How can I normalize the baseline of a displacement?

Hello all,

I am working on the analysis of multiple displacement trials (fig.). In order to perform the analysis, I need to normalize the trace, so that all the trials baseline start from 0. Of course I need to shift the displacement according to the shift of the baseline.

Thank you very much!

Answer 1

[Image Analyst]

I'd first identify the spike locations, then interpolate the baseline from what's not a spike. Then I'd subtract that from the original signal. Something like (untested)

% Find spikes.
spikeIndexes = signal > 10;
Extract non-spikes
baseLine = signal(spikeLocations);
% Get continuous x
x = 1 : length(signal);
% Interpolate everywhere
baseline = interp1(x(spikeIndexes), baseline, x);
% Subtract
correctedSignal = signal - baseline;