Electrode impedance measurement

A system comprising:

• at least one data processor;
• and
• memory storing instructions which, when executed by the at least one data processor, result in operations comprising:
• monitoring electrocardiogram (ECG) electrodes each electrically connected to a patient body and a corresponding current source;
• injecting one of a plurality of currents, each current having a respective predetermined level, into each ECG electrode;
• measuring a plurality of ECG electrode voltages generated by the plurality of currents;
• selecting a first reference ECG electrode from the monitored ECG electrodes, wherein unselected ECG electrodes include a plurality of non-reference ECG electrodes and a neutral drive electrode;
• adjusting the plurality of currents after measuring the plurality of ECG electrode voltages while maintaining the respective predetermined level through the first reference ECG electrode;
• and
• determining a plurality of impedances, each impedance corresponding to each non-reference ECG electrode, based on the plurality of ECG electrode voltages and the plurality of currents.

A computer programmable product comprising a computer-readable storage medium having computer-readable instructions stored in the computer-readable storage medium for executing the operations comprising:

• monitoring electrocardiogram (ECG) electrodes each electrically connected to a patient body and a corresponding current source;
• injecting one of a plurality of currents, each current having a respective predetermined level, into each ECG electrode;
• measuring a plurality of ECG electrode voltages generated by the plurality of currents;
• selecting a first reference ECG electrode from the monitored ECG electrodes, wherein unselected ECG electrodes include a plurality of non-reference ECG electrodes and a neutral drive electrode;
• adjusting the plurality of currents after measuring the plurality of ECG electrode voltages while maintaining the predetermined level through the first reference ECG electrode;
• and
• determining a plurality of impedances, each impedance corresponding to each non-reference ECG electrode of the ECG electrodes, based on the plurality of ECG electrode voltages and the plurality of currents.