Gardner J F, Ignatoski M, Tasch U, Snyder A J, Geselowitz D B
Pennsylvania State University, University Park 16802.
J Biomech Eng. 1993 May;115(2):187-94. doi: 10.1115/1.2894120.
An adaptive technique for the estimation of the time history of aortic pressure (from applied voltage and position feedback) has been designed, implemented, and bench tested using the Penn State Electric Ventricular Assist Device (EVAD). This method, known in the field of automatic control as a dynamic observer, utilizes gains which were determined using experimental data collected while the EVAD was running on a mock circulatory system. An adaptive scheme provides the observer with a method of changing its initial conditions on a stroke-by-stroke basis which improves observer performance. In both determining the feedback gains and developing the adaptation scheme, a range of beat rates and pressure loads was taken into account to yield satisfactory observer performance over a range of operating conditions. The observer was implemented, its performance was verified in vitro and results are reported. In the six experimental operating conditions, the beat rate ranged from 56-104 beats per minute (bpm) and the span of the mean systolic aortic pressure was 10.7-18.7 kPa (80-140 mmHg). For these cases, the mean deviation between the actual and estimated aortic pressure during the latter two-thirds of systole was 0.41 kPa (3.1 mmHg).
一种用于估计主动脉压力随时间变化情况（基于施加电压和位置反馈）的自适应技术已经被设计、实现，并使用宾夕法尼亚州立大学电动心室辅助装置（EVAD）进行了台架测试。这种方法在自动控制领域被称为动态观测器，它利用了在EVAD在模拟循环系统上运行时收集的实验数据确定的增益。一种自适应方案为观测器提供了一种逐搏改变其初始条件的方法，从而提高观测器性能。在确定反馈增益和开发自适应方案时，考虑了一系列的心率和压力负荷，以便在一系列运行条件下获得令人满意的观测器性能。实现了该观测器，在体外验证了其性能并报告了结果。在六个实验操作条件下，心率范围为每分钟56 - 104次心跳（bpm），平均收缩期主动脉压力范围为10.7 - 18.7千帕（80 - 140毫米汞柱）。对于这些情况，在收缩期后三分之二期间实际主动脉压力与估计主动脉压力之间的平均偏差为0.41千帕（3.1毫米汞柱）。
