Online proceedings - EDA Publishing Association

11-13
May 2011, Aix-en-Provence, France
Energy Harvesting System for Cardiac Implant
Applications
Martin Deterre (1,2,3) , Bertrand Boutaud (1) , Renzo Dalmolin (1) , Sébastien Boisseau (4) , Jean-Jacques Chaillout (4) ,
Elie Lefeuvre (2,3) , Elisabeth Dufour-Gergam (2,3)
(1) Sorin CRM SAS, Clamart 92143, France
(2) Univ Paris- Sud, Laboratoire IEF, UMR 8622, Orsay 91405, France
(3) CNRS, Orsay 91405, France
(4) CEA-LETI, MINATEC, Grenoble 38054, France
Abstract- The miniaturization process in active medical
implantable devices is driving the development of novel energy
sources such as small volume, high longevity energy harvesting
systems. In this study, we present an approach for the design
of an inertial energy scavenger powering cardiac implants
from heart generated vibrational energy. The heart
acceleration spectrum has been measured and analyzed.
Achievable power level and design parameters are determined
from a spectral analysis to about 100µW before electronics
efficiencies for a 0.5 cm 3 volume.
I. INTRODUCTION
Advances in microfabrication and bio/chemical
engineering techniques are now enabling a large variety of
miniaturized implantable systems for sensing, health
monitoring or deficiency treatments. This progress is
driving physicians and patients to express an increasing
need for miniaturized implantable devices as they are
offering less invasive implantation procedures, greater
comfort for the patient, improved performance, and often
provide innovative measurements and treatments [1]. Fig. 1
illustrates the recent remarkable expansion of the
application field of these devices.
Fig. 1. Broadening diversity of the implantable medical devices
applications [1].
These devices most often need to include an energy
source to power their active elements, such as sensing
components or transmission modules, while keeping the
size at the smallest level. Some progress has been made in
battery technology, but batteries have more and more
difficulties to follow the size reduction rhythm of the active
components without significantly shortening the device
lifetime [2, 3]. An alternative approach is to harvest the
energy available from the surrounding environment. But
traditionally energy harvesting devices can produce only a
limited amount of power as the quantity of wasted energy to
be harvested is small. Hence, first energy harvesting
applications were limited to very low duty cycle systems.
But progress in electronics power management in
conjunction with the above-mentioned miniaturization
process is now increasingly reducing sensors and
miniaturized devices power requirements. In the meantime,
performances and efficiencies of harvesting devices are
improving [4, 5, 6]. This opens energy harvesting power to
an always greater number of applications including medical
implants. Furthermore, the substantial amount of energy
produced by the human body motivates the development of
an element that could extract a part of it. This humangenerated
energy is available at various locations in the
body and can take different forms: dissipated heat, inertia,
muscle contraction, joint movement, heel strike, etc…
Numerous types of human body energy sources are
presented in a study by Starner [7, 8]. For instance,
consumed power levels are calculated to be in the order of
several watts from body heat, about one watt from breathing
and one watt from blood pressure. The latter energy source
has been exploited by Clark and Mo [9] where a
piezoelectric membrane for blood pressure variation energy
harvesting has been studied. Some commercial applications
of human-powered devices have already been developed,
such as shake-driven flashlights, thermal or inertia driven
wristwatches or heel-strike powered LEDs to name a few
[10]. A more extensive review of human body energy
scavenging microsystems has been published by Romero et
al. [11].
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