Class SCPECG

java.lang.Object
com.pixelmed.scpecg.SCPECG

public class SCPECG extends Object

A class to encapsulate an entire SCP-ECG object.

Typically this class would be used to read an SCP-ECG object from a file, and to do something with the decompressed waveform data values. For example:

try {                   
        BinaryInputStream i = new BinaryInputStream(new BufferedInputStream(new FileInputStream(arg[0])),false);        // always little endian
        SCPECG scpecg = new SCPECG(i,verbose);
        short[][] data = scpecg.getDecompressedRhythmData();
        BinaryOutputStream o = new BinaryOutputStream(new BufferedOutputStream(new FileOutputStream(arg[1])),false);    // little endian
        // write interleaved raw little endian data
        int numberOfChannels = data.length;
        int nSamplesPerChannel = data[0].length;        // assume all the same
        for (int sample=0; sample<nSamplesPerChannel; ++sample) {
                for (int lead=0;lead<numberOfChannels; ++lead) {
                        o.writeSigned16(data[lead][sample]);
                }
        }
        o.close();
}
catch (Exception e) {
        slf4jlogger.error("",e);
}
 

One might want to dump the entire contents of the instance as a string, as follows:

System.err.print(scpecg);
 

or perhaps to display the contents as a JTree:

ApplicationFrame af = new ApplicationFrame();
JScrollPane scrollPane = new JScrollPane();
SCPTreeBrowser browser = new SCPTreeBrowser(scpecg,scrollPane);
af.getContentPane().add(scrollPane);
af.pack();
af.setVisible(true);
 
  • Constructor Details

    • SCPECG

      public SCPECG(BinaryInputStream i, boolean verbose) throws IOException

      Read an SCP-ECG object from an input stream.

      As errors are encountered, they are described on stderr.

      The sections are also validated as they are read, and Section 0 is validated against the other sections.

      Parameters:
      i - the input stream (should have been opened as little endian)
      verbose - if true, then the progress of the read is described
      Throws:
      IOException
  • Method Details

    • getDecompressedRhythmData

      public short[][] getDecompressedRhythmData()

      Get the decompressed rhythm data.

      This includes undecimating and adding in any reference beat.

      Note that interpolation and filtering are NOT applied in the current implementation.

      Returns:
      arrays of samples for each lead
    • getDecompressedReferenceBeatData

      public short[][] getDecompressedReferenceBeatData()

      Get the decompressed reference beat data.

      Returns:
      arrays of samples for each lead
    • toString

      public String toString()

      Dump the object as a String.

      Overrides:
      toString in class Object
      Returns:
      the object as a String
    • getSection1

      public Section1 getSection1()
    • getSection2

      public Section2 getSection2()
    • getSection3

      public Section3 getSection3()
    • getSection4

      public Section4 getSection4()
    • getSection5

      public Section5Or6 getSection5()
    • getSection6

      public Section5Or6 getSection6()
    • getSection7

      public Section7 getSection7()
    • getSection8

      public Section8Or11 getSection8()
    • getSection10

      public Section10 getSection10()
    • getSection11

      public Section8Or11 getSection11()
    • getNumberOfLeads

      public int getNumberOfLeads()

      Get the number of leads.

      Returns:
      the number of leads
    • getNumbersOfSamples

      public long[] getNumbersOfSamples()

      Get the number of samples for each lead.

      Returns:
      an array of the number of samples for each lead
    • getDecompressedRhythmDataSampleTimeInterval

      public int getDecompressedRhythmDataSampleTimeInterval()

      Get the sample time interval that will be applicable to the decompressed rhythm data.

      Note that this is the value after undecimation if the rhythm data was decimated; specifically in such cases it will be the sample time interval of the reference beat.

      Returns:
      the sample time interval in microSeconds
    • getNamedField

      public String getNamedField(String fieldName)

      Get the concatenated values of all the occurences of a named field from Section 1 as a String.

      Returns:
      the values as a String
    • getLeadNames

      public String[] getLeadNames()

      Get the names of the leads from Section 3.

      Returns:
      the names of the leads
    • getLeadNumbers

      public int[] getLeadNumbers()

      Get the numbers of the leads from Section 3.

      Returns:
      the numbers of the leads (using the codes in the standard and encoded in the data)
    • getSectionIterator

      public Iterator getSectionIterator()

      Get an Iterator over all the sections.

      Returns:
      an iterator of objects of type Section
    • main

      public static void main(String[] arg)

      For testing.

      Parameters:
      arg - one, two or three arguments, the input filename, optionally a output raw data filename, and optionally a text dump filename