Computer Simulations and Medical Imaging Towards Healing Damaged Hearts.

我们的心脏是一个非凡的泵，它在我们生命的每一秒都在跳动，为我们的身体提供富含氧气的血液。然而，某些疾病，如心脏病发作，可能会引发危险的恶性循环，阻碍心脏的泵血功能，通常被称为心力衰竭。这种疾病影响了3%-5%的成年人，但在老年人中尤其致命，50%的人在确诊后5年内死亡，这每年给加拿大经济造成28亿美元的损失。虽然心力衰竭是一种复杂的疾病，涉及许多细胞和分子机制，但整体变化与生物力学条件的变化有关，如液体和结构应力。不幸的是，常规的医学图像，如CTA或MRI，无法提供这些压力。因此，大多数临床决策都是基于解剖学和人群平均生物标志物。缺乏为患者量身定做的方法，并通过工程设计进行优化，最终导致不理想的干预措施和长期并发症。在这项拟议的研究中，我们将调查生物力学压力在心力衰竭中所起的作用，并开发计算和实验方法，为患者提供量身定制的治疗方案。为达致这些目标，我们会推行三项措施。首先，我们将开发新的计算模拟方法，将物理方程集成到医学图像中以估计生物力学应力，这最终将使我们能够虚拟地执行干预以优化治疗计划。第二项举措将侧重于模拟方法的验证。在这项计划中，我们将开发出逼真的3D打印心脏，并将它们连接到液压泵上。通过实验模拟这些3D打印心脏的流动，我们将获得速度、压力和其他量，并与计算模拟方法进行比较。该实验平台将提供进行手术前培训的机会，并在植入患者之前测试新的医疗设备(例如心脏瓣膜)。第三项计划将探索不同的生物力学压力如何改变心脏功能。首先，我们将诱导小鼠心力衰竭，并利用超声系统研究心功能的变化。其次，我们将制造一个系统来容纳新鲜收获的小鼠心脏，并通过泵施加不同的生物力学压力。这些方法将使我们能够探索生物力学应力的变化(如湍流与光滑)如何改变心脏组织结构。生物力学压力被认为在心脏病和衰竭中起着关键作用；然而，加拿大和全球卫生行业缺乏针对患者量身定做的方法来估计这些压力并将其用于临床决策。拟议的基础工程研究将为工程师和医生提供为患者量身定做的方法，以更好地诊断和治疗，并最终改善心力衰竭患者的预后。

Our heart is a remarkable pump that beats every second of our lives to provide oxygen-rich blood to our body. However, certain diseases, such as heart attack, can initiate a dangerous and vicious cycle that can impede the pumping function of the heart, generally known as a heart failure. This disease affects 3-5% of adult population but is particularly fatal in older adults, with 50% dying within 5 years of diagnosis, which costs the Canadian economy $2.8 Billion each year. Although heart failure is a complex disease, and involves many cellular and molecular mechanisms, the global alterations are linked to changes in biomechanical conditions, such as fluid and structural stresses. Unfortunately, routine medical images, such as CTA or MRI, are unable to provide these stresses. Hence, most clinical decisions are based on anatomical and population-averaged biomarkers. The lack of patient-tailored approaches, optimized with engineering design, ultimately lead to suboptimal interventions and long-term complications. In the proposed research, we will investigate the role that biomechanical stresses play in heart failure, and develop computational and experimental methods to provide patient-tailored treatment options. Towards these goals, we will pursue three initiatives. First, we will develop novel computational simulation methods that integrate physical equations into medical images to estimate biomechanical stresses, which will ultimately allow us to virtually perform interventions to optimize treatment planning. Second initiative will focus on validation of the simulation methods. In this initiative, we will develop realistic 3D printed hearts, and attach these to a hydraulic pump. By experimentally simulating flow through these 3D printed hearts, we will obtain velocity, pressures and other quantities to compare against computational simulation methods. The experimental platform will open up opportunities to perform pre-surgical training and also test novel medical devices (e.g. heart valves) before implanting in patients. The third initiative will explore how distinct biomechanical stresses alter heart function. First, we will induce heart failure in mice and study the changes in heart function using ultrasound system. Second, we will fabricate a system to house freshly harvested mice hearts, and impose distinct biomechanical stresses through a pump. These methods will allow us to explore how variation in biomechanical stresses (e.g. turbulent vs smooth) alter heart tissue structure. Biomechanical stresses are thought to play a key role in heart disease and failure; however, Canadian and global health industry lacks patient-tailored methodologies that can estimate these stresses and utilize them in clinical decision-making. The proposed basic engineering research will provide engineers and doctors with patient-tailored approaches to better diagnose and treat, and ultimately improve outcomes of heart failure patients.