TriVec Labs
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RAGHealthcareEvaluation

Building an AI-assisted medical coding platform

A clinical coding pipeline that reads documents, extracts concepts, and produces a principal ICD code grounded in the patient's medical history.

Healthcare technology provider · AI Engineering

01

Problem

Clinical coding requires interpreting large unstructured clinical documents and matching diagnoses and procedures against complex coding systems.

02

Challenges

large unstructured medical notes
large ICD taxonomy
hallucination risk
retrieval accuracy
explainability
deterministic output structure
model cost and latency
03

Architecture

system flow7 stages
01

Clinical Document

02

Concept Extraction

03

ICD Candidates

04

Episode Reportability & Sequencing

05

Medical History

06

Discharge Notes

07

Principal ICD Code

04

Engineering decisions

01

Separating retrieval from generation

Retrieval runs as its own stage with its own evaluation, so it can be tuned and tested independently of the model.

02

Structured LLM output

Every model response is constrained to a typed schema — ranked codes with confidence — so downstream systems never parse free text.

03

Restricting model context

The prompt is built from retrieved snippets and coding guidance only, bounding what the model reasons over and shrinking the hallucination surface.

04

Validation layer

Suggestions pass a rules-based gate — code validity, formatting, and consistency — before anything is returned or stored.

05

Asynchronous processing

Document ingestion and analysis run as background jobs with retries and idempotency, so long-running work never blocks the API.

06

API architecture

A FastAPI service with typed request and response contracts, containerized and deployed behind Nginx.

05

Technology

PythonFastAPIVector databaseSemantic cachingLLMsRAGDockerNginx
06

Related reading

Demo

Try AutoMedicoder

Run a clinical document through the pipeline and inspect the ranked suggestions.

* This demo runs on a low tier cloud infrastructure and is backed by gpt-mini. High latency for some requests is expected

Launch AutoMedicoder