Finite Element Analysis for Medical Devices & Biomaterials

Exponent has expertise in finite element (FE) analysis of biomaterials, containers and closures, drug delivery systems including injectors, implantable and patch pumps, medical device components / sub-assemblies and systems and associated manufacturing, sterilization and distribution processes using state-of-the-art modeling and analysis software (ABAQUS®, ANSYS®, COMSOL®, STAR CCM+®). We specialize in developing and validating detailed computational models for due diligence, ideation, concept selection, requirements identification and generation, design evaluation and optimization, generating design output elements for verification / risk management and regulatory submissions, supplier notification of change (SNC) and change order assessment, CAPA investigations, regulatory audit responses, manufacturing VIP projects, FCA assessments, intellectual property litigation, product liability design history file remediation post acquisitions and evaluation of device end of life planning. We assist clients solve a variety of challenges associated with device design, design optimization, and interaction with calcified and soft tissues.

Exponent also has many years of industry and research experience in FE modeling of orthopedic, spine, vascular, as well as biomaterial modeling. We combine this experience with our long standing expertise in metallurgy, polymer science, and failure analysis to provide our clients with a unique perspective for addressing complex computational projects required in the medical device industry.

Orthopedic Implants

Exponent’s expertise covers technical issues from all major joint replacement interventions and orthopedic bone trauma. Specific FE experience includes the following:

  • Models have been developed analyzing hip, knee, ankle, shoulder, elbow, wrist, finger and toe joint replacements
  • Experience developing models to analyze fracture fixation for trauma
  • Subject-specific anatomy based on medical imaging 
  • Non-homogeneous bone moduli based on bone mineral density (via calibrated CT) 
  • Robust contact algorithms for implant and bone interactions 
  • Customized implant geometries 
  • Virtual experiments to simulate implantation of devices 
  • Parametric analysis to account for variations in design, surgical, and patient factors 
  • Topological shape optimization for load bearing medical devices
  • Development of kinematic gait models for the evaluation of orthotic and high performance footwear

Spine Implants

Exponent conducts FE modeling to evaluate in situ stress states of implantable spinal devices and surrounding biological structures, and to explore natural and device associated spinal kinematics. Results from these analyses, combined with data from our retrieval collection and cadaveric spine simulator, provide valuable insight into performance and potential failure modes for spine implant devices.

  • Subject-specific anatomy based on medical imaging 
  • Non-homogeneous bone moduli based on bone mineral density (via calibrated CT) 
  • Robust contact algorithms for implant and facet interactions 
  • Analysis of total disc replacement impingement mechanics 
  • Evaluation of implant functionality 

Craniomaxillofacial and Plastic Surgery

Exponent engineers have development FE models of both craniomaxillofacial and plastic surgery reconstructive procedures including:

  • Evaluation of wound closure forces and tissue strains for plastic surgery
  • Finite element modeling tool development for surgical planning and preparation
  • Analysis of bone stress and resorption surrounding dental implants 
  • Development of models to analyze fracture fixation and healing for craniomaxillofacial applications 
  • Qualitative evaluation of the risk for implanted device migration in soft tissue

Cardiovascular Implants

Exponent has developed FE models of various cardiovascular implants for evaluating design, manufacturing, and delivery procedures, along with clinical performance. Modeling experience includes the following:

  • Cardiovascular and peripheral stents—self-expanding and balloon expanding 
  • Vena cava filters 
  • Abdominal aortic aneurysm (AAA) grafts 
  • Artificial heart valves and devices—percutaneous (TAVI/TAVR) and surgically placed 
  • Ventricular reconstruction modeling 
  • User-defined material models for shape memory alloys 
  • Device life predictions using implant-vessel interaction models 
  • Bridge to implant or destination therapy LVADs 

Ophthalmic Devices

Exponent’s FE model of the eye has been used to evaluate surgical interventions and device deployment, as well as to assess traumatic injury to the eye, with and without the use of protective equipment. Other applications include:

  • Evaluate the risk for globe rupture and optic nerve injury due to impact by projectiles during sporting activities 
  • Contribution and effect of physiological factors on individual structures of the eye, including disease and age related degeneration 
  • Orbital mechanics and eye motility evaluations based on complex three-dimensional tissue interaction between the eye, orbit, muscles, ligaments and fatty support 
  • Biomechanics of surgical procedures such as corneal reshaping, scleral buckling, retinal prosthesis, intraocular lens (IOL) implants, glaucoma valves, cataract surgery, keratectomies, vitrectomy 
  • LASIK 
    • In depth analysis of patient and intraoperative factors on eye function is a common focus of analysis, including considerations for incision location, cutting modality (laser, electrosurgical, scalpel), and patient factors. 

Hemostats, Surgical Sealants and Glues

Exponent engineers have developed modeling capabilities to understand and predict in-situ stresses, transport fluxes and sealing capabilities of biomaterials that are used as hemostats, surgical sealants and glues. Applications include:

  • Understanding underlying loading/deformation characteristics of the in-vivo environment 
  • Assessing if the deployed biomaterial will result in stress shielding or concentration through stiffness mismatch. 
  • Predicting tissue surface gas pressures for risk assessment in gas assisted delivery devices 
  • Predicting feasibility and limits of the ability to suture through a biomaterial 
  • Predicting gas/liquid sealing capabilities of the biomaterial 
  • Evaluating biomaterial function during the degradation process 

Specifically, we can incorporate the following in our numerical simulations:

  • Subject-specific model geometry based on medical images (x-ray, CT, MRI, intravascular ultrasound [IVUS], microCT, optical microscopy, cryosections) 
  • Nonlinear, validated material models for polymers, superelastic (Nitinol), and other alloys. State of the art material modeling capabilities include the following: 
  • Anisotropic material property characterization 
  • Large deformation hyperelastic material fitting and analysis 
  • CT scan based bone density mapping 
  • Superelasticity and shape memory 
  • Other user defined material models 
  • Robust contact algorithms for device/device and device/tissue interactions 
  • Modeling interaction between solid structures (vessels, airways, devices) and fluids (air, blood)



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