High Energy Density Polymer Film Capacitors for ICDs

Project Summary
An implantable cardioverter defibrillator ICD is a small battery powered electric pulse
generator about the size of a stopwatch that is implanted into the chest of patients who are at
risk of sudden cardiac death due to ventricular fibrillation and ventricular tachycardia The ICD
uses a capacitor to deliver a shock defibrillation to the heart which stops the abnormal rhythm
Without this therapy the dangerously rapid rhythm could lead to sudden cardiac arrest and
sudden cardiac death within minutes Sudden death due to cardiac arrest affects
people each year in the United States alone meaning that almost people die from it each
day ICDs have been shown to effectively stop or more of these dangerously fast heart
rhythms
ICDs place unique requirements on the capacitor used to generate the electrical pulse requiring
a combination of high voltage high capacitance and small case size While metalized polymer
film capacitors are used AEDs the energy density of current materials is too low to be used in
implantable devices Without the availability of high energy density polymer films ICDs have
been limited to aluminum electrolytic capacitors which are undesirable for many reasons
resulting from the use of a liquid electrolyte Polymer film capacitors are solid state and thus
require no volatile compounds that would pose safety risks once implanted Existing polymer
film capacitors such as those produced from polypropylene or polyethylene have a low
volumetric capacitance and low energy density J cc making them unsuitable for ICDs
HARP Engineering recently developed a new composition for thin film capacitors that provides
the highest energy density ever reported This technology is would allow a times smaller
capacitor than the aluminum electrolytic capacitors used in current implantable cardioverter
defibrillators ICDs and a reduction in total device volume Since ICDs are implanted
the package size is critical to the patientandapos s quality of life after surgery especially in pediatric
cases and the reduction of late complications such as skin erosion which is highly impacted by
the size of the device and reported to occur in of cases Furthermore the more recent
development of subcutaneous ICDs which eliminate complications from intravenous leads
require roughly three times greater energy to achieve defibrillation thus producing even greater
need for smaller capacitors Under this SBIR HARP Engineering proposes to collaborate with
St Jude Medical and Boston Scientific to manufacture test and demonstrate ultra high energy
density capacitors for use in ICDs Project Narrative
Implantable cardioverter defibrillators ICDs are implanted into the chest of patients who
are at risk of sudden cardiac death due to ventricular fibrillation and ventricular
tachycardia The proposed SBIR seeks to develop a polymer film capacitor that can
reduce the total ICD volume by leading to greater patient comfort improved
reliability and reduced late complications