RESUMO
Objective To measure the shear modulus of biological tissues by using Zener model so as to overcome the limitation of Voigt model-based ultrasound vibrometry, and to provide effective approaches of tissue characterization. Methods The mechanical constitutive relation-based shear wave propagation velocity formula was utilized to estimate the shear modulus in terms of the velocities at multiple frequencies via mathematical methods. To obtain shear wave velocities in different objects, experiments were conducted by using different consistencies-based gelatin models and thermally damaged porcine livers as subjects, in which shear waves were induced by ultrasound radio forces. Results Voigt and Zener models were utilized to fit the velocities respectively. The Zener model exhibited higher fitting accuracy than the Voigt model, and the shear modulus could well distinguish gelatin models with different consistencies or porcine livers of different damage degrees. Conclusions The method in this paper provides a potential means of measuring the shear modulus of biological tissues non invasively, which is very promising for tissue characterization and disease diagnosis in medicine.