ADS1298: There has some issue that the ECG output can‘t been display normally when the power of ADS1298 from unipolar supplies

Part Number:ADS1298

Dear sir，

       There has some issue that the ECG output can‘t been display normally when the power of ADS1298 from unipolar supplies. After measuring ，the input impedance and the CMRR of ADS1298 is unnormal and it is impossible to identify the waveform.But the work is ok when  the power of ADS1298 from bipolar supplies. So could you help give some advice about the issue when the power of ADS1298 from unipolar supplies and share the refer design （SCH&User manual）about the power of ADS1298 from unipolar supplies 

Thanks a lot

The SCH is as below