Objective To explore the value of endothelial dysfunction assessment in predicating major adverse cardiac and cerebrovascular events (MACCE) in peritoneal dialysis (PD) patients.Methods A prospective cohort study included 136 end stage renal disease (ESRD) patients from Jan 1,2009 to Dec 31,2011 was conducted.Endothelial function was assessed by flowmediated dilation (FMD) of brachial artery.Kaplan-Meier method was used to estimate survival rate.The survival difference between the two groups was compared by the log-rank test.Multivariate Cox proportional hazards regression was used to determine the independent risk factors of MACCE.Results In the follow-up period,18 patients in low FMD (FMD≤2.7％) group occurred MACCE,and 13 patients in high FMD (FMD ＞ 2.7％) group occurred MACCE.Compared with high FMD group,MACCE-free survival rate in the low FMD group had a significantly decreased (x2=4.190,P=0.041).Multivariate Cox proportional hazards regression analysis showed that higher level of total cholesterol,lower FMD,longer PD time and higher levels of hs-CRP were all independent predictors of MACCE.Conclusion Reduced brachial artery FMD is an independent risk factor of MACCE,and the application of FMD contributes to the risk stratification of cardiac and cerebrovascular disease in PD patients.

The paper first analyses the principles of measurement of the two-wave oximeter and their limitations in technology. We propose to filter off motion interference from pulse oximeter signal using an algorithm based on the Beer-Lambert law that requires a three-wave probe (660 nm, 850 nm, and 940 nm). Based on the new algorithm, this paper describes the design principle of the circuitry and the software flowchart. Also, we study the calibration method of the pulse oximeter sensor and discuss the results in this paper.
Calibration ; standards ; Equipment Design ; Humans ; Oximetry ; instrumentation ; Oxygen ; metabolism ; Oxyhemoglobins ; analysis