Treatment Modeling

One way to accelerate thermal ablation device and system design is by computer-aided design. We use numerical simulations to predict how devices will perform in experimental and clinical environments. Simulations allow us to interrogate more parameters (device geometry, tissue properties, power inputs, anatomic placement, blood flow, etc.) than is feasible in experimental setups. Simulations also provide more a more controlled environment for design. However, the simulation output is only as good as the inputs provided, so we are working to improve numerical models of tissue properties.

Ablation Biophysics

Thermal ablation is a dynamic process that can involve electromagnetics, heat transfer, mass transfer, structural dynamics, and phase change. Understanding and predicting such complex interactions helps us taylor therapies for individual applications. We were the first to measure and report the significant drops in relative permittivity and conductivity that occur during high-temperature ablation. That observation allowed us to develop a temperature-dependent model that increased microwave ablation simulation accuracy:

A sigmoidal model of dielectric properties in temperature (left) improved our ability to simulate microwave ablations (right). Learn more.

It is very easy to see the reason for such changes, as large amounts of water vapor can be created during microwave ablation:

Gas expansion during a microwave ablation in ex vivo liver. Click the image to restart.

Numerical Simulation

As we improve the input models, we can expect to see more accurate simulations. Those simulations can then be used to help develop devices such as microwave ablation antennas. Our work in this area also applies to other types of thermal ablation, including radiofrequency and cryoablation.