Brachial-Ankle Pulse Wave Velocity Calculation Methods Based On Oscillometric Pressure Measurement For Arterial Stiffness Assessment

Abstract

Brachial-ankle pulse wave velocity (baPWV) is a vascular parameter used to assess the stiffness of arterial segments between the brachial and femoral arteries, including aorta. The baPWV value is determined by the distance and the time difference between two wave patterns in the upper arm and ankle. This research studied six calculation methods to find specific reference point on the oscillometric waveform (OMW) from cuff pressure measurement to calculate time difference between two OMW patterns. The methods used were maximum value, minimum value, maximum first derivative, maximum second derivative, intersection between tangent of maximum first derivative and minimum value points, and intersection between tangent of maximum second derivative and minimum value points. baPWV calculation was performed during three levels of cuff pressure. At each pressure level, at least 3 waves were used for calculation. The best baPWV calculation method was determined by the smallest value of data variance. The method test was performed on 81 subjects in which 77 subjects were for general test and 4 subjects were for repetition test. General test results showed that the maximum second derivative method provides the most consistent baPWV value, meanwhile the repetition test results from 6 OMW data for each subject showed that the maximum first derivative method also gave the most consistent baPWV value with insignificant differences compared to the maximum second derivative method.