Implantable medical devices, and methods of use therewith, that detect MRI systems with enhanced specificity

A method for use with an implantable medical device (IMD) that is implanted within a patient, wherein the IMD includes a magnetic field sensor and an accelerometer and the IMD is capable of mode switching to a magnetic resonance imaging (MRI) safe mode, the method comprising:

• using the accelerometer to determine whether a positional condition associated with the patient is detected;
• controlling sampling of the magnetic field sensor or at least one signal output therefrom, based on the positional condition associated with the patient, wherein the controlling sampling includes
• during a first period of time, during which the positional condition is detected, using a first sampling rate to perform the sampling of the magnetic field sensor or the at least one signal output therefrom, and
• during a second period of time, during which the positional condition is not detected, using a second sampling rate that is slower than the first sampling rate to perform the sampling of the magnetic field sensor or the at least one signal output therefrom, to thereby conserve power;
• determining, based on results of the sampling, whether a magnetic field condition is detected, which when detected is indicative of the patient likely being within or otherwise exposed to an MRI system;
• and
• performing a mode switch to the MRI safe mode in response to determining, based on results of the sampling, that the magnetic field condition is detected.