Spread of Respiratory Droplets in a Simulated Ophthalmic Surgery.
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ABSTRACT:
SUBMITTER: Felfeli T
PROVIDER: S-EPMC7539939 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:One of the main challenges during the COVID-19 pandemic is the lack of safety measures and guidelines to reduce the risk of viral spread among people during gatherings. This study was conducted to evaluate the distance of oral and nasal droplet spread in a model that simulates coughing and sneezing in a public setting, specifically a school setting, to guide faculty and staff members with safety measures and guidelines to reduce droplet spread. Several models were prepared to observe and visualize the spread of fluid simulating respiratory droplets in places such as the classroom and the cafeteria, in which a student would be more susceptible to contract a virus since individuals cannot wear masks while eating. For all trials, a 2.54 centimeter balloon with 0.3 milliliters of diluted fluorescent paint was placed inside a mannequin head and was exploded outwards from the mannequin's mouth at 5 pounds per square inch (psi). Using a black light, the expelled fluorescent macroscopic droplets were visualized. When applying safety precautions and guidelines such as mandating face masks, the results of the experiments conducted in this study with a surgical mask, were extremely positive. However, without other safety precautions such as face masks and barriers, social distancing proved to be ineffective. In conclusion the most effective way to prevent droplet spread during activities where masks simply cannot be worn, such as eating, is to apply barriers between the individuals. Applying barriers and wearing masks successfully prevented macroscopic droplet spread.
| S-EPMC8099066 | biostudies-literature
Project description:Centers for Disease Control and Prevention (CDC) warns the use of one-way valves or vents in face masks for potential threat of spreading COVID-19 through expelled respiratory droplets. Here, we have developed a nanoceutical cotton fabric duly sensitized with non-toxic zinc oxide nanomaterial for potential use as a membrane filter in the one-way valve for the ease of breathing without the threat of COVID-19 spreading. A detailed computational study revealed that zinc oxide nanoflowers (ZnO NFs) with almost two-dimensional petals trap SARS-CoV-2 spike proteins, responsible to attach to ACE-2 receptors in human lung epithelial cells. The study also confirmed significant denaturation of the spike proteins on the ZnO surface, revealing removal of the virus upon efficient trapping. Following the computational study, we have synthesized ZnO NF on a cotton matrix using a hydrothermal-assisted strategy. Electron-microscopic, steady-state, and picosecond-resolved spectroscopic studies confirm attachment of ZnO NF to the cotton (i.e., cellulose) matrix at the atomic level to develop the nanoceutical fabric. A detailed antimicrobial assay using Pseudomonas aeruginosa bacteria (model SARS-CoV-2 mimic) reveals excellent antimicrobial efficiency of the developed nanoceutical fabric. To our understanding, the nanoceutical fabric used in the one-way valve of a face mask would be the choice to assure breathing comfort along with source control of COVID-19 infection. The developed nanosensitized cloth can also be used as an antibacterial/anti CoV-2 washable dress material in general.
| S-EPMC8231689 | biostudies-literature
Project description: Not available
| S-EPMC7193306 | biostudies-literature
Project description:BackgroundOphthalmic viscoelastic devices (OVDs) used during small-incision cataract surgery have numerous advantages. However, OVDs have longer retention time in an eye after surgery resulting in intraocular pressure (IOP) spikes. The purpose of this study is to analyze and quantify the effect of various OVDs on both IOP and best corrected visual acuity (BCVA) by systematically reviewing the literature and performing meta-analysis.MethodsNumerous databases from January 1, 1985, to present were systematically searched. Thirty-six (3893 subjects) of 3313 studies identified were included for analysis. Standardized mean difference (SMD) was computed, and meta-analysis was performed.ResultsA total of 3313 records were retrieved including 1114 from database search and 2199 from grey literature search. Significant increase in postoperative IOP in 1-day follow-up with Healon (SMD = 0.37, CI: [0.07, 0.67]), Viscoat (SMD = 0.29, CI: [0.13, 0.45]), Provisc (SMD = 0.46, CI: [0.17, 0.76]), and Soft Shell (SMD = 0.58, CI: [0.30, 0.86]) was computed. On the other hand, results implied a nonsignificant increase in postoperative IOP with Healon GV (SMD = 0.07, CI: [-0.28, 0.41]), Healon5 (SMD = 0.15, CI: [-0.33, 0.64]), 2% HPMC (SMD = 0.32, CI: [-0.0, 0.64]), and OcuCoat (SMD = 0.26, CI: [-0.37, 0.9]). Additionally, a nonsignificant reduction in postoperative IOP was inferred with Viscoat + Provisc (SMD = -0.28, CI: [-2.23, 1.68]).ConclusionImprovement in IOP was shown with Viscoat + Provisc. Additionally, IOP nonsignificant upsurge was observed with Healon GV, Healon5, 2% HPMC, and OcuCoat compared to significant upsurge with Healon, Viscoat, and Soft Shell.
| S-EPMC7593745 | biostudies-literature
Project description:PURPOSE:To investigate the effects of topical application of ophthalmic 5% povidone-iodine eye drops, which has been reported to cause apnea in spontaneously breathing children during general anesthesia. METHODS:The authors conducted a randomized, controlled, single-blinded study comparing the effect of balanced salt solution eye drops and povidone-iodine eye drops on respiration in spontaneously breathing children during general anesthesia with sevoflurane via a laryngeal mask airway. Fifty patients received balanced salt solution eye drops and 50 patients received 5% povidone-iodine eye drops. RESULTS:None of the control patients had a significant change in respiration. Thirty of the 50 (60%) povidone-iodine patients had a slowing of respiration within the first 6 breaths after eye drop instillation (P < .001). The median time of respiratory pause in those 30 patients was 18.5 seconds (range: 4.36 to 96.2 seconds). Among the povidone-iodine patients, children with a history of a prior tonsillectomy and adenoidectomy and/or bilateral myringotomy had a 7.2 times greater chance of experiencing a change in respiration after instillation of the povidone-iodine eye drops. CONCLUSIONS:Topical application of 5% povidone-iodine eye drops causes a slowing and pause in spontaneous ventilation in a majority of children prior to strabismus surgery. This may represent activation of the diving reflex. [J Pediatr Ophthalmol Strabismus. 2019;56(6):378-382.].
| S-EPMC7340011 | biostudies-literature
Project description:PurposeThis study aims to investigate the feasibility of robot-assisted simulated strabismus surgery using the new da Vinci Xi Surgical System and to report what we believe is the first use of a surgical robot in experimental eye muscle surgery.MethodsRobot-assisted strabismus surgeries were performed on a strabismus eye model using the robotic da Vinci Xi Surgical System. On the lateral rectus of each eye, we performed a procedure including, successively, a 4-mm plication followed by a 4-mm recession of the muscle to end with a 4-mm resection. Operative time from conjunctival opening to closing and successful completion of the different steps with or without complications or unexpected events were assessed.ResultsRobot-assisted strabismus procedures were successfully performed on six eyes. The feasibility of robot-assisted simulated strabismus surgery is confirmed. The da Vinci Xi system provided the appropriate dexterity and operative field visualization necessary to perform conjunctival and Tenon's capsule opening and closing, muscle identification, suturing, desinsertion, sectioning, and resuturing. The mean duration to complete the whole procedure was 27 minutes (range, 22-35). There were no complications or unexpected intraoperative events.ConclusionsExperimental robot-assisted strabismus surgery is technically feasible using the new robotic da Vinci Xi Surgical System. This is, to our knowledge, the first use of a surgical robot in ocular muscle surgery.Translational relevanceFurther experimentation will allow the advantages of robot-assisted microsurgery to be identified while underlining the improvements and innovations necessary for clinical use.
| S-EPMC6543922 | biostudies-literature
Project description:Transmission of infectious respiratory diseases starts from pathogen-laden respiratory droplets released during coughing, sneezing, or speaking. Here we report an on-mask chemical modulation strategy, whereby droplets escaping a masking layer are chemically contaminated with antipathogen molecules (e.g., mineral acids or copper salts) preloaded on polyaniline-coated fabrics. A colorimetric method based on the color change of polyaniline and a fluorometric method utilizing fluorescence quenching microscopy are developed for visualizing the degree of modification of the escaped droplets by H+ and Cu2+, respectively. It is found that even fabrics with low fiber-packing densities (e.g., 19%) can readily modify 49% of the escaped droplets by number, which accounts for about 82% by volume. The chemical modulation strategy could offer additional public health benefits to the use of face covering to make the sources less infectious, helping to strengthen the response to the current pandemic or future outbreaks of infectious respiratory diseases.
| S-EPMC7598905 | biostudies-literature
Project description:We investigate, by means of pore-scale lattice Boltzmann simulations, the mechanisms of interception of respiratory droplets within fibrous porous media composing face masks. We simulate the dynamics, coalescence, and collection of droplets of the size comparable with the fiber and pore size in typical fluid-dynamic conditions that represent common expiratory events. We discern the fibrous microstructure into three categories of pores: small, large, and medium-sized pores, where we find that within the latter, the incoming droplets tend to be more likely intercepted. The size of the medium-sized pores relative to the fiber size is placed between the droplet-to-fiber size ratio and a porosity-dependent microstructural parameter Lϵ*=ϵ/(1-ϵ) , with ϵ being the porosity. In larger pores, droplets collection is instead inhibited by the small pore-throat-to-fiber size ratio that characterizes the pore perimeter, limiting their access. The efficiency of the fibrous media in intercepting droplets without compromising breathability, for a given droplet-to-fiber size ratio, can be estimated by knowing the parameter Lϵ* . We propose a simple model that predicts the average penetration of droplets into the fibrous media, showing a sublinear growth with Lϵ* . Permeability is shown also to scale well with Lϵ* but following a superlinear growth, which indicates the possibility of increasing the medium permeability at a little cost in terms of interception efficiency for high values of porosity. As a general design guideline, the results also suggest that a fibrous layer thickness relative to the fiber size should exceed the value Lϵ* in order to ensure effective droplets filtration.
| S-EPMC8404382 | biostudies-literature
Project description:BackgroundWe have developed a new compact lightweight 8K ultra-high-definition (UHD; 7,680×4,320 pixels) camera and started medical application with an ophthalmic surgical microscope which is interchangeable with the conventional high-definition (1,920×1,080 pixels)/4K UHD (3,840×2,160 pixels) microscopic camera.MethodsWe did a feasibility study to apply our 8K UHD microscope in cataract surgery, glaucoma surgery and vitreous surgery using pig cadaver eyes. The 8K UHD microscope comprises a surgical microscope, a camera adaptor with relay lenses, an 8K UHD camera and an 8K UHD LCD to share the 8K UHD images with all surgical staff in real time.ResultsIn ophthalmic surgeries, higher resolution images than conventional microscopic cameras were obtained with 8K UHD LCD equivalent to the observation through the microscopic eye pieces.ConclusionBased on the results of this feasibility study, clinical trials on human ophthalmic surgery using the new 8K UHD microscopic camera should be conducted in the near future.
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Project description: Not available
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