Patient memory and digital twin

Executive summary

Patient memory is the longitudinal context Copilot reads: summarised history, extracted items and the timeline of confirmed facts. The digital twin is a per-tooth projection of the patient’s current state, maintained from confirmed facts and completed exams. Both are projections — they never become a source of truth that bypasses clinician confirmation.

Overview

ProductionReason · Patient memory and digital twin
Give every module the patient’s current state and history without re-reading every record, and without promoting anything unconfirmed.

Pipeline

Confirmed facts and completed exams publish events on the fact bus.
The projection worker updates the timeline, per-tooth state and twin.
Memory extraction and summarisation turn conversations and records into memory items and summaries.
Copilot and the HUD read memory and twin as context; twin analyses (change detection, risk estimates, simulation) run on demand as drafts.

Data owned

Memory conversations, messages, events, items, summaries
Holds
Longitudinal memory and its provenance
Digital twins
Holds
Per-patient, per-tooth state projection
Timeline
Holds
Ordered clinical events from confirmed facts

Store	Holds
Memory conversations, messages, events, items, summaries	Longitudinal memory and its provenance
Digital twins	Per-patient, per-tooth state projection
Timeline	Ordered clinical events from confirmed facts

Models and engines

Memory extraction and summary
Model or engine
Gemini 3 Flash-Lite (flash tier)
Notes
Self-hosted Qwen3-8B memory adapter when the worker is enabled
Twin change detection, risk estimates, simulation, insights
Model or engine
Gemini 3 Flash (pro tier)
Notes
Drafts, never facts

Step	Model or engine	Notes
Memory extraction and summary	Gemini 3 Flash-Lite (flash tier)	Self-hosted Qwen3-8B memory adapter when the worker is enabled
Twin change detection, risk estimates, simulation, insights	Gemini 3 Flash (pro tier)	Drafts, never facts

Guardrails

Projections are rebuilt from confirmed facts; a draft never changes them.
Memory summaries are governed artifacts under the same review rules as every other AI output.
Timeline dual-read compares the new projection with the legacy timeline before it replaces it.

Rollout and status

ProductionMemory and twin projections
Fed by Scribe and Perio fact writers
ShadowTimeline dual-read
New projection compared against the legacy read

Interfaces

Consumes
What
Confirmed facts and completed exams
Emits
What
Patient context for Copilot, HUD and Treatment Planning

Direction	What
Consumes	Confirmed facts and completed exams
Emits	Patient context for Copilot, HUD and Treatment Planning

SOURCE OF TRUTH

server/services/memory/
server/services/clinicalFacts/
server/db/schema/memory.ts