public DicomWaveformGroup GetWaveformGroup(
int index
)
public:
DicomWaveformGroup^ GetWaveformGroup(
int index
)
index
The zero-based index of the group to retrieve.
DicomWaveformGroup object which holds the waveform group attributes and data.
In DICOM, a waveform consists of one or more multiplex groups, each encoded into an item in the "Waveform Sequence" (5400,0100). Call this method to extract the specified multiplex group. This method populates the returned object with the multiplex group attributes and for each channel in the group, adds a new channel by calling the AddChannel method.
This is the main method for extracting waveforms from a DICOM Data Set. Call the methods defined either by DicomWaveformGroup or DicomWaveformChannel, providing you comprehensive DICOM waveform support.
using Leadtools;
using Leadtools.Dicom;
public void InsertECGCWaveform(DicomDataSet inputDS, short[] samples, int count)
{
// Our new waveform group
DicomWaveformGroup ECGWaveformGroup = new DicomWaveformGroup();
// Reset the waveform group, we don't
// really need to call this!
ECGWaveformGroup.Reset();
// Set the number of samples per channel. You can call
// DicomWaveformGroup.GetNumberOfSamplesPerChannel to get
// the number of samples
ECGWaveformGroup.SetNumberOfSamplesPerChannel(count);
// Set the sampling frequency. You can call
// DicomWaveformGroup.GetSamplingFrequency to
// get the sampling frequency
ECGWaveformGroup.SetSamplingFrequency(240.00);
// Set sample interpretation
ECGWaveformGroup.SetSampleInterpretation(DicomWaveformSampleInterpretationType.Signed16BitLinear);
// Just in case!
Debug.Assert(ECGWaveformGroup.GetSampleInterpretation() == DicomWaveformSampleInterpretationType.Signed16BitLinear);
// No Multiplex Group Time Offset
// You can call DicomWaveformGroup.GetMultiplexGroupTimeOffset
// to get the time offset
ECGWaveformGroup.SetMultiplexGroupTimeOffset(false, 0.0);
// No Trigger Time Offset
// You can call DicomWaveformGroup.GetTriggerTimeOffset
// to get the trigger time offset
ECGWaveformGroup.SetTriggerTimeOffset(false, 0.0);
// No Trigger Sample Position
// You can call DicomWaveformGroup.GetTriggerSamplePosition
// to get the trigger sample position
ECGWaveformGroup.SetTriggerSamplePosition(false, 0);
// Waveform originality is original
ECGWaveformGroup.SetWaveformOriginality(DicomWaveformOriginalityType.Original);
// Just in case!
Debug.Assert(ECGWaveformGroup.GetWaveformOriginality() == DicomWaveformOriginalityType.Original);
// Set the multiplex group label
ECGWaveformGroup.SetMultiplexGroupLabel("SCPECG Waveform");
Debug.Assert(ECGWaveformGroup.GetMultiplexGroupLabel() == "SCPECG Waveform");
// Set the Waveform padding value
// You can call DicomWaveformGroup.GetWaveformPaddingValue
// to get the waveform padding value
ECGWaveformGroup.SetWaveformPaddingValue(true, 32768);
InsertECGCChannel(ECGWaveformGroup, samples, count);
// Delete any waveform groups that already exist in the dataset
for (int index = 0; index < inputDS.WaveformGroupCount; index++)
{
inputDS.DeleteWaveformGroup(index);
}
// Insert the new waveform group into the dataset
inputDS.AddWaveformGroup(ECGWaveformGroup, 0);
}
// Add an ECG channel to the group
void InsertECGCChannel(DicomWaveformGroup ECGWaveformGroup, short[] samples, int count)
{
// Add a channel to the group
DicomWaveformChannel ECGChannel = ECGWaveformGroup.AddChannel(1);
if (ECGChannel == null)
{
return;
}
// If we want to update a channel, we can first call
// DicomWaveformGroup.DeleteChannel and then call
// DicomWaveformGroup.AddChannel with the same
// index we passed to DeleteChannel
// Make sure that the channel really got added
// This is for the purposes of this sample only, because
// the check we did in the previous statement is enough
if ((ECGWaveformGroup.ChannelCount != 1) ||
(ECGWaveformGroup.GetChannel(0) == null))
{
return;
}
// We can call DicomWaveformChannel.GetWaveformGroup to access the waveform
// group that the channel belongs to
if (ECGChannel.Index != 0)
{
return;
}
/*
Set the channel samples
The data we are setting in here is 16 bit data.
We would call SetChannelSamples8 if the data were 8 bit.
We can also call SetChannelSamples32, which will set the data
as either 8-bit or 16-bit depending on the sample interpretation
*/
if (ECGChannel.SetChannelSamples16(samples, count) != count)
{
return;
}
if ((ECGChannel.GetChannelSamples() == null) || (ECGChannel.GetChannelSamplesCount() == 0))
return;
// Set the channel source and sensitivity
SetChannelSourceAndSensitivity(ECGChannel);
// Set the channel status
ECGChannel.SetChannelStatus(DicomChannelStatusType.OK);
if (ECGChannel.GetChannelStatus() != DicomChannelStatusType.OK)
{
return;
}
// Set the channel time skew. You can call
// LDicomWaveformChannel::GetChannelTimeSkew to get the time skew
// You can also call DicomWaveformChannel.SetChannelSampleSkew
// And DicomWaveformChannel.GetChannelSampleSkew to set and get
// the channel samples skew
ECGChannel.SetChannelTimeSkew(0.000000);
// Set the waveform channel number
ECGChannel.SetWaveformChannelNumber(true, 0);
if (ECGChannel.GetWaveformChannelNumber() != 0)
return;
// Set the channel label
ECGChannel.SetChannelLabel("First Channel");
if (ECGChannel.GetChannelLabel() != "First Channel")
return;
// No channel offset
// You can also call DicomWaveformChannel.GetChannelOffset
// To get the channel offset
ECGChannel.SetChannelOffset(false, 0.0);
// Set filter low frequency
// You can also call DicomWaveformChannel.GetFilterLowFrequency
// To get the filter low frequency
ECGChannel.SetFilterLowFrequency(true, 0.050);
// Set filter high frequency
// You can also call DicomWaveformChannel.GetFilterHighFrequency
// To get the filter high frequency
ECGChannel.SetFilterHighFrequency(true, 100.00);
// Set the channel minimum value
ECGChannel.SetChannelMinimumValue(true, -386);
// Set the channel maximum value
ECGChannel.SetChannelMaximumValue(true, 1264);
if (ECGChannel.GetChannelMinimumValue() != -386)
return;
if (ECGChannel.GetChannelMaximumValue() != 1264)
return;
/*
You can also call the following functions to set and get the notch
filter frequency and bandwidth
DicomWaveformChannel.SetNotchFilterFrequency
DicomWaveformChannel.GetNotchFilterFrequency
DicomWaveformChannel.SetNotchFilterBandwidth
DicomWaveformChannel.GetNotchFilterBandwidth
*/
// Last, but not least, set the channel annotations!
SetChannelAnnotations(ECGChannel);
}
//Set the channel source and sensitivity
void SetChannelSourceAndSensitivity(DicomWaveformChannel channel)
{
// Let's use the DICOM context group tables!
///////////////////////Channel Source/////////////////////////
// Load the ECG Leads table
DicomContextGroupTable.Instance.Load(DicomContextIdentifierType.CID3001);
DicomContextGroup ECGLeadsGroup = DicomContextGroupTable.Instance.Find(DicomContextIdentifierType.CID3001);
Assert.IsNotNull(ECGLeadsGroup);
DicomContextIdentifierType type = ECGLeadsGroup.ContextIdentifier;
DicomCodedConcept codedConcept = DicomContextGroupTable.Instance.FindCodedConcept(ECGLeadsGroup, "MDC", "2:1");
Assert.IsNotNull(codedConcept);
using (DicomCodeSequenceItem codeSequenceItem = new DicomCodeSequenceItem())
{
codeSequenceItem.CodeValue = codedConcept.CodeValue;
codeSequenceItem.CodingSchemeDesignator = codedConcept.CodingSchemeDesignator;
codeSequenceItem.CodingSchemeVersion = codedConcept.CodingSchemeVersion;
codeSequenceItem.CodeMeaning = codedConcept.CodeMeaning;
// Set the channel source
channel.SetChannelSource(codeSequenceItem);
}
///////////////////////Channel Sensitivity////////////////////////
using (DicomCodeSequenceItem sourceSequenceItem = new DicomCodeSequenceItem())
{
sourceSequenceItem.CodeValue = "mV";
sourceSequenceItem.CodingSchemeDesignator = "UCUM";
sourceSequenceItem.CodingSchemeVersion = string.Empty;
sourceSequenceItem.CodeMeaning = "millivolt";
// Set the channel sensitivity
channel.SetChannelSensitivity(true, 0.001220, sourceSequenceItem, 1.0, 0.0);
}
}
// Add annotations for the channel
void SetChannelAnnotations(DicomWaveformChannel channel)
{
// Delete any existing channel annotations
for (int index = 0; index < channel.GetAnnotationCount(); index++)
{
if (channel.GetAnnotation(index) != null)
{
channel.DeleteAnnotation(index);
}
}
DicomWaveformAnnotation waveformAnnotation = new DicomWaveformAnnotation();
DicomCodeSequenceItem codedName = new DicomCodeSequenceItem();
codedName.CodeValue = "8867-4";
codedName.CodeMeaning = "Heart rate";
codedName.CodingSchemeDesignator = "LN";
codedName.CodingSchemeVersion = "19971101";
waveformAnnotation.CodedName = codedName;
//Over here we can access other properties such as
// waveformAnnotation.CodedValue and waveformAnnotation.UnformattedTextValue
DicomCodeSequenceItem measurementUnits = new DicomCodeSequenceItem();
measurementUnits.CodeValue = "{H.B.}/min";
measurementUnits.CodeMeaning = "Heart beat per minute";
measurementUnits.CodingSchemeDesignator = "UCUM";
measurementUnits.CodingSchemeVersion = "1.4";
waveformAnnotation.MeasurementUnits = measurementUnits;
waveformAnnotation.SetNumericValue(new double[] { 69.00 }, 1);
channel.AddAnnotation(waveformAnnotation);
}