News Column

Patent Issued for Electromagnetic Interference Shielding in an Implantable Medical Device

July 21, 2014

By a News Reporter-Staff News Editor at Cardiovascular Week -- From Alexandria, Virginia, NewsRx journalists report that a patent by the inventor Fonte, Timothy A. (San Clemente, CA), filed on July 18, 2013, was published online on July 8, 2014 (see also Cameron Health, Inc.).

The patent's assignee for patent number 8774921 is Cameron Health, Inc. (St. Paul, MN).

News editors obtained the following quote from the background information supplied by the inventors: "Implantable cardiac stimulus devices, as well as many other implantable medical devices, typically include control circuitry that is adapted to perform various functions such as sensing, communication and/or stimulus delivery. Such devices operate within a patient's body, and are subject to various sources of electromagnetic interference (EMI) including, for example, noise from other electrical devices inside or outside of the patient's body, power line noise, noise generated by the patient's body itself, and, for some devices, noise that the device itself generates. For example, implantable cardiac stimulus devices typically deliver electric pulses to regulate or correct cardiac activity, and their sensing algorithms are often configured to avoid capturing self-generated signals. Some such devices, known as implantable cardioverter defibrillators (ICDs), deliver very large stimuli to shock a patient's heart out of an arrhythmic state such as ventricular tachycardia or ventricular fibrillation. When large pulses are delivered, it is desirable to limit the effects of the large pulse on operation of internal circuitry. New and alternative designs for limiting such effects in implantable medical devices are desired."

As a supplement to the background information on this patent, NewsRx correspondents also obtained the inventor's summary information for this patent: "The present invention, in an illustrative embodiment, includes an implantable medical device that includes operational circuitry contained in a housing. An EMI shield is disposed between the operational circuitry and the housing. The EMI shield, in an illustrative embodiment, includes an inner conductive layer which is coupled to a reference voltage. The EMI shield also includes an outer conductive layer that is exposed on its outer surface to the interior of the housing. The inner and outer conductive layers, which may be formed of conductive metals, for example, silver or copper, are separated by a dielectric layer. By exposing the outer conductive layer to contact with the interior of the housing, air gaps between the outer conductive layer and the housing are prevented from becoming sources for nonlinear electrical conduction such as corona discharge."

For additional information on this patent, see: Fonte, Timothy A.. Electromagnetic Interference Shielding in an Implantable Medical Device. U.S. Patent Number 8774921, filed July 18, 2013, and published online on July 8, 2014. Patent URL:

Keywords for this news article include: Cardiology, Cardio Device, Medical Devices, Cameron Health Inc..

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC

For more stories covering the world of technology, please see HispanicBusiness' Tech Channel

Source: Cardiovascular Week

Story Tools Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters