Ochsner Gregor, Wilhelm Markus J, Amacher Raffael, Petrou Anastasios, Cesarovic Nikola, Staufert Silvan, Röhrnbauer Barbara, Maisano Francesco, Hierold Christofer, Meboldt Mirko, Schmid Daners Marianne
From the *pd|z Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland; †Department of Cardiovascular Surgery, University Hospital Zurich and University of Zurich, Zurich, Switzerland; ‡Wyss Translational Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland; §Division for Surgical Research, University Hospital Zurich and University of Zurich, Zurich, Switzerland; and ¶Micro- and Nanosystems Group, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland.
ASAIO J. 2017 Sep/Oct;63(5):568-577. doi: 10.1097/MAT.0000000000000533.
Turbodynamic left ventricular assist devices (LVADs) provide a continuous flow depending on the speed at which the pump is set, and do not adapt to the changing requirements of the patient. The limited adaptation of the pump flow (PF) to the amount of venous return can lead to ventricular suction or overload. Physiologic control may compensate such situations by an automatic adaptation of the PF to the volume status of the left ventricle. We evaluated two physiologic control algorithms in an acute study with eight healthy pigs. Both controllers imitate the Frank-Starling law of the heart and are based on a measurement of the left ventricular volume (LVV) or pressure (LVP), respectively. After implantation of a modified Deltastream DP2 blood pump as an LVAD, we tested the responses of the physiologic controllers to hemodynamic changes and compared them with the response of the constant speed (CS) mode. Both physiologic controllers adapted the pump speed (PS) such that the flow was more sensitive to preload and less sensitive to afterload, as compared with the CS mode. As a result, the risk for suction was strongly reduced. Five suction events were observed in the CS mode, one with the volume-based controller and none with the pressure-based controller. The results suggest that both physiologic controllers have the potential to reduce the number of adverse events when used in the clinical setting.
涡轮动力左心室辅助装置（LVAD）根据泵的设定速度提供持续血流，无法适应患者不断变化的需求。泵流量（PF）对静脉回流量的适应性有限，可能导致心室抽吸或过载。生理控制可通过使PF自动适应左心室容量状态来补偿此类情况。我们在一项针对八只健康猪的急性研究中评估了两种生理控制算法。两种控制器均模仿心脏的Frank-Starling定律，分别基于左心室容积（LVV）或压力（LVP）的测量。植入改良的Deltastream DP2血泵作为LVAD后，我们测试了生理控制器对血流动力学变化的反应，并将其与恒速（CS）模式的反应进行比较。与CS模式相比，两种生理控制器均能调节泵速（PS），使血流对前负荷更敏感，对后负荷更不敏感。结果，抽吸风险大大降低。在CS模式下观察到五次抽吸事件，基于容积的控制器出现一次，基于压力的控制器未出现。结果表明，两种生理控制器在临床应用中均有可能减少不良事件的发生次数。
