enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Spirometry - Wikipedia

    en.wikipedia.org/wiki/Spirometry

    Spirometry (meaning the measuring of breath) is the most common of the pulmonary function tests (PFTs). It measures lung function, specifically the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled.

  3. Breathing performance of regulators - Wikipedia

    en.wikipedia.org/wiki/Breathing_performance_of...

    It specifies the following, under test conditions of a breathing rate of 62.5 litres (2.2 cu ft) per minute and an ambient pressure of 6 bars (600 kPa): [18] Work of breathing: <3.0 joules per litre; Peak respiratory pressure: ±25 mbar (±2.5 kPa) (inhalation or exhalation) Inhalation work of breathing: <0.3 joule per litre; Pressure spikes ...

  4. Pulmonary function testing - Wikipedia

    en.wikipedia.org/wiki/Pulmonary_function_testing

    The plethysmography technique applies Boyle's law and uses measurements of volume and pressure changes to determine total lung volume, assuming temperature is constant. [8] There are four lung volumes and four lung capacities. A lung's capacity consists of two or more lung volumes.

  5. Breathing - Wikipedia

    en.wikipedia.org/wiki/Breathing

    Doubling the volume of the lungs halves the pressure in the lungs at any altitude. Having the sea level air pressure (100 kPa) results in a pressure gradient of 50 kPa but doing the same at 5500 m, where the atmospheric pressure is 50 kPa, a doubling of the volume of the lungs results in a pressure gradient of the only 25 kPa.

  6. Spirometer - Wikipedia

    en.wikipedia.org/wiki/Spirometer

    The earliest attempt to measure lung volume can be dated back to the period A.D. 129–200. Claudius Galen, a Roman physician and philosopher, did a volumetric experiment on human ventilation. He had a child breathe in and out of a bladder and found that the volume did not change. The experiment proved inconclusive.

  7. Respiratory system - Wikipedia

    en.wikipedia.org/wiki/Respiratory_system

    Doing the same at 5500 m, where the atmospheric pressure is only 50 kPa, the intrapulmonary air pressure falls to 25 kPa. Therefore, the same change in lung volume at sea level results in a 50 kPa difference in pressure between the ambient air and the intrapulmonary air, whereas it result in a difference of only 25 kPa at 5500 m. The driving ...

  8. Alveolar gas equation - Wikipedia

    en.wikipedia.org/wiki/Alveolar_gas_equation

    The partial pressure of oxygen (pO 2) in the pulmonary alveoli is required to calculate both the alveolar-arterial gradient of oxygen and the amount of right-to-left cardiac shunt, which are both clinically useful quantities. However, it is not practical to take a sample of gas from the alveoli in order to directly measure the partial pressure ...

  9. Lung volumes and capacities - Wikipedia

    en.wikipedia.org/wiki/Lung_volumes_and_capacities

    Lung volumes and lung capacities are measures of the volume of air in the lungs at different phases of the respiratory cycle. The average total lung capacity of an adult human male is about 6 litres of air. [1] Tidal breathing is normal, resting breathing; the tidal volume is the volume of air that is inhaled or exhaled in only a single such ...