Exam B-RX

From WikiSonix
Jump to: navigation, search

Exam 6.0.3[edit]

B-RX.jpg

Receive Beam Forming[edit]

Starting version 6.x. The Rx aperture curve is no longer used. Instead, a fixed F-number is used to determine the aperture size for each focal depth. This parameter can be set through:

  • Rx F Number

The correct Sound Velocity is needed for properly calculating the delays in the delay-and-sum algorithm of the beam forming. The value for most soft tissue is 1540 m/s.

  • Sound Velocity

Apodization: The pre beam forming RF data from different elements in the aperture are weighted according to an apodization function such as Guassian or Hanning. The B Weidth Type selects this function.

  • B Weight Type (0: Boxcar, 1-12: different versions of Hanning, 13: Hamming, 14: Blackman)

Note: The following parameters reside in the menu from the earlier versions, but are deprecated and have no effect in this version of the software:

  • Rx Aperture
  • Rx Aperture Max
  • Rx Curve Depth
  • Use Rx Aperture (Accum)
  • Rx Aperture (Accum)
  • Rx Aperture Max (Accum)
  • Rx Curve Depth (Accum)

Exam 5.x[edit]

Receive Beam Forming[edit]

The aperture opening for different depths is determined through a curve, Rx Aperture, which represents the receive aperture as a function of elements vs depth (see System Curves). The maximum number of elements that can be in the receive aperture is determined by Rx Aperture Max. Value represents half the aperture, as all calculations are symmetrical. The maximum depth at which the Rx Aperture Curve is valid for is determined by Rx Curve Depth. All depths beyond this value will use the last calculated value of the curve at this depth.

  • Rx Aperture
  • Rx Aperture Max
  • Rx Curve Depth

If the sequence involves multiple acquisitions of each scan line through the Accumulator parameter, a second aperture opening curve can be programmed for a second scan line. The use of the second aperture curve is determined by the Use Rx Aperture (Accum) parameter. The Accumulator MUST be set to two.

  • Use Rx Aperture (Accum)
  • Rx Aperture (Accum)
  • Rx Aperture Max (Accum)
  • Rx Curve Depth (Accum)

The correct Sound Velocity is needed for properly calculating the delays in the delay-and-sum algorithm of the beam forming. The value for most soft tissue is 1540 m/s.

  • Sound Velocity