While performing biopotential measurements on the MAX30003/1, 60Hz noise may dominate the ECG signal. Here are some tips for reducing this noise, which is coupled to the body and leads from nearby AC electrical wiring.
- Disconnect the power supply and other peripherals and run off a battery. Isolate your body and board from AC power.
- Reduce sampling rate to 128sps (reasoning below).
- Enable software filters on GUI (60Hz notch filter).
- Connect the third VCM lead to bias the body and reduce common mode noise.
- Twist ECG leads together and keep the leads and board close to the body.
The digital LPF in the biopotential channel has a transfer function that depends on the sampling rate. At 128sps, the filter has a notch right at 60Hz, so the noise is filtered more aggressively. At higher sampling rates, it is recommended to add a software notch filter at 60Hz.