Methods and devices for monitoring brain functions by magnetic field measuring of MEG signal via an ear cavity
An example device includes a first magnetoresistance sensor configured for detecting magnetoencephalography (MEG) signals from a first ear cavity of a user. The example device also includes a first enclosure configured to magnetically shield the first magnetoresistance sensor. The first magnetoresistance sensor is positioned entirely within the first enclosure, and the first enclosure has an opening through which the first magnetoresistance sensor is configured to detect the MEG signals propagated from the user to the opening of the first enclosure. The example device further includes circuitry coupled to the first magnetoresistance sensor and configured to monitor brain function of the user based on the MEG signals. Methods for detecting a magnetic field from an ear cavity with a magnetoresistance sensor are also disclosed.
1 . An ear-based brain function monitoring device, comprising:
a first magnetoresistance sensor positioned within a first enclosure and configured for detecting a magnetic field to measure magnetoencephalography (MEG) signals from a first ear cavity of a user, the magnetic field containing indications of brain function of the user;
the first enclosure configured to magnetically shield the first magnetoresistance sensor from environmental magnetic noise, wherein the first enclosure has an opening through which the magnetic field from the first ear cavity enters the first enclosure to be detected by the first magnetoresistance sensor;
a second magnetoresistance sensor positioned within a second enclosure and configured for detecting a second magnetic field from a second ear cavity, the second magnetic field containing second indications of the brain function of the user; and
one or more processors coupled with the first magnetoresistance sensor and the second magnetoresistance sensor; and
memory storing instructions for execution by the one or more processors, the stored instructions including instructions for:
receiving, from the first magnetoresistance sensor, first signals indicating the magnetic field from the first ear cavity;
receiving, from the second magnetoresistance sensor, second signals indicating the second magnetic field from the second ear cavity;
comparing the magnetic field from the first ear cavity and the second magnetic field from the second ear cavity by comparing the first signals and the second signals; and
monitoring the brain function of the user based on the comparing.
2 . The device of claim 1 , wherein the first magnetoresistance sensor is positioned entirely within the first enclosure.
3 . The device of claim 1 , wherein at least a portion of the first magnetoresistance sensor is positioned outside the first enclosure.
4 . The device of claim 1 , further comprising one or more signal filters for filtering noises in signals from the first magnetoresistance sensor.
5 . The device of claim 1 , further comprising a first flux concentrator coupled with the first magnetoresistance sensor.
6 . The device of claim 1 , wherein:
the second magnetoresistance sensor is positioned entirely within the second enclosure; and
the second enclosure has an opening through which the second magnetoresistance sensor detects a change in the second magnetic field.
7 . The device of claim 1 , wherein at least a portion of the second magnetoresistance sensor is positioned outside the second enclosure.
8 . The device of claim 1 , further comprising one or more signal filters for filtering noises in signals from the second magnetoresistance sensor.
9 . The device of claim 1 , further comprising a second flux concentrator coupled with the second magnetoresistance sensor.
10 . The device of claim 1 , wherein the stored instructions include instructions for determining a delay between the first signals and the second signals.
11 . The device of claim 1 , wherein the stored instructions include instructions for:
determining a peak amplitude of the first signals;
determining a peak amplitude of the second signals; and
comparing the peak amplitude of the first signals and the peak amplitude of the second signals.
12 . The device of claim 1 , further comprising a sound generator configured to generate audio signals that are provided to the user to induce a response from the user that is measurable by the first magnetoresistance sensor.