zea.beamform.pfield

Pressure field computation for ultrasound imaging.

This module provides routines for automatic computation of the acoustic pressure field used for compounding multiple transmit (Tx) events in ultrasound imaging.

The pressure field is computed by simulating the acoustic response of the probe and medium for each transmit event. The computation involves:

  • Subdividing each probe element into sub-elements to satisfy the Fraunhofer approximation.

  • Calculating the distances and angles between each grid point and each sub-element.

  • Computing the frequency response of the probe and the pulse spectrum.

  • Summing the contributions from all relevant frequencies, taking into account transmit delays, apodization, and directivity.

  • Optionally normalizing and thresholding the resulting field for use in transmit compounding or adaptive beamforming.

The main entry point is compute_pfield(), which returns a normalized pressure field array for all transmit events.

Functions

normalize_pressure_field(pfield[, alpha, ...])

Normalize the input array of intensities by zeroing out values below a given percentile.
zea.beamform.pfield.normalize_pressure_field(pfield, alpha=1.0, percentile=10.0)[source]

Normalize the input array of intensities by zeroing out values below a given percentile.

Parameters:

  • pfield (array) – The unnormalized pressure field array of shape (n_tx, grid_size_z, grid_size_x).

  • alpha (float, optional) – Exponent to ‘sharpen or smooth’ the weighting. Higher values result in sharper weighting. Default is 1.0.

  • percentile (int, optional) – minimum percentile threshold to keep in the weighting. Higher is more aggressive. Default is 10.

Returns:

Normalized intensity array.

Return type:

ops.array