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How do I filter TDMS voltage traces after acquisition?

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Simple question. We have acquired a lot of electrophysiological data using signal express. We now need to filter the data after acquisition for further analysis. I can import the TDMS Voltage files from previous experiments but can't seem to run the filters we used on the acquisition side to filter the already acquired traces. Is there a simple way to do this?

 

-smb

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Hello Chinchilla,

 

Can you further describe what software are you planning to use to process the data. Are you going to use LabVIEW, CVI, Visual Studio?

 

Based on that I believe I can provide you information on how to read the data from the TDMS and then apply the processing.

 

Regards,

Randy @Rscd27@
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I was hoping to process from Signal Express, but we do have LabView so help on loading TDMS data and filtering in that environment would be greatly appreciated. Our acquisitons are for several hours and at 4096 samples per second. A simple low-pass filter to eliminate sporadic noise from a heating system is needed to clean up our electrophysiological traces.

 

In the future is there a way to save the filtered output that I see in Signal Express?

 

-smb

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Solution
Accepted by topic author chinchilla

Hello Chinchilla,

 

I am attaching some screenshots on how to add a filtering step to an analog input. You can select the type of filter and the order too.

 

Screenshot_1.jpg

 

In this screenshot you can verify how to change the configuation of the filter

 

Screenshot_2.jpg

 

Finally you can access the TDMS file from LabVIEW with one of the examples of TDMS. Please follow these instructions:

 

1- Open LabVIEW

2- Go to Help>Find Examples to open the "Example Finder"

3- Go to Fundamentals>File Input and Output>TDMS>Standard Read and Write and select the VI named TDMS Read Events.vi

Screenshot_3.jpg

You will need to be aware of the data present in the file to be able to read it properly. For this you can use the TDMS File Viewer VI:

 

http://zone.ni.com/reference/en-XX/help/371361K-01/glang/tdms_file_viewer/

 

Or you can use the Toolkit for excel: http://www.ni.com/example/27944/en/ (This will allow to transfer the data to Microsoft Excel).

 

4- After Reading the data you will have to apply a filter. You can find the filter Functions in the Signal Processing Palette.

 

Screenshot_4.jpg

 

Please let me know if you have any question about this.

 

Regards,

Randy @Rscd27@
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Thanks for the detailed solution. We do use the filter step in our Signal Express acquisition runs but cannot access the fully filtered trace after saving so the Labview walk-thru was extremely helpful.

 

Warmest Regards,

 

smb

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