Measurement of tissue and hemodynamic wave phenomena in cardiac function

由于正常心脏功能的复杂性，以及获取足够真实功能描述的高质量体内数据的困难，从工程学的角度对心脏力学和血流的研究是具有挑战性的。不足为奇的是，我们的心脏如何工作的基本方面仍然没有被描述。在拟议的计划中，特别令人感兴趣的是心脏功能中“波”的重要性，即心肌中的机械波和在血液中传播的压力波。波通常在血管中被观察到，例如，引起通常在手腕处测量的脉搏，但波在心脏中的表现还不是很清楚。我们认为，没有波形描述就不能准确地描述心脏功能本身的基本方面，这将代表目前对心脏的生物力学描述的转变。高时间和高空间分辨率的成像数据(来自磁共振成像)将被采集和处理，以评估心脏中肌肉应变随时间和空间的模式，这对于研究肌肉中的波的传播是必要的。心脏血池内的类似测量将被用来显示心脏的波状运动如何在血液中产生类似的波动模式，最终驱动我们身体所依赖的血液流动。这项工作的长期目标是开发工具来研究心脏和血液运动，并描述工作心脏的真实机械和流体动力学，这最终是理解许多心脏疾病中正常功能和异常功能所必需的。

The study of the cardiac mechanics and blood flow is challenging from an engineering perspective due to the complexity of normal heart function and the difficulty in acquiring high quality in-vivo data that is sufficient for realistic descriptions of function. Not surprisingly there remain fundamental aspects of how our heart works that are not described. Of particular interest in the proposed program is the importance of "waves" in heart function, both mechanical waves in the heart muscle and pressure waves that travel in the blood. Waves are commonly observed in the blood vessels, giving rise to the pulse commonly measured at ones wrist, for example, but the manifestation of waves in the heart is not well understood. We propose that fundamental aspects of heart function itself cannot be accurately described without a wave description, which would represent a shift in the current biomechanical descriptions of the heart. High temporal and high spatial resolution imaging data (from magnetic resonance imaging) will be acquired and processed to evaluate the patterns of muscle strain over time and space in the heart that are necessary to study the propagation of waves within the muscle. Similar measurements within the blood pool in the heart will be used to show how wave-like motion of the heart gives rise to comparable wave patterns in the blood which ultimately drive the blood flow that our bodies depend upon. The long term goals of this work are to develop tools to study heart and blood motion and to describe the realistic mechanical and fluid dynamics of the working heart, which ultimately are necessary to understand both normal function and abnormal function in the many diseases of the heart.