基于近红外光谱实现心输出量无创检测的色素谱分析方法

针对当前临床上心输出量参数检测技术存在的有创伤、操作复杂和患者易受感染而死亡的问题，研究了一种基于近红外光谱原理，动态测量和分析作为指示剂的吲哚氰绿色素在患者动脉血液中的浓度变化情况，从而根据其特征参数实现心输出量连续测量的无创检测方法。将吲哚氰绿色素经肘静脉注入患者体内后，光电脉搏色素谱测量装置作为下位机，连续、同步采集和记录其指端处的805和940 nm两个特征波长点的脉搏波信号，并将数据上传至上位计算机，由后者绘制色素稀释和排泄的浓度衰减曲线，以及计算平均循环时间等关键参数，最后推导出心输出量的数值。将该方法与作为“金标准”的热稀释法的测量结果相比较，其最大相对误差为9.76%，而平均相对误差为4.39%。该试验结果表明，所提出的方法为临床上的心输出量检测，提供了一种操作简便、无创和连续测量的解决方案。

A Dye Densitometry Analysis Method for Noninvasive Measurement of Cardiac Output Based on NIRS

Currently, there exist technology problems in cardiac output (CO) parameter detection clinically, such as invasive and complex operation, as well as possibility of infection and death for patients. In order to solve these problems, a noninvasive and continuous method based on NIRS for CO detection was presented. In this way, the concentration changing of indocyanine green (ICG) dye in the patient’s arterial blood was dynamically measured and analyzed, so that the CO could be noninvasively and continuously measured according to the characteristic parameters of dye densitometry curve. While the ICG dye was injected into the patient’s body by the median cubital vein, block of photoelectric pulse dye densitometry measurement system as the lower machine acquired pulse wave data and uploaded the data to upper computer. In the scheme, two specialized light sources of LED at 940 and 805 nm were used to capture the signals of sufferer’s fingertip pulse wave synchronously and successively. The CO value could then be successfully calculated through drawing complete ICG concentration variation of dye dilution and excretion process and computing mean transmission time (MTT) by upper computer. Compared with the “gold standard” method of thermodilution, the maximum relative error of this method was below 9.76%, and the mean relative error was below 4.39%. The result indicates that the method can be used as a kind of convenient operation, noninvasive and continuous solution for clinical CO measurement.