      Ultrasound Beamformer Program FocusInstall.exe - Ultrasound Beamformer - Written by Kevin Aylward B.Sc. This program calculates data associated with medical imaging ultrasound beamformers, such as what delays, apodization (gaussian amplitude weightings) and when are they required to focus sound at specific depths. It was written a while back, so uses a hlp file format not directly supported on Windows 7/ Vista. However, you can download a fix from MS.   Technical Notes Number of Elements The number of elements for a given focal depth is determined from the following equations: Linear Array:  Beamwidth = Pitch Aperture = Number of elements × Pitch Number of elements = 1.22 Velocity × Focal distance ÷ Beamwidth ÷ Frequency ÷ Aperture Convex Array: Beamwidth = Pitch × (Radius + Focal Distance) ÷ Radius Aperture = 1.22 Velocity × Focal distance ÷ Beamwidth ÷ Frequency ÷ Beamwidth Angle = arccos(1 - 0.5 × Aperture × Aperture ÷ Radius ÷ Radius) Number of elements = Angle × Radius ÷ Pitch Differential Beam Delay The delay difference of the beam is given by the following equations: X = element number × Pitch depth = Focal distance Linear Array:  delta distance = depth - sqrt(depth×depth-2×depth×X×sin(beam_angle)+X×X) delta time = delta distance ÷ velocity Convex Array: k = sqrt(depth×depth+radius×radius+2×depth×radius×cos(beam_angle)) psi = asin(depth/k×sin(beam_angle)) theta = X/radius - psi; delta distance = dept - sqrt(k×k+radius×radius-2× k×radius×cos(theta));  Annular Arrays: The beam angle is the beam angle swept out per scan line of the sector. Aperture = 1.22 × velocity / frequency / beam angle  The nearest average diameter to the required aperture is selected from the list of element rings © Kevin Aylward 2013 All rights reserved Website last modified 27th April 2013 www.kevinaylward.co.uk 