血流动力学参数的指示剂光密度检测方法研究

血流动力学参数检测一直是临床医学研究的热点。针对临床上测量血流动力学参数的方法存在有创、操作复杂、不适合重复测量的问题，研究了一种结合指示剂稀释理论与近红外光谱技术的指示剂光密度测量法，实现了血流动力学参数的无创检测。通过体外注射吲哚氰绿(ICG)色素指示剂，建立其在血液循环系统中稀释代谢的动力学模型，利用近红外发光探头在指端分时发送735，805和940 nm三个波长的近红外光, 同时在手指对侧实时接收携带脉搏波信息的透射光信号，将测得的信号上传至计算机进行分析处理得到随时间变化的ICG浓度并将其绘制成连续的色素浓度曲线，根据该曲线确定色素平均传输时间MTT及初始色素含量C_t0等中间变量，进一步推算出心排出量CO及循环血容量CBV两项血流动力学参数。将该方法与临床上测量上述两种参数的“金标准”—热稀释法、碘-131同位素标记法进行临床试验对比，测得10组CO及CBV的试验对比数据，经误差分析得到两项参数的相对误差最大值分别为8.88%和4.28%，平均相对误差值均低于5%，满足临床检测的精度要求，为临床上血流动力学参数的测量提供了一种安全性强、连续性好、适应范围更为广泛的方法。

Study on Indicator Densitometry Determination Method of Hemodynamic Parameters

Measurement for hemodynamic parameters has always been a hot spot of clinical research. Methods for measuring hemodynamic parameters clinically have the problems of invasiveness, complex operation and being unfit for repeated measurement. To solve the problems, an indicator densitometry analysis method is presented based on near-infrared spectroscopy (NIRS) and indicator dilution theory, which realizes the hemodynamic parameters measured noninvasively. While the indocyanine green (ICG) was injected into human body, circulation carried the indicator mixing and diluting with the bloodstream. Then the near-infrared probe was used to emit near-infrared light at 735, 805 and 940 nm wavelengths through the sufferer’s fingertip and synchronously capture the transmission light containing the information of arterial pulse wave. By uploading the measured data, the computer would calculate the ICG concentration, establish continuous concentration curve and compute some intermediate variables such as the mean transmission time (MTT) and the initial blood ICG concentration (c_t0). Accordingly Cardiac Output (CO) and Circulating Blood Volume (CBV) could be calculated. Compared with the clinical “gold standard” methods of thermodilution and I-131 isotope-labelling method to measure the two parameters by clinical controlled trials, ten sets of data were obtained. The maximum relative errors of this method were 8.88% and 4.28% respectively, and both of the average relative errors were below 5%. The result indicates that this method can meet the clinical accuracy requirement and can be used as a noninvasive, repeatable and applied solution for clinical hemodynamic parameters measurement.