Ultrasound simulator

Overview

• Any number of moving, intersecting objects can be simulated
• Each object is defined by a surface mesh and its acoustic material properties
• Position and orientation of objects can be obtained in real-time from a tracking device, from pre-recorded files, or tracker simulator
• Individual scanlines are computed using a simple ultrasound physics based model, which includes attenuation, absorption, surface reflection (depending on incidence angle), speckle (using Perlin noise). Refraction, speed of sound, and beamwidth are not modeled.
• Both linear and curvilinear transducer geometry is supported.
• With minor modification in the device set configuration file image acquisition can be switched to use a real ultrasound device.

Device configuration settings

• 
  Type = "UsSimulator"
  
• 
  AcquisitionRate
  

  Default = "30"
• 
  LocalTimeOffsetSec
  

  Default = "0"
• 
  DataSources Exactly one DataSource child element is required
  
  • 
    DataSource
    
    • 
      PortUsImageOrientation
      
    • 
      ImageType
      

      Default = "BRIGHTNESS"
    • 
      BufferSize
      

      Default = "150"
    • 
      AveragedItemsForFiltering
      

      Default = "20"
    • 
      ClipRectangleOrigin
      

      Default = "0 0 0"
    • 
      ClipRectangleSize
      

      Default = "0 0 0"

Example configuration file PlusDeviceSet_Server_SimulatedUltrasound_3DSlicer.xml

<PlusConfiguration version="2.3">

  <DataCollection StartupDelaySec="1.0" >
    <DeviceSet 
      Name="PlusServer: Vascular needle insertion simulation"
      Description="Usage:
* Install 3D Slicer and its SlicerIGT extension (http://www.slicer.org).
* Load the SimulatedUltrasound_Scene.mrb scene file (it is in the configuration directory) into 3D Slicer.
* Change the ProbeToTracker and NeedleToTracker transforms in 3D Slicer to simulate probe and needle movement.

Tool positions are received through OpenIGTLink, simulated images are broadcasted through OpenIGTLink. ProbeToTracker, ReferenceToTracker, NeedleToTracker transforms has to be provided as an input by an OpenIGTLink server.
To use with Ascension tracker instead of a simulated tracker: enable the Ascension3DG device and disable the OpenIGTLinkTracker device. Ports: 1 Probe, 2 Reference, 3 Stylus."
    />
    
    <!--
      For getting transforms from 3D Slicer through OpenIGTLink
      (Slicer requires UseReceivedTimestamps="false", UseLastTransformsOnReceiveTimeout="true")
    -->
    <Device
      Id="TrackerDevice"
      Type="OpenIGTLinkTracker"
      MessageType="TRANSFORM"
      ServerAddress="127.0.0.1"
      ServerPort="18946"
      IgtlMessageCrcCheckEnabled="true"
      UseReceivedTimestamps="false"
      UseLastTransformsOnReceiveTimeout="true"
      LocalTimeOffset="0.0"
      ToolReferenceFrame="Tracker" >
      <DataSources>
        <DataSource Type="Tool" Id="Probe"  />
        <DataSource Type="Tool" Id="Reference"  />
        <DataSource Type="Tool" Id="Needle"  />
      </DataSources>
      <OutputChannels>
        <OutputChannel Id="TrackerStream">
          <DataSource Id="Probe" />
          <DataSource Id="Reference" />
          <DataSource Id="Needle"/>
        </OutputChannel>
      </OutputChannels>
    </Device>    
    <!-- For getting transforms from an Ascension tracker -->
    <!--
    <Device
      Id="TrackerDevice" 
      Type="Ascension3DG" 
      LocalTimeOffsetSec="0.0" 
      FilterAcWideNotch="1"
      ToolReferenceFrame="Tracker" >
      <DataSources>
        <DataSource Type="Tool" Id="Probe" PortName="0"  />
        <DataSource Type="Tool" Id="Reference" PortName="1"  />
        <DataSource Type="Tool" Id="Needle" PortName="2"  />
      </DataSources>
      <OutputChannels>
        <OutputChannel Id="TrackerStream" >
          <DataSource Id="Probe"/>
          <DataSource Id="Reference"/>
          <DataSource Id="Needle"/>
        </OutputChannel>
      </OutputChannels>
    </Device>
    -->

    <!-- For getting images from the US simulator -->
    <Device
      Id="VideoDevice"
      Type="UsSimulator"
      LocalTimeOffsetSec="0.0"
      AcquisitionRate="15" >
      <DataSources>
        <DataSource Type="Video" Id="Video" PortUsImageOrientation="MF" />  
      </DataSources>      
      <InputChannels>
        <InputChannel Id="TrackerStream" />
      </InputChannels>
      <OutputChannels>
        <OutputChannel Id="VideoStream" VideoDataSourceId="Video" />
      </OutputChannels>      
      <vtkPlusUsSimulatorAlgo
        ImageCoordinateFrame="Image"
        ReferenceCoordinateFrame="Reference"
        IncomingIntensityMwPerCm2="300"
        BrightnessConversionGamma="0.2"
        BrighntessConversionOffset="30"
        NumberOfScanlines="128"
        NumberOfSamplesPerScanline="1000"
        NoiseAmplitude="5.0"
        NoiseFrequency="2.5 3.5 1"
        NoisePhase="50 20 0"        
        >
        <SpatialModel
          Name="Air"
          DensityKgPerM3="1.2"
          SoundVelocityMPerSec="343"
          AttenuationCoefficientDbPerCmMhz="100.0"
          BackscatterDiffuseReflectionCoefficient="0.1"
          SurfaceReflectionIntensityDecayDbPerMm="50"
        />
        <SpatialModel
          Name="GelBlock"
          ObjectCoordinateFrame="Reference"
          ModelFile="SimulatedUltrasound_GelBlockModel_Reference.stl"
          DensityKgPerM3="910"
          SoundVelocityMPerSec="1540"
          AttenuationCoefficientDbPerCmMhz="3.0"
          BackscatterDiffuseReflectionCoefficient="0.1"
          SurfaceSpecularReflectionCoefficient="0.1"
          SurfaceDiffuseReflectionCoefficient="0.0"
          TransducerSpatialModelMaxOverlapMm="50"
        />        
        <SpatialModel
          Name="Vessel"
          ObjectCoordinateFrame="Reference"
          ModelFile="SimulatedUltrasound_VesselModel_Reference.stl"
          ModelToObjectTransform="
            1 0 0 0
            0 1 0 0
            0 0 1 0
            0 0 0 1"
          DensityKgPerM3="1800"
          SoundVelocityMPerSec="2000"
          AttenuationCoefficientDbPerCmMhz="0.0001"
          BackscatterDiffuseReflectionCoefficient="0.03"          
          SurfaceSpecularReflectionCoefficient="0.1"
          SurfaceDiffuseReflectionCoefficient="0.0"
        />
        <SpatialModel
          Name="Needle"
          ObjectCoordinateFrame="NeedleTip"
          ModelFile="SimulatedUltrasound_NeedleModel_NeedleTip.stl"
          ModelToObjectTransform="
            1 0 0 0
            0 1 0 0
            0 0 1 0
            0 0 0 1"
          DensityKgPerM3="2000"
          SoundVelocityMPerSec="2000"      
          AttenuationCoefficientDbPerCmMhz="8.0"
          BackscatterDiffuseReflectionCoefficient="0.2"
          SurfaceSpecularReflectionCoefficient="0.1"
          SurfaceDiffuseReflectionCoefficient="0.0"
          SurfaceReflectionIntensityDecayDbPerMm="5"
        />
        <RfProcessing>
          <ScanConversion
            TransducerName="Ultrasonix_L9-4/38"
            TransducerGeometry="LINEAR"
            ImagingDepthMm="60.0"
            TransducerWidthMm="40.0"
            OutputImageSizePixel="820 616"
            TransducerCenterPixel="410 0"
            OutputImageSpacingMmPerPixel="0.084 0.087"/>
          <!-- Example for a curvilinear transducer: -->
          <xScanConversion
            TransducerName="Ultrasonix_C5-2/60"
            TransducerGeometry="CURVILINEAR"
            RadiusStartMm="60.0"
            RadiusStopMm="120.0"
            ThetaStartDeg="-28.0"
            ThetaStopDeg="28.0"
            TransducerCenterPixel="410 100"
            OutputImageSizePixel="820 616"
            OutputImageSpacingMmPerPixel="0.084 0.087" />
        </RfProcessing>
      </vtkPlusUsSimulatorAlgo>

    </Device>

    <!-- For getting images from a real US system -->    
    <!--
    <Device
      Id="VideoDevice"
      Type="SonixVideo" 
      AcquisitionRate="30" 
      LocalTimeOffsetSec="0.0"
      IP="localhost" 
      Depth="50" 
      CompressionStatus="0"
      SoundVelocity="1500">
      <DataSources>
        <DataSource
          Type="Video" Id="Video" PortName="B" PortUsImageOrientation="UF" 
          />
      </DataSources>
      <OutputChannels>
        <OutputChannel Id="VideoStream" VideoDataSourceId="Video"/>
      </OutputChannels>
    </Device>
    -->
    
    <Device 
      Id="TrackedVideoDevice" 
      Type="VirtualMixer" >
      <InputChannels>
        <InputChannel Id="TrackerStream" />
        <InputChannel Id="VideoStream" />
      </InputChannels>
      
      <OutputChannels>
        <OutputChannel Id="TrackedVideoStream"/>
      </OutputChannels>
    </Device>

    <Device
      Id="CaptureDevice"
      Type="VirtualCapture"
      BaseFilename="RecordingTest.igs.mha"
      EnableCapturingOnStart="FALSE" >
      <InputChannels>
        <InputChannel Id="TrackedVideoStream" />
      </InputChannels>
    </Device>

    <Device
      Id="VolumeReconstructorDevice"
      Type="VirtualVolumeReconstructor"
      OutputVolDeviceName="RecVol_Reference">
      <InputChannels>
        <InputChannel Id="TrackedVideoStream" />
      </InputChannels>
      <VolumeReconstruction
        ImageCoordinateFrame="Image" ReferenceCoordinateFrame="Reference"
        Interpolation="LINEAR" Optimization="NONE" CompoundingMode="MEAN" FillHoles="ON" NumberOfThreads="2"
        ClipRectangleOrigin="0 0" ClipRectangleSize="820 616"
        OutputOrigin="60 -10 -15" OutputExtent="0 334 0 396 0 542" OutputSpacing="0.15 0.15 0.15" >
        <HoleFilling>
          <HoleFillingElement
            Type="STICK"     
            StickLengthLimit="9"
            NumberOfSticksToUse="1" />
        </HoleFilling>
      </VolumeReconstruction>
    </Device>
    
  </DataCollection>

  <PlusOpenIGTLinkServer
    MaxNumberOfIgtlMessagesToSend="10"
    MaxTimeSpentWithProcessingMs="50"
    ListeningPort="18944"
    SendValidTransformsOnly="true"
    OutputChannelId="TrackedVideoStream" >
    <DefaultClientInfo>
      <MessageTypes>
        <Message Type="IMAGE" />
        <Message Type="TRANSFORM" />
      </MessageTypes>
      <TransformNames>
        <Transform Name="ProbeToReference" />
        <Transform Name="NeedleTipToReference" />        
      </TransformNames>
    <ImageNames>
      <Image Name="Image" EmbeddedTransformToFrame="Reference" />
    </ImageNames>
    </DefaultClientInfo>
  </PlusOpenIGTLinkServer>

  <CoordinateDefinitions>
    <Transform From="NeedleTip" To="Needle"
      Matrix="
         1 0 0 0
         0 1 0 0
         0 0 1 0
         0 0 0 1" />  
    <Transform From="Image" To="Probe"
      Matrix="
        -0.00228039 0.0860508 -0.00121134 52.5973
        -0.0860501 -0.00229763 -0.00122624 35.9178
        -0.00125802 0.0011783 0.0860722 16.3705
        0 0 0 1"
      Error="0.582721" Date="2012.02.06 17:57:00" />
    <Transform From="Image" To="TransducerOriginPixel"
      Matrix="1 0 0 -410
              0 1 0 5
              0 0 1 0
              0 0 0 1" />    
  </CoordinateDefinitions> 

</PlusConfiguration>