Photoacoustic cell for ultrasound contrast agent characterization

Area of Science:

• Biomedical Optics
• Acoustics
• Materials Science

Background:

• Photoacoustics is increasingly used in biomedical applications.
• Microbubbles are crucial as ultrasound contrast agents in echographic imaging.
• Characterizing microbubble shell properties is essential for optimizing their performance.

Purpose of the Study:

• To design and realize a photoacoustic sensor for analyzing photothermal signals from microbubble solutions.
• To model the microbubble shell using an effective surface tension parameter.
• To evaluate the sensor's reliability for testing ultrasound contrast agents.

Main Methods:

• A closed-cell photoacoustic sensor acting as a Helmholtz resonator was developed.
• Photothermal volume variations in microbubble solutions caused membrane deflection.
• Laser probe interferometry measured membrane displacement.
• A laser chopped light beam generated photoacoustic signals.
• Resonance frequency shifts were analyzed to determine surface tension.

Main Results:

• The photoacoustic sensor successfully analyzed photothermal signals from microbubble solutions.
• The microbubble shell was modeled using an effective surface tension parameter.
• The shift in resonance frequencies was significant and reliable.
• The sensor proved effective for bubble shell characterization.

Conclusions:

• The developed photoacoustic sensor is a reliable tool for testing ultrasound contrast agents.
• The sensor enables accurate characterization of microbubble shell properties.
• This technology has potential for advancing ultrasound imaging and diagnostics.