Feasibility study for removing calcified material using a planar rectangular ultrasound transducer

Area of Science:

• Biomedical Engineering
• Medical Physics

Background:

• Investigating novel methods for treating atherosclerosis.
• Developing minimally invasive techniques for plaque removal.

Purpose of the Study:

• To assess the feasibility of using a 5.3 MHz MRI-compatible transducer for destroying calcified material in vitro.
• To evaluate the potential application in treating arterial atherosclerosis.

Main Methods:

• Testing an MRI-compatible flat rectangular transducer (3 mm × 10 mm) on calcium rods and a hydroxyapatite-polylactide model.
• Performing a parametric study varying intensity, pulse repetition frequency (PRF), and duty factor (DF).
• Monitoring temperature to ensure operation in pure mechanical mode (below 1°C increase).

Main Results:

• Calcified material removal was directly proportional to ultrasound intensity, PRF, and DF.
• The presence of bubbles significantly accelerated the removal of calcified material.
• Controlled experiments confirmed mechanical mode ultrasound was employed.

Conclusions:

• Ultrasound parameters (intensity, PRF, DF) directly influence the efficacy of calcified material removal.
• Bubbles enhance the mechanical disruption of calcified deposits.
• The developed method shows promise for future in vivo applications in treating vascular calcifications.