How can I define EMG-Onset Markers?

Hello,

I am trying to analyze 2 EMG-traces. Therefore I need to define burst onset markers.

Here is my script so far:

load('XXX_1_A.mat') %loading my file

D=cell2mat(Data); %transforming from cell to double

X=D(:,1); %trace 1

Y=D(:,2); %trace 2

X1(:,1)=X(1:end-2); X1(:,2)=X(2:end-1); X1(:,3)=X(3:end); Xm=X1(:,2).^2-X1(:,1).*X1(:,3);Xm=Xm/std(Xm);

Y1(:,1)=Y(1:end-2); Y1(:,2)=Y(2:end-1); Y1(:,3)=Y(3:end); Ym=Y1(:,2).^2-Y1(:,1).*Y1(:,3); Ym=Ym/std(Ym);

%Teager-Kaiser algorythm for EMG preprocessing

plot([1:length(Xm)]/1500,abs(Xm)) %plotting both EMG-traces, rectifying, 1500Hz sampling rate

hold

plot([1:length(Ym)]/1500,abs(Ym))

Next I want to manually set onset markers on one (trace 1) of both EMG-traces using "ginput", returning the time point (x-axis). From this time point I need the average of 1sec pre-marker baseline activity of the other (trace 2) trace. As soon as this average baseline activity is exceeded by 3 standard deviations I would like to automatically set a second burst onset marker on trace 2 and return the according time point.

All of this is done to compute the latency between both traces.

How can I implement this?

Thanks! Tom