A Harmonic Dual-Frequency Transducer for Acoustic Cluster Therapy

Area of Science:

• Biomedical Engineering
• Oncology
• Acoustic Technologies

Background:

• Acoustic Cluster Therapy (ACT) is an emerging cancer treatment utilizing microbubbles and microdroplets.
• ACT aims to improve drug delivery to tumors via ultrasound-induced microbubble cavitation.
• Current pre-clinical studies require complex setups with multiple transducers.

Purpose of the Study:

• To design and test a novel dual-frequency ultrasound transducer for Acoustic Cluster Therapy (ACT).
• To evaluate the transducer's suitability for pre-clinical in vivo studies of ACT on murine tumor models.
• To simplify the experimental setup for ACT research.

Main Methods:

• Developed a dual-frequency transducer using the 5th harmonic (2.7 MHz) and fundamental (0.5 MHz) of a single piezoceramic disk.
• Optimized beam alignment using different aperture radii for high-frequency and low-frequency outputs.
• Conducted in vitro and in vivo experiments, using murine kidneys as tumor surrogates for validation.

Main Results:

• The dual-frequency transducer successfully generated both high-frequency (2.7 MHz) and low-frequency (0.5 MHz) ultrasound.
• The 5th harmonic (2.7 MHz) demonstrated 44% efficiency, sufficient for evaporating microbubble/microdroplet clusters.
• In vivo tests confirmed the transducer's efficacy in mimicking ACT requirements, replacing a cumbersome two-transducer system.

Conclusions:

• The developed dual-frequency transducer is effective and suitable for pre-clinical in vivo studies of Acoustic Cluster Therapy.
• This innovation simplifies experimental setups, facilitating further research into ACT for cancer treatment.
• The 5th harmonic's efficiency supports its use in ACT applications.