Characterization of cavitational activity in lithotripsy fields using a robust electromagnetic probe

Area of Science:

• Biomedical Engineering
• Acoustics
• Fluid Dynamics

Background:

• Investigating cavitational activity is crucial for understanding lithotripsy effectiveness.
• Existing methods for cavitation detection may lack precision or in-situ capabilities.

Purpose of the Study:

• To develop and validate a robust electromagnetic probe for investigating cavitation dynamics.
• To characterize the pressure waves generated by inertial cavitation during lithotripsy.

Main Methods:

• Utilized a robust electromagnetic probe to study cavitation in vitro with extracorporeal and intracorporeal lithotripters.
• Derived empirical expressions for cavitational force and low-frequency sawtooth pressure waves.
• Conducted a pilot study on patients undergoing extracorporeal lithotripsy.

Main Results:

• The probe head movement correlated with the pressure gradient from radial cavitation bubble motion.
• Described a novel low-frequency sawtooth pressure wave produced by inertial cavitation.
• Established a linear relationship between negative pressure amplitude and bubble lifetime; negative pressures exceeded calculus tensile strength.

Conclusions:

• The electromagnetic probe effectively detects and quantifies in vitro cavitational activity.
• The probe shows potential for in vivo applications and diverse medical/industrial uses due to its sensitivity and remote detection capabilities.