Leadless Pacemaker Betavoltaic Power Source

PROJECT SUMMARY
Lithium-based batteries have reached a technological limit of ~0.6 cc for use in leadless cardiac pacemaker
(LCP) applications and a useful life of only 7-10 years1. The 0.6 cc volume comprises over 60% of the
LCP’s total volume and is a technological miniaturization limit to LCPs. City Labs is developing a small
betavoltaic power source with sufficient current density to power a pulse generator circuit. The battery’s
volume can be as small as 0.1 cc, while providing a consistent ≥3.8 μW for 20 years. This size reduction
would allow for an LCP to be implanted in the atria, permitting multi-chamber leadless pacing for patients
previously relegated to conventional pacemakers. Furthermore, a decrease in size grants both the
manufacturer of delivery catheters and the clinicians operating them a higher degree of flexibility, both in
developing the device design process and implantation protocol, even permitting multiple LCPs in a single
chamber. A longer-lived pacemaker also expands the potential use of LCPs to younger demographics.
LCPs’ retrieval is difficult, so they are often used in patients who are not projected to outlive the device2,3.
We will be designing and manufacturing a polyimide-based package that will be biocompatible and safe. It
will fit in a leadless pacemaker’s titanium housing, providing double encapsulation. The project goal is to
make the most reliable polyimide device configuration and manufacturing approach for transition to market
approval with the pacemaker manufacturing partner. We propose a research and development optimization
of industrial production methods necessary to ensure consistent and controlled scale-up manufacturing
according to recognized quality standards and FDA requirements. City Labs has developed and utilized
helium generation and leak models for the predictive design of packaging and components indicative of
measured values. Model and measured data will undergo rigorous tuning and analysis under this CRP to
ensure adequate predictability and tolerance for diffusion rates in a polyimide package. Furthermore, all
packages will be tested to ensure they meet the designed leak rate. The final optimization of the prototype
entails the sealing of end caps, feedthroughs, wall thickness, and leak rates associated with components
and sealing processes. We will quantify the component and sealing process leak rates with a helium leak
detector. This will enable us to produce a package, with controlled hermeticity and minimized volume, from
components fabricated in-house, like additively manufactured end caps and specialized electrical contacts.
To fabricate and seal such polyimide components, we will acquire and customize an advanced 3-D printer
capable of manipulating high performance thermoplastics. The CRP effort will support development needed
to harmonize the modeling, prototyping, and manufacturing processes. This project aims to develop the
manufacturing capability and commercialization maturity our pacemaker manufacturing partners require.

Grant Number: 5SB1HL174312-02
NIH Institute/Center: NIH
Principal Investigator: Peter Cabauy