Nonlinear Acoustics in Ultrasound Metrology and other Selected Applications.

Area of Science:

• Ultrasound Physics
• Biomedical Engineering
• Materials Science

Background:

• Initial skepticism regarding nonlinear (NL) wave propagation in biological tissues.
• Development of wideband piezoelectric polymer hydrophone probes to investigate NL effects.
• Verification of nonlinear distortion and harmonic generation in diagnostic ultrasound waves (1-5 MHz) within tissue.

Purpose of the Study:

• Review the implications of piezoelectric polyvinylidene fluoride (PVDF) polymer.
• Present advances in ultrasound metrology driven by regulatory bodies (FDA, IEC).
• Discuss therapeutic, cosmetic, and industrial applications of nonlinear ultrasonics (NLU).

Main Methods:

• Design and utilization of wideband piezoelectric polymer hydrophone probes.
• Development of absolute calibration techniques and spatial averaging corrections for hydrophones (up to 100 MHz).
• Implementation of acousto-optic sensors for "point-receiver" hydrophone probes.

Main Results:

• Confirmation of nonlinear distortion and harmonic generation in diagnostic ultrasound waves.
• Advancements in ultrasound metrology enabling precise measurements.
• Demonstration of NLU's efficacy in therapeutic and cosmetic applications.

Conclusions:

• Piezoelectric polymer hydrophones were crucial in verifying nonlinear wave propagation in tissue.
• Significant progress in ultrasound metrology has been achieved.
• Nonlinear ultrasonics (NLU) offers a wide range of applications, including therapeutic, cosmetic, and industrial uses.