Mechanical Issues in Pulsatile Blood Flow

脉动血流的机械问题

• 批准号: RGPIN-2019-04749
• 负责人: Zamir, Mair
• 金额: $ 2.84万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=687374
• 关键词: Mechanical; Issues; Pulsatile; Blood; Flow

The aim of this proposal to gain insight into the underlying fluid dynamic design involved in each of the blood supply systems below, working in close collaboration with clinical researchers to ensure that the issues being addressed are pertinent.****1. Myocardial Perfusion. Vascular trees originating at the epicardium must reach highly active tissue deep within the ventricular wall in a specific pattern which is not fully understood. A pilot study in collaboration with the Mayo Clinic, in which we used a combination of micro-CT imaging and a dedicated vascular tree computer analysis program, has been successfully completed. The study was limited to vasculature on the macro scale and the aim was mainly to test the methodology. We plan now to use this methodology to study the microvasculature in a series of myocardial tissue biopsies. The subject is important for a better understanding of ischemic events within the myocardium.****2. Baroreflex Control of Blood Flow. The baroreflex mediates changes in heart rate in response to changes in blood pressure. I have an active collaboration with a neurovascular research group at Western in which I use time series analysis to examine the correlation between heart rate and blood pressure recordings. In a pilot study we showed that current theory of baroreflex function, based on an open-loop control model, is inconsistent with physiological data. Our aim is to formulate and test a closed-loop model. The subject is important in relation to the deterioration of baroreflex sensitivity with aging or disease.****3. Pulsatile Blood Flow Within the Rigid Confines of the Skull. Mechanics of this flow are not fully understood because of lack of access. Clinical focus is largely on intracranial pressure (ICP), the effects of which are still unclear. In a pilot study, in collaboration with the neurovascular group at Western, I used Fourier analysis to show that ICP is only one element in the mechanics of this flow, another is a combination of intravascular and extravascular compliance. My aim is to build an analytical model based on these early findings. The subject is important in relation to the underlying mechanics of concussion and hydrocephalus.****4. Uteroplacental Blood Flow. Blood supply to the uterus involves a group of spiral arteries which undergo dramatic transformation during pregnancy. I was invited by researchers at Washington University School of Medicine in St Louis MO for a collaborative study of the underlying fluid mechanics of this system. The results of a pilot study in which we examined the curvature and added length effects on the flow in a spiral artery has been completed. Our next step is to model the course of pregnancy whereby an increasing portion of the spiral artery is converted into an open funnel. My aim is to build a computerized model of the fluid dynamics of this spiral-funnel combination. The subject is important in relation to the failure of this blood supply system in preeclampsia.******

该提案的目的是深入了解以下每个血液供应系统所涉及的基础流体动力学设计，与临床研究人员密切合作，以确保所解决的问题是相关的。****1。心肌灌注。起源于心外膜的血管树必须以一种尚未完全了解的特定模式到达心室壁深处的高度活跃的组织。与梅奥诊所合作的一项试点研究已成功完成，其中我们结合使用了显微 CT 成像和专用血管树计算机分析程序。该研究仅限于宏观尺度的脉管系统，目的主要是测试该方法。我们现在计划使用这种方法来研究一系列心肌组织活检中的微血管系统。该主题对于更好地了解心肌内的缺血事件非常重要。****2。压力反射控制血流。压力感受反射根据血压的变化调节心率的变化。我与西部大学的一个神经血管研究小组积极合作，在该小组中我使用时间序列分析来检查心率和血压记录之间的相关性。在一项试点研究中，我们表明当前基于开环控制模型的压力反射功能理论与生理数据不一致。我们的目标是制定并测试闭环模型。该主题对于压力反射敏感性随衰老或疾病的恶化具有重要意义。****3。头骨刚性范围内的脉动血流。由于缺乏访问权限，这一流程的机制尚未被完全理解。临床焦点主要集中在颅内压（ICP）上，其影响仍不清楚。在一项与 Western 神经血管小组合作的试点研究中，我使用傅里叶分析表明 ICP 只是该流动机制中的一个要素，另一个要素是血管内和血管外顺应性的组合。我的目标是根据这些早期发现建立一个分析模型。该主题对于脑震荡和脑积水的基本机制很重要。****4。子宫胎盘血流量。子宫的血液供应涉及一组螺旋动脉，它们在怀孕期间经历巨大的转变。我受到密苏里州圣路易斯华盛顿大学医学院研究人员的邀请，对该系统的基础流体力学进行合作研究。我们检查了曲率和附加长度对螺旋动脉血流的影响的初步研究结果已经完成。我们的下一步是模拟怀孕过程，其中越来越多的螺旋动脉部分转变为开放漏斗。我的目标是建立这种螺旋漏斗组合的流体动力学计算机模型。该主题对于先兆子痫中血液供应系统的故障很重要。******