I'm having a problem with my filters IIR . I am trying to filter a ECG (Electrocardiogram) signal through a filter that passes low IIR, and then through a high pass IIR. The problem is that this filter is unstable at first. And because of being unstable, it adds a nonexistent peak early on, stabilizing later.
I tried to use the filter by initializing the output values Y with a value equal to 0 but it still remains unstable at first. I think the values of B and A are correct because I am copying them from a program in python that works correctly.
At this moment I am working on C# (although this will not be very relevant x))
If anyone knows what I meant by this instability at the beginning, I would appreciate it.
Thank you.