An Intraventricular Soft Robotic Pulsatile Assist Device for Right Ventricular Heart Failure1

Abstract

Heart failure occurs when either or both ventricles of the heart cannot pump sufficient blood to meet the metabolic needs of the body. While symptoms vary widely depending on which ventricle is failing and the underlying cause, the standard indicator of failure is low ejection fraction, which is the volumetric proportion of blood ejected when the ventricle contracts. Effective therapies for heart failure target the etiology, but treatment of symptoms is also necessary to sustain patient health and quality of life. Though early-stage heart failure can be treated with drugs, more advanced cases require support from a ventricular assist device (VAD) [1]. Such devices assume some or all of the heart’s pumping work, unloading the heart and restoring normal circulation, until the patient recovers or a transplant becomes available. Due to its more complex geometry and motion, right ventricular heart failure (RVHF) is less understood than left ventricular heart failure and has fewer treatment options. Currently, only 1 implantable and 2 paracorporeal devices are FDA-approved for mechanical circulatory support of the right ventricle [2], and all are originally LVADs set to produce lower pressures. Implantation requires cannulation via sternotomy, which is a very invasive procedure. In addition, all current VADs require blood to flow through the device, which presents a thrombogenic risk. Newer VADs mitigate this by using magnetic suspension for contactless bearings, but this is power-intensive and reduces portability. This paper presents the design of a VAD tailored for the right ventricle, which leverages its specific geometry and lower pressure in order to avoid the major pitfalls of current VADs.