Gello Expression Language
The GELLO Expression Language was started in 2001 and introduced in 2002; in 2005, GELLO was adopted as an international standard by HL7 International and ANSI for a decision support language. GELLO Release 2 was completed and approved by ANSI in June 2010. The GELLO specifications have been developed in coordination with the HL7 Clinical Decision Support TC (CDSTC)
GELLO is a class-based object-oriented programming language and a relative of the Object Constraint Language (OCL). OCL is a well-developed constraint language that makes it attractive for use as an expression language. The intention was for GELLO to evolve as a standard query and expression language for decision support.
GELLO creates the potential for many decision support options, as the full array of atomic patient data is greatly accessible to complement better, safer clinical decision making by health professionals. Furthermore this enables specialist clinicians to customize their current systems and create flexible purpose built decision support systems.
Standardization of GELLO it has made this language compatible with the HL7 version 3.0 Reference Information Model (RIM). GELLO uses an abstract "virtual medical record" (vMR) so that the same GELLO code can run on multiple systems accessing data stored in different formats. The vMR is a simplified view of the HL7 RIM.
Uses for GELLO
The GELLO language can be used to:
- Build up queries to extract and manipulate data from medical records.
- Construct decision criteria by building up expressions to reason about particular data features/values. These criteria can be used in decision-support knowledge
bases such as those designed to provide alerts and reminders, guidelines, or other decision rules.
- Create expressions, formulae, and queries for other applications.
- "Description and status update on GELLO: a proposed standardized object-oriented expression language for clinical decision support". Stud Health Technol Inform 107 (Pt 1): 164–8. 2004. PMID 15360796.