FOCUS SPLITTING ASSOCIATED WITH PROPAGATION OF FOCUSED ULTRASOUND THROUGH THE RIB CAGE.

Area of Science:

• Acoustics
• Biomedical Engineering
• Medical Physics

Background:

• Focused ultrasound (FUS) is a non-invasive therapeutic technology.
• Propagation of FUS through bone structures like the rib cage can alter beam characteristics.
• Understanding these alterations is crucial for effective FUS applications in thoracic regions.

Purpose of the Study:

• To theoretically investigate the phenomenon of focus splitting of FUS after propagation through a rib cage.
• To identify the underlying mechanism causing focus splitting.
• To derive analytical estimates for focus splitting parameters.

Main Methods:

• Theoretical investigation of wave propagation.
• Analysis of wave interference from spatially separated sources (intercostal spaces).
• Derivation of analytical estimates for focus splitting parameters.

Main Results:

• Focus splitting is caused by wave interference from multiple sources, such as intercostal spaces.
• Analytical estimates for the number, amplitude, diameter, and distance of foci were obtained.
• The study identified optimal rib cage and radiator configurations for effective FUS delivery.

Conclusions:

• Rib cage anatomy significantly impacts FUS beam focusing.
• Understanding focus splitting is essential for optimizing FUS treatments in the thorax.
• The findings provide guidance for planning FUS procedures involving the rib cage.