How it works

From a label photo to a grounded answer.

Five steps, all on the phone. The model never decides whether an interaction exists — it only explains a fact that was retrieved from a real dataset and cited.

Capture

The camera takes a photo of a pill bottle or medication label. The image never leaves the device.

OCR on-device

QVAC's OCR reads the label text locally (no cloud OCR). The recognizer is fetched once (~15 MB) and cached, then runs offline.

Normalize to a generic name

A model-free n-gram match against the DDInter vocabulary resolves brand/printed text to a generic ingredient — e.g. "ASPIRIN 81 mg" → acetylsalicylic acid. If nothing resolves, it abstains.

Look up the interaction

The resolved drug is checked against your saved shelf in a bundled offline copy of DDInter 2.0 (~160k drug-drug pairs with severity). The hit — pair, severity, and source IDs — is the cited fact.

Explain in plain language

The on-device MedPsy model explains only the retrieved fact in 2–3 patient-friendly sentences, ending by advising confirmation with a pharmacist. Internal reasoning is stripped from the output.

The safety contract

Three rules that keep it honest

📚

Grounded

Severity comes from DDInter, not the model. The explanation asserts and cites only the hard fact ("A + B = severity X").

🛑

Abstains

If a drug doesn't resolve to the dataset, Pharos refuses to guess and says it can't verify that one. Unknown is never treated as safe.

🚫

No fabrication

If two resolved drugs have no documented interaction, it reports zero — it never invents one to seem helpful.

A real coverage example, kept honest: a paracetamol label abstains, because the international name isn't in DDInter (which lists acetaminophen). A safe non-answer beats a confident wrong one.

Every scan leaves a trail

Auditable by design

Each scan writes a structured audit log (JSONL) of the grounded chain and a resource log (CSV) of on-device cost. Together with a packet capture during an offline scan, they're the evidence that the answer was retrieved, local, and reproducible.