Summary of the OnScale HIFU Simulation
The video demonstrates the acoustic solve for a High Intensity Focussed Ultrasound (HIFU) simulation. We generate the model from an imported tissue map of a human abdomen from the Visible Human Project.
Calculating the thermal dose delivered by therapeutic treatments is dependent on many factors, and can be a complex process. OnScale combines piezoelectric, acoustic, and thermal solvers to allow true multi-physics analysis of large problems, such as HIFU, requiring more than 1 million elements.
Technical details of the OnScale simulation
To generate this HIFU simulation, we applied a continuous wave of 200 kHz at the transducer abdomen interface. We run the simulation until a steady state acoustic field is generated through the main portion of the abdomen, which we can use to extract the energy loss per cycle or pulse length. We can then apply the calculated losses as a pulse modulated signal to determine the temperature variation within the model.
Typically, we separate the acoustic and thermal simulations due to the difference in timescales between mechanical and thermal effects (microseconds vs seconds). As a result, each simulation can run at its optimal time step to achieve fast runtimes.
Computational Resources required for the OnScale simulation
- Model size: 1,461,776 elements
- Solve Time: 156s (2 CPU)
- Memory Usage: 194 MB
- Core Hours: 0.15
The simulation produces a number of useful outputs, including:
- Maximum pressure fields
- Losses throughout the model to drive a thermal simulation
- Visualization of the acoustic wave paths