (German Research Foundation) with the CRC 1461- Neurotronics (Project-ID 434434223 – SFB 1461).[1] S. Veziroglu et al. (2018). Photocatalytic growth of hierarchical au needle clusters on highly active TiO2 thin film. Advanced Materials Interfaces, 5(15), 1800465.[2] N. Ganesh et al. (2007). Enhanced fluorescence emission from quantum dots on a photonic crystal surface. Nature nanotechnology, 2(8), 515-520.[3] J. Buhl et al. (2023). Resonance‐Based Directional Light Emission from Organic Light‐Emitting Diodes: Comparing Integrated Nanopatterns and Color Conversion Waveguide Gratings. Advanced Photonics Research, 4(2), 2200143. Figure 1. (Left) Fluorescence image of optical probe layer on nanooptical substrate for 355 nm laser excitation. (Middle) Schematic of nanooptical substrate with grating pitch (in nm) and number of periods given. Same colors represent identical grating features. (Right) Field emission scanning electron microscopy (FESEM) image of one node with 6 connections. Figure 1

Atypical melanocytes of an atypical Spitz tumour observed with optical super-high magnification dermoscopy.

A 64-year-old woman presented with a 6-mm pigmented lesion on her thigh. Dermatoscopy revealed the ‘starburst’ dermatoscopic pattern of a Spitzoid tumour. Before excision, the lesion was examined under ×400 magnification dermoscopy using the videoscope Fotofinder Medicam 1000 (Fotofinder System, Bad Birnbach, Germany) and in vivo Reflectance Confocal Microscopy (RCM) (Vivascope 1500®, MAVIG GmbH, Munich, Germany).

Challenges in non-destructive X-ray CT testing of riveted joints in the automotive industry

Despite recent advancements, contemporary laboratory-based industrial computed tomography (CT) technology has not yet achieved the status of an efficient and economically viable in situ non-destructive method for examining riveted joints that are commonly used in the automotive industry. 2D X-ray or 3D CT systems can only reliably assess a rivet joint’s condition in rare, and favorable circumstances. Moreover, a comprehensive analysis to identify the obstacles preventing CT from efficiently capturing high-resolution, and contrast-rich scans of riveted joints in general is lacking. This work delves into the challenges and limitations of the technology that prevent operators from reaching the desired precision required for rigorous quality control. The study specifically addresses questions concerning in situ reachability and positioning of the sample structure, radiodensity and beam hardening, the relationship between spot size and power, and economic feasibility—all within the context of analyzing riveted joints in the automotive industry. Additionally, we provide an abstracted overview of the current industrial X-ray tube market, which informs our discussion on these specific aspects. Through a combination of experimental findings, analytical insights, and deductions, we shed light on the persistent difficulties in achieving resolutions comparable to macro-sectioning and microscopy, which are currently considered the gold standard in examining riveted joints. Our investigation further explores the potential of a photon-counting detector paired with a conventional, laboratory-based X-ray source. Furthermore, we investigate the use of a synchrotron beamline as an X-ray source in conjunction with a custom-designed detector optimized for such beam geometries. This detector employs scintillators coupled with optical magnification, functioning similarly to an X-ray microscope. Our findings and data collection conclusively reveal that commercially available CT systems still fail to meet the requirements for efficient testing, underscoring the urgent need for further research and development to enable widespread implementation.

Robotic surgeries in pediatric patients: an early experience in a single center.

Robotic surgery (RS) has the advantages of 3-dimensional view, optical magnification, motional scaling, and improved ergonomics and degree of freedom. Although RS has widely been performed on pediatric patients lately, there are still numerous restrictions and ambiguous indications. The purpose of this study was to report our early experience with RS on pediatric patients at a single center. Electronic medical records of patients who underwent RS with the da Vinci Xi surgical platform (Intuitive Surgical, Inc.) in Seoul National University Children Hospital from November 2019 to August 2021 were reviewed retrospectively. The median follow-up was 21.0 months (range, 12.3-31.8 months). An online survey was conducted to investigate satisfaction with robotic surgical scars. Fifty-four patients underwent robotic surgeries (median age at operation, 11.1 years [range, 0.1-17.8 years]). In our hospital, patients had 20 different kinds of robotic surgeries, including choledochal cyst excision with hepaticojejunostomy, ovarian mass excision, and others. Median operation time and console time were 157.5 minutes (range, 45-505 minutes) and 40 minutes (range, 11-360 minutes), respectively. All cases were done without conversion into open or laparoscopic methods. Postoperative complications were found in 5 patients. According to an online survey, over half of patients (60.9%) answered that they felt satisfied with scars. Our early experience demonstrated the safety and feasibility of RS in children with a range of diagnoses and complicated procedures. With more experience, RS could be an alternative to traditional open or laparoscopic operations in pediatric patients. Further studies are needed to clarify indications of pediatric RS.

Nanosecond Laser Fabrication of Dammann Grating-like Structure on Glass for Bessel-Beam Array Generation

The generation of optical beam arrays with prospective uses within the realms of microscopy, photonics, non-linear optics, and material processing often requires Dammann gratings. Here, we report the direct fabrication of one- and two-dimensional Dammann grating-like structures on soda lime glass using a nanosecond pulsed laser beam with a 1064 nm wavelength. Using the fabricated grating, an axicon lens, and an optical magnification system, we propose a scheme of generation of a diverging array of zero-order Bessel beams with a sub-micron-size central core, extending longitudinally over several hundred microns. Two different grating fabrication strategies are also proposed to control the number of Bessel beams in an array. It was demonstrated that Bessel beams of 12 degrees conical half-angle in an array of up to [5 × 5] dimensions can be generated using a suitable combination of Dammann grating, axicon lens and focusing optics.

Spatially Resolved Raman Spectroscopic Investigation of Uranyl Fluoride: A Case Study in the Importance of Instrument Optimization.

Raman spectroscopy is an emerging technique for rapid and nondestructive analysis of nuclear materials for forensic and nonproliferation applications as it is a powerful tool for distinguishing multiple chemical forms of materials with similar stoichiometries. Recent developments in spectroscopic software have enabled rapid data collection with high-speed Raman spectroscopic mapping capabilities. However, some uranium-rich materials are susceptible to degradation in humid air and/or laser-induced phase transformations. To mitigate environmental or measurement-related sample degradation of potential samples of interest, we have taken a systematic approach to define optimized data collection parameters for high-throughput measurements of uranyl fluoride (UO2F2), which is an important intermediate material in the nuclear fuel cycle. First, we systematically describe the influence of optical magnification (5× to 100×), laser power, and exposure time on obtained signal for identical particles of UO2F2 and find that at low laser power and exposure times, comparable signal is obtained regardless of optical magnification. Second, we ensure sample integrity during data collection, and third, collect spectroscopic maps that employ optimized parameters to reduce the time required to obtain spatially resolved spectroscopic information. Reductions of 90% and 99% in measurement times are discussed as they relate to differences in resolving spectroscopic features of particles in identical mapping areas. During this work, we found that additional data processing options were needed and thus developed a customized Python script for importing, processing, analyzing, and visualizing Raman spectroscopic map data.

Machine Learning Classification of Self-Organized Surface Structures in Ultrashort-Pulse Laser Processing Based on Light Microscopic Images.

In ultrashort-pulsed laser processing, surface modification is subject to complex laser and scanning parameter studies. In addition, quality assurance systems for monitoring surface modification are still lacking. Automated laser processing routines featuring machine learning (ML) can help overcome these limitations, but they are largely absent in the literature and still lack practical applications. This paper presents a new methodology for machine learning classification of self-organized surface structures based on light microscopic images. For this purpose, three application-relevant types of self-organized surface structures are fabricated using a 300 fs laser system on hot working tool steel and stainless-steel substrates. Optical images of the hot working tool steel substrates were used to learn a classification algorithm based on the open-source tool Teachable Machine from Google. The trained classification algorithm achieved very high accuracy in distinguishing the surface types for the hot working steel substrate learned on, as well as for surface structures on the stainless-steel substrate. In addition, the algorithm also achieved very high accuracy in classifying the images of a specific structure class captured at different optical magnifications. Thus, the methodology proposed represents a simple and robust automated classification of surface structures that can be used as a basis for further development of quality assurance systems, automated process parameter recommendation, and inline laser parameter control.

MORPHOMETRIC PARAMETERS OF MATURITY OF PLACENTAL CHORINAL VILLI IN PREMATURE LABOR

Aim – to establish some morphometric parameters of placental villi in premature birth in comparison with physiological pregnancy.Material and methods. The material (30 placentas in premature births and 30 placentas in physiological pregnancies) was fixed for 22-24 hours in a neutral buffered 10% formalin solution. Next, the material was dehydrated in an ascending battery of alcohols and embedded into paraffin at 580С. Serial histological sections 5 μm thick were made on a sled microtome. After deparaffinization, serial histological sections were stained with hematoxylin and eosin, and with a chromotrope - water blue according to N.Z.Slinchenko. In addition to the descriptive method of histopathological examination, computer morphometry was performed on previously obtained digital copies of optical microscopic images of the tissue (Delta Optical Evolution 100 microscope {planachromatic lenses according to the required optical magnification} and Olympus SP550UZ digital camera). Digital copies of the image were analyzed using a freeware copy of the ImageJ v1.52 computer program specialized for digital histometric studies. In particular, the percentage of different types of chorionic villi was calculated on digital copies of optical images using the unrepeatable score test method. The obtained digital data were processed statistically. In particular, with the help of a copy of the free (freeware) computer program for statistical calculations PAST v 4.14, a preliminary test for the normality of the distribution was applied according to the Wilkie-Hahn-Shapiro test. For all studied statistical samples, according to this criterion, the hypothesis about the normality of the distribution was not rejected (at p=0.05), therefore, parametric methods of statistical analysis were used: calculation of the arithmetic mean and its error, the odd two-sided Student's test. Along with the Student's test, the non-parametric Mann-Whitney U test was also used. Results. It was considered most important to start assessing the state of the placenta according to the percentage ratios between different types of villous formations. In particular, according to modern ideas about different types of chorionic villi in the II and III trimesters of pregnancy, the following types of villous formations of the placenta were distinguished: stem villi ("early" and late"), intermediate villi (immature and mature), terminal villi, terminal "specialized" villi, mesenchymal villi, embryonic villi, trophoblastic and villous processes. The total amount of the specified villi should be equal to 100%. The division of villi into primary, secondary, and tertiary villi is relevant only for the 1st trimester of pregnancy, therefore, it is not suitable for studying the morphological features of premature birth.Conclusions. According to the obtained morphometric data, the immaturity of the chorionic tree is noted in premature birth compared to physiological pregnancy. This can be seen from a noticeable increase in the percentage of stem "early" villi, intermediate immature and mature villi, mesenchymal and embryonic villi, trophoblastic and villous processes, but with a significant decrease in the percentage of terminal villi.

Adopting molecular tagging velocimetry for high-resolution measurements of oscillating grid turbulence

AbstractSingle-component molecular tagging velocimetry (1c-MTV) experiments are conducted in an oscillating grid turbulence facility to systematically clarify the trade-offs between maximizing measurement dynamic range and minimizing measurement uncertainty. The primary aim is to obtain reliable turbulence data with the maximum possible vector resolution ($$\varDelta {x}_{1}$$ Δ x 1 ). Four optical magnifications ($$M{_{0}}$$ M 0 =0.11, 0.22, 0.45, 1.11) with four interframe time delay ($$\varDelta {t}$$ Δ t ) values, for each optical magnification case, ranging from 3 to 10 ms, are investigated. The grid oscillates with a frequency (f) of 3.2 and 4.1 Hz, and a single fixed stroke length (S) of 55 mm. The measurement quality is quantified using three important turbulence descriptors — the second-order transverse velocity correlation function $$(\langle {g(r)}\rangle )$$ ( ⟨ g ( r ) ⟩ ) , the second-order transverse velocity structure function $$([\Delta {_{g}u}]^2)$$ ( [ Δ g u ] 2 ) , and the turbulence energy dissipation rate ($$\langle \epsilon \rangle$$ ⟨ ϵ ⟩ ). Other descriptors such as the longitudinal integral length scale (l) and the longitudinal Taylor microscale ($${\lambda }$$ λ ) are also used to compare with reference values reported in literature. The degree of agreement with the reference values from literature, and insensitivity of the descriptor estimates to different MTV design parameters are used to determine the most robust means of obtaining high-resolution turbulence data from 1c-MTV. The experimental design parameters are contextualized using the Kolmogorov length ($${\eta }$$ η ), time ($${\tau _{\eta }}$$ τ η ), and velocity ($${u_{\eta }}$$ u η ) scales that are based on the most reliable $$\langle {\epsilon }\rangle$$ ⟨ ϵ ⟩ estimates from the current experiments. The pixel-displacement corresponding to $${u_{\eta }}$$ u η $$({\varDelta {x}{_{2}}{_{\eta }}})$$ ( Δ x 2 η ) describes the interdependencies between $${M_{0}}$$ M 0 and $$\varDelta {t}$$ Δ t . The data set with $${M_{0}}=0.45$$ M 0 = 0.45 ($${\eta =}18{\varDelta {x}_{1}}$$ η = 18 Δ x 1 for f=3.2 Hz, and $${\eta =}13{\varDelta {x}_{1}}$$ η = 13 Δ x 1 for f=4.1 Hz) represents the most reliable and the highest resolution case. This conclusion was deduced by taking the performance of all the turbulence descriptors into account. As far as the interframe time delay is concerned, $$\varDelta {t} \ge$$ Δ t ≥ 4 ms ($${\varDelta {x}{_{2}}{_{\eta }}}\ge 0.5 \text {pixels}$$ Δ x 2 η ≥ 0.5 pixels ) works well for all $${{M}_{0}}$$ M 0 . To the authors’ knowledge, the present study documents the first instance of a series of 1c-MTV experiments conducted for a systematic clarification of the nature of balancing the available dynamic range and the measurement uncertainty. Additionally, since the study involves turbulent flow with negligible mean-flow, it serves as an adequate representation of 1c-MTV performance in a three-dimensional flow.

Microsurgical Training: A Review of Existing Methods and an Innovative Practice Model

Abstract Surgery under magnification with the use of the operating microscope has seen great advances, and numerous surgical procedures today depend on optical magnification. Training (to impart basic skills) in microsurgery is particularly essential to enable surgeons to take their place in the surgical team and learn further as they progressively observe, assist, and in time, perform microsurgical procedures. Various materials and models are used and have been objectively assessed and validated for simulation in microsurgical training. One such model, the live animal model (with all its disadvantages), has been the “gold standard” for simulation in microsurgical training. We have identified and put into use a new tissue model for training in microvascular surgery – the chicken mesentery, which will offer a good practical solution where the live animal model is unavailable. Further studies using this model for training at various centers will be required for validation and comparison of this tool against existing methods.

Frequency selection rule for the HDHF Lissajous scanning imaging with a low-voltage one axis actuated PZT scanner based on an asymmetric fiber cantilever.

Lissajous micro scanners are very attractive in compact laser scanning applications for biomedical endoscopic imaging, such as confocal microscopy, endomicroscopy or optical coherence tomography. The scanning frequencies have a very important effect on the quality of the resulting Lissajous scanning imaging. In this paper, we propose a frequency selection rule for high definition and high frame-rate (HDHF) Lissajous scanning imaging, by deriving the relationship among the scanning field of view (FOV), actuation frequencies and pixel size based on the characteristics of the scanning trajectory. The minimum sampling rate based on the proposed frequency selection rule is further discussed. We report a lead zirconate titanate piezoelectric ceramic (PZT) based Lissajous fiber scanner to achieve HDHF Lissajous scanning imaging. Based on the frequency selection rule, different frequency combinations are calculated, under which the Lissajous fiber scanner can work at the frame rate (FR) of 10 Hz, 20 Hz, 40 Hz and 52 Hz. The trajectory evolution of the Lissajous scanning at the frame rate of 10 Hz has been obtained to verify the applicability of the proposed rule. The measured resolution of the scanner is 50.8 lp/mm at the unit optical magnification, and the measured FOV at the FR of 10 Hz and 40 Hz are 1.620 mm ×1.095 mm and 0.405 mm ×0.27 mm, respectively. HDHF Lissajous scanning images of the customized spatial varying binary pattern are obtained and reconstructed at the FR of 10 Hz and 40 Hz, demonstrating the practicability of the frequency selection rule.

10× continuous optical zoom imaging using Alvarez lenses actuated by dielectric elastomers.

Optical zoom is an essential function for many imaging systems including consumer electronics, biomedical microscopes, telescopes, and projectors. However, most optical zoom imaging systems have discrete zoom rates or narrow zoom ranges. In this work, a continuous optical zoom imaging system with a wide zoom range is proposed. It consists of a solid lens, two Alvarez lenses, and a camera with an objective. Each Alvarez lens is composed of two cubic phase plates, which have inverted freeform surfaces concerning each other. The movement of the cubic phase masks perpendicular to the optical axis is realized by the actuation of the dielectric elastomer. By applying actuation voltages to the dielectric elastomer, cubic phase masks are moved laterally and then the focal lengths of the two Alvarez lenses are changed. By adjusting the focal lengths of these two Alvarez lenses, the optical magnification is tuned. The proposed continuous optical zoom imaging system is built and the validity is verified by the experiments. The experimental results demonstrate that the zoom ratio is up to 10×, i.e., the magnification continuously changes from 1.58× to 15.80× when the lateral displacements of the cubic phase masks are about 1.0 mm. The rise and fall response times are 150 ms and 210 ms, respectively. The imaging resolution can reach 114 lp/mm during the optical zoom process. The proposed continuous optical imaging system is expected to be used in the fields of microscopy, biomedicine, virtual reality, etc.

Endoscopic submucosal dissection and JNET classification for colorectal neoplasia: A North American academic center experience.

Endoscopic submucosal dissection (ESD) enables minimally invasive resection of superficial gastrointestinal neoplasms en bloc regardless of size. The Japan narrow band imaging expert team (JNET) classification utilizes optical magnification and narrow band imaging (NBI) to predict pathology. In North America, ESD is far from ubiquitous, and regional outcomes are not widely described. To date there are no North American studies describing the application and yield of the JNET classification as applied in the practice of ESD. A retrospective, single-center, cohort analysis was performed on a prospectively maintained database of ESD procedures. Between July 2016 and February 2023, all consecutive patients treated with ESD for colorectal lesions were identified and stratified by lesion location, JNET, NBI International Colorectal Endoscopic, lateral spreading tumors, and Paris classifications. Univariate analysis was used for clinicopathological data. p<0.05 was considered statistically significant. A total of 112 patients were identified. One lesion, a lipoma, was excluded. Overall, 49.5% (55/111) of lesions were colonic and 50.5% (56/111) rectal. Most lesions were lateral spreading tumors (60.4%, 67/111). Overall, 96.4% (107/111) ESDs were successfully completed, 98.1% (105/107) en bloc, and 87.9% (94/107) R0. Adverse events occurred in 1.8% (2/111) of procedures. The median diameter was 4.0cm and resected in a median time of 62.0min. Overall, 70.1% (47/67) lesions were upstaged from pre-ESD biopsy. JNET 2B showed 80.2% (95% CI 71.5-87.1) accuracy for high-grade dysplasia or sm1. All JNET type 3 were ≥sm2 (p<0.001). ESD permits safe and effective resection of superficial colorectal neoplasms. JNET classification was more accurate than pre-resection biopsy at predicting histology in this series.

Vulvoscopy: anachronism or a time-tested method?

Objective. Due to the growing number of patients with various diseases of the vulva, there is a need to evaluate the available diagnostic tools. Vulvoscopy is one of the widely used methods, the diagnostic sensitivity and specificity of which varies significantly.Purpose of the work. Based on the analysis of publications to determine the diagnostic significance of vulvoscopy.Material and methods. The data of modern research and publications were used in the preparation of the work.Results. The authors of a number of publications warn against considering vulvoscopy as a variant of colposcopy. A high percentage of false positive results when performing tests with acetic acid may be due to a variety of reasons and is not highly specific for papillomavirus infection. The use of the test with toluidine blue is not recommended due to low sensitivity.Conclusions. A positive aspect of vulvoscopy is the ability to examine the vulva area with optical magnification, in a position convenient for examining the patient, which makes it possible to identify areas to be biopsied. The use of additional tests with acetic acid should be limited, and tests with toluidine blue and Lugol solution are not recommended due to low sensitivity.

High magnification versus optical magnification in hypospadias surgery: a randomized controlled trial

BackgroundHypospadias is the most common congenital abnormality of the urethra affecting live male births. The incidence is rising with the increasing pollution. During the last 50 years, developments in surgical instrumentation and optical systems allowed surgeons to increasingly undertake microsurgical procedures. Optical magnification is essential in pediatric surgery. Magnifying loupes are the most frequently used, although they often cause neck pain to the surgeon. Recent advances led to the development of a compact video microscope (VITOM; Karl Storz Endoscopy GmbH, Tuttlingen, Germany) that displays high-definition magnified images on a flat screen.ObjectiveEvaluate VITOM as a potential substitute for loupes in complex open pediatric procedures and explore VITOM as an effective intraoperative teaching modality for open surgery.MethodsFifty-two patients enrolled in our study were divided into two groups: Group A (26): high magnification was used either (VITOM Karl Storz Endoscopy GmbH, Tuttlingen, Germany) or (Surgical microscope, Carl Zeiss Microscopy GmbH), along with microsurgical instruments. Vicryl 8-0 suture was used for urethroplasty. Group B (26): patients were operated upon by conventional instruments (fine tip but not microsurgical instruments), sutures, and magnification (3.5×). Vicryl 6-0 suture was used for urethroplasty, with loupes-assisted magnification.ResultsMore complications were found in group B. Using VITOM was accompanied by less neck pain, enhanced visualization, and an enhanced teaching environment.ConclusionOperating with high magnification tools minimizes post-operative complications in hypospadias surgery. They enhanced identification of the penile anatomy and topography which facilitated reconstruction techniques as well as enhanced the comfort of the surgeon.Level of evidenceI.

Capillary optics for full‐field x‐ray detectors with a magnification factor of 40 and 2.4 μm spatial resolution

AbstractThis article presents recent investigations of newly developed magnifying capillary optics used for full‐field x‐ray spectroscopy. The new cone‐shaped capillary optics reached spatial resolutions of 2.4 μm and increased the magnification factor to 40. These parameters have been evaluated by a confocal full‐field XRF (CFF‐XRF) and a full‐field XRF (FF‐XRF) setup, depicted in this article.

Vision System for Reading Serial Numbers of Hard Disk Drive Slider Bar and Barcode on Its Fixture

Part traceability is one of the inevitable requirements in most modern manufacturing processes. In a hard disk drive (HDD), magnetic head dictates the performance of read/write operations. A number of manufacturing processes are involved to transform a wafer disc to slider bars and finally gliding sliders of the head. In this work, we concentrate on reading serial numbers of slider bar and its attached fixture prior to a bar-lapping process. Since the serial numbers on a bar are in the scale of 18x30 microns and their reflectance nature is rather poor, special optics and lighting components are required. As nature of high optical magnification with limited depth of focus (DOF), conventional image acquisition system can not cover the bar attachment position variation due to wide tolerance of the slider bar fixture. We proposed a serial number reading system using autofocus module to cope with it. Liquid lens and image processing algorithms are introduced to evaluate and adjust the focus automatically. Since our system has to be augmented to an existing machine, footprint is also another main concern. We therefore designed a special rig so the system meets all the fore-mentioned requirements. The system was tested in the production line and had 98% and 90% accuracy for serial number and barcode decoding, respectively. The main cause of barcode reading inaccuracy was from many cycles of the fixture reuse and cleaning in the production line.