AnaSim

AnaSim is an interactive adult anesthesia and physiology simulator for teaching and model exploration.

[!WARNING] Education and research use

AnaSim is simulation software, not a medical device. Do not use its output to guide clinical care.

What AnaSim models

AnaSim simulates drug delivery, pharmacokinetics, pharmacodynamics, cardiorespiratory physiology, ventilation, fluids, temperature, and common perioperative events in real time. The desktop interface uses standard patient monitor and anesthesia machine conventions. Headless mode supports scripted runs and CSV recording.

AnaSim includes propofol, remifentanil, sevoflurane, rocuronium, sugammadex, norepinephrine, epinephrine, phenylephrine, vasopressin, dobutamine, and milrinone. Ventilation modes include VCV, PCV, PSV, CPAP, and bag-mask ventilation.

Install and start

AnaSim requires Python 3.10 or later. Install it in a virtual environment:

python3 -m venv .venv
source .venv/bin/activate
python -m pip install anasim-simulator
anasim

On Windows, activate the environment with .venv\Scripts\activate.

The package name is anasim-simulator. The command and Python module are both named anasim.

First session

Run the guided TIVA induction to become familiar with the interface:

1. Launch anasim.
2. Select Guided scenario and Induction (TIVA).
3. Confirm the default patient and select Start simulation.
4. Use Open machine, Open medications, and Open events in the objective panel to open each control area.
5. Start the clock when you are ready to observe the physiologic response.

Interface

Guided scenarios cover TIVA and inhalational induction, emergence, hemorrhage, anaphylaxis, septic shock, and oxygen supply failure. Open simulation mode provides direct control of the same environment.

Model scope and limits

AnaSim accepts these patient inputs:

The body-size limits enclose the observed ranges in the healthy-adult cohort used by the Su hemodynamic and Li norepinephrine models. Weight and height must also produce a BMI within the supported range. Renal and hepatic factors are dimensionless model inputs.

AnaSim combines published component models with simulator-specific models for respiratory drug interaction, neuromuscular block and reversal, vasoactive drug response, and arterial pressure display. See model references for sources and implementation details.

Display values include simulated monitor response and may differ from the underlying physiologic state. Acid-base balance, lactate, tissue oxygen debt, and complete anesthesia machine pneumatics are outside the current model scope.

Headless use

Run a reproducible ten-second simulation:

anasim --mode headless --duration 10 --config patient.json --record

Configuration files set patient characteristics, model choices, initial state, random seed, and runtime options. See the CLI guide for the available fields.

Documentation

• CLI usage
• Model references
• Architecture
• Contribution guide
• Changelog

Development

git clone https://github.com/robchiral/AnaSim.git
cd AnaSim
python3 -m venv .venv
source .venv/bin/activate
python -m pip install -e ".[dev]"
ruff check .
QT_QPA_PLATFORM=offscreen python -m pytest -q

Regenerate the animated demo with python scripts/capture_demo.py.

Initial TIVA implementations were derived from Python Anesthesia Simulator.

Citation and license

For teaching or research use, cite the software and release described in CITATION.cff. AnaSim is available under the MIT License.