US Government As Represented by the Secretary of the Army

Charles L Brown

Vincent J Ellis

A phantom test cell and method for testing the response of a cardiac pacemaker to electromagnetic fields. The phantom comprises a substantially rigid shell which has a torso-like section and two leg-like appendages. The entire shell is filled with a tissue-equivalent material, which in one embodiment represents an upper bound approximation of human whole body averages. The phantom's torso is equipped with a plurality of access ports to which a current probe containment vessel may attach when immersed in the tissue-equivalent material. The containment vessel houses a current probe and flooded tube through which an implanted pacemaker's leads may pass, allowing induced currents to be monitored. In operation, lead current measurements are taken within the phantom and are normalized using measurements taken without the presence of a phantom. A transfer function is computed by taking the ratio of the induced current measured and a reference E-field and/or H-field measurement. A source of interest is then convolved with the transfer function to determine what the induced current would be in an implanted pacemaker. In one embodiment, the induced current which is arrived at analytically is then physically injected into a cardiac pacemaker outside the test phantom to reproduce EMI effects.

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Manassas, VA, United States of America

Charles L Brown