TL;DR: The hypothesis that the presence of ILT in AAA correlates to significantly impaired oxygen transport to the aneurysmal wall is supported and it is observed that ILT thickness and length are the parameters that influence decreased oxygen flow and concentration values the most, and thick thrombi exacerbate hypoxic conditions in the arterial wall, which may contribute to increased tissue degradation.
Abstract: The objective of this paper is to analyze the association of intraluminal thrombus (ILT) presence and morphology with oxygen transport in abdominal aortic aneurysms (AAA) and local hypoxia. The biomechanical role of the ILT layer in the evolution of the aneurysm is still not fully understood. ILT has been shown to create an inflammatory environment by reducing oxygen flux to the arterial wall and therefore decreasing its strength. It has been also hypothesized that the geometry of the ILT may further affect AAA rupture. However, no previous research has attempted to explore the effect of morphological features of ILT on oxygen distributions within the AAA, in a systematic manner. In this study, we perform a comprehensive analysis to investigate how physiologically meaningful variations in ILT geometric characteristics affect oxygen transport within an AAA. We simulate twenty-seven AAA models with variable ILT dimensions and investigate the extent to which ILT attenuates oxygen concentration in the arterial wall. Geometric variations studied include ILT thickness and ILT length, as well as the bulge diameter of the aneurysm which is related to ILT curvature. Computer simulations of coupled fluid flow-mass transport between arterial wall, ILT, and blood are solved and spatial variations of oxygen concentrations within the ILT and wall are obtained. The comparison of the results for all twenty-seven simulations supports the hypothesis that the presence of ILT in AAA correlates to significantly impaired oxygen transport to the aneurysmal wall. Mainly, we observed that ILT thickness and length are the parameters that influence decreased oxygen flow and concentration values the most, and thick thrombi exacerbate hypoxic conditions in the arterial wall, which may contribute to increased tissue degradation. Conversely, we observed that the arterial wall oxygen concentration is nearly independent of the AAA bulge diameter. This confirms that consideration of ILT size and anatomy is crucial in the analysis of AAA development.
TL;DR: This paper proposed methods for the development, implementation, and evaluation of academic games and provided concrete practices and detailed instruction in which games can be used as an alternative to a traditional exam to support student mental health.
Abstract: This paper identifies an opportunity to integrate gamification in undergraduate biomedical engineering (BME) classrooms to alleviate student test anxiety and promote student perception of their academic performance. Gamification is a popular educational strategy that does not appear to be widely explored or adopted in higher education, particularly in a BME setting. This study proposes methods for the development, implementation, and evaluation of academic games and provides concrete practices and detailed instruction in which games can be used as an alternative to a traditional exam to support student mental health. The reflection provides the feedback received from students which demonstrates a balanced view of using game-based activities for tests and evaluations, cautiously optimistic based on the initial positive attitude seen from students.
05 Mar 2022
TL;DR: Project ALIEN (Alternative Lifeform Identification and Exploration Navigator) is a comprehensive mission architecture for human exploration of the Martian surface with the goal of searching for evidence of life on Mars, as designed for submission to the 2020 NASA RASC-AL Competition as mentioned in this paper .
Abstract: Project ALIEN (Alternative Lifeform Identification and Exploration Navigator) is a comprehensive mission architecture for human exploration of the Martian surface with the goal of searching for evidence of life on Mars, as designed for submission to the 2020 NASA RASC-AL Competition. This proposed Martian exploration mission has been restructured for feasibility testing in a Mars mission analogue facility on Earth. This paper explores the changes made to the mission architecture to accommodate an Earth-based mission, and the impact those changes are expected to have on the outcome of the analogue. Specifically, we investigate how closely the analogue simulates the conditions expected in a Martian surface mission. Time the crew will spend in launch and transit to Mars are not considered, as the analogue only accounts for the surface mission. Project ALIEN includes custom lander and rover designs; analysis of the impact of these custom designs to the mission provide a strong argument for the added costs, given that the full mission will be a flagship mission. Extravehicular activity (EVA) procedures developed for the analogue to approximate the search for life in Gale Crater will be used to demonstrate the feasibility of Project ALIEN's approach to microbe discovery. The mission will further refine the standard operating procedures to account for human factors considerations expected to be discovered in testing, such as difficulty using standard collection tools in EVA gear. The analogue provides an emulation of a Martian surface mission that allows for feasibility testing of experimental procedures and helps develop systems tailored to this mission's goals to enable a full-scale exploration of the Martian surface through Project ALIEN.
TL;DR: Investigation of the biomechanical role of intraluminal thrombus in an abdominal aortic aneurysm finds that ILT decreases oxygen transport within the tissue significantly, leading to wall hypoxia.
TL;DR: In this article , the authors investigated the effects of ILT structural composition on oxygen flow by adopting a multilayered porous framework and comparing a two-layer ILT model with one-layer models.
Abstract: Determination of abdominal aortic aneurysm (AAA) rupture risk involves the accurate prediction of mechanical stresses acting on the arterial tissue, as well as the wall strength which has a correlation with oxygen supply within the aneurysmal wall. Our laboratory has previously reported the significance of an intraluminal thrombus (ILT) presence and morphology on localized oxygen deprivation by assuming a uniform consistency of ILT. The aim of this work is to investigate the effects of ILT structural composition on oxygen flow by adopting a multilayered porous framework and comparing a two-layer ILT model with one-layer models. Three-dimensional idealized and patient-specific AAA geometries are generated. Numerical simulations of coupled fluid flow and oxygen transport between blood, arterial wall, and ILT are performed, and spatial variations of oxygen concentrations within the AAA are obtained. A parametric study is conducted, and ILT permeability and oxygen diffusivity parameters are individually varied within a physiological range. A gradient of permeability is also defined to represent the heterogenous structure of ILT. Results for oxygen measures as well as filtration velocities are obtained, and it is found that the presence of any ILT reduces and redistributes the concentrations in the aortic wall markedly. Moreover, it is found that the integration of a porous ILT significantly affects the oxygen transport in AAA and the concentrations are linked to ILT’s permeability values. Regardless of the ILT stratification, maximum variation in wall oxygen concentrations is higher in models with lower permeability, while the concentrations are not sensitive to the value of the diffusion coefficient. Based on the observations, we infer that average one-layer parameters for ILT material characteristics can be used to reasonably estimate the wall oxygen concentrations in aneurysm models.
TL;DR: In this paper , a BME laboratory course-specific escape room was developed and beta-tested on an initial group of BME students, and the first set of feedback enabled improvements to the design and difficulty of the escape room, which was followed by the final release of the activity for the intended undergraduate BME course.
Abstract: Commercial escape rooms have grown in popularity as an enjoyable experience that also doubles as an exercise in communication and collaboration. Educators can take advantage of these natural qualities to engage and support students in a low-stress learning environment. The primary goal of this study is to share the development and application of an educational escape room as a tool to provide biomedical engineering (BME) students with an immersive and practical experience. A BME laboratory course-specific escape room was developed and beta-tested on an initial group of BME students. The first set of feedback enabled improvements to the design and difficulty of the escape room, which was followed by the final release of the activity for the intended undergraduate BME course. Across an academic year, 74 participants agreed to provide survey feedback for this study. Despite a moderate escape rate (29%), students reported high satisfaction and enthusiasm for the activity. Student survey responses indicated that participants were engaged and empowered to successfully escape even without external motivators. Responses supported the effectiveness of the escape room as a BME learning environment, allowing students to practice and retain course-related knowledge in a challenging but low-risk activity. The foundational structure of escape rooms offers a beneficial environment for experiential knowledge application. We conclude that educational escape rooms show promise as a pedagogical tool in promoting enhanced knowledge retention through immersive, game-based learning.The online version contains supplementary material available at 10.1007/s43683-022-00089-w.
TL;DR: In this paper , the effects of variations in the vocal fold morphological features associated with gender on glottal aerodynamics and tissue deformation were examined by incorporating the transient Navier-Stokes equations to model airflow through the larynx and considering a linear elasticity model for VF dynamics.
Abstract: This paper aims to examine the effects of variations in the vocal fold (VF) morphological features associated with gender on glottal aerodynamics and tissue deformation. Nine three-dimensional geometries of the VFs in the larynx are created with various VF lengths, thicknesses, and depths to perform a parametric analysis according to gender-related geometrical parameters. The computational model is incorporated in a fluid–structure interaction methodology by adopting the transient Navier–Stokes equations to model airflow through the larynx and considering a linear elasticity model for VF dynamics. The model predictions, such as aerodynamic data through the larynx, glottal airflow, and VF deformations, are analyzed. The comparison of the simulation results for the nine cases supports the hypothesis that gender differences in laryngeal dimensions remarkably influence the glottal airflow and deformation of the VFs. Decreasing VF thickness and increasing its length corresponds to a noticeable increase in maximum tissue displacement, while variations in depth affect the flow rate significantly in the small and large larynges. Conversely, we observed that the pressure drop at the glottis is nearly independent of the VF length. A comparison of the glottal area with published imaging data illustrated a direct correlation between the glottal configuration and the morphology of the VFs.