Results
What the model actually does.
Every figure on this page is plotted from the evaluation artifacts, on a held-out fold of patients the model never saw during training or calibration. Nothing here is illustrative.
- ROC AUC
- 0.9670
- Sensitivity
- 0.871
- Specificity
- 0.922
- Calibration error
- 0.0188
1,462 held-out records · 912 NORM · 550 MI-associated · minutium-ecg-res1d-0.1.0
Median probability: NORM 0.021 · MI 0.988
Distribution of calibrated probabilities on the held-out test split, separated by true class. Overlap between the two distributions is the error the headline AUC averages over.
AUC 0.9670 · baseline 0.9293
Held-out test split, against the interpretable baseline.
ECE 0.0188
Temperature scaling was fitted on the validation fold. The dashed line is the same model before scaling.
True negative
841
False positive
71
False negative
71
True positive
479
At threshold 0.430
Operating point chosen on validation to favour sensitivity.
Early stopped at epoch 15; weights taken from epoch 10, the best validation ROC AUC. Seed 1729.
| Metric | Neural | Baseline |
|---|---|---|
| ROC AUC | 0.9670 | 0.9293 |
| PR AUC | 0.9575 | 0.9094 |
| Sensitivity | 0.8709 | 0.8945 |
| Specificity | 0.9221 | 0.7829 |
| PPV | 0.8709 | 0.7130 |
| F1 | 0.8709 | 0.7935 |
| Brier | 0.0654 | 0.0969 |
| ECE | 0.0188 | 0.0298 |
Both trained on the same patient-level splits.
Worked example
One patient, two and a half years apart.
Both recordings below come from the same de-identified PTB-XL patient in the held-out split, the normal one first. This is the comparison the product is built around.
NORM
Stored baseline recording
PTB-XL record 6902 · 58 · male
Probability
29.1%
29% to 64%
- Heart rate
- 95
- Signal
- excellent
- Uncertainty
- wide
Leads the model relied on most
MI-associated
Later recording, MI-associated
PTB-XL record 11899 · 61 · male
Probability
86.1%
73% to 90%
- Heart rate
- 140
- Signal
- excellent
- Uncertainty
- moderate
Leads the model relied on most
The unflattering results
What the headline number does not tell you.
These four measurements exist because a single AUC on a curated retrospective dataset is the easiest number in medicine to over-read. They are on this page for the same reason.
Sensitivity and specificity do not move with prevalence. PPV does, and a person at home with chest pain is a far lower-prevalence population than this cohort.
- full 12 lead0.967
- limb only0.842
- patch 6 lead0.932
- patch 3 lead0.810
- single lead II0.291
An optimistic stand-in for a chest patch. Removing leads keeps the geometry of the remaining ones intact, whereas a real patch changes electrode positions and therefore the lead vectors themselves.
- 0.000 mV0.967
- 0.025 mV0.944
- 0.050 mV0.889
- 0.100 mV0.814
- 0.200 mV0.678
Synthetic noise is a crude proxy for real motion artifact, which is correlated across leads and structured in time rather than Gaussian.
- unknown84.5%
- Stadium II-III85.4%
- Stadium III95.9%
- Stadium I92.9%
- Stadium II100.0%
Caveat: Stage is recorded for only part of the cohort and the acute-stage subgroup is small, so these are indicative rates and not precise subgroup estimates. Wide uncertainty on any group with n below roughly 30.
Recall on MI-positive test records, grouped by PTB-XL's recorded infarction stage. Stadium I is acute, Stadium III is old. A model detecting acute events specifically would score Stadium I far above Stadium III. Similar rates across stages indicate the model is substantially recognising established infarct morphology, including long-healed scar.
Raw artifacts in artifacts/model/. Full method, limitations, and bias risks in the transparency page and MODEL_CARD.md.