Question

Which of the following amplifier circulatory is employed to reduce the hum noise generated by the power supply in the ECG circuit?

(a) band pass filters

(b) high pass filters

(c) notch filters

(d) low pass filters

Answer 1

The correct option is (c) notch filters

The best I can explain: A notch filter is employed to suppress the hum noise generated by the power supply in the ECG circuit. CMRR of the order of 100–120 dB with 5 kW unbalance in the leads is a desirable feature of ECG machines. The instability of the baseline, originating from the changes of the contact impedance, demands the application of the automatic baseline stabilizing circuit.