The Inria Saclay Research Centre was established in 2008. It has developed as part of the Saclay site in partnership with Paris-Saclay University and with the Institut Polytechnique de Paris .

The centre has 40 projects teams, 27 of which operate jointly with Paris-Saclay University and the Institut Polytechnique de Paris; Its activities occupy over 600 people, scientists and research and innovation support staff, including 44 different nationalities.

This project is part of the European Artemis project https://artemis-euproject.eu/, where the SimbiotX team of Inria-Saclay is mainly involved in the work packages on mathematical modelling and model coupling for specific clinical use cases. Our work is carried out in collaboration with Paul Brousse Hospital and Universitätsklinikum Jena.

Topic

The prevalence of metabolic associated steatotic liver disease (MASLD) has increased significantly over the past years. Metabolic factors like obesity, diabetes, and hypertension lead in MASLD to an accumulation of fat in the liver. As this condition progresses, inflammation and liver damage can occur, leading to liver cirrhosis – the scarring of the liver. A scarred liver increases the resistance blood needs to overcome to pass through the organ. As a consequence, blood pressure increases in the portal vein, one of the vessels bringing blood to the liver, leading to portal hypertension. The increased pressure in the portal vein is sensed by the kidneys, which will hold onto water and sodium, thus increasing blood volume. Over time, water and sodium will spill from the blood vessels into the abdominal cavity, which then is called ascites. 

A mathematical model of ascites formation has been proposed [1] and integrated into a simple open-loop model [2]. In our work, we have developed a closed loop, whole-body circulation model of cirrhotic patients in 0D. The goal of this internship is to advance this model to simulate also the build-up of ascites in the abdominal cavity.

The second step of the project will be the variation of model parameters to understand better why some patients build up more ascites, while others don’t. Through a global sensitivity analysis, the most influential parameters on ascites formation will be determined [3, 4].

Bibliography

[1] Levitt, D.G., Levitt, M.D. Quantitative modeling of the physiology of ascites in portal hypertension. BMC Gastroenterol 12, 26 (2012). https://doi.org/10.1186/1471-230X-12-26

[2] Mazumder, Nikhilesh R. MD, MPH1,2,*; Jezek, Filip PhD3,4,*; Tapper, Elliot B. MD1,2; Beard, Daniel A. PhD3. Portal Venous Remodeling Determines the Pattern of Cirrhosis Decompensation: A Systems Analysis. Clinical and Translational Gastroenterology 14(9):p e00590, September 2023. | DOI: 10.14309/ctg.0000000000000590

[3] Eck, V. G., Donders, W. P., Sturdy, J., Feinberg, J., Delhaas, T., Hellevik, L. R., and Huberts, W. (2016) A guide to uncertainty quantification and sensitivity analysis for cardiovascular applications. Int. J. Numer. Meth. Biomed. Engng., 32: n/a. doi: 10.1002/cnm.2755.

[4] Hanna, J. M., Varsos, P., Kowalski, J., Sala, L., Meiburg, R., & Vignon-Clementel, I. E. (2025). A comparative analysis of metamodels for 0D cardiovascular models, and pipeline for sensitivity analysis, parameter estimation, and uncertainty quantification. Computers in Biology and Medicine https://doi.org/10.1016/j.compbiomed.2025.110381

Starting date and duration

Spring 2026 (February – April) with a duration of 4 to 6 months.

You will be located at Inria Saclay Ile-de-France in the SimbiotX team, supervised by Irene Vignon-Clementel. You will be working together with the postdoc Friederike Schäfer.

Contact and application

Would you like to get more information about the project or the team, please contact the responsible persons mentioned below.

Are you convinced this position suits you? Don’t hesitate to apply online with your CV, motivation letter and grades, or contact us for more information:

• Irene Vignon-Clementel: vignon-clementel@inria.fr
• Friederike Schäfer: friederike.schaefer@inria.fr

The position will be filled as soon as the right candidate is found.

Main activities:

• Understand the mathematical models of the physiological phenomena, and implement them in python
• Perform a global sensitivity analysis on a lumped parameter model
• Conduct numerical experiments and devise the most robust numerical model
• Participate in activities of the research group (seminars, meetings, social activities)
• Write a report, contribute to a journal publication and present the results to the research group/conference if applicable

The ideal candidate has

• mechanical/electrical engineering or applied mathematics (ODEs, statistics, optimization) background
• experience in programming (preferably python)
• strong analytical skills
• good communication skills in English
• a clear interest in mathematical modelling in the biomedical field
• experience in uncertainty quantification and sensitivity analysis, but this is not a must

Key words: reduced order modelling, blood flow simulation, cirrhosis, uncertainty quantification, sensitivity analysis.

• Partial reimbursement of public transport costs
• Possibility of teleworking and flexible organization of working hours
• Professional equipment available (videoconferencing, loan of computer equipment, etc.)
• Social, cultural and sports events and activities

Gratification