From the simulation expert to the device designer, it’s never been easier to access the power of multiphysics simulation.

Valerio Marra, Comsol

Because the human body is such an extraordinarily complex system to model and such a hostile environment for medical devices, their design must push the limits of technology. The adoption of multiphysics simulation can help bring devices to the market more efficiently while promoting innovation and collaboration among specialists.

One of the key advantages simulation offers is the ability to reduce physical prototyping. Challenging designs and new ideas can be built and tested in the virtual world of numerical simulation without having to be physically constructed. In an industry where safety is of paramount importance, the capability to investigate different scenarios by specifying boundary conditions, material properties and physiological mechanisms allows for early and harmless correction of design mistakes.

Additionally, simulation measurements of any variable, such as temperature or flow velocity, can be taken at any point in a model, enabling a better interpolation of available experimental data. Especially for medical devices, the fact that simulation results can be accessed in locations where it would be impractical if not impossible to place sensors on a physical prototype or in the human body is greatly appreciated. Design challenges can be surpassed with ease when thousands of ideas are tested and measured before the first physical prototype is built.

The human body is an inherently multiphysics system where multiple physical effects influence each other. Hence medical devices have to be designed in that context to function properly and effectively. Multiphysics simulation allows for a high-fidelity modeling of devices and the systems they operate in.

A real-world example involves a tissue ablation problem. (See model above.) To successfully design such an ablation system, engineers have to take into account different electrical conductivities of tissues, optimize the delivery of electromagnetic energy within the radio frequency and microwave range, and include perfusion to predict the temperature distribution inside and around the tissue being ablated. Multiphysics simulation ensures successful device design by accounting for all of the important variables.

Designers, who have simulation expertise, often find themselves in unique positions. In addition to being able to simply adjust definitions of variables and values and rerun the simulation, they can also make significant modifications to the model, even if they were to realize a phenomenon had not been included or a new material or condition needed to be specified.  However, with the shortage of simulation specialists, often the designer is an expert in the device being designed but not in the numerical methods and software needed to run a multiphysics model. Simulation specialists then find themselves creating a bottleneck for innovation.

To remove this bottleneck and foster a culture of collaboration, the simulation specialists could build a user interface that simplifies the use of a multiphysics model by including only the input and output fields and reports needed by the device designer. Such a packaged simulation application, as shown above, would hide all of the modeling details and show only the inputs needed for the simulation to provide accurate results. The app would only present the results and reports that the designer is interested in and could be shared with a large group of users within an organization or even customers worldwide. Such a group can go beyond the device designer and include, for example, experts in other disciplines, like physiology and healthcare compliance.

Democratizing the use of numerical simulation software for anyone through the deployment of apps is another way multiphysics simulation helps achieve the best design possible.  This lets specialists from a variety of disciplines share their perspectives and skills during the design process of the next breakthrough technology in healthcare.

Multiphysics simulation can boost your device design in many ways, the four we discussed here are: 1) reduced need for physical prototyping, 2) availability of measurements of any modeled variable at any point in a device and its surroundings, 3) high-fidelity modeling by taking into account any physical interactions as they happen in the real-world, 4) facilitating the collaboration between simulation specialists and experts in device design and other disciplines through apps. Multiphysics simulation has a lot to offer the medical device industry, especially through the adoption of simulation apps bringing its predictive power into the hands of simulation experts and device designers alike.

Valerio Marra is the marketing director at Comsol in Burlington, Mass. He received his PhD in fluid machines and energy systems engineering and his MSc in nuclear engineering, focusing on numerical methods for CFD.