Vakily A, Parsaei H, Movahhedi M M, Sahmeddini M A
Department of Medical Physics and Engineering, Shiraz University of Medical Sciences, Shiraz, Iran.
Shiraz Anesthesiology and Critical Care Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
J Biomed Phys Eng. 2017 Jun 1;7(2):181-190. eCollection 2017 Jun.
Cardiac output (CO) is the total volume of blood pumped by the heart per minute and is a function of heart rate and stroke volume. CO is one of the most important parameters for monitoring cardiac function, estimating global oxygen delivery and understanding the causes of high blood pressure. Hence, measuring CO has always been a matter of interest to researchers and clinicians. Several methods have been developed for this purpose, but a majority of them are either invasive, too expensive or need special expertise and experience. Besides, they are not usually risk free and have consequences.
Here, a semi-invasive system was designed and developed for continuous CO measurement via analyzing and processing arterial pulse waves.
Quantitative evaluation of developed CO estimation system was performed using 7 signals. It showed that it has an acceptable average error of (6.5%) in estimating CO. In addition, this system has the ability to consistently estimate this parameter and to provide a CO versus time curve that assists in tracking changes of CO. Moreover, the system provides such curve for systolic blood pressure, diastolic blood pressure, average blood pressure, heart rate and stroke volume.
Evaluation of the results showed that the developed system is capable of accurately estimating CO. The curves which the system provides for important parameters may be valuable in monitoring hemodynamic status of high-risk surgical patients and critically ill patients in Intensive Care Units (ICU). Therefore, it could be a suitable system for monitoring hemodynamic status of critically ill patients.
心输出量（CO）是心脏每分钟泵出的血液总量，是心率和每搏输出量的函数。CO是监测心脏功能、估计全身氧输送以及了解高血压病因的最重要参数之一。因此，测量CO一直是研究人员和临床医生感兴趣的问题。为此已经开发了几种方法，但其中大多数要么是侵入性的，要么成本太高，要么需要特殊的专业知识和经验。此外，它们通常并非没有风险且会带来后果。
在此，设计并开发了一种半侵入性系统，用于通过分析和处理动脉脉搏波来连续测量CO。
使用7个信号对开发的CO估计系统进行了定量评估。结果表明，该系统在估计CO时具有可接受的平均误差（6.5%）。此外，该系统能够持续估计该参数，并提供CO随时间变化的曲线，有助于跟踪CO的变化。此外，该系统还提供收缩压、舒张压、平均血压、心率和每搏输出量的此类曲线。
结果评估表明，开发的系统能够准确估计CO。该系统为重要参数提供的曲线可能对监测高危手术患者和重症监护病房（ICU）重症患者的血流动力学状态具有重要价值。因此，它可能是一种适用于监测重症患者血流动力学状态的系统。
