Temperature-dependent Dispersion Characteristics of Rayleigh Waves in Soft Tissues

The frequency-dependent shear modulus of a soft tissue gives rise to dispersion of (otherwise nondispersive) Rayleigh waves, the measurement of which can offer a means to study various surface properties of the tissue. Among the factors that influence the shear modulus (hence Rayleigh-wave dispersion) of a tissue is temperature, where the shear modulus often decreases with increasing temperature. In this talk, we discuss the temperature dependence of dispersion characteristics of Rayleigh waves propagating along the surface of soft tissues. Rayleigh-wave spectroscopy was performed at temperatures ranging from 25 to 40 °C using soft tissue phantoms that closely mimicked the physical properties human dermis. It was found that Rayleigh-wave dispersion exhibits high sensitivity to change in temperature, which could be used in real-time, noninvasive monitoring of skin temperature.