Patent ID: 8469891
Filing Date: 2013-06-25
Classification: A61B

Abstract:
1. In a non-transitory computer readable storage medium having stored therein data representing instructions executable by a programmed processor for measuring a viscoelastic property of tissue in vivo, the storage medium comprising instructions for: transmitting an amplitude modulated and phase modulated waveform including carrier cycles at different frequencies at different times, the different frequencies being in a range of frequencies, the amplitude modulated and phase modulated waveform comprising a sinusoidal carrier multiplied by a sinusoidal amplitude modulation with a phase varying term such that an envelope of the sinusoidal amplitude modulation includes at least two envelope cycles with each of the envelope cycles separating the sinusoidal carrier at the different frequencies or groups of the different frequencies, the amplitude modulated and phase modulated waveform transmitted to the tissue in a patient; calculating displacement as a function of time of the tissue in response to the amplitude modulated and phase modulated waveform, the displacement calculated from scans of the tissue, the calculating displacement comprising scanning the tissue with ultrasound interleaved with the transmitting, the interleaving synchronized with the envelope; applying a Fourier transform to the displacement over time; and determining the viscoelastic property from a Fourier transform of a shear wave equation and the Fourier transform of the displacement over time.