OpenMedCheck uses a three-layer architecture: the first layer runs Gemma locally via Ollama to read free text and output strict JSON; the second layer is a non-AI program that verifies the model's answers (checking whether quotes appear in the source text, whether semantics match, whether it is negated, whether it concerns a relative, and whether an old event is treated as new); the third layer is a 25-rule if-then table that makes the final decision, of which 23 rules were reviewed by clinical experts and 2 past-history rules were added later and not reviewed.