Typical tracking results of tissue displacement waveform of an elderly female human subject.

<p>(a) obtained under 0% MVC level (at rest), (b) 50% MVC level, and (c) 100% MVC level. The corresponding shear moduli for (a) to (c) were 9 kPa, 213 kPa, and 574 kPa. The solid line represents the tissue displacement waveforms detected at the proximal location, and the dashed line at the distal location, with reference to the vibration source.</p

Correlation between the shear modulus values assessed by indentation method and the corresponding values measured by the vibro-ultrasound method.

<p>Correlation between the shear modulus values assessed by indentation method and the corresponding values measured by the vibro-ultrasound method.</p

Diagram of the vibro-ultrasound system for shear wave velocity measurement using two ultrasound scan lines (left) and the position of the ultrasound probe and the vibrator during the experiment on one human subject (right).

<p>The three positions of the vibrator used for the different vibro-beam distance test were also indicated.</p

The averaged VI shear modulus of ten elderly healthy female subjects and that of ten young healthy female subjects, plotted with the different relative isometric contraction levels (% MVC torque).

<p>The error bar represents the standard deviation among the 10 subjects.</p

Comparison of the shear moduli between (a) 15 mm and 20 mm; and (b) 25 mm and 20 mm, revealed that the vibrator-beam distance appeared to affect very little on the measurement result of shear modulus.

<p>Comparison of the shear moduli between (a) 15 mm and 20 mm; and (b) 25 mm and 20 mm, revealed that the vibrator-beam distance appeared to affect very little on the measurement result of shear modulus.</p