I recorded my ECG with ADS1298 and loaded it using matlab to do post-processing.
However, I found a strange pheonomenon.
I used 60 Hz notch filter to reduce 60 Hz noise, but the filtered signal was distorted as shown below figure.
I think the 60 Hz componet did not reduce in that point, what is the reason? and how can I solve it?
My matlab code and raw data was attached.