The Clinical Measurement Ontology (CMO), Measurement Methods Ontology (MMO), and Experimental Condition Ontology (XCO) are currently being developed at the Rat Genome Database. For more information about these vocabularies please see Shimoyama et al. Three ontologies to define phenotype measurement data. Front Genet. 2012;3:87. Epub 2012 May 28 or contact us (http://rgd.mcw.edu/contact/index.shtml).
Measurement of the length of time between the closing of the mitral valve (the dual-flap valve in the heart that controls blood flow between the left atrium and the left ventricle) at the end of ventricular filling (that is, after atrial contraction) and its opening at the beginning of the next round of ventricular filling.