distensibility

Distensibility is a metric of the stiffness of blood vessels. It is defined as

$D\; =\; \backslash frac\{d\_\{sys\}-d\_\{dias\}\}\{(p\_\{sys\}-p\_\{dias\})d\_\{dias\}\}$,

where $d\_\{sys\}$ and $d\_\{dias\}$ are the diameter of the vessel in systole and diastole, and $p\_\{sys\}$and $p\_\{dias\}$are the systolic and diastolic blood pressure.{{Cite journal|last=Roccabianca|first=S.|last2=Figueroa|first2=C. A.|last3=Tellides|first3=G.|last4=Humphrey|first4=J. D.|date=2014-01-01|title=Quantification of regional differences in aortic stiffness in the aging human|url= |journal=Journal of the Mechanical Behavior of Biomedical Materials|volume=29|pages=618–634|doi=10.1016/j.jmbbm.2013.01.026|issn=1751-6161|pmc=3842391|pmid=23499251}}