Specimen Definition
Summary
SpecimenDefinition defines the template or blueprint for specimen types used in the laboratory. Instead of repeatedly defining the properties of commonly collected specimens (like blood, urine, or sputum), CARE uses SpecimenDefinition to maintain a central, reusable registry of specimen kinds that can be instantiated when needed.
When a specimen is collected during a diagnostic workflow, it is linked to its SpecimenDefinition. The instance retains a snapshot of the original definition to ensure data integrity and historical traceability, even if the definition changes later.
This resource enables structured specimen management aligned with the FHIR specification and supports integration with ActivityDefinition for test planning.
Core Relationships
| Related Resource | Purpose |
|---|---|
ActivityDefinition | Specifies which specimens are required for a test |
Specimen | Concrete instance created from this definition |
Facility | Scope of usage for definition |
Supported Fields
| Field | Description | Example |
|---|---|---|
title | Human-readable label | "Venous Blood" |
slug | Unique internal name | "venous-blood" |
status | Lifecycle status (draft, active, etc.) | "active" |
derived_from_uri | Reference to external source or standard | "http://hl7.org/specs/blood" |
description | Narrative explanation of this specimen type | "Standard blood draw" |
type_collected | Type of specimen (bound to HL7 valuesets) | "venous blood" |
collection | Collection procedure (e.g., venipuncture) | "SNOMED/73761001" |
patient_preparation[] | Pre-collection instructions (e.g., fasting) | ["SNOMED/20430005"] |
Is derived[] | Whether specimen is derived or not | [""] |
Single Use[] | Whether it is meant for a single use or not | [""] |
Specimen Type[] | Type of specimen collected | [""] |
Preference[] | Preferred or alternate | [""] |
Retention Time[] | Amount of time specimen can be retained | [""] |
Requirement[] | To add any additional requirements | [""] |
Container Description[] | Description of container | [""] |
Cap[] | Color of the container cap | [""] |
Capacity[] | Capacity of container | [""] |
Minimum Quantity[] | Minimum quantity of specimen required | [""] |
Preparation[] | To record preparation details | [""] |
Functional Workflow
- Admin defines a SpecimenDefinition for common sample types (e.g., venous blood).
- Linked via ActivityDefinition to relevant lab tests.
- When a lab test is initiated, specimen instances are created from these definitions via a dedicated API.
- Specimen instances store a snapshot of definition fields to preserve traceability.