Exctracting QT from EKG

Hello everyone!

Basically, I want to extract the QT from an EKG signal, for this I am following some steps from an article. Firstly, I am filtering the signal with a pass-band filter, then I have to apply the coiflet-1 CWT transform(never used it before) due to QT Pattern = (CWT Output)^2 and then choose QRS Pattern(i) = {0 , QT Pattern(i) < A QT Pattern(i), otherwise. This is what I did until now, but i found myself in a moment when i don't know what to do next:

clear all
clc
close all
[filename, pathname] = uigetfile('semnal.dat');
if isequal(filename, 0) || isequal(pathname, 0)   
    disp('File input canceled.');  
   ECG_Data = [];  
else
fid=fopen(filename,'r');
end;
time=10;
f=fread(fid,2*360*time,'ubit12');
semnal=f(1:2:length(f));
figure(1)
plot(semnal)

xlabel('samples');
ylabel('time')


fs = 250;     % Sampling Frequency (Hz)



N=length(semnal);
fs=250;
t=[0:N-1]/fs;
fcutlow=0.5;   %low cut frequency in Hz
fcuthigh=40;   %high cut frequency in Hz
[b,a]=fir1(330,[fcutlow,fcuthigh]/(fs/2),'bandpass');
semnal_filtrat=filter(b,a,semnal)
figure(2)
plot(t,semnal_filtrat)

%CTW 


x = [1, 2, 3, 4];
scales = [9];
wavelet_name = 'coif2';
coefs = cwt(x,scales, wavelet_name)

I am waiting for any idea, thank you!!