Abstract
We have investigated the respiratory function of human glottis, over the past 10 years. This paper present results of three consecutive studies for evaluation of the respiratory glottic movements. We have carried out two human and one animal study, including (1) A video fluoroscopic measurement of the glottic airway width in healthy subjects and patients with pulmonary emphysema during eupnea, (2) Effects of a positive pressure lung inflation on respiratory glottic movements in anesthetized dogs, and (3) A glottic area determination by newly developed Acoustic Reflection System in normal subjects and patients with pulmonary emphysema. The results were as follows : “The expiratory glottic narrowing” were a significant phenomenon in subjects with some type of disease condition such as pulmonary emphysema (in study 1). We observed that a positive air way pressure narrows the glottis more markedly than a decrease of the lung volume. The airway pressure was one of the most important contributing factor in expiratory glottic movement (in study 2).Also, We were able to measure dynamic changes of glottic airway area by the acoustic reflection technique introduced by Jackson and Fredberg in 1977 (in study 3). Respiratory glottic movements may reflect airway-lung condition especially changes of the intra-airway pressure caused by changes of the airway resistance in various airway diseases.
Measurements of respiratory changes in the glottic area may be useful for estimation of airway characteristics and pathophysiology in patient with pulmonary diseases. Further investigations are needed for more information.
The acoustic reflection technique is a unique, non-invasive technique for evaluating cross-sectional area of airway, especially for estimation of changes in glottic airway area due to respiratory glottic movement.
