A simple apparatus for safety assessment of magnetically induced torque on active implantable medical devices (AIMDs) under 1.5 T and 3.0 T MRI

Abstract

Objective Our goal is to design and validate a simple apparatus for the safety assessments of magnetically induced torques by four active implantable medical devices (AIMDs) in 1.5 T and 3.0 T magnetic resonance imaging (MRI) environments. Materials and methods A simple apparatus was designed to measure the magnetically induced torque. Before testing the apparatus, its effectiveness was first evaluated with a commercially available weights. The torque values of the four AIMDs, namely implantable cardioverter defibrillator (ICD), pacemaker, bone conduction implant, and cochlear implant, under 1.5 T and 3.0 T MRI environments were measured and compared with established international standard. Results The ICD, pacemaker, bone conduction implant, and cochlear implant had average torques of 1.405, 0.255, 9.460, and 5.490 N center dot cm under 1.5 T MRI and 2.950, 0.668, 14.618, and 11.484 N center dot cm under 3.0 T MRI, respectively. Discussion The apparatus developed in this study was verified to be feasible for measuring magnetically induced torques, with tests on four types of AIMDs under 1.5 T and 3.0 T MRI environments. Although the designed structure is simple, the apparatus was shown to measure torque values of AIMDs under MRI accurately.