Multiple-focus ultrasound phased-array pattern synthesis: optimal driving-signal distributions for hyperthermia

Area of Science:

• Medical Physics
• Acoustic Engineering
• Biomedical Engineering

Background:

• Hyperthermia treatment requires precise control of energy deposition in target tissues.
• Ultrasonic phased arrays offer potential for non-invasive thermal therapy.
• Current methods may face challenges in achieving complex focal patterns and efficient energy delivery.

Purpose of the Study:

• To develop and validate a computational method for synthesizing multiple-focus ultrasonic fields.
• To enable precise control over power deposition at specific points within a treatment volume.
• To optimize driving signals for efficient energy transfer in ultrasonic hyperthermia.

Main Methods:

• A computational method for calculating array element amplitude and phase distributions.
• Direct synthesis of multiple-focus field patterns using ultrasonic phased arrays.
• Weighting of the complex excitation vector to manage signal dynamic range.

Main Results:

• The method successfully produces desired field levels at specified control points.
• It allows for adjustment of complex pressure to achieve targeted power deposition and avoid hot spots.
• Weighting of the excitation vector reduces driving signal dynamic range without altering relative field levels.

Conclusions:

• The described method is a powerful tool for hyperthermia treatment planning.
• It facilitates precise control over thermal dose delivery using ultrasonic phased arrays.
• The approach enhances efficiency and safety in non-invasive thermal therapies.