Problems reading a .mat ECG file into the biosignal viewer

[PA_UW]

Hi there,

I am new to the biomedical workbench and I am trying to read in a .mat ECG file into the biosignal viewer and it keeps saying file not supported.  I have searched for what format of .mat file is supported - but haven't found anything.  My data is stored as three channels of U8 data - so just a 2d array of U8s.

I have also tried reading a .mat file that I converted from the physionet ATM and I that would not load either.  Does anyone have experience with this?

Thanks so much for your help!

[Haier_Xu]

Hi,

Could you paste your .mat ECG file here or send it to me (haier.xu@ni.com)?

Thanks!

Haier Xu

[Haier_Xu]

Hi Jennifer,

The .mat file you sent to me can be loaded successfully using Biosignal Viewer 2012 on my test machine. Perhaps you should reinstall biomedical workbench and try to load this file again. Keep me posted on the results. Thanks:)

Haier Xu

[PA_UW]

I just uninstalled and reinstalled and I can't open the file...  so weird!

[PA_UW]

Is there something special that I have to do once the program is open?  I just selct the file from the bottom left control and then the error pops up...

[PA_UW]

I just tried resaving my file in matlab transposed so that the channels are in columns not rows and this seemed to work.  Did you somehow do this automatically when loading the file in the biosignal viewer?

Thanks

[PA_UW]

one more quick question - how do you set the SF and gain and base for the biosignal viewer when loading a .mat file?  I can't seem to change the SF...

[Haier_Xu]

Hi,

Normally, you need just browse the File path to load your testECG.mat file by using Biosignal Viewer without other operations. The following snapshot shows the result of testECG.mat file on a clean test machine with 2012 Biomedical Workbench installed.

Workaround:  you could use File format Converter application in the Biomedical Workbench to convert your files from .mat to TDMS, and then use Biomedical Viewer to open the TDMS files. Only TDMS files allow to add and save annotations in Biosignal Viewer. Refer to the document https://decibel.ni.com/content/docs/DOC-23864

for details.

For 2012 version, we haven't supported changing sampling rate or other channel properties.

Thanks!

Haier Xu