I am using AD8232 as ECG front end for developing ambulatory ECG device. AD8232 is said to reject electrode offsets as large as ±300 mV. According to the standard ANSI/AAMI/IEC 60601-2-47, I need to verify this by supplying a sine wave of 4 Hz (1mv) embedded with ±300 mV dc offset and verifying that there is no more than 10% change in output amplitude of the sine wave. However I observe that the sine wave shrinks by more than half with -300mV offset. How can I solve this? I am using CARDIAC MONITOR CONFIGURATION circuit of the AD8232 datasheet. In the Test circuit switches S1 and S2 are closed. AC voltage is a 1v 4Hz sine wave which is attenuated to 1mV with the resistor network.