On the Model Validation of Active Implantable Medical Device for MRI Safety Assessment

In this article, we discuss the model validation for active implantable medical devices (AIMDs) used for safety evaluations under magnetic resonance imaging (MRI) radio frequency (RF) coil emission. A mathematical derivation is presented to provide the guidance on selecting meaningful pathways for the model validation. Suggested validation pathways from current ISO 10974 are used as examples. It is shown that these standard pathways are: 1) inefficient since validations from several pathways are theoretically redundant and 2) incomplete or false since significantly different AIMD models can have identical validation outputs. Based on the developed guidance, two sets of pathways are proposed. It is demonstrated that for efficient and correct model validation, the electric-field distributions along validation pathways should be orthogonal to each other or at least has low correlations between each other. These guidelines can be implemented for future AIMD model validations in ISO10974.