BioFoundation: Foundation Models for Biosignals

Overview

BioFoundation is an open-source research framework for developing and deploying foundation models for biomedical signal analysis, with a particular focus on EEG (electroencephalography) data. The project powers the latest generation of topology-agnostic biosignal models — including LUNA (NeurIPS 2025), FEMBA (EMBC 2025), and CEReBrO (arXiv 2025) — and provides the shared infrastructure that enables them to scale across datasets, montages, and downstream tasks.


LUNA: Foundation Model for EEG Analysis

Accepted at NeurIPS 2025 🏆

Our flagship model, LUNA (Lightweight Unified Network for EEG Analysis), addresses a critical challenge in brain signal processing: different EEG datasets use varying electrode configurations, which has historically hindered the development of large-scale foundation models.

Key Innovations

Topology-Agnostic Architecture

  • Works seamlessly across different electrode layouts
  • Uses learned queries and cross-attention mechanisms
  • Compresses multi-channel EEG into unified latent representations

Unprecedented Efficiency

  • 300× reduction in FLOPs compared to standard transformers
  • 10× reduction in GPU memory usage
  • Linear complexity relative to channel count (not quadratic)

Large-Scale Pretraining

  • Pretrained on 21,000+ hours of EEG data
  • Diverse electrode configurations and recording conditions
  • Masked-patch reconstruction objectives

State-of-the-Art Performance

  • 0.921 AUROC on TUAR artifact-detection benchmark
  • Strong transfer across four clinical tasks:
    • Abnormality detection (TUAB)
    • Artifact rejection (TUAR)
    • Slowing classification (TUSL)
    • Emotion recognition (SEED-V)

Flagship Foundation Models

BioFoundation maintains a family of EEG foundation models, all sharing the same training stack, data tooling, and evaluation harness:

LUNA · NeurIPS 2025

  • Topology-agnostic architecture with channel unification and cross-attention
  • Linear complexity with respect to electrode count
  • Pre-trained on 21k+ hours of EEG and released on Hugging Face: thorir/LUNA

FEMBA · EMBC 2025

  • Bidirectional Mamba state-space architecture with linear-time scaling
  • 81.82% balanced accuracy on TUAB and 0.949 AUROC on TUAR
  • Available on Hugging Face: thorir/FEMBA

CEReBrO · arXiv 2025

  • Alternating-attention encoder that jointly models temporal and spatial correlations
  • 2× speed improvement and 6× lower memory vs. dense self-attention
  • Released via the BioFoundation codebase (see repository)

All models share:

  • Codebase: pulp-bio/biofoundation
  • Licensing: Apache 2.0 for code, CC BY-ND 4.0 for official weight releases
  • Configuration system: Hydra + PyTorch Lightning for reproducible experiments
  • Evaluation: Consistent TUAB/TUAR/TUSL benchmarks and downstream EEG tasks

Applications

The BioFoundation models target both clinical and research scenarios:

Clinical Workflows

  • Abnormality detection for diagnostic triage
  • Seizure prediction and monitoring on wearable EEG
  • Artifact rejection and signal cleaning
  • Sleep staging and long-term physiological monitoring

Research & Interfaces

  • Emotion recognition and affective computing
  • Brain-computer interfaces with low-channel wearables
  • Cognitive workload and attention tracking
  • Neurofeedback with topology-agnostic electrodes

Resources


Citation

If you use BioFoundation in your research, please cite:

@inproceedings{doner2025luna,
  title={{LUNA}: Efficient and Topology-Agnostic Foundation Model for {EEG} Signal Analysis},
  author={D{\"o}ner, Berkay and Ingolfsson, Thorir Mar and Benini, Luca and Li, Yawei},
  booktitle={Neural Information Processing Systems},
  year={2025}
}

Collaboration

This project is actively developed and we welcome contributions! Whether you’re interested in:

  • Extending the framework to new biosignals
  • Improving model architectures
  • Adding new downstream tasks
  • Optimizing for edge deployment

Get involved:


This project is part of ongoing research at ETH Zurich’s Integrated Systems Laboratory (IIS) in collaboration with leading researchers in TinyML and biomedical signal processing.

Thorir Mar Ingolfsson
Thorir Mar Ingolfsson
Postdoctoral Researcher

I develop efficient machine learning systems for biomedical wearables that operate under extreme resource constraints. My work bridges foundation models, neural architecture design, and edge deployment to enable real-time biosignal analysis on microwatt-scale devices.

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