Swamy Gokul, Xu Da, Mukkamala Ramakrishna
Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:2362-4. doi: 10.1109/IEMBS.2009.5335013.
We previously proposed a new technique to estimate the physiologically and clinically more relevant central aortic pressure (AP) waveform from a conveniently and safely measured peripheral artery pressure (PAP) waveform distorted by wave reflections. In contrast to conventional generalized transfer function (GTF) techniques, the technique is able to adapt the transfer function relating PAP to AP to the inter-patient and temporal variability of the arterial tree by defining it through a tube model and invoking the fact that aortic flow is negligible during diastole to estimate the unknown model parameters. We conducted feasibility testing of this adaptive transfer function technique here with respect to radial artery pressure (RAP) waveforms, for the first time, as well as femoral artery pressure (FAP) waveforms from four swine instrumented with AP catheters during several hemodynamic conditions. Our results showed that the AP waveforms estimated by the technique from the RAP and FAP waveforms were in superior agreement to the measured AP waveforms (overall respective errors of 4.1 and 4.8 mmHg) than the two unprocessed PAP waveforms (9.1 and 8.1 mmHg) and a previous GTF technique trained on a subset of the same data (5.0 and 5.8 mmHg).
我们之前提出了一种新技术，可从因波反射而失真的、方便且安全测量的外周动脉压（PAP）波形中，估算出在生理和临床方面更具相关性的中心主动脉压（AP）波形。与传统的广义传递函数（GTF）技术不同，该技术能够通过管模型定义将PAP与AP相关联的传递函数，以适应患者间和动脉树的时间变异性，并利用舒张期主动脉血流可忽略不计这一事实来估算未知的模型参数。我们首次在此针对桡动脉压（RAP）波形以及在多种血流动力学条件下植入了AP导管的四只猪的股动脉压（FAP）波形，对这种自适应传递函数技术进行了可行性测试。我们的结果表明，与两个未处理的PAP波形（误差分别为9.1和8.1 mmHg）以及基于同一数据子集训练的先前GTF技术（误差分别为5.0和5.8 mmHg）相比，该技术从RAP和FAP波形估算出的AP波形与测量的AP波形具有更好的一致性（总体误差分别为4.1和4.8 mmHg）。
