FEA simulations can be applied to life science to improve product design and advance medical research.
Computer-aided engineering (CAE) has improved design and development processes in industries as diverse as aerospace, green energy, and high-tech devices. However, nowhere does CAE have a more direct impact on quality of life than in the life sciences.
During my time as a graduate student, postdoctoral researcher, and CAE simulation engineer at Caelynx, I have had numerous opportunities to use finite element analysis (FEA) along with multibody dynamics (MBD) solutions in life science applications. It can be used to guide designers, doctors, and engineers as they search for solutions to human problems. As I will show in this article, when advanced simulation technology is combined with the right research, it can improve comfort, reduce injury, and even save lives.
1. Consumer goods.
Life sciences simulations can be applied to a range of consumer products, from wearable items, such as shoes or backpacks, to furniture or objects that require an ergonomic design. In the field of consumer goods, life sciences simulations model the biomechanics of human engagement with a product. Examples of such simulations might include energy return, fatigue, comfort, support, and stress distributions.
These simulations could easily be implemented into other applications, such as the design of a chair, to illustrate how changes in the design might impact body posture, or the design of a mattress, to find how different materials might affect sleep quality.
Consumer Goods Example 1: Foam Bed Optimization
We worked with one of our clients to optimize the foam density for a mattress. In this study, we used Isight’s built-in nonlinear sequential quadratic programming algorithm to determine the optimum structural stiffness of the foam, with the goal of creating a mattress that would provide greater comfort and more restful sleep for buyers.
Consumer Goods Example 2: Insole Study
We were looking for ways to predict stress at the interface between foot and shoe (i.e., plantar stress) which is known to play an important role in the development of foot ulcers in diabetic patients. Our task was to study the effect of insole-to-midsole heel height on the plantar stress using a finite element (FE) model in order to find the best ratio of height between the two, with the goal of identifying the optimum thickness for each.
We developed a nonlinear, axisymmetric, two-dimensional model of a human heel-shoe in Abaqus/CAE, and assigned a nonlinear foam material to the insole and midsole geometries. We changed the insole and midsole thickness accordingly using Isight, while we estimated the plantar stress by measuring the predicted maximum contact pressure between the heel and the insole to find out which iteration provided minimum stress.
Using similar methodologies, we could apply these tools to identify the key performance indicators for a variety of consumer good applications, with the ability to obtain analytical output quantities from simulation.
2. Athletic and military training programs.
FEA simulations aren’t only used for product design. In fact, because the models are designed to simulate the human body, they can be used to understand the effect of training programs or lifestyle habits on physical fitness. These include simulations that measure the influences of repetitive movements on the body, or how bone and soft tissue might be strained or strengthened under certain conditions.
Training Example 1: Exercise Machine Linkage
Many people turn to exercise machines as a central part of their physical fitness routine. On a recent project, we worked with a client to generate a design for a fitness machine that was lighter, provided increased stiffness performance, and felt more fluid to the user (i.e. reduced rotational inertia effects). Our optimization approach, using Tosca Structure, was specifically tailored to the design goals associated with the linkage. After mastering the optimized (organic) shape in CAD, the design was validated by FEA to confirm the final geometry.
Training Example 2: Load Carriage on Tibia Bone Strength
As part of my doctoral research prior to joining Caelynx, I co-authored a study examining the influences of load carriage and physical activity on tibia bone strength. This project was designed to address a problem in the military, where new recruits had a high incidence of tibia stress factors. We compared recreational basketball players to recreational runners by having each carry loads of increasing weight. We then used a combination of subject-specific multibody musculoskeletal simulations and an FE model of the tibial bone to measure bone strain and the rate of strain. The results of this study showed that the varied, multidirectional training of the basketball players make them more resilient to load bearing than that of the recreational runners.
While this study had applications for the military, similar studies could also be applied to athletic programs. In elite sports programs, where an injured player can cost a league millions of dollars in lost talent, simulations that can identify more effective training regimens can save athletic programs financially, while also leading to healthier athletes.
These examples illustrate how FEA simulations could be used in similar applications, such as physiotherapy, to help doctors and physical trainers find more effective treatments for patients as they recover from an injury.
3. Medical device companies.
Medical devices are perhaps the largest group of possible applications for life sciences simulation. This group comprises external devices, such as braces or prosthetics, implanted devices such as heart monitors or artificial hips, and medical equipment, such as the cardiopulmonary bypass pumps used in open heart surgery.
Medical Device Example 1: Wheelchair and Hospital Chair Drop Test
Using a detailed FE model during a drop test simulation, Caelynx was able to optimize the strength and structural weight of a wheelchair’s design. We ran a similar study on a hospital chair. We built a detailed FE model of the hospital chair, then correlated it to the physical test to evaluate any design improvements suggested by the engineering team.
Medical Device Example 2: EMS Cot Performance Load Fastener
We worked with the design team of an OEM for EMS cots to perform front, side, rear, and top crash test simulations using Abaqus Unified FEA. We focused on the locking mechanism of the cot to the ambulance, using the analysis to drive design changes and enhancements. These included an optimization of the effort of the current carry over components on the cot to try to find lightweight solutions with enhanced load carrying capabilities, as well as FE models of a redesigned cot for future development.
Medical Device Example 3: Hospital Bed Comfort Design
For this project, Caelynx partnered with a hospital bed manufacturer to design pneumatic bags that would reduce bed sores and enhance patient comfort. We did this, again, using Abaqus Unified FEA for highly nonlinear structural simulation of soft materials in high deformation.
Medical Device Example 4: Blood Flow Simulation
In this project, we simulated blood flow paths through two different pipe assembly configurations for transfusion machines and blood platelet separators. Because poor recirculation can lead to clotting, it was our goal to find a configuration that would reduce undesired flows and turbulence. By performing an A/B study for each assembly we compared the predicted pressure, turbulence energy, and velocity, as experienced by the blood flow. Our simulations were able to demonstrate which configuration provided a clean laminar flow with minimum turbulence.
In each of these cases, FE simulations helped design safer devices that were easier for medical workers to use or led to increased comfort and improved health for patients. This intersection of product design and life sciences illustrates the many ways CAE can be used to improve patient outcomes.
4. Advanced research funded by hospitals or universities.
Many of the applications listed above are areas in which FEA is regularly being used to advance product development, improve health, and reduce injury. The progress already made with this research demonstrates the value of FEA alone or combined with other solutions in aiding medical research. It also highlights untapped areas of research that will benefit from advanced CAE simulations.
Advanced Research Example 1: Dental Implants
In a collaborative project between the University of Michigan and Caelynx, we used CAE simulations to find an optimum tightening torque for a dental implant design. We also predicted the adhesive strength using a FE model at bone/crown interfaces.
Advanced Research Example 2: Knee Biomechanics
During my postdoctoral research, I worked directly with surgeons using simulations of knee biomechanics in an MBD framework environment to help doctors determine the correct amount of external rotation of the femoral component required during TKA. Our ability to isolate bone shapes and ligaments through computational models helped us deliver better outcomes to patients and revealed a potential new surgical technique.
While these examples represent project capabilities of Caelynx, new simulation tools are expanding the possibilities of this field. Recently, Dassault Systèmes collaborated with the FDA on a five-year project to create a model of a human heart. The Living Heart Project advances the cutting edge of medical research, with the potential to deliver new tools to physicians and surgeons as they plan medical treatments. Hospitals and research groups need more than access to these simulations—they need experts who can help them apply these advanced engineering solutions to their research.
Our engineering team has direct experience working on these projects.
As a field, life sciences poses both a complex subject for FEA simulation, and an exciting opportunity for advances that could have a significant impact on the health, comfort, and quality of life for people around the globe. Researchers, engineers, and product designers have access to powerful software that can simulate the bone and soft tissue of the human body, but understanding the intersection of human biology and engineering technology requires a new skillset—one that Caelynx has been building for years.
We have always prided ourselves on the strength of our team. The engineers who work here possess expertise not only in creating and running complex simulations with CAE software, but also the experience of working in hospitals and with medical research teams. This allows us to undertake high-level life science projects for any number of applications.
If you are looking for an FEA partner to help you develop simulations for use cases in the life sciences field—large or small—contact us. We can discuss them with you and help you find a solution.