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When a patient have severe heart diseases, Ventricular Assist Device (VAD) implantation may be necessary. However, the improvement of the interaction between the device and the patient΄s behavior is crucial. Currently, the control of these pumps does not follow changes in patient behavior and the devices are no safe. Therefore, if VAD has no faults tolerance and no dynamic behavior according to the cardiovascular system performance, there is a serious limitation on expected results. This research investigates a mechatronic approach for this class of devices based on advanced techniques for control, instrumentation and automation to define a method for developing a hierarchical supervisory control system to control a VAD dynamically and securely. To apply this method, concepts based on Petri nets and Safety Instrumented Systems are used. This innovation reduces the interventions and unnecessary drugs, enabling a reduction of deposable material and patient hospitalization, and contributes to sustainability concept. [ABSTRACT FROM AUTHOR]

Approximately 5 million Americans have congestive heart failure (CHF), and every year about 50,000 new cases are diagnosed. Advances in medical therapy, biventricular pacing, defibrillator implantation, and the ability to successfully perform surgery in high-risk patients have revolutionized the management of patients with CHF and greatly delayed CHF progression to end stage. Once patients develop end-stage CHF, treatment options are limited and typically ineffective, and the mortality is high. Heart transplant thus becomes the last resort for end-stage CHF patients. Ventricular assist devices (VAD), especially left ventricular assist devices (LVAD), have been increasingly used to support such ill patients as a bridge-to-transplant therapy in the last decade. More recently, these devices have been used as a destination therapy for end-stage CHF as well. A newer generation of VADs with better mechanics, smaller size, and longer durability has been developed in recent years. [ABSTRACT FROM AUTHOR]

This paper studies the cardiovascular response under heart failure condition supported by two types of ventricular assist devices (VADs): the positive displacement pump and the impeller pump. The cardiovascular system is modeled using the concentrated parameter method developed previously, by considering flow resistance, vessel elasticity and inertial effects of blood in individual conduit segments. The dynamic modeling of displacement and impeller pumps is represented by VAD inlet/outlet flow-rate changes. Results show that in each simulation, the diseased ventricle is effectively unloaded, and the physiological variables of arterial pressure and systemic flow are adequately maintained. The numerical model is under further development for more sophisticated studies of the interaction of the native cardiovascular system with VAD support and other cardiac prosthetic devices. [ABSTRACT FROM AUTHOR]