An evaluation of a gas collection valve for use in metabolic measurements in high flow CPAP systems
Related Experiment Video
Updated: Oct 22, 2026

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
Published on: February 20, 2017
Abstract:
We have developed a valved gas collection assembly for high-flow CPAP systems that permits the isolation of expired gases for the analysis and computation of oxygen uptake and carbon dioxide production. Using volunteer subjects we compared the valved assembly with a high-flow valveless CPAP system for volume, pressure, and flow differences at end-expiratory pressure levels of 5, 7, 10, and 12 cm H2O and found that the valve produced no significant differences in the flow/pressure pattern.
More Related Videos
Related Concept Videos
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
Oxygen Delivering System I: Nasal Cannula and Face Mask
Nasal Cannula
A nasal cannula is a lightweight tube split at one end into two prongs and placed in the nostrils. It is typically used to deliver low to medium levels of oxygen.
Suggested flow rate: The suggested flow rate for a nasal cannula typically ranges between 1 and 6 L/min.
Oxygen percentage setting:...
Oxygen Delivering System II: Venturi Mask and Transtracheal Oxygen
Venturi Mask
The Venturi mask, named after the Venturi effect, is designed to deliver precise oxygen concentrations. It consists of a large tube with an oxygen inlet that narrows down, causing a pressure drop that pulls air in through adjustable side ports. The mask is a lightweight,...
Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation (NIPPV)
Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation:
Pipe Flowrate Measurement
The orifice meter is a simple,...

