Research Of Methods For Hepatic Functional Reserves And Cardiac Hemodynamics Parameters Detecting Based On Pulse Dye Densitometry Analysis

Liver and heart diseases are always occupying the centre of the medical stage asthey have the large number of cases and deaths. When liver diseases occurred with theseverely damage of the liver cells, it will lead to the decline of liver functionalreserves as well as the change of blood flow state. Before the liver surgery, accuratelyevaluate the liver functional reserves and monitor the blood flow state is an importantway to avoid accidents in the course of operation.The traditional methods of monitoring the liver functional reserves and cardiachemodynamic parameters are blood calibration and thermo dilution. Both of these twomethods are not widely used because they are very complicated to operate and need tobe operated by medical workers with professional skills, moreover, they are invasivewhich not only put pressure on patients, but also can make the medical workers infect.For these reasons, this paper gives a method of detecting hepatic functional reservesand cardiac hemodynamics parameters based on pulse dye densitometry analysis. Themethod is on the basis of the Lambert-Beer’s law. Taking the advantage of therelationship between tissue optics and human physiological signal characteristics, andwith the Indocyanine Green(ICG) as indicator, the concentration spectral was built bypulse dye-densitometry. By the analysis of the ICG concentration spectral, theparameters of reflecting the hepatic functional reserves and the blood flow state canbe acquired, including the average of cycle time, the disappearance rate of bloodplasma, cardiac output, oxygen saturation of blood and heart rate. Finally, thenon-invasive detection method of the liver functional reserves and cardiachemodynamic parameters was realized.According to the characteristics of photoelectric pulse wave signal, the empiricalmode decomposition algorithm was studied. By decomposition the photoelectric pulsewave signal with noise, the signal reconstruction can be done based on the signalfrequency characteristic. Among a number of the signal reconstruction schemes, thebest can be defined as the high signal to noise ratio and the low root mean squareerror.The ICG concentration spectral includes the first circular curve and the second circular curve, which can characterize the dilution process and the excretion processof the ICG respectively. In the first circular curve, the cardiac output was achieved.Cardiac output is the important cardiac parameter of hemodynamic, which can reflectthe capacity of heart blood supply. In the second circular curve, the disappearance rateof blood plasma was achieved. Disappearance rate of blood plasma is the importantparameter of the liver functional reserves, which can evaluate the function directly.This paper researched of the method of monitoring the hepatic functional reservesand the cardiac hemodynamics, get the parameters of the hepatic functional reservesand the cardiac hemodynamics by using the photoelectric pulse wave signal and gavea software for data processing and interpretation. Finally, the production of this paperwas applied to the clinical trials in the First Hospital of Jilin University. By using thecorrelation and the Bland-Altman method between the experimental results and thehospital test reports, and with the good correlation and consistency, the accuracy andthe practical significance of the algorithm was full verified.