A Prototype Therapy System for Boiling Histotripsy in Abdominal Targets Based on a 256-Element Spiral Array

Area of Science:

• Medical Physics
• Biomedical Engineering
• Acoustic Medicine

Background:

• Boiling histotripsy (BH) utilizes high-amplitude ultrasound (US) pulses for mechanical tissue fractionation.
• Effective BH treatment of abdominal organs necessitates a high-power phased array system with electronic focus steering and aberration correction.

Purpose of the Study:

• To develop and characterize a preclinical boiling histotripsy system for abdominal organ treatments.
• To evaluate the system's capability for electronic focus steering and aberration correction.

Main Methods:

• A custom 256-element 1.5-MHz phased array was integrated with a Verasonics US system and a 1.2-kW power source.
• System performance was assessed via hydrophone measurements and nonlinear wave simulations.
• Electronic steering and power compensation strategies were evaluated for consistent BH exposures.

Main Results:

• The system achieved a pulse average acoustic power of 2.2 kW, generating 100-MPa shocks at the focus.
• Electronic steering capabilities were demonstrated, with power compensation strategies identified.
• Continuous volumetric BH lesions were successfully created in ex vivo bovine liver.

Conclusions:

• The developed preclinical BH system is capable of generating high-amplitude acoustic shocks for tissue fractionation.
• The system's electronic steering and aberration correction features are crucial for targeted BH treatments in abdominal organs.
• This technology holds promise for advancing non-invasive therapeutic interventions.