Fluid-Structure Interaction (FSI) Modeling is Transforming the Medical Device Industry
Fluid-structure interaction (FSI) modeling is transforming the medical device industry by simulating complex dynamics between biological fluids and medical devices. In a field where safety and precision are paramount, FSI modeling offers engineers and researchers a powerful tool to design, test, and optimize devices in a virtual environment before physical prototypes are created or clinical trials are conducted.
What is FSI modeling, why is it important in medical device development, and how is it revolutionizing the medical device industry?
What is Fluid-Structure Interaction (FSI) Modeling?
Fluid-structure interaction (FSI) refers to the interaction between a fluid (like blood or air) and a solid structure (such as a stent, valve, or implant) where both elements influence each other. In the medical field, FSI involves understanding how medical devices respond to forces exerted by biological fluids and how those fluids behave when interacting with the device.
FSI modeling uses advanced computational methods to simulate these interactions, providing detailed insights into how a device might perform under different conditions. This two-way coupling allows engineers to assess how fluid flow deforms a structure, and how the structure’s movement or deformation alters the flow of the fluid.
The Importance of FSI Modeling in Medical Devices
Medical devices often need to operate in highly dynamic and sensitive environments, where even slight deviations in behavior could lead to adverse outcomes. FSI modeling enables medical device manufacturers to:
- Predict Performance in Complex Environments – Devices such as heart valves or stents interact continuously with moving fluids like blood. FSI modeling allows for accurate predictions of how these devices might behave over time, ensuring they maintain functionality in real-world conditions.
- Improve Safety and Reliability – By simulating interactions between devices and fluids, manufacturers can identify potential points of failure that can be addressed before they occur in physical prototypes. This leads to more reliable devices and reduces the likelihood of recalls or safety concerns post-market.
- Optimize Design for Better Outcomes – FSI modeling speeds the optimization of medical devices by allowing engineers to virtually experiment with different designs, materials, and configurations in a virtual environment. The result is a more efficient design process and devices that are better tailored to patient needs.
- Reduce Costs and Time to Market – Traditionally, medical devices go through multiple rounds of prototyping and testing, which can be time-consuming and costly. FSI modeling can reduce the need for physical prototypes and early-stage animal testing, shortening the design cycle and reducing expenses.
Applications of FSI in the Medical Device Industry
- Cardiovascular Devices
Cardiovascular devices like stents, heart valves, and vascular grafts are some of the most critical applications for FSI modeling. Blood flow is inherently dynamic, pulsating with each heartbeat, and devices placed within blood vessels must endure these constant forces. FSI modeling helps predict how stents will behave under pressure, how heart valves will open and close without causing abnormal blood flow patterns, and how devices will interact with blood flow to prevent clotting or damage to surrounding tissue.- Stents: FSI modeling helps in understanding how stents expand when deployed and how they interact with blood flow post-deployment. Engineers can optimize the design to minimize complications such as restenosis (re-narrowing of arteries).
- Heart Valves: In the development of prosthetic heart valves, FSI simulation can reveal the valve’s opening and closing actions, ensuring that blood flow remains smooth and unimpeded, and reducing the risk of turbulent flow or valve fatigue. Figure 1 below shows the simulation results for the opening and closing of the valve during the cardiac cycle and points of highest deformation.
- Electronics Enclosures Thermal Management
FSI can be an effective tool in simulating the internal heat transfer and flow conditions in electronics enclosures especially components that are heat sensitive and require high accuracy. As shown in Figure 2 below, it can uncover how the components interact with each other thermally, localized flow patterns and how the thermal stresses develop in response to expansions/contractions. - Drug Delivery Systems
Devices like insulin pumps, inhalers, catheters and infusion pumps rely on precise fluid dynamics to ensure that medication is delivered in accurate doses. FSI modeling can simulate how drugs are dispensed and absorbed, whether a device can sustain and perform appropriately considering factors such as fluid viscosity, pressure, and the interaction between the drug delivery device and human tissues. This ensures more reliable drug delivery and improves patient outcomes. - Respiratory Devices
Respiratory devices like ventilators benefit from FSI modeling to ensure the correct air pressure and flow rate are maintained throughout usage. FSI models simulate how air flows through respiratory masks, intubation tubes and into the lungs, ensuring devices are comfortable for patients and deliver effective treatment. FSI can also reveal possible failure modes or factors that can affect the performance of the devices. - Orthopedic Implants
Orthopedic devices such as artificial joints or bone implants must interact with the body’s fluids, particularly synovial fluid, which lubricates joints. FSI simulation can be used to simulate how an implant will move and flex under stress, while ensuring the surrounding fluids provide adequate lubrication, reducing wear and tear over time. - Dialysis Devices
In dialysis machines, where blood is filtered outside of the body, FSI modeling helps optimize the flow of blood through the machine, ensuring that the interaction between the fluid (blood) and the solid components (filters, tubing) is smooth, reducing the risk of clotting or hemolysis (the breakdown of red blood cells). FSI modeling can also be a useful tool in designing and optimizing devices such as pumps, catheters and filters etc. for similar reasons.
The Future of FSI in Medical Device Development
As computational power increases and software continues to evolve, the scope and accuracy of FSI modeling will grow. Advances in artificial intelligence (AI) and machine learning will likely lead to even more precise simulations, reducing the gap between virtual models and real-world performance. Additionally, with more regulatory agencies recognizing the value of simulation, expect FSI modeling to play an even bigger role in the development, approval, and refinement of medical devices.
Fluid-structure interaction (FSI) modeling is transforming medical device development by enabling engineers to simulate the complex interactions between biological fluids and medical devices. It is paving the way for safer, more effective, and patient-specific devices, while reducing development time and costs. As technology continues to advance, FSI modeling will move to the forefront of innovation, ensuring that medical devices meet the highest standards of performance and safety in increasingly complex clinical environments.
Muhammad Jamil, PhD, is a Research and Development (R&D) Engineer in the Design and Analysis group at Starfish Medical. As part of the design and development team, he specializes in using Computational Modeling and Simulation in making design decisions and to accelerate the medical device development.
Images: StarFish Medical