Temperature Rise Mechanism of Pacemaker Induced by a Time-Varying Gradient Magnetic Field

The temperature rise effect caused by a time-varying magnetic field in an MRI scanner on active implantable medical devices (AIMDs) is related to the safety of patients. A reasonable experimental design is an important step to objectively evaluate the temperature rise of the equipment. To clarify the influence of key parameters of the temperature rise experiment on the results, this work theoretically modeled the physical mechanism of the temperature increase and studied the temperature increase of the device by experiments under different initial system temperatures, gel thicknesses, and magnetic field waveforms. The results show that the initial temperature has no effect on the temperature increase of the device. A thicker gel thickness corresponds to a smaller temperature increase. Under identical effective magnetic field switching rates, the sine wave magnetic field has a significantly stronger temperature rise effect than the triangular wave magnetic field. In addition, the point where the device has the largest temperature increase is located near the battery. This result indicates that the influence of these factors on temperature increase must be thoroughly considered during all phases of the device's design, development, testing, and evaluation.