Methods and systems for controlling a state of a neurostimulator

An implantable medical device comprising:

• a magnet sensor configured to generate a signal that varies as a function of whether or not the magnet sensor is in a presence of a magnetic field;
• a timer configured to track a time period over which the magnet sensor continuously detects the magnetic field and to start tracking time when the presence of the magnetic field is detected and to stop tracking time when the presence of the magnetic field is no longer detected;
• and
• a magnet tracking system configured to:
• compare an elapsed time calculated by the timer and corresponding to a period over which the magnetic field is detected to a first interval characterized by a first endpoint and a second interval characterized by a second endpoint,
• maintain the state of the implantable medical device in a current state if the elapsed time corresponds to a time prior to the first endpoint, the current state being on or a therapy enabled state or a therapy disabled state,
• generate an output that causes the implantable medical device to transition from the current state to a different state if the elapsed time corresponds to a time within an interval between the first endpoint and the second endpoint, the different state being:
• 1) the therapy disabled state when the current state is the therapy enabled state, and 2) the therapy enabled state when the current state is the therapy disabled state,
• generate an output that causes the implantable medical device to transition to a predetermined one of either the current state or the different state if the elapsed time is greater than or equal to the second endpoint,
• monitor a number of times the state of the implantable medical device has transitioned from the therapy enabled state to the therapy disabled state within a period of time due to terminations of the elapsed time, and
• prevent the state of the implantable medical device from being changed from the therapy disabled state to the therapy enabled state when the elapsed time terminates between the first endpoint and the second endpoint, and the number of times exceeds a threshold value.