Attenuation Constant

Attenuation Constant

The following table contains values for the acoustic attenuation of all tissues and includes statistical information on the standard deviation and the spread in the values. 

For attenuation, a frequency dependence of the form α=α0*fb is assumed, where α (Np/m) is the absorption coefficient for a given frequency f, α0 (Np/m/Hz) is a medium constant, and b is also a numerical constant dependent on the tissue type. In the absence of information (e.g., data points that permit fitting) b is assumed to be 1. For the attenuation relationship, the parameters α and b are obtained by fitting the available data. Whenever a source provides a frequency dependence over a given frequency range, that function is sampled throughout the interval, with a ratio between neighboring frequencies of 1.2 to provide data points for the fit.


expBody ='';return 'Tissue' 'Attenuation Constant (Np/m)'
expRow = d['B'+r];d['B'+r] var freq=parseFloat($('#freqField').val())*parseFloat($('#scale').val()); var a0=parseFloat(d['BX'+r]); var b=parseFloat(d['BY'+r]); var att=a0*Math.pow(freq,b); expRow += "\t" + att + "\n"; if (d['B'+r] != null){ expBody += expRow }; return sprintf('%g',att)