A Novel Electro-Mechanical Ventricular Assist
Device for Refractory Cardiac Insufficiency
Antonio Boccaccio
Dipartimento di
Ingegneria Meccanica
e Gestionale,
Politecnico di Bari
Bari, Italy
Carmine Carbone
Cardiochirurgia,
Casa di Cura
“Villa Bianca”,
Bari, Italy
Umberto Galietti
Dipartimento di
Ingegneria Meccanica
e Gestionale,
Politecnico di Bari
Bari, Italy
Filippo Mastropasqua
Salvatore Maugeri
Foundation, Institute
for Clinical Care and
Research (IRCCS),
Scientific Institute of
Cassano Murge, Bari,
Italy
Carmine Pappalettere
Dipartimento di
Ingegneria Meccanica
e Gestionale,
Politecnico di Bari
Bari, Italy
Abstract—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.
Keywords-component; Cardiac Failure; Ventricular Assist
Device; Circulatory Assist Devices
I. INTRODUCTION
Although heart transplantation remains the gold standard
for patients who remain in advanced heart failure in spite of
optimal medical management, the limited availability of donors
allows, in the US, only about 2000 transplants, each year, to be
conducted. For this reason, the attention of cardiologists has
focused on the development of mechanical circulatory support
systems, such as the ventricular assist devices, for this ever-
growing population of sick patients [1]. The first application of
a ventricular assist system was in 1963 by DeBakey [2] for
support of postoperative cardiogenic shock. Since the 1980s
Left Ventricular Assist Devices (LVADs) as well as
biventricular assist devices have been used for the treatment of
patients with severe heart failure accompanied by shock and
multiple organ dysfunction, with perspective of future
transplantation [3]. During these years, four principal types of
pulsatile-flow LVADs developed: ABIOMED, Thoratec,
Novacor, Heartmate [3]. Later, new LVADs have been
designed to guarantee a continuous flow. In early 2000, the
new system Jarvik 2000 has been introduced that requires less
invasive implantation procedure than the Heartmate or
Novacor devices [4]. Almost in the same years, the DeBakey
VAD has been developed as well, it is comprised of a heart
pump the design of which has been studied -based in part on
technology used in space shuttle fuel pumps- to minimize
haemolysis. The availability of efficient technologies, as well
as the development of innovative materials allowed high
performance LVADs to be designed and realized, thus
originating the concept of LVAD as a destination therapy [5] or
as a bridge to recovery [3]. The most important limitation of
using the LVADs is their invasivity. They work as a bypass
between the left ventricular apex and the ascending aorta, the
blood is constrained to flow through the components of the
circulatory device and the risk of thrombogenesis, haemolysis
and infections can be run. Such a limitation appears yet more
severe in light of the results reported by Birks et al. [6], who
found that sustained reversal of severe heart failure secondary
to nonischemic cardiomyopathy could be achieved in selected
patients with the use of a LVAD and a specific pharmacologic
regimen. After drug therapy, the patients have to undergo
explantation of the LVAD; given the highly invasive nature of
the device, explantation could be a dangerous surgical
operation [6].
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. It is the case of the latissimus dorsi cardiomyoplasty
utilized for the treatment of patients with dilated or ischemic
cardiomyopathyes [7]. However, long-term benefits of this
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