A New Method for Estimation of Dynamic Brachial Artery Compliance Based on Oscillometry

• Main Authors: Hao-Min Chen, 陳浩民
• Other Authors: Shyh-Hau Wang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/96844142015667216007

碩士 === 中原大學 === 醫學工程研究所 === 95 === We propose a new method for assessing the dynamic compliance of the brachial artery using an oscillometry-based approach that is mathematically based on artery and air-cuff models. The cuff dynamics during the inflation period were characterized by simultaneously recording the cuff volume and internal pressure with a pressure transducer and an airflow meter, respectively, which yielded the envelope of the oscillation amplitudes (OAs) in the air cuff. This allowed the change in the arterial volume during each heartbeat at different cuff pressures to be calculated, yielding an arterial dynamic volume–pressure curve. The oscillometry-derived dynamic compliance of the brachial artery (Cosci) can be determined from the volume–pressure curve as the dynamic volume divided by the pulse pressure. Furthermore, we developed a direct scheme to calibrate the calculated dynamic change in arterial volume. In addition, the proposed Cosci was validated by comparing it with the compliance of the brachial artery (Cecho) estimated echocardiographically from the brachial arterial blood flow in 32 patients whose lower limbs exhibited numbness or lack of strength. The results showed that Cosci and Cecho were significantly correlated between the cuff pressures levels and the mean arterial pressure, systolic pressure, and diastolic pressure (r = 0.707, 0.648, and 0.770, respectively; p < 0.0001). This suggests that a useful measure of the dynamic arterial compliance can be derived from the pattern of the OA waveform in addition to oscillometry-based blood pressure measurements.