Nawrat Z, Malota Z
Foundation for Development of Cardiac Surgery and Silesian Medical Academy, Zabrze, Poland.
Artif Organs. 1998 Oct;22(10):898-904. doi: 10.1046/j.1525-1594.1998.05074.x.
The energy dissipated in blood or on a total artificial heart (TAH) chamber's elements directly or indirectly decreases the biological or technical safety of the TAH's work. The energetic analysis of the Polish total artificial heart (POLTAH) external work with the objective of estimating the valve and membrane roles in energy dissipation has been performed. The simulation of left and right artificial heart chamber work under physiological conditions using a self-constructed physical model of the circulatory system has been performed for the full systole percent and frequency range and for different valves. The total energy dissipated on valves equals 15-30% of the chambers' work value. Energy losses on valves are influenced by the driving mode. The usage of inappropriate systolic and diastolic times increases the value of the energy dissipated on the membrane and on valves in the overall energy balance. The absolute value of the energy dissipated on the valves increases with the increase of the cycle time and depends on the valve type. The energy dissipated on the outlet valve decreases with the frequency (if the remaining driving parameters are kept constant) and for 150 bpm is nearly 3 times lower than that for 30 bpm. The energy dissipated on the membrane equals 10-50% of the TAH's work during systole, depending on the driving parameters. The filling process is assisted by the pressure from the atrium, and a great amount of energy during the diastolic period is consumed by the start of the membrane movement. We have also estimated the influence of the driving parameters on the valves' functions, measuring the acoustic wave intensity. The conclusions drawn are of a general character; they are applicable to all membrane, pneumatically powered blood pumps.
血液中或全人工心脏（TAH）腔室元件上直接或间接耗散的能量会降低TAH工作的生物安全性或技术安全性。已对波兰全人工心脏（POLTAH）的外部工作进行了能量分析，目的是评估瓣膜和隔膜在能量耗散中的作用。使用自行构建的循环系统物理模型，对不同瓣膜在整个收缩期百分比和频率范围内的生理条件下左右人工心脏腔室的工作进行了模拟。瓣膜上耗散的总能量等于腔室工作值的15%-30%。瓣膜上的能量损失受驱动模式影响。使用不适当的收缩期和舒张期时间会增加隔膜和瓣膜在总能量平衡中耗散的能量值。瓣膜上耗散的能量绝对值随循环时间的增加而增加，并取决于瓣膜类型。出口瓣膜上耗散的能量随频率降低（如果其余驱动参数保持不变），在150次/分钟时比30次/分钟时低近3倍。隔膜上耗散的能量在收缩期等于TAH工作的10%-50%，具体取决于驱动参数。充盈过程由心房压力辅助，舒张期大量能量在隔膜运动开始时被消耗。我们还通过测量声波强度评估了驱动参数对瓣膜功能的影响。得出的结论具有普遍性；它们适用于所有隔膜式气动血泵。
