Effects of Strain Relief Loop on MRI RF-Induced Heating of Active Implantable Medical Devices

This paper discusses the effects of strain relief loops on the RF-induced heating of Active Implantable Medical Devices (AIMDs) during an MRI procedure. A method to estimate the effect of the strain relief loop location on the AIMD heating is developed based on the differentiation of cumulative summation (DCS) of the product between the transfer function and the tangential component of the electric field along the device length. Placing a loop at the peak location of DCS can significantly reduce the heating while placing the loop at the nulls of the DCS would lead to a higher temperature rise. Numerical simulations and experimental validations are performed to demonstrate this method.