MATLAB: How can i plot the ECG from this txt file

ecg

I got txt files of ecg records, but i can not open them. Can somebody help me.

Best Answer

That has to be the strangest format for an EKG file I have ever seen. There appear to be 9 different leads. (It appears to demonstrate ‘electrical alternans’, possibly secondary to pericardial effusion or tamponade. I do not see any T-waves.)

This seems to work, at least for the file you attached:

fidi = fopen('956.txt','rt');
D = textscan(fidi, 'A%sA%sA%sA%sA%sA%sA%sA%sA%s', 'CollectOutput',1);
EKG = str2double(D{:});
figure
plot(EKG(:,1))                                          % Plot Channel #1
grid
% axis([0  500    ylim])

You need to determine the sampling frequency so that you can create the appropriate time vector for your EKG, and do any signal processing on it that you want.

Experiment to get the result you want.

Related Solutions

MATLAB: FFT of signal from text file

I don’t see the error in your code, but the code here I wrote (plotting half of the fft) works:

fidi = fopen('John Smith emg.txt', 'rt');
T_EMG = textscan(fidi, '%f%f', 'Delimiter',' ');
t = T_EMG{1};
EMG = T_EMG{2};
L = length(t);
Ts = mean(diff(t));                                 % Sampling Time
Fs = 1/Ts;                                          % Sampling Frequency
Fn = Fs/2;                                          % Nyquist Frequency
FEMG = fft(EMG)*2/L;                                % Fourier Transform (Normalised)
Fv = linspace(0, 1, fix(L/2)+1)*Fn;                 % Frequency Vector
Iv = 1:length(Fv);                                  % Index Vector
figure(1)
plot(Fv, abs(FEMG(Iv)))
grid

MATLAB: How to use FFT in matlab using imported data in time domain excel file

Use the examples in the documentation on fft (link) to calculate the Fourier transform.

Example Code For Your Signal —

[d,s] = xlsread('1.5V.csv');
t = d(:,1)*1E-3;                                        % Convert To ‘seconds’ From ‘milliseconds’
v = d(:,2);                                             % Voltage (?)
L = length(t);
Ts = mean(diff(t));                                     % Sampling Interval (sec)
Fs = 1/Ts;                                              % Sampling Frequency
Fn = Fs/2;                                              % Nyquist Frequency
vc = v - mean(v);                                       % Subtract Mean (‘0 Hz’) Component
FTv = fft(vc)/L;                                        % Fourier Transform
Fv = linspace(0, 1, fix(L/2)+1)*Fn;                     % Frequency Vector (Hz)
Iv = 1:length(Fv);                                      % Index Vector
figure(1)
plot(Fv, abs(FTv(Iv))*2)
grid
xlabel('Frequency (Hz)')
ylabel('Amplitude (V?)')

I did not post the plot, since my code will plot the Fourier transform of your data.

Best Answer

Related Solutions

MATLAB: FFT of signal from text file

MATLAB: How to use FFT in matlab using imported data in time domain excel file

Related Question