Patent ID: 8679019

Claim:
A method for measuring thicknesses of materials of a multilayered structure, comprising: transmitting one or more ultrasound signals including different frequencies into the multilayered structure, comprising two or more materials, with one or more ultrasound transducers; measuring the materials, based on known acoustic properties which are different at the frequencies in use; measuring the materials of the multilayered structure, based on speed of sound and attenuation coefficient, wherein the attenuation coefficients are different for materials and frequencies in use; measuring and correcting an effect of overlying soft tissue on acoustic measurement of bone by measuring the ultrasound signals reflected from an interface between the soft tissue and the bone with the same one or more ultrasound transducers; determining thicknesses of the tissue layers within the overlying soft tissue from the reflected ultrasound signals; wherein reflection of the ultrasound signal from the interface of soft tissue and bone is measured, and wherein the time of flight and frequency spectrum of the reflection are calculated, wherein frequency spectrum is compared to frequency spectrum of a reference measurement, wherein the reflection coefficients from the interface of soft tissue and bone at two or more different frequencies are determined, wherein values for speed of sound and attenuation coefficients and measured time of flight and reflection coefficients are used to calculate thicknesses of the tissue layers within the overlying soft tissue structure, and using the information on thicknesses of the tissue layers within the overlying soft tissue structure, wherein the soft tissue effect on the ultrasound measurement of the bone is removed and corrected values of the bone parameters are calculated.