Interferometric technique to measure shock-induced surface velocities in tissues for the determination of dynamic mechanical properties

摘要

Abstract: We present an interferometric technique to measure free surface velocities of a tissue phantom when subjected to a high power laser pulse. Such information is useful for the determination of the dynamic mechanical properties of tissues and tissue phantoms. We deliver a 4-nanosecond doubled Nd:YAG laser pulse to a tamped surface of a slab sample and probe the opposite free surface with a HeNe laser beam. The stress-wave induced motion of the rear-surface imparts a Doppler shift to the reflected HeNe probe. We monitor the Doppler shift with a velocity interferometer sensitive to velocities as low as 1 - 2 m/s. !9