Extended numerical analysis of an eyeball injury under direct impact

2021 ◽  
Author(s):  
Mateusz Koberda ◽  
Andrzej Skorek ◽  
Pawel Kłosowski ◽  
Marcin Żmuda-Trzebiatowski ◽  
Krzysztof Żerdzicki ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Numerical Model ◽  
Blunt Injury ◽  
Blunt Force ◽  
Blunt Force Trauma ◽  
Injury Mechanisms ◽  
Significant Impairment ◽  
Specialist Treatment ◽  
Extent Of Damage ◽  
The Impact

The objective of this study was to develop a numerical model of the eyeball and orbit to simulate a blunt injury to the eyeball leading to its rupture, as well as to conduct a comparative analysis of the results obtained using the finite element method against the clinical material concerning patients who had suffered an eyeball rupture due to a blunt force trauma. Using available sclera biometric and strength data, a numerical model of the eyeball, the orbital contents, and the bony walls were developed from the ground up. Then, eight different blunt force injury scenarios were simulated. The results of numerical analyses made it possible to identify possible locations and configurations of scleral rupture. The obtained results were compared against the clinical picture of patients hospitalized at the Clinic of Ophthalmology in 2010–2016 due to isolated blunt force trauma to the eyeball. It has been demonstrated that the extent of damage observed on the numerical model that indicated a possible location of eyeball rupture did not differ from the clinically observed configurations of the scleral injuries, however this applies to injuries the extend of which did not exceed 2–3 clock-hours on the eyeball. It has been found that the direction of the impact applied determines the location of eyeball rupture. Most often the rupture occurs at the point opposite to the clock-hour of the impact application. The eyeball rupture occurs in the first 7–8 milliseconds after the contact with the striking object, assuming that it strikes at a speed close to the speed of a human fist. It has been established that the injuries most often affected the upper sectors of the eyeball. Men are definitely more likely to sustain such injuries. Eyeball ruptures lead to significant impairment of visual acuity being most often degraded to light perception in front of the eye. Despite immediate specialist treatment, it is possible to achieve, on average, a visual acuity of 0.26 as per the Snellen scale. This study may contribute to a better understanding of injury mechanisms and better treatment planning. It may also contribute to the development of eyeball protection methods for persons exposed to the above-mentioned injuries.

Khmer Rouge Regime Massacres

Massacres ◽  
2018 ◽  
pp. 115-135
Author(s):  
Julie M. Fleischman ◽  
Sonnara Prak ◽  
Vuthy Voeun ◽  
Sophearavy Ros
Keyword(s):  
Khmer Rouge ◽  
Skeletal Remains ◽  
Important Work ◽  
Blunt Force ◽  
Blunt Force Trauma ◽  
The People ◽  
Khmer Rouge Regime ◽  
Base Of The Skull ◽  
The Impact

Chapter 8 discusses the impact of the Khmer Rouge regime on the people of Cambodia and the importance of documenting the evidence of violence. This study focuses on the important work being done at the Choeung Ek Genocidal Center analyzing the skeletal remains of the victims. In particular, a recent study performed on a sample of Khmer Rouge victims is discussed and, through analysis of the perimortem trauma, confirms eyewitness accounts that blunt force trauma to the base of the skull was often utilized to execute the victims.

Noise Exposure and Hearing Disorders

2017 ◽  
Author(s):  
David C. Byrne ◽  
Thais C. Morata
Keyword(s):  
Hearing Loss ◽  
Noise Exposure ◽  
Hearing Protection ◽  
Noise Induced Hearing Loss ◽  
Hearing Disorders ◽  
Industrial Noise ◽  
Significant Impairment ◽  
Protection Devices ◽  
The Impact ◽  
Occupational Hearing Loss

Exposure to industrial noise and the resulting effect of occupational hearing loss is a common problem in nearly all industries. This chapter describes industrial noise exposure, its assessment, and hearing disorders that result from overexposure to noise. Beginning with the properties of sound, noise-induced hearing loss and other effects of noise exposure are discussed. The impact of hearing disorders and the influence of other factors on hearing loss are described. Typically, noise-induced hearing loss develops slowly, and usually goes unnoticed until a significant impairment has occurred. Fortunately, occupational hearing loss is nearly always preventable. Therefore, this chapter gives particular attention to recommendations for measures to prevent occupational hearing loss such as engineering noise controls and hearing protection devices.

scholarly journals A Model for the Thermal Behaviour of an Offshore Cable Installed in a J-Tube

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 31
Author(s):  
Jeremy Arancio ◽  
Ahmed Ould El Moctar ◽  
Minh Nguyen Tuan ◽  
Faradj Tayat ◽  
Jean-Philippe Roques
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Model ◽  
Thermal Behaviour ◽  
Energy Production ◽  
Power Transmission ◽  
Temperature Fields ◽  
Sobol Indices ◽  
Lumped Element ◽  
Thermal Phenomena ◽  
The Impact

In the race for energy production, supplier companies are concerned by the thermal rating of offshore cables installed in a J-tube, not covered by IEC 60287 standards, and are now looking for solutions to optimize this type of system. This paper presents a numerical model capable of calculating temperature fields of a power transmission cable installed in a J-tube, based on the lumped element method. This model is validated against the existing literature. A sensitivity analysis performed using Sobol indices is then presented in order to understand the impact of the different parameters involved in the heating of the cable. This analysis provides an understanding of the thermal phenomena in the J-tube and paves the way for potential technical and economic solutions to increase the ampacity of offshore cables installed in a J-tube.

The impact of cataract surgery on depressive symptoms for bilateral cataract patients in Ho Chi Minh City, Vietnam

2013 ◽  
Vol 26 (2) ◽  
pp. 307-313 ◽  
Author(s):  
Kien Gia To ◽  
Lynn B. Meuleners ◽  
Michelle L. Fraser ◽  
Dat Van Duong ◽  
Dung Van Do ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Depressive Symptoms ◽  
Cataract Surgery ◽  
Contrast Sensitivity ◽  
Depression Scale ◽  
Epidemiological Studies ◽  
Ho Chi Minh City ◽  
Bilateral Cataract ◽  
Vietnamese Population ◽  
The Impact

ABSTRACTBackground:Depression is common among older populations with cataract. However, the impact of cataract surgery on depression in both developed and developing countries remains unclear. The aim of this study is to determine the impact of cataract surgery on depressive symptoms and to examine the association between objective visual measures and change in depressive symptoms after surgery among a Vietnamese population in Ho Chi Minh City.Methods:A cohort of older patients with bilateral cataract were assessed the week before and one to three months after first eye surgery only or first- and second-eye cataract surgeries. Visual measures including visual acuity, contrast sensitivity, and stereopsis were obtained. Depressive symptoms were assessed using the 20-item Center for Epidemiological Studies-Depression Scale (CES-D). Descriptive analyses and a generalized estimating equations (GEE) analysis were undertaken to determine the impact of cataract surgery on depressive symptoms.Results:Four hundred and thirteen participants were recruited into the study before cataract surgery. Two hundred and forty-seven completed the follow-up assessment after surgery. There was a significant decrease (improvement) of one point in the depressive symptoms score (p = 0.04) after cataract surgery, after accounting for potential confounding factors. In addition, females reported a significantly greater decrease (improvement) of two points in depressive symptom scores (p = 0.01), compared to males. However, contrast sensitivity, visual acuity, and stereopsis were not significantly associated with change in depressive symptoms scores. First-eye cataract surgery or both-eye cataract surgery did not modify the change in depressive symptoms score.Conclusion:There was a small but significant improvement in depressive symptoms score after cataract surgery for an older population in Vietnam.

Endovascular Stent Graft Treatment of Acute Thoracic Aortic Transections Due to Blunt Force Trauma

2009 ◽  
Vol 16 (2) ◽  
pp. 147-154 ◽  
Author(s):  
Marc A. Bjurlin ◽  
Eugene M. Tanquilut ◽  
Aswath Subram ◽  
Peggy Kalkounos ◽  
Gary J. Merlotti
Keyword(s):  
Stent Graft ◽  
Endovascular Stent ◽  
Endovascular Stent Graft ◽  
Blunt Force ◽  
Blunt Force Trauma

Evaluation of a calculation model to estimate the impact of the COVID-19 pandemic lockdown on visual acuity in neovascular AMD

2021 ◽  
pp. 112067212110523
Author(s):  
Martin Stattin ◽  
Anna-Maria Haas ◽  
Daniel Ahmed ◽  
Alexandra Graf ◽  
Katharina Krepler ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Real Life ◽  
Treatment Interruption ◽  
Term Treatment ◽  
Calculation Model ◽  
Life Outcomes ◽  
Short Term ◽  
Short Term Treatment ◽  
The Real ◽  
The Impact

Purpose A model was calculated during the first Austrian coronavirus disease-2019 (COVID-19) pandemic lockdown to estimate the effect of a short-term treatment interruption due to healthcare restrictions on visual acuity (VA) in neovascular age-related macular degeneration (nAMD). The model was compared to the real-life outcomes before treatment re-started. Methods Retrospective data-collection of 142 eyes in 142 patients receiving repeated intravitreal injections with anti-VEGF at a retina unit in Vienna in a personalized pro-re-nata regimen prior to the COVID-19 associated lockdown, when treatment was deferred between March 16 and May 4, 2020. During the lockdown, the preliminary data was integrated into pre-existing formulae based on the natural course of the disease in untreated eyes in the long term. Patients were re-scheduled and treated after gradually opening operating rooms. The calculation model was compared to the effective VA change. Results The model calculated an overall VA loss of 3.5 ± 0.8 letters early treatment diabetes retinopathy study (ETDRS) ( p < 0.001 [95% CI:3.3;3.6]) on average compared to 2.5 ± 6 letters ETDRS ( p < 0.001 [95% CI:1.5;3.5]) as measured with a mean treatment delay of 61 ± 14 days after previously scheduled appointments. The total difference between the model exercise and the real-life outcomes accounted for 1 ± 5.9 letters ETDRS ( p = 0.051 [95% CI: 0.1;1.9]). Conclusion The herein presented calculation model might not be suitable to estimate the effective VA loss correctly over time, although untreated eyes and eyes under therapy show similarities after short-term treatment interruption. However, this study demonstrated the potentially negative impact of the COVID-19 pandemic lockdown on patients compromised by nAMD.

scholarly journals Patterns of blunt force homicide in the West Metropole of the City of Cape Town, South Africa

2017 ◽  
Vol 113 (5/6) ◽  
Author(s):  
Courtnee Clark ◽  
Calvin G. Mole ◽  
Marise Heyns ◽  
◽  
◽  
...  
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Future Research ◽  
The West ◽  
Blunt Force ◽  
Blunt Force Trauma ◽  
Lack Of Information ◽  
Salt River ◽  
The City ◽  
Ballistic Trauma

There is currently a lack of information regarding the prevalence of and characteristics associated with blunt force trauma related homicides in South Africa. Information relating to the patterns of blunt force trauma could assist in the development and implementation of interventions targeted at specific areas or individuals as well as direct future research towards areas in need of investigation. This study is a 5-year retrospective review of autopsy reports obtained from Salt River Mortuary (Cape Town, South Africa). The prevalence of blunt force trauma was considered for unnatural deaths with a focus on homicide. The patterns of homicidal blunt force trauma are also presented. A total of 15 519 autopsy cases was analysed. In 1198 (7.72%) of these cases, the cause of death was found to be blunt force trauma and 828 (5.32%) of these cases were classified as homicides. Approximately 11% of blunt force homicide cases occurred in combination with sharp and/or ballistic trauma. Men from poor socio-economic areas were shown to be most at risk of blunt force homicide in the City of Cape Town.

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