Removing drift from EMG signal

i want to remove the drift from my emg signal that i obtained. i am using the following script

the original emg looks like this:

with the scipt above i get the following detrend:

u can see that the drift isnt completely removed, can anyone see what i am doing wrong or what i can change in my script to get the perfect result around y=0

thanks in advance!

[Star Strider]

One option woould be to calculate the fft of the signal to see where the low-frequency variations are, then using a highpass filter to pass everything above those frequencies. That should eliminate the baseline variations.

It will be necessary to experiment to determine the best cutoff frequency.

Answer 1

[Chunru]

%% detrend
% Remove polynomial trend

t = 0:20;
x = 3*sin(t) + t;
y = detrend(x);
plot(t,x,t,y,t,x-y,':k')
legend('Input Data','Detrended Data','Trend','Location','northwest')