Sean‘s pick this week isedfReadbyBrett Shoelson.

EDF Read

A MATLAB user asked me yesterday if we have support for the binary file formatEDF, short for “European Data Format”. I’d never heard of it. However, apparently my colleague, Brett, had already written a reader for it.

[hdr, record] = edfread('ecgca998.edf');

Step 1 of 2: Reading requested records. (This may take a few minutes.)... Step 2 of 2: Parsing data...

The function returns the header information and a matrix where each row is the data for that variable.

disp(hdr)

ver: 0 patientID: 'X F X Gestation_32+3 ' recordID: 'Startdate 29-JAN-2004 X X X ' startdate: '29.01.04' starttime: '23.38.00' bytes: 2048 records: 45 duration: 5 ns: 7 label: {1×7 cell} transducer: {1×7 cell} units: {'mV' 'mV' 'uV' 'uV' 'uV' 'uV' ''} physicalMin: [-5 -5 -500 -500 -500 -500 -1] physicalMax: [5 5 500 500 500 500 1] digitalMin: [-32768 -32768 -32768 -32768 -32768 -32768 -32768] digitalMax: [32767 32767 32767 32767 32767 32767 32767] prefilter: {1×7 cell} samples: [5000 5000 5000 5000 5000 5000 500] frequency: [1000 1000 1000 1000 1000 1000 100]

Today, it might be easier to store some of this as a table.

T = array2table(record','VariableNames', hdr.label); T.Properties.VariableUnits = hdr.units; T.Properties.VariableDescriptions = hdr.transducer;

head(T)

ans = 8×7 table Thorax_1 Thorax_2 Abdomen_1 Abdomen_2 Abdomen_3 Abdomen_4 EDFAnnotations ________ ________ _________ _________ _________ _________ ______________ -1.0331 -0.22179 -22.133 -22.21 -22.118 -22.194 0.37633 -1.04 -0.5642 -50.866 -28.13 -66.934 -20.958 0.15688 -1.0117 -0.54879 -50.942 -26.009 -65.759 -23.262 0.33596 -0.98688 -0.53689 -51.553 -27.901 -67.681 -25.368 0.36086 -0.99832 -0.53887 -52.346 -28.832 -66.781 -25.841 0.4078 -1.0159 -0.54238 -48.867 -28.527 -65.621 -24.559 0.15792 -1.0304 -0.54986 -47.585 -31.67 -67.407 -24.331 0.64312 -1.0468 -0.56466 -48.409 -34.203 -70.184 -25.444 0.1588

summary(T)

Variables: Thorax_1: 225000×1 double Properties: Units: mV Description: AgAgCl electrodes Values: Min -5 Median -0.33333 Max 5 Thorax_2: 225000×1 double Properties: Units: mV Description: AgAgCl electrodes Values: Min -5 Median -0.18532 Max 5 Abdomen_1: 225000×1 double Properties: Units: uV Description: AgAgCl electrodes Values: Min -500 Median -13.603 Max 500 Abdomen_2: 225000×1 double Properties: Units: uV Description: AgAgCl electrodes Values: Min -500 Median -4.2649 Max 500 Abdomen_3: 225000×1 double Properties: Units: uV Description: AgAgCl electrodes Values: Min -500 Median -7.7745 Max 500 Abdomen_4: 225000×1 double Properties: Units: uV Description: AgAgCl electrodes Values: Min -500 Median -2.2354 Max 500 EDFAnnotations: 225000×1 double Values: Min 0 Median 0 Max 0.65097

Comments

Give it a try and let us know what you thinkhereor leave acommentfor Brett.

Get the MATLAB code

Published with MATLAB® R2018b