Introduction Therespiratory system plays a crucial role in our survival, as it functions toallow the exchange of gases between the lungs and the environment.
This systemis divided into two regions: the conduction and respiratory regions. The conductionzone allows air from the environment to reach the lungs while the respiratoryregion is the site in which gas exchange occurs with the circulatory system. Thereare many pathologies that stem from the respiratory system, which arecategorized as either as an obstructive or restrictive disease. It isconsidered to be an obstructive disease when the airflow is reduced into orfrom the lungs caused by ablockage in the conduction region. Restrictive respiratory diseasehowever occurs when the elasticity of the lungs is diminished, which in turn reducesthe ability of lungs to expand, ultimately reducing the air that can beinspired. Spirometryis a technique used to test lung function by measuring the air that flows inand out of a person’s lungs during static or dynamic conditions, and can beused to diagnose the respiratory diseases mentioned. Many different values aremeasured and assessed to define if a person is diagnosed with a respiratory disease.
These values include the tidal volume (VT), vital capacity (VC), inspiratorycapacity (IC), inspiratory reserve volume (IRV) expiratory reserve volume(ERV), residual volume (RV), functional residual capacity (FRC), total lungcapacity (TLC), forced vital capacity (FVC), and lastly the maximum voluntaryventilation (MVV). VT is the volume of air that is inspired or expired with asingle breath during normal breathing, while the VC is the maximum expired airafter a person takes their maximum inspiration. Next, IC is the maximuminspired air at the end of a normal breath. IRV and ERV measure the amount of extra airthat can be inspired and expired after a normal breath respectively.Furthermore, MVV is the greatest volume of air that a person can inspire in aminute while breathing as fast and deeply as possible.
FRC and RV are similar as it assesses thevolume of air remaining in the lungs after expiration, but RV examines thevolume after a maximum while FRC is the volume after a normal expiration. TheVC and the RV can then be added to figure out the TLC, which is the total airin the lungs after a maximum inspiration. In addition, the forced vitalcapacity (FVC) is the volume of gas that is expired as swiftly as possibleafter an individual’s maximum inspiration. The FVC can indicate the forcedexpiratory volume at one sec (FEV1), which can be used to get the FEV% which isthe ratio of FEV1 over the FVC. From the FVC maneuver, the maximum flow of airduring the test, also known as the peak expiratory flow (PEF) can be determinedalong with the FEF25-75, which is the average flow of air over the middlesection of the lung. Thisstudy aims to compare the effect on the measurements mentioned between healthyindividuals vs.
a condition in which an obstructive disease is mimicked in bothstatic and dynamic conditions, which is achieved by placing a stopper to thespirometer. It is hypothesized that since the presence of a stopper will reduceairflow, there will be a decline in the volume of air that can be inspired andexpired. It is then expected that the values measured in both static anddynamic conditions will be lower when an obstructive disease is imitated vs.
the values of healthy individual, except in the case of the RV as it is predictedto increase due to gas being trapped in the lungs1.