An Intracardiac Soft Robotic Device for Augmentation of Blood Ejection
from the Failing Right Ventricle
Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA, USA;
Boston Children’s Hospital,
Harvard Medical School, Boston, MA, USA;
Olin College of Engineering, Needham, MA, USA; and
Harvard John A.
Paulson School of Engineering and Applied Sciences, Cambridge, MA, USA
(Received 11 January 2017; accepted 11 May 2017; published online 16 May 2017)
Associate Editor K. A. Athanasiou oversaw the review of this article.
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 implemen-
tation 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.
Keywords—Right heart failure, Soft robotics, Mechanical
The right ventricle (RV) of the heart pumps venous
blood collected from the body to the lungs for oxy-
The RV has a crescentic shape and is
bordered by a thin free wall and a rightward convex
interventricular septum (IVS) (Fig. 1a). RV contrac-
tion is a complex 3-dimensional motion that includes
wave-like contraction of the RV free wall, approxi-
mation of the RV free wall toward the IVS and
thickening of the IVS, which results in blood ejection
towards a low-resistance pulmonary vascular bed.
Right heart failure (RHF) is a disease entity with
diverse etiology, where RV pumping function is se-
In most cases of advanced
RHF, the RV free wall and the IVS are less contractile,
the RV is dilated and the septum is no longer convex
shaped but rather ﬂattened or even shifted toward the
left ventricle (LV) (Fig. 1b).
RHF is characterized by high morbidity and mor-
The current treatment options include a
wide spectrum of approaches, from pharmacological
therapy in the early stages, to heart or heart–lung
transplantation in end stage of the disease.
vanced RHF, mechanical circulatory support (MCS)
has become a valuable therapeutic solution, when a
donor organ is not available. The state of the art
among MCS devices is one-way ﬂow pumps that divert
blood returning from the body to pulmonary vascu-
We present an alternative approach where a soft
robotic pneumatic artiﬁcial muscle (PAM) is deployed
across the failing RV free wall and IVS to augment
their approximation during systole, leading to ejection
Address correspondence to Nikolay V. Vasilyev, Boston Chil-
dren’s Hospital, Harvard Medical School, Boston, MA, USA.
Electronic mail: email@example.com
Markus A. Horvath and Isaac Wamala have contributed equally
to this work and are co-ﬁrst authors.
Annals of Biomedical Engineering, Vol. 45, No. 9, September 2017 (
2017) pp. 2222–2233
2017 Biomedical Engineering Society