ADS1298R: ECG 12 Lead Power Consumption

I have used AD8232 to get the ECG data, 

I have tested AD8232 before and confirmed its power consumption mentioned in the datasheet. Function of the AD8232 is working absolutely fine according to the datasheet.
However, I want to increase the number of leads for the ecg to acquire 12 lead ecg data,  i have gone through the datasheet of the ADS1298R, it is showing that it has the power consumption of the Low Power: 0.75 mW/channel, so want to understand what does it mean?

if i am using single channel ecg from this chip will i get the power consumption of 0.75mW, what would be it in mA?. I just use standard calculation as per below image, if power consumption is 0.75mW/Channel with constant 3.3v, then power consumption every hour would be 227uA?. is that correct? 

AD8232 Chip has power consumption of 170nA, in comparison to the ADS1298R, it is quite high, let me know if the calculations done by me is correct or not?.

so if i calculate for the 12 lead it would be around 2727 uA.