CARDIAC ELECTROPHYSIOLOGIC IMAGING FROM POTENTIAL FIELDS

拟议工作的总体目标是制定和评估 用于提供稳健的空间估计的改进方法 心脏电生理特性的分布 胞外电位场。这些研究的基本原理是 需要敏感的技术来更好地表征心脏 直接(侵入性)和间接(非侵入性)行为 测量，对于评估疾病尤其重要 信号幅度低的心肌，通常 分馏的。具体目标包括：1)发展和 评价一种新技术，多参考直方图(MRH)， 用于提供局部、心肌激活和 恢复时间，2)评估MRHs对划定的效用 来自无源(非去极化)组织的电活性 检测多个封闭但未耦合的激活前沿，3) 二维和三维宏观水平心肌的特征 各向异性和非均质性通过电学和统计手段， 4)利用非线性时间的方法的发展和评估 对齐、空间相关性与心电图偏转 定量比较细微差异并发现细微差异的领域 局部和全球心脏行为的变化，5) 对测量不确定度、数据 维度和样本完备性影响信息 从心脏转移到体表，以及6)应用 关于早期本地化问题的逆技术 心外膜和腔室电位引起的心室除极 分配。目标将通过理论和 实验研究。拟议工作的意义在于 改进的心脏定征方法的可能性 宏观层面的电生理学将导致改善 区分正常和异常的心脏电活动， 减少心脏疾病解释中的不确定性 电信号，以及改进的心脏事件评估 体表电位。这项工作与健康的相关性在于 需要敏感的、非侵入性的方法来检测和 描述早期和中期的心脏疾病和状况 他们的进化。

The overall objective of proposed work is to develop and evaluate improved methods for providing robust estimates of spatial distributions of cardiac electrophysiologic properties from extracellular potential fields. The rationale for the studies is the need for sensitive techniques to better characterize cardiac behavior from direct (invasive) and indirect (non-invasive) measurements, particularly important for assessing diseased myocardium where signals have low amplitude and are often fractionated. Specific objectives include: 1) development and evaluation of a new technique, multi-reference histograms (MRHs), for providing estimates of local, myocardial activation and recovery times, 2) assessment of utility of MRHs for delineating electrically active from passive (non-depolarizing) tissue and for detecting multiple, close but uncoupled activation fronts, 3) characterization of 2 and 3 dimensional, macro-level myocardial anisotropy and inhomogeneity by electrical and statistical means, 4) development and evaluation of methods using non-linear time alignment, spatial correlation and electrocardiographic deflection areas to quantitatively compare subtle differences and detect small changes in cardiac behavior, both locally and globally, 5) assessment of the extent to which measurement uncertainty, data dimensionality and sampling completeness affect information transfer from the heart to the body surface, and 6) application of inverse techniques to the problem of localizing early ventricular depolarization from epicardial and cavitary potential distributions. Objectives will be met through theoretical and experimental studies. Significance of the proposed work lies in the likelihodd that improved methods for characterizing cardiac electrophysiology at the macro level will lead to improvement in distinguishing normal and abnormal cardiac electrical activity, reduction of uncertainty in the interpretation of cardiac electrical signals, and improved assessment of cardiac events from body surface potentials. Health relatedness of the work lies in the need for sensitive, non-invasive methods to detect and characterize cardiac diseases and conditions early in and during their evolution.