An Ultrasound Array of Emitter-Receiver Stacks for Microbubble-Based Therapy

Area of Science:

• Biomedical Engineering
• Acoustics
• Medical Devices

Background:

• Traditional therapeutic ultrasound systems face a trade-off between emission efficiency and reception sensitivity due to separate emitter and receiver placements.
• This limitation impacts the effectiveness and safety of procedures using long therapeutic pulses.

Purpose of the Study:

• To develop a novel therapeutic ultrasound array that overcomes the limitations of traditional designs by integrating emitters and receivers.
• To enable effective short-pulse ultrasound therapy by enabling simultaneous emission and reception from the same location.

Main Methods:

• Developed a multi-element array using stacked lead zirconate titanate (PZT) emitters and polyvinylidene fluoride (PVDF) receivers.
• Assembled 32 emitter-receiver elements into a 3D-printed dome-shaped frame with a 150 mm focal length.
• Tested the array's performance in free-field and through an ex-vivo human skull, measuring peak-negative pressure and electronic steering capabilities.

Main Results:

• The array achieved a focal size of 4.5 × 4.5 × 32 mm in free-field, producing a peak-negative pressure (PNP) of 2.12 MPa.
• Demonstrated electronic steering capabilities of ±15 mm laterally and >±15 mm axially.
• Successfully produced a PNP of 0.63 MPa through an ex-vivo human skull and localized microbubble emissions.

Conclusions:

• The developed stacked emitter-receiver array effectively overcomes traditional trade-offs in therapeutic ultrasound devices.
• This technology represents a significant advancement for short-pulse and microbubble-based therapeutic ultrasound applications.
• The novel design has the potential to substantially improve the safety and efficacy of ultrasound treatments.