Read Biosignal Express VI

Owning Palette: Biomedical File I/O Express VIs

Requires: Biomedical Toolkit

Reads biosignals from files. This VI reads biosignals block by block and supports reading multiple channels and reading annotations.

Details  Examples

Dialog Box Options

Block Diagram Inputs

Block Diagram Outputs

Dialog Box Options

Parameter	Description
File path	Specifies the path to the file from which this VI reads biosignals.
File contents	Lists all the channel groups and channels in the file that you specify in File path. You can select one or multiple channels. You cannot select multiple channels that belong to different groups.
Annotation/comment list	Lists all the annotations and comments in the channel group that you select in File contents.
Configure annotation details	Specifies the configuration of the annotation type. This option displays the Configure Annotation Details dialog box.
Show the selected annotation/comment	Specifies whether to show the annotations and comments in Waveform Graph.
Output all annotations/comments	Specifies whether this VI returns all the annotations or comments of the channel group that you specify.
Properties	Specifies the properties of the channel that you specify. Channel selection—Specifies the channel for which you want to display the properties. Channel properties—Displays the properties of the channel that you specify in Channel selection.
Waveform Values	Displays the waveform values of the channel that you specify. Waveform selection—Specifies the channel for which you want to display the waveform values. Waveform values—Display the waveform values of the channel that you specify in Waveform selection.
Waveform Graph	Displays the preview of the channel that you specify. Start—Specifies the start time of the channel to preview, in seconds. Start must be greater than 0. The default is 0. Block size—Specifies the block size of the signals, in seconds, each time this VI loads from file. This also impacts the window size. Block size must be greater than 0. The default is 1. Signal preview—Displays the preview of the channel that you specify.

Block Diagram Inputs

Parameter	Description
file path	Specifies the path of the file from which you want to read biosignals. The value you wire to this input overrides the value you specify in the configuration dialog box.
group name in	Specifies the name of the channel group from which you want to read biosignals. The value you wire to this input overrides the value you specify in the configuration dialog box. If you wire value to file path and leave this input unwired, this VI reads the first group from the file that you specify.
channel names in	Specifies the name of the channel from which you want to read biosignals. The value you wire to this input overrides the value you specify in the configuration dialog box. If you wire value to file path and leave this input unwired, this VI reads all channels from the group that you specify.
start	Specifies the position, in seconds, where this Express VI starts to read the biosignal from the file.
error in (no error)	Describes error conditions that occur before this node runs.
block size	Specifies the size, in seconds, of the blocks of data that this Express VI reads from the biosignal.
initialize?	Specifies whether to read the file from the start index again. The default is FALSE.

Block Diagram Outputs

Parameter	Description
biosignals	Returns the biosignals that this VI reads from the files.
group name out	Returns the name of the channel group from which this VI reads biosignals.
channel names out	Returns the name of the channel from which this VI reads biosignals.
EOF?	Returns TRUE if the output of this VI reaches the end of the file that you want to read.
error out	Contains error information. This output provides standard error out functionality.
annotations	Returns the annotation information that this VI reads from the files.
comments	Returns the comments that this VI reads from the files.

Read Biosignal Details

This VI supports reading biosignals from files in the following file types:

• TDMS (.tdms)
• LVM (.lvm)
• MATLAB® (.mat)
• PhysioBank Database (.hea)
• Axon Instruments data file formats (.abf)
• TDM (.tdm)
• Audio (.mp3, .wma, .wav)
• CSV (.csv)
• European Data Format (.edf, .rec)
• HL7_aECG (.hl7)
• SCP (.scp)
• ACQ (.acq)
• EMGWorks (.emg)
• AstroMed (.dcr)
• C3D (.c3d)
• DDF (.ddf)
• iWorx (.iwxdata)
• Plexon (.ddt)

Examples

Refer to the following VIs for examples of using the Read Biosignal VI:

• Read Biosignals from Different File Formats VI: labview\examples\Biomedical\Biosignal
• Biosignal File Format Converter VI: labview\examples\Biomedical\Biosignal
• Read Annotation and Comment VI: labview\examples\Biomedical\Biosignal
• Biosignal Preprocessing Comparison VI: labview\examples\Biomedical\Biosignal
• ECG Feature Extractor VI: labview\examples\Biomedical\Biosignal