Fissures are double folds of pleura that divide the lung into lobes. There are three lobes in the right lung and two in the left lung. The lobes are further divided into segments and then into lobules, which are hexagonal divisions of the lungs that are the smallest visible subdivision.
Spectrophotometers are color measurement devices used to capture and evaluate color, including specification and communication of color, and monitoring color accuracy.
Plethysmography uses blood pressure cuffs or other sensors attached to an instrument called a plethysmograph (or pulse volume recorder) to measure changes in the volume of a limb (or extremity). Because these volume changes are directly related to the amount of blood flowing through the limb, plethysmography helps to identify problems affecting blood circulation.