Correlation analysis on human upper limb parameters and oscillometric signal during blood pressure measurement

Abstract

Blood pressure (BP) is one of the most frequently measured bio-signal. It is encouraged to measure regularly due to its high correlation with cardiovascular diseases (CVDs) which is the number one cause of global death. Meanwhile, the most widely used method for measuring blood pressure is an oscillometric method which the automatic blood pressure measuring devices are based on. The pulse from the brachial artery is transmitted to the air in the cuff as an oscillometric signal and the systolic blood pressure (SBP) and the diastolic blood pressure (DBP) are estimated based on the envelop of the signals. Regarding the oscillometric signals, the studies have been conducted mainly on the accuracy of the blood pressure estimation and the influence of external factors on estimating blood pressure. In this thesis, the correlation between oscillometric signal and the upper limb parameter is studied by analyzing the effect on the signal when the parameters are changed, and thereby the possibility of extracting information other than blood pressure from the oscillometric signal is evaluated. The parameters with the largest effect on the oscillometric signal are found through the parametric studies with the upper limb models and the results are verified by the experiments with the upper limb phantoms. The possibility of obtaining vessel-related information from the oscillometric signal is then confirmed via the amplitude variations of the signal from the actual human body.