A novel electro-mechanical Ventricular Assist Device for refractory cardiac insufficiency

The most severe limitation of the Left Ventricular Assist Devices (LVADs) currently utilized is their invasivity; they work as a bypass between the left ventricular apex and the aorta. A possible strategy that can be adopted to overcome such a limitation consists in utilizing systems that assist the heart in its contraction from the outside without directly transporting the blood and that do not require highly invasive surgical treatments. In this study we conduct the feasibility analysis of a novel LVAD design that allows the principal limitations of traditional circulatory support systems to be overcome. An experimental set-up was assembled to measure the main quantities necessary for a preliminary design of the proposed appliance. The device includes a stepper motor, three metallic wires and three elastic elements configured to surround the heart. It works alternatively between a contraction condition and a release condition. A first prototype of the proposed appliance was realized. The values of force acting on the wires as well as the values of current supplied to the stepper motor were measured and utilized for a preliminary study design of the device. The experimental measurements demonstrated the feasibility of the proposed appliance. The next step consists in testing the device in a survival animal experiment. The introduction of such a device in the clinical world would allow solving most of the problems related with the highly invasive nature of the traditional ventricular assist devices.