Institute of Medicine, School of Medicine, Chung-Shan Medical University; Department of Internal Medicine, Chung-Shan Medical University Hospital, Taichung 402, Taiwan.
Department of Computer Science and Information Engineering, Chaoyang University of Technology, Taichung 413, Taiwan.
Sensors (Basel). 2018 Oct 12;18(10):3420. doi: 10.3390/s18103420.
The pulse contour method is often used with the Windkessel model to measure stroke volume. We used a digital pressure and flow sensors to detect the parameters of the Windkessel model from the pulse waveform. The objective of this study was to assess the stability and accuracy of this method by making use of the passive leg raising test. We studied 24 healthy subjects (40 ± 9.3 years), and used the Medis CS 1000, an impedance cardiography, as the comparing reference. The pulse contour method measured the waveform of the brachial artery by using a cuff. The compliance and resistance of the peripheral artery was detected from the cuff characteristics and the blood pressure waveform. Then, according to the method proposed by Romano et al., the stroke volume could be measured. This method was implemented in our designed blood pressure monitor. A passive leg raising test, which could immediately change the preloading of the heart, was done to certify the performance of our method. The pulse contour method and impedance cardiography simultaneously measured the stroke volume. The measurement of the changes in stroke volume using the pulse contour method had a very high correlation with the Medis CS 1000 measurement, the correlation coefficient of the changed ratio and changed differences in stroke volume were ² = 0.712 and ² = 0.709, respectively. It was shown that the stroke volume measured by using the pulse contour method was not accurate enough. But, the changes in the stroke volume could be accurately measured with this pulse contour method. Changes in stroke volume are often used to understand the conditions of cardiac preloading in the clinical field. Moreover, the operation of the pulse contour method is easier than using impedance cardiography and echocardiography. Thus, this method is suitable to use in different healthcare fields.
脉搏轮廓法常与 Windkessel 模型结合，用于测量心搏量。我们使用数字压力和流量传感器，从脉搏波形中检测 Windkessel 模型的参数。本研究的目的是利用被动抬腿试验评估该方法的稳定性和准确性。我们研究了 24 名健康受试者（40 ± 9.3 岁），并使用 Medis CS 1000 阻抗心动图作为比较参考。脉搏轮廓法使用袖带测量肱动脉的波形。通过袖带特性和血压波形检测外周动脉的顺应性和阻力。然后，根据 Romano 等人提出的方法，可以测量心搏量。该方法在我们设计的血压监测仪中实现。进行被动抬腿试验，可立即改变心脏的前负荷，以验证我们方法的性能。脉搏轮廓法和阻抗心动图同时测量心搏量。脉搏轮廓法测量心搏量变化与 Medis CS 1000 测量具有很高的相关性，心搏量变化比和变化差异的相关系数分别为² = 0.712 和² = 0.709。结果表明，使用脉搏轮廓法测量的心搏量不够准确。但是，使用这种脉搏轮廓法可以准确测量心搏量的变化。心搏量变化常用于了解临床领域中心脏前负荷的情况。此外，脉搏轮廓法的操作比使用阻抗心动图和超声心动图更简单。因此，该方法适用于不同的医疗保健领域。
