Evaluation of Arterial Properties through Acceleration Photoplethysmogram

This work aimes to provide, that acceleration photoplethysmogram produces useful information in assessing arterial properties. The development and progression of arterial vascular disease is a multifactorial process. Risk factors for cardiovascular disease mediate their effects by altering the structure, properties and function of wall and endothelial components of the arterial blood vessels that vary between different vascular beds. Monitoring arterial vascular walls as well as risk factors such as hypertension, hypercholesterolemia and other blood biochemical profiles can potentially help to identify individuals having an increased risk of developing cardiovascular disease in adulthood.

Pulse wave analysis has been shown to provide valuable information on aortic stiffness and elasticity, and it has been widely used to evaluate the vascular effects of aging, hypertension and atherosclerosis. The second derivative of the PPG or acceleration photoplethysmogram (APG) was developed as a method allowing more accurate recognition of the inflection points and easier interpretation of the original plethysmogram wave. Although obtained from the periphery of the circulation, APG provides information about both central and peripheral arterial properties.

A computer based PPG analyzer was developed. With the APG signal, four separate systole waves (named a-d) and a diastole wave (named e) were obtained. A study with 40 people, 20 healthy volunteers and 20 subjects with previously diagnosed cardiovascular disease (diabetes mellitus, atherosclerosis, hypertension) was carried out. A t-tested distribution between healthy volunteers and patients showed a significant differences in calculated parameters: b/a (-0.742 vs -0.361, p < 0.0001), d/a (-0.083 vs -0.482, p < 0.0001), e/a (0.182 vs 0.061, p< 0.0001), and for c/a (-0.039 vs -0.148, p < 0.005). In conclusion, APG signal has shown to be a noninvasive indicator for vascular assessments.