Influences of biological structural features on the acoustic nonlinearity parameter B/A

The influences of structural factors of biological media on the acoustic nonlinearity parameter B/A were studied at tissue, cellular and molecular levels, using both the thermodynamic method and the finite amplitude method. Experiments were designed to measure the B/A changes by altering structural factors of media physically and biochemically, while keeping chemical compositions unchanged. Evidences were found to support significant structural dependences of the B/A at all three levels. Further analysis suggests that about 26% of dry weight contribution to the total B/A, the B/A value with water contribution subtracted, is due to cell-cell adhesive force in liver tissues, 20% to the hepatocyte cellular structure, and 15% to the molecular structure of protein. No significant B/A changes were observed between the in vivo and in vitro B/A values in cat livers and during the digestion of protein. In addition, it is found that B/A exhibits an unusually large value near the phase transition regions of liposomes, suggesting the effect of relaxational processes on the B/A value. Finally, implications of the above findings are discussed in the light of the previous studies on the compositional dependence of B/A, and a possible rationale by which the B/A depends on both the chemical composition and structural factors is suggested.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Zhang, Jian

Contributors dc:contributor

• Dunn, Floyd

• Engineering, Biomedical
• Biophysics, Medical

Statement dc:rights

• Copyright 1990 Zhang, Jian

Language dc:language

eng

Identifier

AAI9021780
(UMI)AAI9021780

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20285