History of UCUM

The Unified Code for Units of Measures was created in 1999 by then Regenstrief Institute investigators Gunther Schadow, MD, and Clement J. McDonald, MD. Both individuals remain involved with the standard’s development.

Seminal article

Along with authors Jeffrey G. Suico, MD, Ulrich Föhring, MD, and Thomas Tolxdorff, PhD, the initial findings of Schadow and McDonald were published in the March/April 1999 issue of Journal of the American Medical Informatics Association, PMID 10094068; PMC Full Text; PDF. Abstract:

The authors surveyed existing standard codes for units of measures, such as ISO 2955, ANSI X3.50, and Health Level 7’s ISO+. Because these standards specify only the character representation of units, the authors developed a semantic model for units based on dimensional analysis. Through this model, conversion between units and calculations with dimensioned quantities become as simple as calculating with numbers. All atomic symbols for prefixes and units are defined in one small table. Huge permutated conversion tables are not required. This method is also simple enough to be widely implementable in today’s information systems. To promote the application of the method the authors provide an open-source implementation of this method in JAVA. All existing code standards for units, however, are incomplete for practical use and require substantial changes to correct their many ambiguities. The authors therefore developed a code for units that is much more complete and free from ambiguities.