System and method for testing contact quality of electrical-biosignal electrodes

A method comprising:

• receiving selection of a set of channels of interest;
• selecting a first subset of sense electrodes, in a set of sense electrodes integrated into an electroencephalography headset, corresponding to the set of channels of interest;
• selecting a second subset of sense electrodes, in the set of sense electrodes, differing from the first subset of sense electrodes;
• during a test period beginning at a first time:
• outputting a drive signal through a driven electrode integrated into the electroencephalography headset worn by a user, the drive signal comprising an alternating-current component oscillating at a reference frequency and a direct-current component;
• reading a first set of sense signals from the first subset of sense electrodes;
• reading a second set of sense signals from the second subset of sense electrodes;
• in response to a second sense signal read from a second sense electrode in the second subset of sense electrodes excluding a first signal component oscillating at the reference frequency at a second time succeeding the first time, detecting abnormal contact between the the user's skin and the second sense electrode;
• and
• in response to detecting abnormal contact between the user's skin and the second sense electrode, deactivating the second sense electrode.

A method comprising:

• receiving selection of a set of channels of interest;
• selecting a first subset of sense electrodes, in a set of sense electrodes integrated into an electroencephalography headset, corresponding to the set of channels of interest;
• during a test period, outputting a drive signal through a driven electrode integrated into the electroencephalography headset worn by a user, the drive signal comprising an alternating-current component oscillating at a reference frequency and a direct-current component;
• over a first duration within the test period:
• reading a first set of sense signals from the first subset of sense electrodes;
• calculating a first linear combination of the first set of sense signals;
• and
• adjusting the direct-current component of the drive signal according to the first linear combination;
• over a second duration within the test period:
• reading a second set of sense signals from the first subset of sense electrodes;
• in response to a second sense signal read from a first sense electrode in the first subset of sense electrodes excluding a first signal component oscillating at the reference frequency, detecting abnormal contact between the user's skin and the first sense electrode;
• calculating a second linear combination of the second set of sense signals less the second sense signal;
• and
• adjusting the direct-current component of the drive signal according to the second linear combination.