Person:
Feldman, Charles Lawrence

Profile Picture

Email Address

AA Acceptance Date

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Feldman

First Name

Charles Lawrence

Name

Feldman, Charles Lawrence
Author's Publications: search.filters.isAuthorOfPublication.80bb3c3a-ac51-4446-950b-df11b3bde35c

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Publication
    Hydrokinetic Approach to Large-Scale Cardiovascular Blood Flow
    (Elsevier, 2010) Melchionna, Simone; Bernaschi, Massimo; Succi, Sauro; Kaxiras, Efthimios; Rybicki, Frank John; Mitsouras, Dimitris; Coskun, Ahmet U.; Feldman, Charles Lawrence
    We present a computational method for commodity hardware-based clinical cardiovascular diagnosis based on accurate simulation of cardiovascular blood flow. Our approach leverages the flexibility of the Lattice Boltzmann method to implementation on high-performance, commodity hardware, such as Graphical Processing Units. We developed the procedure for the analysis of real-life cardiovascular blood flow case studies, namely, anatomic data acquisition, geometry and mesh generation, flow simulation and data analysis and visualization. We demonstrate the usefulness of our computational tool through a set of large-scale simulations of the flow patterns associated with the arterial tree of a patient which involves two hundred million computational cells. The simulations show evidence of a very rich and heterogeneous endothelial shear stress pattern (ESS), a quantity of recognized key relevance to the localization and progression of major cardiovascular diseases, such as atherosclerosis, and set the stage for future studies involving pulsatile flows.
  • Thumbnail Image
    Publication
    Thin-Capped Atheromata With Reduced Collagen Content in Pigs Develop in Coronary Arterial Regions Exposed to Persistently Low Endothelial Shear Stress
    (Ovid Technologies (Wolters Kluwer Health), 2013) Koskinas, K. C.; Sukhova, Galina; Baker, A. B.; Papafaklis, M. I.; Chatzizisis, Y. S.; Coskun, A. U.; Quillard, T.; Jonas, M.; Maynard, C.; Antoniadis, Antonios; Shi, Guo-Ping; Libby, Peter; Edelman, Elazer; Feldman, Charles Lawrence; Stone, Peter
    Objective—The mechanisms promoting the focal formation of rupture-prone coronary plaques in vivo remain incompletely understood. This study tested the hypothesis that coronary regions exposed to low endothelial shear stress (ESS) favor subsequent development of collagen-poor, thin-capped plaques. Approach and Results—Coronary angiography and 3-vessel intravascular ultrasound were serially performed at 5 consecutive time points in vivo in 5 diabetic, hypercholesterolemic pigs. ESS was calculated along the course of each artery with computational fluid dynamics at all 5 time points. At follow-up, 184 arterial segments with previously identified in vivo ESS underwent histopathologic analysis. Compared with other plaque types, eccentric thin-capped atheromata developed more in segments that experienced lower ESS during their evolution. Compared with lesions with higher preceding ESS, segments persistently exposed to low ESS (<1.2 Pa) exhibited reduced intimal smooth muscle cell content; marked intimal smooth muscle cell phenotypic modulation; attenuated procollagen-I gene expression; increased gene and protein expression of the interstitial collagenases matrix-metalloproteinase-1, -8, -13, and -14; increased collagenolytic activity; reduced collagen content; and marked thinning of the fibrous cap. Conclusions—Eccentric thin-capped atheromata, lesions particularly prone to rupture, form more frequently in coronary regions exposed to low ESS throughout their evolution. By promoting an imbalance of attenuated synthesis and augmented collagen breakdown, low ESS favors the focal evolution of early lesions toward plaques with reduced collagen content and thin fibrous caps—2 critical determinants of coronary plaque vulnerability.
  • Thumbnail Image
    Publication
    Evaluation of Artery Visualizations for Heart Disease Diagnosis
    (Institute of Electrical and Electronics Engineers, 2011) Borkin, Michelle; Gajos, Krzysztof; Randles, Amanda Elizabeth; Mitsouras, Dimitrios; Melchionna, Simone; Rybicki, Frank John; Feldman, Charles Lawrence; Pfister, Hanspeter
    Heart disease is the number one killer in the United States, and finding indicators of the disease at an early stage is critical for treatment and prevention. In this paper we evaluate visualization techniques that enable the diagnosis of coronary artery disease. A key physical quantity of medical interest is endothelial shear stress (ESS). Low ESS has been associated with sites of lesion formation and rapid progression of disease in the coronary arteries. Having effective visualizations of a patient's ESS data is vital for the quick and thorough non-invasive evaluation by a cardiologist. We present a task taxonomy for hemodynamics based on a formative user study with domain experts. Based on the results of this study we developed HemoVis, an interactive visualization application for heart disease diagnosis that uses a novel 2D tree diagram representation of coronary artery trees. We present the results of a formal quantitative user study with domain experts that evaluates the effect of 2D versus 3D artery representations and of color maps on identifying regions of low ESS. We show statistically significant results demonstrating that our 2D visualizations are more accurate and efficient than 3D representations, and that a perceptually appropriate color map leads to fewer diagnostic mistakes than a rainbow color map.