EVALUATIONS OF PROSTHETIC CARDIAC VALVES--IN VIVO STUDIES

摘要：本项目的研究是对正在进行的开发的研究 幼体活体原位动物模型系统的建立和应用 用于评估心脏瓣膜和心血管血流动力学的绵羊。 这些研究使用了多学科的调查技术： 外科-生理学、形态学和病理学、生物力学和 物理和化学科学。前几年的研究表明 集中于常规的水力/血流动力学评估 正常心脏瓣膜和人工心脏瓣膜替代物，以及 根据形态和物理特征，钙化性变性 生物瓣膜。本年度的努力强调了 心腔内血流动力学定量评价冠脉狭窄程度的研究 反流性病变。这些研究表明：1)观察到的 使用动量连续性保持原理的收敛流可以 可用于心腔内血流量的定量检测 返流性病变；以及2)明确两个空间 (几何)和时间(脉动性)特征在 将流体力学的基本物理理论应用于 心脏瓣膜血流动力学的复杂性。

SUMMARY: The studies of this project are those of the ongoing development and application of an in vivo, in situ animal model system using juvenile sheep for evaluating cardiac valves and cardiovascular flow dynamics. The studies use multiple disciplines of investigative techniques: surgery, -physiology, morphology and pathology, biomechanics, and the physical and chemical sciences. Previous years' studies have concentrated upon conventional hydraulic/hemodynamic evaluations of normal cardiac valves and prosthetic cardiac valvular substitutes, and upon morphologic and physical characterization the calcific degeneration of bioprosthetic valves. Efforts during the current year have emphasized studies of intracardiac flow dynamics for quantifying stenotic and regurgitant lesions. These studies demonstrate: 1) that observations of convergent flow using principles of momentum continuity preservation may be used to quantitate intracardiac flow volumes for both stenotic and regurgitant lesions; and 2) that clarification of both spatial (geometric) and temporal (pulsatility) characteristics are important in applying fundamental physical theories of fluid mechanics to the complexities of cardiac valvular flow dynamics.