Sistema de controle fisiológico síncrono aplicado a dispositivos de assistência ventricular.

Abstract

Ventricular assist devices (VADs) are mechanical pumps used to provide support to the circulatory system of patients with some ventricular disfunction and that are waiting for a heart transplantation. When this support lasts for weeks or months, physiological control systems can improve this treatment by changing automatically the pump output in response to changes in the cardiovascular system. In this work, a physiological control system was developed to adjust the pump ejection pressure at each cardiac cycle to keep the mean aortic pressure at a specified reference value. A heart beat detection algorithm based on electrocardiogram signals (ECG) is used in such way the control system works in synchronization with the heart beat. Mathematical models of the peditaric cardiovascular system and of a specific pulsatile pediatric pump were used to evaluate the cardiovascular response under ventricular assistance. Computational simulation results were analyzed and one may conclude the synchronous physiological control system adapted the cardiovascular response to the changes in references values, defined in accordance with the patient clinical status.