Physiological mechanisms underlying real-world dynamic cardiorespiratory and cerebrovascular control

现实世界动态心肺和脑血管控制的生理机制

• 批准号: RGPIN-2018-04729
• 负责人: Hughson, Richard
• 金额: $ 3.42万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=713041
• 关键词: Physiological; mechanisms; underlying; real; world

For 40 years, my NSERC-supported research program has contributed to the training of exceptional HQP through exploring the complex dynamic physiological adaptations of the cardiorespiratory and cerebrovascular systems to challenges typical of daily life. Three major inter-related themes with 7 hypotheses provide details on our work for the next five years. Theme 1, involving PhD students, post-docs and undergraduate students, will extend recent work using wearable sensors and machine learning to predict the time course of change of aerobic metabolism during transitions in exercise intensity and during activities of daily living. We will extend the research to test the hypothesis (1.1) that these methods will extract indicators of aerobic system dynamics from higher intensities of exercise that require complex considerations of nonlinear system dynamics. These new models will have application to high intensity exercise such as athletic training, and to studies of astronauts. We have confirmed access to 8 astronauts over the next 5 years while they are wearing a Canadian-designed smart shirt allowing us to test the hypothesis (1.2) that our new methods of analysis will be sensitive to changes in fitness with spaceflight and recovery. Theme 2 experiments involving post-docs and training senior undergraduates will develop and apply coded hemodynamic imaging, a wide-field camera assessment of infrared signals from humans. This system monitors vascular pulsatility without contact of the skin surface. We will test the following hypotheses. (2.1) That we can track changes in central venous pressure and its pulsatility induced by changes in body position and central blood volume. (2.2) That arrival time of arterial pulsations at different locations on the body can provide a non-contact method to assess arterial stiffness. (2.3) That changes in regional tissue oxygenation measured without skin contact will track traditional near infrared spectroscopy during manipulations of muscle O2 delivery. Theme 3 experiments involving MSc students, post-docs and undergraduate students, will determine regulatory factors affecting arterial and cerebrovascular hemodynamics. We will test the hypothesis (3.1) that rapid drops in cerebral perfusion pressure will identify the point of zero flow coinciding with the theoretical construct known as critical closing pressure for the cerebral circulation under conditions that vary cerebral flow by changing arterial PCO2. Changes in arterial stiffness affect cerebrovascular pulsatility. We will test the hypothesis (3.2) that central artery stiffness is unaffected, but peripheral arteries will appear stiffer during acute interventions affecting neural control of the vascular system. These experiments provide outstanding opportunities to train HQP in an interdisciplinary environment linking key physiological questions to technological innovations.

40年来，我的NSERC支持的研究项目通过探索心肺和脑血管系统对日常生活中典型挑战的复杂动态生理适应，为训练特殊的HQP做出了贡献。三个相互关联的主题和7个假设提供了我们未来五年工作的细节。主题1涉及博士生、博士后和本科生，将扩展最近使用可穿戴传感器和机器学习来预测运动强度转变和日常生活活动期间有氧代谢变化的时间进程的工作。我们将扩展研究以检验假设(1.1)，即这些方法将从需要复杂考虑非线性系统动力学的较高强度的运动中提取有氧系统动力学的指标。这些新模型将应用于高强度运动，如运动训练，以及对宇航员的研究。我们已经证实，在接下来的5年里，我们可以接触到8名穿着加拿大设计的智能衬衫的宇航员，这让我们可以检验假设(1.2)，即我们的新分析方法将对太空飞行和恢复过程中体能的变化敏感。主题2实验涉及博士后和培训大四的本科生，将开发和应用编码血流动力学成像，这是一种对来自人类的红外信号进行广域相机评估的方法。该系统无需接触皮肤表面即可监测血管搏动。我们将检验以下假设。(2.1)我们可以跟踪由于身体位置和中心血容量的变化而引起的中心静脉压及其搏动性的变化。(2.2)动脉搏动在人体不同部位的到达时间可以提供一种非接触式的方法来评估动脉僵硬。(2.3)在没有皮肤接触的情况下测量的局部组织氧合的变化将跟踪肌肉氧气输送操作过程中的传统近红外光谱。主题3实验涉及理科学生、博士后和本科生，将确定影响动脉和脑血管血流动力学的调节因素。我们将检验假设(3.1)，即在通过改变动脉二氧化碳分压来改变脑流量的条件下，脑灌流压力的快速下降将识别出与被称为脑循环临界关闭压的理论构造一致的零流点。动脉僵硬的变化会影响脑血管的搏动。我们将检验假设(3.2)，即中央动脉僵硬不受影响，但在影响血管系统神经控制的急性干预期间，外周动脉会显得更僵硬。这些实验提供了在将关键生理学问题与技术创新联系起来的跨学科环境中培训HQP的绝佳机会。