Integrated Real-Time Therapy and Monitor Study of a Dual-Frequency Focusing Transducer Based on Vibroacoustic Signals

Area of Science:

• Biomedical Engineering
• Acoustic Physics
• Medical Imaging

Background:

• Accurate temperature monitoring is critical for High-Intensity Focused Ultrasound (HIFU) therapy.
• Traditional methods like MRI thermometry have limitations in cost and real-time performance.

Purpose of the Study:

• To develop and validate a novel temperature monitoring and control strategy for HIFU therapy.
• To utilize Ultrasound-Stimulated Acoustic Emission (USAE) signals combined with Vibro-Acoustography (VA) for real-time assessment of tissue temperature and damage.

Main Methods:

• Employed dual-frequency HIFU transducers for synchronous acquisition of dual-frequency confocal excitation and USAE signals.
• Conducted validation experiments on graphite models, ex vivo bovine heart tissue, and in vivo tissue.
• Integrated USAE signal analysis with VA technology for comprehensive monitoring.

Main Results:

• USAE signal amplitude and temperature showed a positive correlation before tissue injury.
• Demonstrated linear temperature increase in graphite models (0.65°C/s, R²=0.98) and rapid rise in bovine heart tissue (7.31°C/s, R²=0.96).
• Observed decreased USAE signal amplitude and reduced temperature change rate upon thermal coagulation, consistent with tissue structural evolution.

Conclusions:

• USAE signal-based temperature feedback is applicable to HIFU therapy.
• Provides a foundation for real-time, non-invasive acoustic feedback systems.
• Enhances safety and efficacy of HIFU treatments through accurate temperature monitoring.