1. Introduction
Health systems do not maintain a canonical representation of individual health state over time.
What exists instead are institution-scoped records and narrative artifacts optimized for local objectives. These representations are mutable, partially ordered, and authority-shifting. Corrections overwrite prior state. Provenance is incomplete. Time is implicit.
As automation increases, these properties amplify distortion. Interpretations persist as facts. Temporary conditions become durable attributes. Downstream systems cannot distinguish correction from revision.
The failure is structural. There is no canonical health state.
2. Canonical State
A canonical state is authoritative by construction.
Canonical does not imply correctness, completeness, or consensus. It implies that all other representations are derived from it and may be reproduced, revised, or discarded without altering the underlying record.
In existing health architectures, no such state exists. Each institution maintains a partial ledger. Ordering is inconsistent. Authority migrates implicitly at each handoff.
Canonical state must be verifiable. Its integrity must be independently confirmable without reliance on the asserting system.
Canonical state refers to the authoritative record of what has been observed and asserted over time, not a claim about correctness or agreement.
HealthMemory defines a canonical state for individual health.
3. Assertions
The atomic unit of HealthMemory is an assertion.
An assertion is an immutable statement about health-relevant state, bound to:
- a time of occurrence,
- a time of assertion, if distinct,
- an asserting authority,
- and its provenance.
Assertions may represent observation or authorized interpretation. Only observational state constitutes canonical substrate state. Interpretive assertions are preserved but do not alter it.
Assertions are appended. They are never overwritten.
Late-arriving knowledge produces new assertions. Prior assertions remain intact.
4. Time
Time is a first-class property.
HealthMemory preserves temporal ordering, contradiction, and absence. Gaps are not imputed. Silence is not inferred.
Rewrite collapses causality. Systems that permit overwrite cannot distinguish correction from fabrication. HealthMemory disallows rewrite entirely.
Irreversibility is a structural requirement.
5. Authority
Authority determines who may assert canonical state, not who may read it.
Authority is anchored to the individual. External entities may assert state only under explicit, scoped delegation from the individual. Revocation prevents future assertions but does not erase historical ones.
Access control is orthogonal. Visibility does not confer authority.
6. Provenance
Every assertion carries provenance.
Provenance binds an assertion to its source, the asserting entity, and the authority context under which it was made. Assertions without provenance are undefined.
Provenance is inseparable from canonical state.
7. Derived Systems
Domain-specific representations, including medical, administrative, analytical, and algorithmic interpretations, are derived systems.
Derived systems interpret canonical state, apply domain logic, and may disagree or change over time. Derived state may be revised or discarded.
Derived state is never written back into canonical form.
Medical reasoning operates as one lens over HealthMemory, not as its substrate.
8. Invariants
HealthMemory enforces the following invariants:
- Canonical state is append-only
- Assertions are immutable
- Authority is explicit
- Provenance is mandatory
- Canonical state is verifiable
- Consent is structurally bound to access and assertion context
- Derived systems cannot mutate canonical state
Violating any invariant collapses canonicality.
9. Discussion
HealthMemory introduces a missing systems primitive: a canonical, time-consistent, authority-anchored representation of individual health state.
It performs no interpretation and does not delegate governance to downstream systems alone. Structural constraints, including authority and consent binding, are enforced at the level of the substrate.
By constraining itself narrowly, HealthMemory preserves truth under scale, correction, and automation.