SAR Object

The Specific Absorption Rate (SAR) is defined as the time derivative of the incremental energy (dW) absorbed by an incremental mass (dm) contained in a volume element (dV) of a given mass density (r). The SAR calculation is done as a post processing step after the simulation, based on a previously defined power loss density monitor.

• Methods

• Default Settings

Methods

Reset

Resets all internal values to their default settings.

PowerlossMonitor ( name sName )

Defines the power loss density monitor that is used for the SAR calculation.

AverageWeight ( double dValue )

Local SAR values refer to a certain volume element, specified by an averaged weight value. Here a cuboid volume is used to calculate the averaged tissue weight, which must be between 0.0001g and 5000g. Default is 10g.

Volume ( double xmin, double xmax, double ymin, double ymax, double zmin, double zmax )

Specifies the volume for which the SAR calculation is performed.

SetLabel ( name sName )

Sets the label for the SAR result files and tree entry.

SetOption ( string option )

Can set options before executing calculation. Available options are:

• "no subvolume": does not use any subvolume specification

• "use subvolume for statistics"

• "subvolume only": limits the SAR calculation on the user defined volume to save execution time.

• "rescale double": The results are scaled to the specified input power value in W(rms).

• "no rescale"

• "scale accepted": Define accepted power as reference.

• "scale stimulated": Define stimulated power as reference.

• "volaccuracy <value>": Sets the fractional accuracy of the averaging volume to <value>.

• "use ar results": The balance from an AR-filter calculation is used, if corresponding results are available.

• "no ar results": The standard balance is used.

The averaging method can be set by the name as seen in the specials dialog.

GetValue ( string name ) double

Takes the name of a SAR calculation result (as in the SAR dialog box) as a string and delivers the corresponding value. (always rms)

• "stimulation"

• "accepted"

• "volume"

• "tissue volume"

• "tissue mass"

• "power"

• "average power"

• "total sar"

• "point sar"

• "max sar"

• "max sar x"

• "max sar y"

• "max sar z"

• "avg vol min x"

• "avg vol min y"

• "avg vol min z"

• "avg vol max x"

• "avg vol max y"

• "avg vol max z"

• "sel volume"

• "sel tissue volume"

• "sel tissue mass"

• "sel power"

• "sel average power"

• "sel total sar"

• "sel point sar"

• "sel max sar"

• "sel max sar x"

• "sel max sar y"

• "sel max sar z"

Create

Executes the SAR calculation. All necessary settings have to be made previously.

Load

Loads the SAR result file previously specified by SetLabel. Use GetValue to query the desired result value.

Default Settings

AverageWeight (10)

SetOption ("IEEE C95.3")

SetOption ("no rescale")

SetOption ("no subvolume")

SetOption ("volaccuracy 0.05")

Example

With SAR

.Reset

.PowerlossMonitor ("loss (f=1.8) [pw]")

.AverageWeight (8)

.SetOption ("CST C95.3")

.SetOption ("rescale 1.0")

.SetOption ("scale accepted")

.Create

MsgBox Str$(.GetValue("max sar"))

End With