# Clinical System One decision model released for fast patient record analysis

> Researchers unveil CS1-4B, a 4‑billion‑parameter model that answers clinical questions across records in one pass and routes uncertain cases to clinicians.

Oossa · 2026-10-21 · https://oossa.com/en/clinical-system-one-decision-model-released-for-fast-patient-record-analysis

A team led by Andrew Zhang and colleagues announced Clinical System One (CS1-4B), a decision model for health records. It has 4 billion parameters and was trained on 12.4 million question‑answer pairs from 3.6 million patients. The model can answer multiple typed questions in a single forward pass and provides a probability for each answer, letting clinicians review uncertain cases. In tests on 963,408 held‑out patients, CS1‑4B beat larger open models on 13 of 14 tasks and was 6.4 times faster on external data sets.

## The facts

- 4 billion parameters; trained on 12.4 million Q&A pairs from 3.6 million patients
- Published 2026‑10‑21 ("Wed Oct 21 2026 06:00:00 GMT+0200")

## Why it matters

Hospitals could use CS1‑4B to screen patients for trial eligibility faster and with fewer errors, freeing clinicians to focus on care.

## Sources & references

1. [A general-purpose System One decision model for clinical records](https://arxiv.org/abs/2610.27099) – arXiv, 2026-10-21

Last updated: 2026-10-21