Sensitivity of the transfer function of a helix lead on the dielectric properties of the surrounding media: A case study

In this case study of radio frequency (RF) induced heating of tissue near the lead tip we show how the RF-induced power deposition (P) and the lead electromagnetic model (LEM) depend on the presence of heterogeneous tissues around the lead tip. For most clinically relevant lead lengths, we observed a visible non-linear dependence of P on a small volume of a different tissue surrounding the lead tip, (e.g. a fatty pocket). Thus, using LEMs derived in a homogeneous media can result in large systematic errors in predicting P, and consequently the lead tip heating, of active implantable medical devices (AIMDs) inside the human body.