A Computationally Efficient Formal Optimization of Regional Myocardial Contractility in a Sheep With Left Ventricular Aneurysm
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- Kay Sun
- Department of Surgery, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Nielen Stander
- Livermore Software Technology Corporation, Livermore, CA
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- Choon-Sik Jhun
- Department of Surgery, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Zhihong Zhang
- Department of Surgery, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Takamaro Suzuki
- Department of Surgery, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Guan-Ying Wang
- Department of Radiology, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Maythem Saeed
- Department of Radiology, University of California, San Francisco, CA
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- Arthur W. Wallace
- Department of Anesthesia, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Elaine E. Tseng
- Department of Surgery, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Anthony J. Baker
- Department of Radiology, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- David Saloner
- Department of Radiology, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Daniel R. Einstein
- Biological Monitoring and Modeling, Pacific Northwest National Laboratory, Olympia, WA
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- Mark B. Ratcliffe
- Department of Surgery, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
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- Julius M. Guccione
- Department of Surgery, University of California, San Francisco, CA; Department of Veterans Affairs Medical Center, San Francisco, CA
説明
<jats:p>A noninvasive method for estimating regional myocardial contractility in vivo would be of great value in the design and evaluation of new surgical and medical strategies to treat and/or prevent infarction-induced heart failure. As a first step toward developing such a method, an explicit finite element (FE) model-based formal optimization of regional myocardial contractility in a sheep with left ventricular (LV) aneurysm was performed using tagged magnetic resonance (MR) images and cardiac catheterization pressures. From the tagged MR images, three-dimensional (3D) myocardial strains, LV volumes, and geometry for the animal-specific 3D FE model of the LV were calculated, while the LV pressures provided physiological loading conditions. Active material parameters (Tmax_B and Tmax_R) in the noninfarcted myocardium adjacent to the aneurysm (borderzone) and in the myocardium remote from the aneurysm were estimated by minimizing the errors between FE model-predicted and measured systolic strains and LV volumes using the successive response surface method for optimization. The significant depression in optimized Tmax_B relative to Tmax_R was confirmed by direct ex vivo force measurements from skinned fiber preparations. The optimized values of Tmax_B and Tmax_R were not overly sensitive to the passive material parameters specified. The computation time of less than 5 h associated with our proposed method for estimating regional myocardial contractility in vivo makes it a potentially very useful clinical tool.</jats:p>
収録刊行物
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- Journal of Biomechanical Engineering
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Journal of Biomechanical Engineering 131 (11), 111001-, 2009-10-16
ASME International