signal processing (segmentation in time domain)

how i can segment ECG signal in real time domain (not numbers of samples) , like this :

sig=ecgsignal;
t=timevalues;
x=[t,sig];
sig1=x(.34:4);% from .34 second to second 4 .
sig2=x(6:8.5);

Answer 1

[Adam]

sig1 = sig( t >= 0.34 && t <= 4 );
sig2 = sig( t >= 6 && t <= 8.5 );

If you also need the t vector then apply it similarly. Just pull out the logic from there into two variables and apply them to both sig and t.

Or, index into x in the same way to get both times and signal values.