Estimation of the value of reverse blood flow in the artery by the second derivative of the pulse pressure wave

Background and Objectives: Previously, the diastolic section of the pulse wave was most often analyzed as the result of reflection of a direct wave from the elements of peripheral vessels. However, measurements of the negative linear velocity of blood flow using ultrasound dopplerograms clearly indicate the presence of reverse blood flow in the arteries. The aim of the work was to establish the relationship of the second derivative of the pulse pressure wave with the value of the reverse blood flow in the arterial bed. Materials and Methods: The shape of the pressure pulse wave was calculated based on the two-element windkessel model. The calculation of the second derivative of the pulse pressure wave was performed taking into account the direct and reverse blood flow occurring in the arteries at different values of the reverse blood flow. Results: The linear dependence of the second derivative of the pulse wave on the value of the blood volume of the reverse wave on the diastole is obtained. Conclusions: It is concluded that the second derivative of the pulse pressure wave can be used to estimate the value of the reverse blood flow in the artery, which depends on the state of the peripheral vascular system.