Feedthrough EMI filter with ground isolation for cardiac pacemakers and implantable cardioverter defibrillators

This paper describes an Isolated Ground Capacitor (IGC) electromagnetic interference (EMI) feedthrough filter that generally makes cardiac pacemakers and implantable cardioverter defibrillators (ICDs) immune to the RF fields generated by cellular phones and other emitters. The IGC filter consists of a monolithic ceramic capacitor (MLC) in a feedthrough configuration which is directly mounted onto the hermetic terminal of the implantable medical device. The IGC MLC employs unique electrode plate geometry and manufacturing techniques that provide for isolation of pacemaker or ICD circuitry from the titanium shield (ground plane).