FAQ

Is this a clinical diagnostic tool?

No. Cardiology in Gradient Biotech is a research and exploratory analysis workspace. Outputs must not be used for clinical decision-making. Interpretations include explicit disclaimers.

Do I need MATLAB or WFDB installed locally?

No. Everything runs in the browser — upload your recording and the platform handles preprocessing and analysis.

Preprocessing failed — what should I check?

WFDB uploads include both .hea and .dat
CSV time column is numeric and strictly increasing
Recording is long enough (minimum row count enforced)
EDF channel index is valid for the file

Open the failed run's Logs tab for the specific error.

HRV button is disabled — why?

For ECG datasets, complete Preprocess ECG first. For RR CSV uploads, HRV should be available immediately after upload.

Why does "Failed runs" on Readiness or the subject table show a count for a dataset I already fixed?

It shouldn't stay stuck — the count only reflects the most recent run of each pipeline for that dataset. If an earlier attempt failed and you successfully reran the same pipeline, it no longer counts. If a count won't clear, it usually means the failed run used a different pipeline than the one that later succeeded (for example a stray full_ecg_analysis attempt against a non-ECG dataset) — open that run from History and delete it if it's a known-irrelevant leftover.

Signal Quality still shows "Preprocess needed" even though HRV is computed for that dataset

Signal Quality's SQI comes specifically from ECG/PPG preprocessing. If HRV was computed some other way (for example directly from an existing RR interval file), that satisfies "has HRV" but never produced a quality score. Use Preprocess all pending on the Signal Quality tab, or run preprocessing individually on that dataset, to backfill it.

Interpret returns an error

Confirm a completed metrics run exists as input for the interpretation you're trying to generate. If the error persists, AI interpretation may not be enabled for your workspace — ask your administrator.

How do I compare treatment vs control?

Import subjects with a treatment_group column
Link datasets to subjects
Run HRV (Analyze → Bulk Pipelines, or the Batch HRV analysis panel on Cohort comparison, if needed)
Open Analyze → Cohort comparison → group by treatment_group → compare

Can I upload WFDB and CSV in the same batch?

No — one format per upload action. Create separate datasets for each recording.

What's the difference between descriptive and mechanistic interpret?

Descriptive summarizes metrics from one run or cohort comparison. Mechanistic proposes cross-domain physiological hypotheses when a subject has metrics from multiple modalities (for example HRV + BP + baroreflex).