Foundation model

QECGBERT (VQ-VAE beat-token BERT ECG FM; Afghah lab)

Parameters
21.4M
Year
2026
Form factor
Other
ECGWeights: not released
PreprintCatalog paper date: 2026Added to atlas: Oct 27, 2026Source

Activity counts measure attention, not model quality. Missing counts are unknown. Publication status follows the linked source; a listed venue alone does not confirm peer review.

Compact (21.4 M) ECG FM: VQ-VAE waveform tokens per cardiac segment, BERT MLM pretraining on MIMIC-IV-ECG, LoRA fine-tuning. Best macro-AUROC at 100% labels: PTB-XL superclass 88.92, rhythm 89.03; CPSC2018 93.02; CSN 90.71; CS 95.34 (paper Tables 1–2).

Parameters
21.4M
Signals
ECG
Pretraining data
MIMIC-IV-ECG (800,035 12-lead ECGs, 161,352 patients)
Form factor
Other
Year
2026
Architecture

Per-segment VQ-VAE tokenizers (P, PQ, QRS, ST, T; 6.4M) → beat sentences with continuous waveform features → BERT encoder (15M) pretrained with MLM (15% masking, 80/10/10); LoRA fine-tuning

At a glance
Type
Foundation model
Modalities
ECG
Form factor
Other
Parameters
21.4M
Architecture
Per-segment VQ-VAE tokenizers (P, PQ, QRS, ST, T; 6.4M) → beat sentences with continuous waveform features → BERT encoder (15M) pretrained with MLM (15% masking, 80/10/10); LoRA fine-tuning
Venue
Not reported
Year
2026
DOI
Not reported
Code
Not released
Weights
Not released
Licence
Not reported
Caveats
Not reported
Added
Oct 27, 2026
Updated
Oct 27, 2026

Abstract

AI foundation models play a pivotal role in advancing heart disease diagnosis from electrocardiogram (ECG) data, particularly for rare diseases where the lack of sufficient labeled data hinders supervised learning. However, most self-supervised learning methods treat ECGs as generic sequence or image data without exploiting underlying physiological structure. To address this limitation, we propose QECGBERT, a self-supervised ECG language model that explicitly encodes physiological semantics by tokenizing the P, QRS, T, and isoelectric background waveforms. Vector-quantized variational autoencoder (VQ-VAE) tokenization is applied to each 12-lead ECG, with tokens enriched by continuous waveform features to preserve morphology lost during quantization without increasing sequence length. This design enables compact BERT masked language modeling with short sequences, improving scalability and reducing computational cost relative to long-sequence approaches. QECGBERT applies BERT pre-training to the MIMIC-IV dataset containing over 800,000 unlabeled ECG recordings, and fine-tuning on labeled PTB-XL, CPSC2018, and Chapman–Shaoxing–Ningbo datasets for evaluation. The results demonstrate that QECGBERT achieves comparable or superior performance to published benchmarks, offering a scalable, physiologically aware approach to ECG foundation modeling for cardiac diagnosis.

Verbatim fromarXiv· arXiv metadata (abstracts are released under CC0)

Key results

100%
AUROC
Best macro-AUROC at 100% labels: PTB-XL superclass 88.92, rhythm 89.03

How it works

How QECGBERT (VQ-VAE beat-token BERT ECG FM; Afghah lab) works: Input signals → Foundation model → Downstream tasksInput signals: ECG (Electrocardiogram). Datasets: MIMIC-IV-ECG, PTB-XL, Chapman–Shaoxing–Ningbo 12-lead ECG arrhythmia database (PhysioNet). Foundation model: QECGBERT (VQ-VAE beat-token BERT ECG FM; Afghah lab), 21.4M parameters (Transformer · Language-aligned).Input signalsECG: ElectrocardiogramECGElectrocardiogramDatasets: MIMIC-IV-ECG, PTB-XL, Chapman–Shaoxing–Ningbo 12-lead ECG arrhythmia database (PhysioNet)DatasetsMIMIC-IV-ECG, PTB-XL +1 moreFoundation model×NQECGBERT (VQ-VAE beat-token…21.4M parametersTransformer · Language-aligned

Datasets linked in the hub; pretraining vs evaluation roles follow the paper.

Pretraining data
MIMIC-IV-ECG (800,035 12-lead ECGs, 161,352 patients)
Architecture
Per-segment VQ-VAE tokenizers (P, PQ, QRS, ST, T; 6.4M) → beat sentences with continuous waveform features → BERT encoder (15M) pretrained with MLM (15% masking, 80/10/10); LoRA fine-tuning
Inputs
ECG
Approach
ECG · foundation model · tokenization · VQ VAE · BERT

Datasets· 3

Cite

APA

Mohan, A., Ozek, B., Zilbershot, O., & Afghah., F. (2026). QECGBERT: a scalable ECG foundation model based on self-supervised language learning via VQ-VAE waveform tokenization. arXiv 2610.33964v1. https://arxiv.org/abs/2610.33964

BibTeX

@misc{mohan2026qecgbert,
  title         = {{QECGBERT: a scalable ECG foundation model based on self-supervised language learning via VQ-VAE waveform tokenization}},
  author        = {Mohan, Aruna and Ozek, Burcu and Zilbershot, Or and Afghah., Fatemeh},
  year          = {2026},
  howpublished  = {arXiv 2610.33964v1},
  eprint        = {2610.33964},
  archivePrefix = {arXiv}
}

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History

  1. Added to the ChatPPG research hub