A Heating from a Standard Active Implantable Medical Device under MRI Exposure

The paper, based on the technical specification ISO TS 10974, assesses the safety of Standard Active Implantable Medical Devices (S-AIMD) exposed to RF exposure of MRI devices at 64 MHz (1.5 T). A modelled implant has a form of a normalized wire lead that is typically used as a feeding electrode of cardiac pacemakers or deep brain stimulators. Such an elongated implant was placed in standarized tissue mim-icking liquid phantom. In the current investigation, the electro-thermal analyses of S-AIMD based on the finite-difference time-domain (FDTD) method is presented and the temperature around the implant was estimated with the Fourier Law. In addition, the specific absorption rate (SAR) distribution on the axis of the wire-implant is evaluated and compared to the ISO standard. Importantly, the presented procedure may be helpful during the MRI exposure risk assessment for AIMD patients.