SCOUT: Skull-Corrected Optimization for Ultrasound Transducers

Area of Science:

• Neurosurgery
• Biomedical Engineering
• Acoustic Physics

Background:

• Transcranial focused ultrasound offers non-invasive treatment for brain diseases.
• The skull significantly distorts ultrasound waves, causing issues like pressure drop and defocusing.
• Accurate ultrasound focusing is crucial for effective and safe transcranial therapies.

Purpose of the Study:

• To develop an optimization algorithm for determining the optimal transducer placement for transcranial focused ultrasound.
• To mitigate the effects of skull-induced aberrations on ultrasound focus.
• To enhance the safety and success rate of non-invasive brain treatments using focused ultrasound.

Main Methods:

• An optimization algorithm was developed to simulate and compare ultrasound beam profiles at various transducer locations.
• The algorithm identified optimal locations by first finding those with sufficient normalized peak-negative pressure (PNP) and then selecting the one with the smallest focal volume.
• A Zeta navigation system was employed for automated transducer placement and error tracking.

Main Results:

• The algorithm successfully identified an optimal transducer location.
• This optimal location achieved a normalized PNP of 0.966.
• The focal volume at the optimal location was 6.8% smaller compared to focusing without considering the skull's effect.

Conclusions:

• The developed algorithm effectively finds optimal transducer positions to counteract skull-induced focus shift and defocusing.
• Integration with the Zeta navigation system allows for precise and automated transducer positioning.
• This approach significantly enhances the safety and efficacy of transcranial focused ultrasound treatments.