Pressure Pulse Fields: Comparison of optical hydrophone measurements with FEM Simulations.

Several approaches for simulating ultrasound are available. The main tools are Finite or Boundary element methods and the spatial impulse response methods. Finite and Boundary Element methods are the most flexible but also the most computationally expensive tools available. On the other hand the spatial impulse response is restricted only to linear acoustic problem, but with low computational demands and prime costs. While with diagnostic ultrasound it’s mostly sufficient to confine the equations on linear acoustics, this simplification is not possible with therapeutic ultrasound. High pressure amplitudes of therapeutic ultrasound transducers create strong nonlinear effects in the medium, which cannot be simulated using linear acoustic theory. We compare two types of optical hydrophones developed for pressure pulse measurements, the fiber-optic-hydrophone and the light-spot-hydrophone. Both are based on reflection changes of a laser beam due to the medium density modulation by a sound wave at the sensitive end of the device. The aim of our work is to compare the measurement of a Panametrics NDT Transducer with simulations using ABAQUS FEM Software. FEM, Abaqus, LSHD, FASO, FOPH, Acoustic Simulation