Inserm U1219 Bordeaux Population Health · AHeaD team · University of Bordeaux

Simulating an emergency department before reorganising it.

Where to place a nurse, how to order a queue, whether to open one more bed: these decisions are made today with no way of testing their effects other than on real patients. My PhD builds the model that lets you try them first — a simulator of the emergency department, calibrated on 225,766 real visits.

I come from theoretical physics and mathematics: an undergraduate physics degree at Orsay, a master's at ENS Ulm, then PDEs and probability at Bordeaux. An emergency department is, to me, a dynamical system like any other — except that its trajectories are patients, and getting it wrong costs hours of waiting.

Research My background Curriculum vitae (PDF)

The department, sped up

An emergency department in miniature: seven areas, a finite number of places, and patients who only give theirs up once they find one further along. That single rule is what pushes the jam back towards the entrance. Play with the sliders.

Time
Patients in department 0 observed: 58
Wait before triage (P90)
Median length of stay observed: 4 h 40
A toy model, built from my thesis simulator. There is no right answer: push the sliders until the department breaks, and watch where it starts. No patient data is used.

Research themes

  • Modelling patient flow and processes in emergency care

    The core of my PhD. An emergency department is a queueing network coupled to finite resources, clinical decisions and a saturated hospital downstream.

  • Repairing degraded hospital records

    No flow model survives false data. The traces a care pathway leaves behind are produced in the course of clinical work, not for research: misordered events, impossible durations, duplicates, broken trajectories.

  • Algorithmic fairness, bias and serious games

    A model trained on a department’s history also learns its biases. With the team, I study the detection of human bias in triage — gender, age, socioeconomic status — using language models, and the use of serious games to make those biases perceptible to clinicians in training..

  • Computer vision and road safety

    Automated assessment of pedestrian crossing safety across France, pairing aerial and street-level imagery to score nine risk factors. An applied project outside the hospital, sharing the same logic: producing at scale a measurement that human expertise cannot deliver across a whole country..

Recent work

2025 Journal article First author

Application of Transformer Neural Networks for Data Cleaning in Emergency Room Logs: A Case Study From the Bordeaux University Hospital

Russon D, Gil-Jardiné C, Marcel L, Chanel L, Faure S, Maury B, Chenais G, Lagarde E

IEEE Journal of Biomedical and Health Informatics · 29(11):8484–8496

Transformer-based reconstruction of emergency activity logs at Bordeaux University Hospital, evaluated against an expert-annotated gold standard.

doi.org/10.1109/JBHI.2025.3586325 PMID 40627474

2025 Journal article First author

Evaluating pedestrian crossing safety: Implementing and evaluating a convolutional neural network model trained on paired aerial and subjective perspective images

Russon D, Guennec A, Naredo-Turrado J, Xu B, Boussuge C, Battaglia V, Hiron B, Lagarde E

Heliyon · 11(4):e42428

Automated scoring of nine risk factors on French pedestrian crossings, from paired aerial and street-level imagery.

Published corrigendum Heliyon 11(14):e43902

doi.org/10.1016/j.heliyon.2025.e42428 PMID 40028551

All publications →