6. Conclusion

This article presents a range of methods based on the application of the standard pulse-echo technique. Emphasis is deliberately placed on the determination of elastic or viscoelastic behavior laws.

Of course, the applications and experimental methods are so numerous that to be exhaustive is impossible. This is why the reader will find in the literature other more "exotic" methods not presented here. For example, since ultrasonic velocity is temperature-dependent, it is possible to design non-invasive ultrasonic thermometers using the pulse-echo method. This approach has been successfully applied in power ultrasound treatment of prostate tumors, and has recently been applied in cardiac surgery to complement infrared analysis