Peripheral Nerve Stimulation (PNS) caused by fast switching gradient fields is a well-known MR safety concern. A previous calculation showed significant increase of gradient-switching-induced electric field near a metallic spinal-fusion implant.¹ A recent analysis showed that eddy current induced fields from nearby metallic objects can be a significant contributor to PNS.² We simulated a realistic gradient coil model loaded with an anatomically detailed human model with a metallic implanted canister (infusion pump) to demonstrate the implications of implanted devices on PNS.All simulations were performed with SEMCAD X (v14.8.4, SPEAG). A generic shielded Y-axis gradient coil (150cm length, 60cm diameter)³ was investigated. Human model Duke (1.77m, 72.4kg, IT’IS Foundation)⁴ was positioned into the gradient coil model with the heart aligned at isocenter (Fig.1), resulting in strong dB/dt at an implanted infusion pump canister, which was simulated by a hollow titanium (conductivity 1.28 x 10⁶ S/m) cylinder (80mm OD, 20mm height and 1mm wall thickness) in the lower right abdomen (Fig.2). The longitudinal axis of the cylinder was aligned with anterior-posterior direction to represent a realistic orientation in the body. Magneto quasi-static simulations were performed with low frequency solver at 1 kHz frequency. Corresponding tissue parameters were applied, and two simulations (with and without the cylinder) were performed. Gradient slew rate was set at 200T/m/s. The strong time varying gradient magnetic fields (especially the concomitant Y component as seen in Fig.3) of the Y-axis gradient coil induce large electric fields in the coronal cross-sectional plane of the patient. The presence of a highly conductive metal canister provides a low impedance path for the induced currents in the body, which concentrates the electric fields around the canister and can result in up to a 3x increase in the local electric fields around the device (Fig.4).Electric fields induced by switching gradient field can be increased significantly by the presence of highly conductive materials, like implanted devices, and hence increase the possibility of PNS. Future study will investigate more imaging situations (patient location, gradient coil configuration, implanted device configuration and location etc.).Detailed numerical simulations showed that implanted devices can significantly increase the electric fields around the device, which may increase the likelihood of PNS.