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Left atrial wall thickness and its relationship with reconnection after pulmonary vein isolation in patients with atrial fibrillation evaluated using a three-dimensional wall thickness map

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International Journal of Arrhythmia 2021年第1期22卷 1-13页

作者： Oh, Seil Joo, Yoon Ha Lee, Euijae Lee, So-Ryoung Cha, Myung-Jin Choi, Eue-Keun Lee, Jung Chan Lee, Whal Department of Internal Medicine Seoul National University College of Medicine and Seoul National University Hospital Seoul Republic of Korea Interdisciplinary Program in Bioengineering Seoul National University Seoul Korea Department of Biomedical Engineering Seoul National University College of Medicine Seoul Korea Department of Radiology Seoul National University Hospital Seoul Korea

The major cause of recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF) is PV reconnection, and thicker wall could be associated with reconnection. This study aimed to evaluate the wall thickness of the PV antrum in reconnection sites using a three-dimensional (3D) wall thickness map. A total of 91 patients who underwent a second ablation procedure due to AF recurrence were evaluated. The locations of the PV reconnection sites were confirmed in electroanatomical maps. A 3D atrial wall thickness (AWT) map was created using computed tomography scan data. The AWT values of the ablation lines of the index procedure were graded in each segment of the PV antrum: grade 1, 0.5 < AWT ≤ 1.0 mm; grade 2, 1.0 < AWT ≤ 1.5 mm; grade 3, 1.5 < AWT ≤ 2.0 mm; grade 4, 2.0 < AWT ≤ 2.5 mm; grade 5, AWT > 2.5 mm. A total of 281 PV reconnection sites among 1256 segments of the PV antrum in 79 patients were detected. The average AWT grades were 2.7 ± 1.0 and 2.2 ± 1.0 in the reconnected and non-reconnected segments, respectively (P < 0.01). Higher AWT grades were observed in the reconnected superior segments of the left superior PV, carina and inferior segments of the left inferior PV, superior and posterior segments of the right superior PV, and posterior and inferior segments of the right inferior PV. The reconnected segments of the PV antrum showed thicker myocardium than the non-reconnected ones in patients with recurrent AF after catheter ablation. A wall thickness map for PV isolation could be considered for customized ablation in order to reduce PV reconnection.

关键词： Catheter ablation Atrial fibrillation Pulmonary vein Wall thickness

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BPS2025 - Analyzing the biophysical properties of pulmonary surfactant during bacterial infection using multiscale computational models

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Biophysical Journal 2025年第3期124卷 635a-636a页

作者： Jonathan R. Fritz Ian D. Bentley Joshua A. Englert Samir N. Ghadiali Interdisciplinary Biophysics Program Ohio State University Columbus OH USA Division of Pulmonary and Critical Care Medicine Department of Internal Medicine Ohio State Wexner Medical Center Columbus OH USA Department of Biomedical Engineering Ohio State University Columbus OH USA

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A Reflection on Teaching Design Thinking to First-Year engineering Students

A Reflection on Teaching Design Thinking to First-Year Engin...

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2019 IEEE International Conference on engineering, Technology and Education, TALE 2019

作者： Maneeratana, Kuntinee Chancharoen, Ratchatin Thongnuek, Peerapat Sukmuen, Potcharawan Inkaew, Chamaiporn Suwannatthachote, Praweenya Chulalongkorn University Department of Mechanical Engineering Bangkok Thailand Chulalongkorn University Interdisciplinary Program of Biomedical Engineering Thailand Chulalongkorn University Department of Educational Communication and Technology Thailand

ISBN: (纸本)9781728126654

A short ***-style design thinking project was offered to first-year engineering students as an option in an introduction to engineering course. Using the Stanford *** bootcamp bootleg as the guideline, students went through the process - empathy, define, ideate, prototype, and test - very fast with different levels of depth. The works were evaluated using the *** rubric and found to gain limited success. In order to improve the instructional design, the formal developmental study was initiated. Using class observation, focus-group interview and comparison with similar classes, the instructional design was analyzed and weakness identified. The major problems included the student preparation, engagement, participation, core concept understanding as well as active learning activities, technology utilization, feedback and reflection, in short, the class control and facilitation. The instruction design was adjusted with detailed activities such that it would be implemented in the next iteration. © 2019 IEEE.

关键词： Students

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Composite B-Spline Regularized Delta Functions for the Immersed Boundary Method: Divergence-Free Interpolation and Gradient-Preserving Force Spreading

arXiv

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arXiv 2024年

作者： Gruninger, Cole Griffith, Boyce E. Department of Mathematics University North Carolina Chapel HillNC United States Department of Applied Physical Sciences University of North Carolina Chapel HillNC United States Department of Biomedical Engineering University of North Carolina Chapel HillNC United States Carolina Center for Interdisciplinary Applied Mathematics University of North Carolina Chapel HillNC United States Computational Medicine Program University of North Carolina School of Medicine Chapel HillNC United States McAllister Heart Institute University of North Carolina School of Medicine Chapel HillNC United States

This paper presents an approach to enhance volume conservation in the immersed boundary (IB) method by employing regularized delta functions derived from composite B-splines. These delta functions are constructed using tensor product kernels, similar to the conventional IB method. However, the kernels are B-splines whose polynomial degree varies according to the normal and tangential directions of each velocity component. The conventional IB method, while effective for fluid-structure interaction applications, has long been challenged by poor volume conservation, particularly evident in simulations of pressurized, closed membranes. We demonstrate that composite B-spline regularized delta functions significantly enhance volume conservation through two complementary properties: they provide continuously divergence-free velocity interpolants and maintain the gradient character of forces corresponding to mean pressure jumps across interfaces. By correctly representing these forces as discrete gradients, they eliminate a key source of spurious flows that typically plague immersed boundary computations. Our approach maintains the local nature of the classical IB method, avoiding the computational overhead associated with the non-local Divergence-Free Immersed Boundary (DFIB) method’s construction of an explicit velocity potential which requires additional Poisson solves for interpolation and force spreading operations. Through a series of numerical experiments, we show that sufficiently regular composite B-spline kernels can maintain initial volumes to within machine precision. We provide a detailed analysis of the relationship between kernel regularity and the accuracy of force spreading and velocity interpolation operations. Our findings indicate that composite B-splines of at least C1 regularity produce results comparable to the DFIB method in dynamic simulations, with errors in volume conservation primarily dominated by truncation error of the employed time-stepping s

关键词： Delta functions

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Extracellular Matrix Protein Composition Dynamically Changes During Murine Forelimb Development

SSRN

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SSRN 2023年

作者： Jacobson, Kathryn R. Saleh, Aya M. Lipp, Sarah N. Tian, Chengzhe Watson, Audrey R. Luetkemeyer, Callan M. Ocken, Alexander R. Spencer, Sabrina L. Kinzer-Ursem, Tamara L. Calve, Sarah Purdue University Interdisciplinary Life Science Program Purdue University West LafayetteIN47907 United States Weldon School of Biomedical Engineering Purdue University West LafayetteIN47907 United States The Indiana University School of Medicine IndianapolisIN46202 United States Department of Biochemistry University of Colorado Boulder BoulderCO80303 United States BioFrontiers Institute University of Colorado Boulder BoulderCO80303 United States Austrian Academy of Sciences Vienna Austria Paul M. Rady Department of Mechanical Engineering University of Colorado Boulder BoulderCO80309 United States Paul M. Rady Department of Mechanical Engineering United States

The extracellular matrix (ECM) is an integral part of multicellular organisms, connecting different cell layers and tissue types. During morphogenesis and growth, tissues undergo substantial reorganization. While it is intuitive that the ECM remodels in concert, little is known regarding how matrix composition and organization change during development. Here, we quantified ECM protein dynamics in the murine forelimb during appendicular musculoskeletal morphogenesis (embryonic days 11.5-14.5) using tissue fractionation, bioorthogonal non-canonical amino acid tagging, and mass spectrometry. Our analyses indicated that ECM protein (matrisome) composition in the embryonic forelimb changed as a function of development and growth, was distinct from other developing organs (brain), and was altered in a model of disease (osteogenesis imperfecta murine). Additionally, the tissue distribution for select matrisome were assessed via immunohistochemistry in the wild-type embryonic and postnatal musculoskeletal system, which did not directly correlate with single-cell transcriptomic expression profiles, indicating the importance for investigating the proteome in addition to the transcriptome. This resource will guide future research investigating the role of the matrisome during complex tissue development. © 2023, The Authors. All rights reserved.

关键词： Mass spectrometry

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Polar transform network for prostate ultrasound segmentation with uncertainty estimation

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Medical Image Analysis 2022年第0期78卷 1页

作者： Xu, Xuanang Sanford, Thomas Turkbey, Baris Xu, Sheng Wood, Bradford J. Yan, Pingkun Department of Biomedical Engineering and the Center for Biotechnology and Interdisciplinary Studies Rensselaer Polytechnic Institute TroyNY12180 United States Department of Urology The State University of New York Upstate Medical University SyracuseNY13210 United States Molecular Imaging Program National Cancer Institute National Institutes of Health BethesdaMD20892 United States Center for Interventional Oncology Radiology & Imaging Sciences at National Institutes of Health BethesdaMD20892 United States

Automatic and accurate prostate ultrasound segmentation is a long-standing and challenging problem due to the severe noise and ambiguous/missing prostate boundaries. In this work, we propose a novel polar transform network (PTN) to handle this problem from a fundamentally new perspective, where the prostate is represented and segmented in the polar coordinate space rather than the original image grid space. This new representation gives a prostate volume, especially the most challenging apex and base sub-areas, much denser samples than the background and thus facilitate the learning of discriminative features for accurate prostate segmentation. Moreover, in the polar representation, the prostate surface can be efficiently parameterized using a 2D surface radius map with respect to a centroid coordinate, which allows the proposed PTN to obtain superior accuracy compared with its counterparts using convolutional neural networks while having significantly fewer (18%∼41%) trainable parameters. We also equip our PTN with a novel strategy of centroid perturbed test-time augmentation (CPTTA), which is designed to further improve the segmentation accuracy and quantitatively assess the model uncertainty at the same time. The uncertainty estimation function provides valuable feedback to clinicians when manual modifications or approvals are required for the segmentation, substantially improving the clinical significance of our work. We conduct a three-fold cross validation on a clinical dataset consisting of 315 transrectal ultrasound (TRUS) images to comprehensively evaluate the performance of the proposed method. The experimental results show that our proposed PTN with CPTTA outperforms the state-of-the-art methods with statistical significance on most of the metrics while exhibiting a much smaller model size. Source code of the proposed PTN is released at https://***/DIAL-RPI/PTN. © 2022 Elsevier B.V.

关键词： Image segmentation

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M2FN: Multi-step modality fusion for advertisement image assessment

arXiv

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arXiv 2021年

作者： Park, Kyung-Wha Ha, Jung-Woo Lee, JungHoon Kwon, Sunyoung Kim, Kyung-Min Zhang, Byoung-Tak Interdisciplinary Program in Neuroscience Seoul National University Korea Republic of NAVER AI LAB NAVER CLOVA Statistics and Actuarial Science Soongsil University Korea Republic of School of Biomedical Convergence Engineering Pusan National University Korea Republic of Department of Computer Science and Engineering Seoul National University Korea Republic of Surromind Robotics

Assessing advertisements, specifically on the basis of user preferences and ad quality, is crucial to the marketing industry. Although recent studies have attempted to use deep neural networks for this purpose, these studies have not utilized image-related auxiliary attributes, which include embedded text frequently found in ad images. We, therefore, investigated the influence of these attributes on ad image preferences. First, we analyzed large-scale real-world ad log data and, based on our findings, proposed a novel multi-step modality fusion network (M2FN) that determines advertising images likely to appeal to user preferences. Our method utilizes auxiliary attributes through multiple steps in the network, which include conditional batch normalization-based low-level fusion and attention-based high-level fusion. We verified M2FN on the AVA dataset, which is widely used for aesthetic image assessment, and then demonstrated that M2FN can achieve state-of-the-art performance in preference prediction using a real-world ad dataset with rich auxiliary attributes. © 2021, CC BY-NC-SA.

关键词： Marketing

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Correction: Assessing the Effects of Dasatinib on Mesenchymal Stem/Stromal Cells

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Cellular and molecular bioengineering 2024年第6期17卷 619页

作者： David P Heinrichs Vitali V Maldonado I Kade K Ardana Ryan M Porter Rebekah M Samsonraj Department of Biomedical Engineering Engineering Research Center College of Engineering University of Arkansas 700 W Research Center Boulevard Fayetteville AR 72701 USA. Cell and Molecular Biology Interdisciplinary Program University of Arkansas Fayetteville AR 72701 USA. Department of Orthopedic Surgery University of Arkansas for Medical Sciences Little Rock AR 72205 USA.

[This corrects the article DOI: 10.1007/s12195-024-00830-1.].

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Flagellum Pumping Efficiency in Shear-Thinning Viscoelastic Fluids

arXiv

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arXiv 2023年

作者： Barrett, Aaron Fogelson, Aaron L. Gregory Forest, M. Gruninger, Cole Lim, Sookkyung Griffith, Boyce E. Department of Mathematics University of Utah Salt Lake CityUT United States Departments of Mathematics and Biomedical Engineering University of Utah Salt Lake CityUT United States Department of Mathematics University of North Carolina Chapel HillNC United States Department of Applied Physical Sciences University of North Carolina Chapel HillNC United States Department of Biomedical Engineering University of North Carolina Chapel HillNC United States Carolina Center for Interdisciplinary Applied Mathematics University of North Carolina Chapel HillNC United States Department of Mathematical Sciences University of Cincinnati CincinnatiOH United States Computational Medicine Program University of North Carolina School of Medicine Chapel HillNC United States McAllister Heart Institute University of North Carolina School of Medicine Chapel HillNC United States

Microorganism motility often takes place within complex, viscoelastic fluid environments, e.g., sperm in cervicovaginal mucus and bacteria in biofilms. In such complex fluids, strains and stresses generated by the microorganism are stored and relax across a spectrum of length and time scales and the complex fluid can be driven out of its linear response regime. Phenomena not possible in viscous media thereby arise from feedback between the swimmer and the complex fluid, making swimming efficiency co-dependent on the propulsion mechanism and fluid properties. Here we parameterize a flagellar motor and filament properties together with elastic relaxation and nonlinear shear-thinning properties of the fluid in a computational immersed boundary model. We then explore swimming efficiency, defined as a particular flow rate divided by the torque required to spin the motor, over this parameter space. Our findings indicate that motor efficiency (measured by the volumetric flow rate) can be boosted or degraded by relatively moderate or strong shear-thinning of the viscoelastic environment. Copyright © 2023, The Authors. All rights reserved.

关键词： Shear thinning

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engineering Choroid Plexus-on-A-Chip with Oscillatory Flow for Modeling Brain Metastasis

SSRN

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SSRN 2023年

作者： Lim, Jungeun Rhee, Stephen Choi, Hyeri Lee, Jungseub Kuttappan, Shruthy Nguyen, Tri Tho Yves Kim, Yongtae Jeon, Noo Li School of Mechanical Engineering Seoul National University Seoul08826 Korea Republic of George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology North Ave NW AtlantaGA30332 United States Interdisciplinary Program in Bioengineering Seoul National University Seoul08826 Korea Republic of Institute of Advanced Machinery and Design Seoul National University Seoul08826 Korea Republic of Parker H. Petit Institute for Bioengineering and Bioscience Georgia Institute of Technology AtlantaGA30332 United States Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology AtlantaGA30332 United States Institute for Electronics and Nanotechnology Georgia Institute of Technology AtlantaGA30332 United States

The human brain choroid plexus (ChP) is a highly organized secretory tissue with a complex vascular system and epithelial layers in the ventricles of the brain. The ChP is the body’s principal source of cerebrospinal fluid (CSF) and also functions as a barrier separating the blood from CSF, where the movement of CSF through the body is pulsatile in nature. It has been challenging to recreate the specialized architecture and dynamics of the ChP with a physiologically relevant microenvironment. Here, we recapitulated the ChP structure by developing a microfluidic chip with established design rules and CSF dynamics. Human ChP cells were cultured in the device with an engineered brain-specific extracellular matrix (ECM). The drug screening capabilities of our human ChP-on-a-chip were observed through physiologically relevant drug responses from breast cancer cells spread in the ChP. ChP immune response was also recapitulated in this device shown through the motility and cytotoxic effects of macrophages, the most prevalent immune cells in the ChP. Our human ChP-on-a-chip can facilitate understanding of ChP pathophysiology and aid in therapeutics development to treat cancers metastasized into choroid plexus. © 2023, The Authors. All rights reserved.

关键词： Cerebrospinal fluid

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