Search results for " Simulation"
showing 10 items of 4034 documents
Teaching Technology Usage in the ENT Medical Subdomain via a Flipped Classroom Approach
2018
The flipped classroom approach is supporting a continuous interaction of students and instructors via online communication and strengthens the ability to solve problems by self-organization. This is especially important in medical domains, like the one of ENT-Head/Neck (ENT: Ear-Nose-Throat) surgeries and treatment. Surgical corrections of the nasal airways, like FESS (Functional Endoscopy Sinus Surgery) or in the field of plastic surgery, are the second frequent surgical interventions in otorhinolaryngology. They have to be prepared very carefully and airflow simulation with Computational Fluid Dynamics (CFD) is gaining importance for diagnostics here. New in silico procedures, like imagin…
A Multi-Variate Predictability Framework to Assess Invasive Cardiac Activity and Interactions during Atrial Fibrillation
2017
Objective: This study introduces a predictability framework based on the concept of Granger causality (GC), in order to analyze the activity and interactions between different intracardiac sites during atrial fibrillation (AF). Methods: GC-based interactions were studied using a three-electrode analysis scheme with multi-variate autoregressive models of the involved preprocessed intracardiac signals. The method was evaluated in different scenarios covering simulations of complex atrial activity as well as endocardial signals acquired from patients. Results: The results illustrate the ability of the method to determine atrial rhythm complexity and to track and map propagation during AF. Conc…
Variations in acoustical beam properties of intracoronary Doppler catheters.
1993
The limitations of coronary angiography in assessing the functional significance of coronary obstructions is well known. While the critical variable of coronary blood flow cannot be readily measured, intraluminal Doppler sonography offers useful related functional information on blood flow velocity. In order to fully evaluate Doppler signals it is essential to have exact knowledge of the transducer transmission characteristics and of the ultrasound beam topology. In an experimental set-up, the transmitter-receiver characteristics of five commonly used Doppler catheters were investigated. In comparing the beam characteristics we found inhomogeneities in the lateral beam spread. At a penetrat…
A Multicenter International Randomized Controlled Manikin Study on Different Protocols of Cardiopulmonary Resuscitation for Laypeople: The MANI-CPR T…
2021
Background Compression-only cardiopulmonary resuscitation (CPR) is a suggested technique for laypeople facing out-of-hospital cardiac arrest (OHCA). However, it is difficult performing high-quality CPR until emergency medical services arrival with this technique. We aimed to verify whether incorporating intentional interruptions of different frequency and duration increases laypeople's CPR quality during an 8-minute scenario compared with compression-only CPR. Methods We performed a multicenter randomized manikin study selecting participants from 2154 consecutive laypeople who followed a basic life support/automatic external defibrillation course. People who achieved high-quality CPR in 1-m…
Validating an Efficient Method to Quantify Motion Sickness
2011
Objective: Motion sickness (MS) can be a debilitating side effect associated with motion in real or virtual environments. We analyzed the effect of expectancy on MS and propose and validate a fast and simple MS measure.Background: Several questionnaires measure MS before or after stimulus presentation, but no satisfactory tool has been established to quickly capture MS data during exposure. To fill this gap, we introduce the Fast MS Scale (FMS), a verbal rating scale ranging from zero (no sickness at all) to 20 (frank sickness). Also, little is known about the role of expectancy effects in MS studies. We conducted an experiment that addressed this issue.Method: For this study, 126 volunteer…
Studying hypertension in ocular fundus images using Hausdorff dispersion ordering.
2010
Retinal arterial and vein diameters are altered in individuals at risk of cardiovascular events mainly due to high blood pressure. The measurement of retinal vessel diameters has been proved to reflect individuals' vascular health. Dispersion of such measures which are obtained by means of ocular fundus images is a major factor not usually considered in clinical research. In this paper, a method to evaluate if different levels of clinically relevant covariables induce greater dispersion in retinal arterial and vein diameters is proposed. A multivariate dispersion ordering, the Hausdorff dispersion order, is used to compare the level of dispersion in such diameters for different groups of pa…
Quantification of myocardial blood flow and blood flow reserve in the presence of arterial dispersion: A simulation study
2002
Myocardial blood flow (MBF) can be quantified using dynamic T1-weighted MRI of diffusible tracers and a mathematical model of underlying vasculature. Quantification of MBF by means of T1- weighted MRI requires knowledge of the arterial input function (AIF). The AIF can be estimated from the left ventricular (LV) cavity. However, dispersion may occur between the LV and the tissue of interest because of the laminar blood flow profiles, branching of venules, and because of stenosis. To evaluate the influence of dispersion on the results of MBF quantification, a simulation study was performed. The dispersion was described as a convolution of the AIF with an exponential residue function. Synthet…
Mathematical simulation of Doppler changes in late-onset smallness; progression patterns of cerebral and umbilical anomalies define two types of late…
2019
To evaluate the progression of Doppler abnormalities in fetuses with late-onset fetal smallness (SGA) that become growth restricted (FGR).524 Doppler examinations of the umbilical and cerebral arteries systems, belonging to 442 late-onset SGA fetuses after week 34, were studied, evaluating by means of the statistical difference with the respective abnormal centiles, the pattern of progression into abnormal Doppler values and the distribution and cumulative sum of Doppler anomalies according to the interval to delivery.Only one third (33.5%,Two thirds of late-onset fetal smallness occurs without hemodynamic changes. In half of the remaining cases an initial cerebral vasodilation defines a gr…
Clinical Simulation in pediatrics and neonatology using EDISON: an educational innovation project
2021
Introduction: Clinical simulation is a tool that allows creating controlled and safe spaces that mimic reality, where students can acquire skills and abilities prior to facing real situations. Methodology: This is a study with two phases. The first quasi-experimental phase where 3 questionnaires were used; two of them to assess knowledge (pretest - posttest) and the other one to assess the satisfaction of the training action. And the second phase was analytical, where the effectiveness of a training intervention in a confinement context based on the use of audiovisual materials created through EDISON was evaluated. Results: In 2019 the average satisfaction of the students was 9.22 (SD 0.72)…
Prediction of dilutional acidosis based on the revised classical dilution concept for bicarbonate
2004
Due to the controversy surrounding the term dilutional acidosis, the classical dilution concept for bicarbonate has been rigorously revised for the prediction of pH, actual bicarbonate concentration, and base excess. In the algorithms derived for buffer solutions, blood, and whole body (1-, 2-, and 3-fluid compartment), only bicarbonate is considered. On dilution at constant Pco2, the final concentration of bicarbonate is the sum in terms of pH, due to the following processes: dilution, formation from chemical reaction with the nonbicarbonate buffers phosphate, hemoglobin, and plasma proteins, and transfer from erythrocytes and interstitial fluid to plasma. At constant Pco2, the level of c…