Convert ECG signal waveform into text file

Hi.

I want to ask is it possible to convert ECG signal waveform into text file? And if it is possible how to perform it?

I am able to load the ecg data file in .mat file from database and processed it through according to the matlab code written.

Answer 1

[KALYAN ACHARJYA]

Steps:

%load the mat file 
data=load('mat_file.mat');
%Save the data in txt file 
dlmwrite('filename.txt',data)

[NOORAISYAH NABILAH]

Thank you for the reply sir.

However, the second command to save the data in txt file, error as follow popped up:

Undefined function 'real' for input arguments of type 'struct'.

Error in dlmwrite (line 181)

str =

sprintf('%.*g%+.*gi',precn,real(m(i,j)),precn,imag(m(i,j)));

[KALYAN ACHARJYA]

Can you attach a sample ECG mat file?

[NOORAISYAH NABILAH]

Here I attached the file.

[Walter Roberson]

%load the mat file 
data=load('mat_file.mat');
%Save the data in txt file 
dlmwrite('filename.txt',data.val(:))

The (:) will force it to write one value per line; the current data is a row of data values.

[NOORAISYAH NABILAH]

The .mat has successfully converted into .txt. Thank you sir for your help.

If I may ask sir, the data values written in the .txt file reflect which waveform? Is it the R peak only or all the points of the ECG signal?

[KALYAN ACHARJYA]

@NOORAISYAH NABILAH All the data points. @Walter Roberson Thanks Sir

[NOORAISYAH NABILAH]

Okay, thank you sir KALYAN ACHARJYA. Thank you sir @Walter Roberson.

[NOORAISYAH NABILAH]

Sir @Walter Roberson @KALYAN ACHARJYA, how can we distinguish datapoints of the x and y axis of the waveform. I mean it only have the amplitude value of the waveform. How can we know the x axis value (time (s)) corresponding with the y axis value (amplitude)?

How to convert with both values and time?

[Walter Roberson]

@NOORAISYAH NABILAH

time = (0:length(val)-1)/Fs;

Here Fs needs to be the sampling frequency, in hertz (cycles per second.)

Nothing in the .mat file has information about the sampling frequency; you cannot deduce it from the data itself. You would need to find it as external information.