Abstract：
Heart failure is a major health risk, and with limited availability of donor organs, there is an increasing need for developing cardiac assist devices (CADs). Mock circulatory loops (MCL) are an important in-vitro test platform for CAD\'s performance assessment and optimisation. The MCL is a lumped parameter model constructed out of hydraulic and mechanical components aiming to simulate the native cardiovascular system (CVS) as closely as possible. Further development merged MCLs and numerical circulatory models to improve flexibility and accuracy of the system; commonly known as hybrid MCLs. A total of 128 MCLs were identified in a literature research until 25 September 2020. It was found that the complexity of the MCLs rose over the years, recent MCLs are not only capable of mimicking the healthy and pathological conditions, but also implemented cerebral, renal and coronary circulations and autoregulatory responses. Moreover, the development of anatomical models made flow visualisation studies possible. Mechanical MCLs showed excellent controllability and repeatability, however, often the CVS was overly simplified or lacked autoregulatory responses. In numerical MCLs the CVS is represented with a higher order of lumped parameters compared to mechanical test rigs, however, complex physiological aspects are often simplified. In hybrid MCLs complex physiological aspects are implemented in the hydraulic part of the system, whilst the numerical model represents parts of the CVS that are too difficult to represent by mechanical components per se. This review aims to describe the advances, limitations and future directions of the three types of MCLs.
摘要：
心力衰竭是一个主要的健康风险，由于供体器官的供应有限，越来越需要开发心脏辅助装置(CAD)。模拟循环回路（MCL）是CAD性能评估和优化的重要体外测试平台。MCL是由液压和机械组件构建的集总参数模型，旨在尽可能接近地模拟天然心血管系统（CVS）。进一步的开发合并了MCL和数值循环模型，以提高系统的灵活性和准确性；通常称为混合MCL。直到2020年9月25日，在一项文献研究中总共发现了128个MCL。发现MCL的复杂性多年来不断上升，最近的MCL不仅能够模仿健康和病理状况，但也实施了大脑，肾和冠状动脉循环和自动调节反应。此外，解剖模型的发展使得流动可视化研究成为可能。机械MCL表现出优异的可控性和可重复性，然而,通常CVS过于简化或缺乏自动监管反应。在数值MCL中，与机械试验台相比，CVS用更高阶的集总参数表示，然而,复杂的生理方面往往被简化。在混合MCL中，系统的液压部分实现了复杂的生理方面，而数值模型代表了CVS的一部分，这些部分很难由机械部件本身来表示。这篇综述旨在描述这些进展，三种类型MCL的局限性和未来发展方向。
