Education

• Ph.D. Applied Mathematics with concentration in Physiology, 2008, North Carolina State University, [“Cardiovascular and Respiratory Regulation, Modeling and Parameter Estimation"; Adviser: Mette S. Olufsen]
• M.S. Applied Mathematics with concentration in Computational Mathematics, 2005, North Carolina State University
• B.S. in Chemical Engineering, 1999, University of Wisconsin, Madison

Research Interests

Ellwein Fix develops mathematical models to simulate and analyze transport phenomena in cardiorespiratory physiology. Her primary focus is on lumped parameter models describing system level dynamics and regulation, and she also has experience with distributed parameter models of local hemodynamics. Her work is interdisciplinary and she collaborates with researchers in biomedical engineering, medicine and exercise science.

Select Publications

• Harris H, Chan D, Ellwein Fix L, Nicholson B, Acevedo E. (2026) Subject-specific modeling of response to physical stress via hypothalamic-pituitary-adrenal and sympathoadrenal axes. PLoS One, Available online 24 March 2026, https://doi.org/10.1371/journal.pone.0344981.
• Foster R, Ellwein Fix L. (2025) Practical parameter identifiability of respiratory mechanics in the extremely preterm infant. Royal Society Philosophical Transactions A, Available online 02 April 2025, https://doi.org/10.1098/rsta.2024.0226.
• Foster R, Smith B, Ellwein Fix L. (2023) Thoracoabdominal asynchrony in a virtual preterm infant: computational modeling and analysis. Am J Physiol Lung Cell Mol Physiol, 325(2): L190-L205. https://journals.physiology.org/doi/abs/10.1152/ajplung.00123.2022 (IF=6.011) 
  
• Colebank MJ, Paun M, Qureshi MU, Chesler N, Husmeier D, Olufsen MS, Ellwein Fix L. (2019) Influence of image segmentation on one-dimensional fluid dynamics predictions in the mouse pulmonary arteries. J R Soc Interface, https://royalsocietypublishing.org/doi/10.1098/rsif.2019.0284 (IF= 4.118)
  
• Ellwein Fix L, El Khoury J, Moores R Jr., Linkous L, Brandes M, Rozycki H. (2018). Theoretical open-loop model of respiratory mechanics in the preterm neonate. PLoS ONE,  https://doi.org/10.1371/journal.pone.0198425  (IF=2.806)
  
• Ellwein L, Samyn M, Danduran M, Schindler-Ivens S, Liebham S, LaDisa Jr. JF. (2017) Toward translating near-infrared spectroscopy oxygen saturation data for the non-invasive prediction of spatial and temporal hemodynamics during exercise. Biomech Model Mechanobiol, 16(1):75-96. https://doi.org/10.1007/s10237-016-0803-4 (IF=3.323)
  
• Ford Versypt AN, Makrides E, Arciero J, Ellwein L, Layton AT. (2015) Bifurcation study of blood flow control in the kidney. Math Biosci, 263:169-179. https://doi.org/10.1016/j.mbs.2015.02.015 (IF=1.246)
  
• Ellwein LM, Pope S, Xie A, Batzel JJ, Kelley CT, Olufsen MS. (2013) Patient-specific modeling of cardiovascular and respiratory dynamics during hypercapnia. Math Biosci, 241:56-74. https://dx.doi.org/10.1016%2Fj.mbs.2012.09.003 (IF=1.246)
  
• Ellwein LM, Otake H, Gundert TJ, Koo B-K, Shinke T, Honda Y, Shite J, Ladisa JF, Jr. (2011) Optical coherence tomography for patient-specific 3D artery reconstruction and evaluation of wall shear stress in a left circumflex coronary artery. Cardiovasc Eng Technol, 2(3): 212-227. https://doi.org/10.1007/s13239-011-0047-5 (IF=1.064)
  
• Olufsen MS, Ottesen JT, Tran HT, Ellwein LM, Lipsitz LA, Novak V. (2005) Blood pressure and blood flow variation during postural change from sitting to standing – modeling and experimental validation. J Appl Physiol, 99(4):1523-1537. https://dx.doi.org/10.1152%2Fjapplphysiol.00177.2005  (IF=3.351

Affiliations

• Society of Industrial and Applied Mathematics (SIAM)
• Association of Women in Mathematics (AWM)
• Society of Mathematical Biology (SMB)