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IScience Oct 2023In the imaging process of conventional optical microscopy, the primary factor hindering microscope resolution is the energy diffusion of incident light, most directly... (Review)
Review
In the imaging process of conventional optical microscopy, the primary factor hindering microscope resolution is the energy diffusion of incident light, most directly described by the point spread function (PSF). Therefore, accurate calculation and measurement of PSF are essential for evaluating and enhancing imaging resolution. Currently, there are various methods to obtain PSFs, each with different advantages and disadvantages suitable for different scenarios. To provide a comprehensive analysis of PSF-obtaining methods, this study classifies them into four categories based on different acquisition principles and analyzes their advantages and disadvantages, starting from the propagation property of light in optical physics. Finally, two PSF-obtaining methods are proposed based on mathematical modeling and deep learning, demonstrating their effectiveness through experimental results. This study compares and analyzes these results, highlighting the practical applications of image deblurring.
PubMed: 37822495
DOI: 10.1016/j.isci.2023.107976 -
Operative Neurosurgery (Hagerstown, Md.) May 2023Microsurgical resection of vestibular schwannoma (VS) is highly challenging, especially because surgical treatment nowadays is mainly reserved for larger (Koos grade 3...
BACKGROUND
Microsurgical resection of vestibular schwannoma (VS) is highly challenging, especially because surgical treatment nowadays is mainly reserved for larger (Koos grade 3 and 4) tumors.
OBJECTIVE
To assess the performance of three-dimensional exoscope use in VS resection in comparison with the operative microscope.
METHODS
Duration of surgery and clinical and radiological results were collected for 13 consecutive exoscopic schwannoma surgeries. Results were compared with 26 preceding microsurgical resections after acknowledging similar surgical complexity between groups by assessment of tumor size (maximum diameter and Koos grade), the presence of meatal extension or cystic components, and preoperative hearing and facial nerve function.
RESULTS
Total duration of surgery was comparable between microscopically and exoscopically operated patients (264 minutes ± 92 vs 231 minutes ± 84, respectively; P = .276). However, operative time gradually decreased in consecutive exoscopic cases and in a multiple regression model predicting duration of surgery, and exoscope use was associated with a reduction of 58.5 minutes (95% CI -106.3 to -10.6; P = .018). Tumor size was identified as the main determinant of duration of surgery (regression coefficient = 5.50, 95% CI 3.20-7.80) along meatal extension and the presence of cystic components. No differences in postoperative hearing preservation and facial nerve function were noted between the exoscope and the microscope.
CONCLUSION
Resection of VS using a foot switch-operated three-dimensional exoscope is safe and leads to comparable clinical and radiological results as resection with the operative microscope.
Topics: Humans; Hearing Tests; Neurilemmoma; Neuroma, Acoustic; Neurosurgical Procedures
PubMed: 36715988
DOI: 10.1227/ons.0000000000000602 -
Biomedical Optics Express May 2020Optical microscopes are an essential tool for both the detection of disease in clinics, and for scientific analysis. However, in much of the world access to...
Optical microscopes are an essential tool for both the detection of disease in clinics, and for scientific analysis. However, in much of the world access to high-performance microscopy is limited by both the upfront cost and maintenance cost of the equipment. Here we present an open-source, 3D-printed, and fully-automated laboratory microscope, with motorised sample positioning and focus control. The microscope is highly customisable, with a number of options readily available including trans- and epi- illumination, polarisation contrast imaging, and epi-florescence imaging. The OpenFlexure microscope has been designed to enable low-volume manufacturing and maintenance by local personnel, vastly increasing accessibility. We have produced over 100 microscopes in Tanzania and Kenya for educational, scientific, and clinical applications, demonstrating that local manufacturing can be a viable alternative to international supply chains that can often be costly, slow, and unreliable.
PubMed: 32499936
DOI: 10.1364/BOE.385729 -
International Journal of Computer... Sep 2021Learning to use a surgical microscope is a fundamental step in otolaryngology training; however, there is currently no objective method to teach or assess this skill....
PURPOSE
Learning to use a surgical microscope is a fundamental step in otolaryngology training; however, there is currently no objective method to teach or assess this skill. Tympanostomy tube placement is a common otologic procedure that requires skilled use of a surgical microscope. This study was designed to (1) implement metrics capable of evaluating microscope use and (2) establish construct validity.
STUDY DESIGN
This was a prospective cohort study.
METHODS
Eight otolaryngology trainees and three otolaryngology experts were asked to use a microscope to insert a tympanostomy tube into a cadaveric myringotomy in a standardized setting. Microscope movements were tracked in a three-dimensional space, and tracking metrics were applied to the data. The procedure was video-recorded and then analyzed by blinded experts using operational metrics. Results from both groups were compared, and discriminatory metrics were determined.
RESULTS
The following tracking metrics were identified as discriminatory between the trainee and expert groups: total completion time, operation time, still time, and jitter (movement perturbation). Many operational metrics were found to be discriminatory between the two groups, including several positioning metrics, optical metrics, and procedural metrics.
CONCLUSIONS
Performance metrics were implemented, and construct validity was established for a subset of the proposed metrics by discriminating between expert and novice participants. These discriminatory metrics could form the basis of an automated system for providing feedback to residents during training while using a myringotomy surgical simulator. Additionally, these metrics may be useful in guiding a standardized teaching and evaluation methodology for training in the use of surgical microscopes.
Topics: Benchmarking; Clinical Competence; Humans; Middle Ear Ventilation; Otolaryngology; Prospective Studies
PubMed: 34089123
DOI: 10.1007/s11548-021-02428-8 -
Journal of Cataract and Refractive... Sep 2023The recent development of high-resolution, heads-up, 3D visualization microscopy systems has provided new technical and visualization options for ophthalmic surgeons. In... (Review)
Review
The recent development of high-resolution, heads-up, 3D visualization microscopy systems has provided new technical and visualization options for ophthalmic surgeons. In this review, we explore the evolution of microscope technologies, the science behind modern 3D visualization microscopy systems, and the practical benefits (as well as disadvantages) that these systems provide over conventional microscopes for intraocular surgical practice. Overall, modern 3D visualization systems reduce the requirements for artificial illumination and provide enhanced visualization and resolution of ocular structures, improving ergonomics, and facilitating a superior educational experience. Even when considering their disadvantages, such as those related to technical feasibility, 3D visualization systems have an overall positive benefit/risk ratio. It is hoped these systems will be adopted into routine clinical practice, pending further clinical evidence on the benefits they may provide on clinical outcomes.
Topics: Humans; Microscopy; Imaging, Three-Dimensional; Eye; Surgery, Computer-Assisted
PubMed: 37144641
DOI: 10.1097/j.jcrs.0000000000001216 -
Biomedical Optics Express Aug 2023Traditional miniaturized fluorescence microscopes are critical tools for modern biology. Invariably, they struggle to simultaneously image with a high spatial resolution...
Traditional miniaturized fluorescence microscopes are critical tools for modern biology. Invariably, they struggle to simultaneously image with a high spatial resolution and a large field of view (FOV). Lensless microscopes offer a solution to this limitation. However, real-time visualization of samples is not possible with lensless imaging, as image reconstruction can take minutes to complete. This poses a challenge for usability, as real-time visualization is a crucial feature that assists users in identifying and locating the imaging target. The issue is particularly pronounced in lensless microscopes that operate at close imaging distances. Imaging at close distances requires shift-varying deconvolution to account for the variation of the point spread function (PSF) across the FOV. Here, we present a lensless microscope that achieves real-time image reconstruction by eliminating the use of an iterative reconstruction algorithm. The neural network-based reconstruction method we show here, achieves more than 10000 times increase in reconstruction speed compared to iterative reconstruction. The increased reconstruction speed allows us to visualize the results of our lensless microscope at more than 25 frames per second (fps), while achieving better than 7 µm resolution over a FOV of 10 mm. This ability to reconstruct and visualize samples in real-time empowers a more user-friendly interaction with lensless microscopes. The users are able to use these microscopes much like they currently do with conventional microscopes.
PubMed: 37799697
DOI: 10.1364/BOE.490199 -
Journal of Oral and Maxillofacial... 2022Pathologists come across various structures in the microscopic sections that are unrelated to the tissues. Artifacts can occur in the tissue from the time the area is...
BACKGROUND
Pathologists come across various structures in the microscopic sections that are unrelated to the tissues. Artifacts can occur in the tissue from the time the area is prepared for biopsy, during fixation, grossing, processing, sectioning and staining of the specimen. Food substances may get entrapped into the oral tissues and can lead to misdiagnosis. The aim of this study was to observe the microscopic appearances of commonly implanted food particles.
METHODS
Fourteen food samples were procured from a local market in Chennai, India. This included guava, chilli, chickpeas, channa dal (split chickpeas), cucumber, brinjal, carrot, capsicum, cabbage and urad dal and brown chickpea. The food samples were fixed in 10% formalin for 24 h and were subsequently processed. Hematoxylin and eosin staining was performed, and the sections were observed under the microscope.
RESULTS
Each specimen revealed unique, distinct histology of each food type. Channa dal microscopically in hematoxylin- and eosin-stained sections revealed round-to-oval structures with central pale eosinophilic lobulation. Capsicum showed round-to-polygonal structures of different shapes and sizes with clear central areas. Urad dal microscopically showed cluster of 5-6 eosinophilic structures separated by regular partitions.
CONCLUSION
It is important to study the microscopic appearances of commonly implanted food particles to prevent any diagnostic dilemmas. Further studies are required involving various other food particles and their microscopic appearances.
PubMed: 36588857
DOI: 10.4103/jomfp.jomfp_117_21 -
Royal Society Open Science Nov 2021We present the OpenFlexure Microscope software stack which provides computer control of our open source motorised microscope. Our diverse community of users needs both...
We present the OpenFlexure Microscope software stack which provides computer control of our open source motorised microscope. Our diverse community of users needs both graphical and script-based interfaces. We split the control code into client and server applications interfaced via a web API conforming to the W3C Web of Things standard. A graphical interface is viewed either in a web browser or in our cross-platform Electron application, and gives basic interactive control including common operations such as Z stack acquisition and tiled scanning. Automated control is possible from Python and Matlab, or any language that supports HTTP requests. Network control makes the software stack more robust, allows multiple microscopes to be controlled by one computer, and facilitates sharing of equipment. Graphical and script-based clients can run simultaneously, making it easier to monitor ongoing experiments. We have included an extension mechanism to add functionality, for example controlling additional hardware components or adding automation routines. Using a Web of Things approach has resulted in a user-friendly and extremely versatile software control solution for the OpenFlexure Microscope, and we believe this approach could be generalized in the future to make automated experiments involving several instruments much easier to implement.
PubMed: 34804575
DOI: 10.1098/rsos.211158 -
Methods in Cell Biology 2021Expansion microscopy (ExM) is a recently introduced technique that enables high-resolution imaging with conventional microscopes by using physical expansion of samples....
Expansion microscopy (ExM) is a recently introduced technique that enables high-resolution imaging with conventional microscopes by using physical expansion of samples. While this technique does not require a complicated microscope setup (like in STED or STORM microscopy), sample preparation and handling require additional attention. Here we describe a workflow for imaging of the neuronal microtubule network with minimal artifacts and sample perturbations. We demonstrate that the use of custom-printed mounting chambers simplifies sample handling and facilitates stable imaging of the sample. In addition, refractive index matching between the sample and the objective greatly improves signal retention deeper in thick samples. To accurately determine the precise expansion factor and determine sample distortion, we describe how samples can be compared using STED and ExM. Together, these procedures enabled us to better resolve different microtubule subsets in neuronal soma and dendrites.
Topics: Cytoskeleton; Microscopy, Fluorescence; Microtubules; Neurons
PubMed: 33478685
DOI: 10.1016/bs.mcb.2020.04.018 -
Frontiers in Chemistry 2022As a typical microscopic imaging technology, the emergence of the microscope has accelerated the pace of human exploration of the micro world. With the development of... (Review)
Review
As a typical microscopic imaging technology, the emergence of the microscope has accelerated the pace of human exploration of the micro world. With the development of science and technology, microscopes have developed from the optical microscopes at the time of their invention to electron microscopes and even atomic force microscopes. The resolution has steadily improved, allowing humans to expand the field of research from the initial animal and plant tissues to microorganisms such as bacteria, and even down to the nanolevel. The microscope is now widely used in life science, material science, geological research, and other fields. It can be said that the development of microscopes also promotes the development of micro- and nanotechnology. It is foreseeable that microscopes will play a significant part in the exploration of the microworld for a long time to come. The development of microscope technology is the focus of this study, which summarized the properties of numerous microscopes and discussed their applications in micro and nanotechnology. At the same time, the application of microscopic imaging technology in micro- and nanofields was investigated based on the properties of various microscopes.
PubMed: 35864864
DOI: 10.3389/fchem.2022.931169