CARDIAC ELECTROPHYSIOLOGIC IMAGING FROM POTENTIAL FIELDS

拟议工作的总体目标是制定和评价 用于提供空间的鲁棒估计的改进方法 心脏电生理特性的分布 细胞外电位场 研究的基本原理是 需要灵敏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，特别是重要的评估疾病 心肌，其中信号具有低幅度并且通常 分馏 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的估计， 恢复时间，2）评估MRH用于描绘 从无源（非去极化）组织电激活， 检测多个接近但未耦合的激活前沿，3） 2维和3维宏观水平心肌的表征 各向异性和不均匀性， 4)使用非线性时间的方法的开发和评价 对齐、空间相关和心电图偏转 定量比较细微差异和检测小 局部和全局心脏行为的变化，5） 测量不确定度、数据 维度和抽样完整性影响信息 从心脏转移到体表，以及6）施用 早期定位问题的逆向技术 心外膜和腔电位心室除极 分布。 目标将通过理论和 实验研究 建议工作的意义在于 改进的心脏特征化方法 宏观水平的电生理学将导致改善， 区分正常和异常心脏电活动， 减少心脏病诊断的不确定性 电信号，并改善对心脏事件的评估， 体表电位 工作的健康相关性在于 需要灵敏的、非侵入性的方法来检测和 表征心脏疾病和状况的早期和期间 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.