The pressure acting on the part of the Rib Cage that is apposed to the costal surface of the lung is quite different from that acting on the part apposed to the diaphragm. The non uniformity of pressure distribution led Agostoni and D’Angelo (1985) to suggest that the rib cage could be usefully regarded as consisting of two compartments mechanically coupled to each other (Agostoni & D’Angelo, 1...

Nearly fifty years ago, Arthur B. DuBois, Julius H. Comroe Jr., and their colleagues published two papers on the use of body plethysmography to measure lung volume and airway resistance. These two articles in the JCI are almost the most-cited doublet in the Journal's entire archive. Remarkably, the methods described then are still in use today in clinical pulmonary function laboratories. Though...

Whole-body plethysmography is widely used to measure ventilation in awake, unrestrained animals. However, the explicit solution for volumetric analysis of the plethysmograph signal depends upon a closed system, which limits experimental design. Although often used, open-flow plethysmography is complicated by the time-decay of pressure signals generated in the open chamber (e.g. equivalent volum...

BACKGROUND The aims of this study were to establish the optimum duration of blood flow occlusion to obtain maximal response and to compare the response after lower-arm and upper-arm occlusion. METHODS Pulse wave amplitude was analysed using a novel finger plethysmograph (EndoPat; Itamar). For measuring reactive hyperaemic index (RHI) induced by forearm cuff occlusion, 30 healthy subjects were...

This laboratory activity is designed to teach students how to measure forearm muscle blood flow (FBF) to describe the mechanisms of peripheral blood flow thermal regulation in healthy subjects. The cold pressor test (CPT) is the clinical procedure used in the experiment to induce arterial vasoconstriction. Strain-gauge plethysmography is applied on the patient's forearm to noninvasive monitor v...

Slow spirometry and forced spirometry (flow volume loop) are often used to measure clinically relevant lung volumes and forced expiratory and inspiratory flows. Dynamic parameters, such as forced expiratory volumes in one second (FEV1) or forced vital capacity (FVC) and static lung volumes, such as expiratory reserve volume (ERV), inspiratory capacity (IC) and inspiratory vital capacity (IVC) c...

abstract background: the current practice to measure rv is either by bpg or helium dilution methods which may not be available in all clinics due to their cost. methods: this paper outlines a method for both direct and indirect calculation of rv via pft with acceptable sensitivity (81 %, 60% ), specificity (71 %, 94%) and validity (76%, 78%) for obstructive and restrictive lung disease respecti...