medical electronics III

AC couplingThe other problems we had were with DC offset, drift and motion artefact. All of these problems are caused by very low-frequencies (DC is zero frequency), so we need to use a high-pass filter with a very low cutoff frequency. We need to keep the cutoff frequency very low to avoid degrading the ECG signal, so the capacitor needs to be large (0.47 or 1 uF) and the resistor similarly large (e.g. 1 MW).

Labels: AC Coupling