Hi,
can you please help me with AC lead-off detection. I'm designing mobile EEG device with 24 channels. I need to measure impedance of the electrodes. I'm planing to do this with AC lead-off and current source of 6nA with frequency of the Fdr/4. Can I measure continuously impedance in that way, or I must apply current source externally? Can you also please tell me how can I separately measure impedance of the electrode on non-inverting and inverting input? I need this because my electrode configuration is next: three ADS1299 IC with shorted inverting inputs to one point (reference electrode) and 24 non-inverting inputs (EEG channels). Can I also measure impedance of the electrode connected to the DRL (Driven Right Leg circuit)?
Best regards,
Vojin Ilic