Pacemaker interference and low-frequency electric induction in humans by external fields and electrodes

The possibility of interference by low-frequency external electric fields w ith cardiac pacemakers is a matter of practical concern. For pragmatic reas ons, experimental investigations into such interference have used contact e lectrode current sources. However, the applicability to the external electr ic field problem remains unclear. The recent development of anatomically ba sed electromagnetic models of the human body, together with progress in com putational electromagnetics, enable the use of numerical modeling to quanti fy the relationship between external field and contact electrode excitation , This paper presents a comparison between the computed fields induced in a 3.6-mm-resolution conductivity model of the human body by an external elec tric field and by several electrode source configurations involving the fee t and either the head or shoulders. The application to cardiac pacemaker in terference is also indicated.