UCUM

UCUM stands for Unified Code for Units of Measure. It is a comprehensive coding system designed to unambiguously represent units of measure in electronic data interchange, clinical documentation, and laboratory results. The goal is to enable consistent storage, retrieval, and processing of quantitative data across software systems by providing a single, machine-readable vocabulary that is compatible with SI units and common non-SI units.

UCUM defines a formal grammar for unit strings, including base quantities, prefixes, multipliers, and operations such as multiplication and division. The specification provides canonical forms to enable unambiguous parsing and straightforward unit conversion between compatible units. It includes mappings to SI units and supports compound units, exponentiation, and parentheses to express complex expressions.

Adoption and usage: UCUM is widely used in health information standards and data exchange frameworks, including HL7, FHIR, and openEHR. It supports automatic interpretation and conversion of quantities in clinical messages and laboratory data, contributing to interoperability and data analytics.

Organization and availability: The UCUM standard is maintained by a community-driven project and is available through the UCUM website and related repositories. It is freely accessible and regularly updated to reflect evolving measurement practices. Examples of UCUM unit strings include meters per second (m/s), liters (L), and millimeters of mercury (mmHg).