Cardioaccelerometery: the assessment of pulse wave velocity using accelerometers

Abstract

In the past recent years, great emphasis has been placed on the role of arterial stiffness in the development of cardiovascular diseases, recognized as the leading cause of death in the world. This hemodynamic parameter, generally associated to age and blood pressure increase, can be assessed by the measurement of the pulse wave velocity (PWV), i.e., the velocity at which the pressure wave propagates along an artery. Although PWV measurement is accepted as the most simple, non-invasive, robust and reproducible method to determine arterial stiffness over the carotid-femoral region, the devices available in the market for this purpose are extremely expensive. This research project aims at developing alternative instrumental methods for the aortic PWV’s hemodynamic characterization and, at a later stage, a software application for acquisition and interpretation of this information. The proposed instruments are constituted by one accelerometric probe and a multisensor acquisition module, which includes classic electrodes of electrocardiography, piezoelectric (PZ) transducers and, foreseen, one pressure sensor. Up to now, in its research usage, it has proved effective in the prolonged follow up of hypertensive patients without and with drug treatment, allowing the study of correlations between the different types of signals. A valuable contribution to this study has been given by the bench models developed in laboratory for the ADXL203 accelerometer calibration and pulsatory system simulation. This report describes not only the aspects related with the overall instrument architecture, the successive developed versions and the results obtained, under medical control, for each of the input signals, but also the calibration and pulsatory models and respective results.