ECG Analysis in MATLAB

I need help figuring out how to input an ECG trace into MATLAB so I can run FFT and AMSA on it during VF. I currently have PDF files of LifePak 15 defibrillator patient records. Is there any way to input these ECG traces into MATLAB either from the original PDFs or a different export feature on LifePak15?

[Asad Mirza]

Do the PDF files have the ECG waveform as a graph itself or does it have a data table of all the voltages with time?

[Shannon Allen]

It has the waveforms as a graph (trace) (example below)

[Star Strider]

If the EKG is an image, you would need to use image processing applications to digitize it, retaining the voltage and time calibrations. Search the File Exchange (link) for an appropriate function first, so you do not have to write it yourself.

If you can get numeric data from the defibrillator, importing it is easy.

Answer 1

[Asad Mirza]

It's a shame that the data is not a different color from the black grid lines. You should first use a program such as WebPlotDigitizer to extract the data from the graph. Another similar program that's MATLAB based instead is GRABIT.

Once you have the data on hand you could use some openly available MATLAB toolboxes to analyze and run the FFT on them such as plot-ecg or easily write your own using MATLAB's built in FFT function.

[Shannon Allen]

Thanks, this was really helpful! I was able to extract the data from the waveform, but I am having trouble plotting the data using plot-ecg (I'm still relatively inexperienced with MATLAB) How can I plot my data set in the plot-ecg program?

[Asad Mirza]

The inputs you need should just be the time vector (x values) and the voltages (y values). Could you post the data for the graph you extracted?