A preliminary study on an innovative soft robotic artificial heart ventricle

In this work, we describe a soft robotic artificial heart ventricle whose novel pumping strategy is based on the programmable deformation of a fluid-containing and passive soft-shell. During pumping, the soft-shell collapses, showing the formation of inward folds that strongly contribute to the volumetric reduction of the soft-shell, thus to the pumping functionality. Our soft robotic artificial ventricle is a stand-alone system actuated by inverse pneumatic artificial muscles, that are arranged in a helical fashion around the soft-shell. We present a cable-driven soft pump as a study platform for preliminary investigation of the pumping strategy and the requirements for actuation. Three typologies of inverse pneumatic artificial muscles were fabricated and experimentally characterized as candidate actuators for the artificial ventricle. Finally, a ventricle prototype constituted by a soft-shell and an actuating system made of five inverse pneumatic actuators was designed and tested under physiologically relevant conditions of preload and afterload pressure. The experimental results demonstrated that our soft robotic artificial ventricle meets the functional requirements of a right heart ventricle operating in pulmonary circulation.