An Intracardiac Soft Robotic Device for Augmentation of Blood Ejection from the Failing Right Ventricle

Abstract

We introduce an implantable intracardiac soft robotic right ventricular ejection device (RVED) for dynamic approximation of the right ventricular (RV) free wall and the interventricular septum (IVS) in synchrony with the cardiac cycle to augment blood ejection in right heart failure (RHF). The RVED is designed for safe and effective intracardiac operation and consists of an anchoring system deployed across the IVS, an RV free wall anchor, and a pneumatic artificial muscle linear actuator that spans the RV chamber between the two anchors. Using a ventricular simulator and a custom controller, we characterized ventricular volume ejection, linear approximation against different loads and the effect of varying device actuation periods on volume ejection. The RVED was then tested in vivo in adult pigs (n = 5). First, we successfully deployed the device into the beating heart under 3D echocardiography guidance (n = 4). Next, we performed a feasibility study to evaluate the device’s ability to augment RV ejection in an experimental model of RHF (n = 1). RVED actuation augmented RV ejection during RHF; while further chronic animal studies will provide details about the efficacy of this support device. These results demonstrate successful design and implementation of the RVED and its deployment into the beating heart. This soft robotic ejection device has potential to serve as a rapidly deployable system for mechanical circulatory assistance in RHF.

Soft robotic ventricular assist device with septal bracing for therapy of heart failure

“…We have previously reported an intracardiac soft robotic device for RV augmentation (25). The device was based on a single McKibben actuator positioned inside the RV perpendicular between the free wall and septum.…”

“…We varied both systolic actuation period (defined as a percentage fraction of the total cardiac cycle) and the time delay after the initial pacemaker signal. The device was actuated during HF for all combinations of systolic periods (25,30,35, and 40% of the cardiac cycle period) and delay periods of 0, 5, and 10% of the total cardiac cycle period (Fig. 5D).…”

“…This distortion of the IVS cannot be corrected with direct cardiac compression devices and can even be exacerbated after implantation of traditional VADs (42). To augment septal motion in HF, a contractile actuator that can be fully implanted inside the RV has been proposed to cause approximation of the RV free wall and the septum during ventricular contraction (25). However, the cardiac augmentation performance of this approach is limited by the contractile range of the actuator and by the fact that the force can only be applied at a single point on the ventricular free wall.…”

Static Kinematics for an Antagonistically Actuated Robot Based on a Beam-Mechanics-Based Model

“…With the growing interest in the use of soft materials [1] for the creation of highly dexterous robots, soft material robotics has established itself as an important research topic within soft robotics. Some roboticists argue that soft robotic technologies will play a key role in the 4 th industrial revolution [2], for safe human-robot interaction in manufacturing [3]- [5], healthcare [6], and minimally invasive surgery (MIS) [7]. Numerous proposals for novel flexible robots, based on soft and hybrid materials, are continuously emerging [8].…”

Soft Robotics. Bio-inspired Antagonistic Stiffening

“…A clear indication is the growth of publications about innovative soft material robots in recently appearing monothematic journals such as "Soft Robotics" [2] and dedicated sessions at major robotics conferences, e.g., ICRA and IROS. Some roboticists argue that soft robotic technologies will play a key role in the 4th industrial revolution [3] for safe human-robot interaction in manufacturing [4,6], healthcare [7], and minimally invasive surgery (MIS) [8]. Numerous proposals for novel flexible robots based on soft and hybrid materials are continuously emerging [9].…”