Abstract
Signals from a gamma camera, ventilatory volume and respiratory phase were simultaneously stored in a computer system. A new parameter, half clearance breath number (B1/2), was used to evaluate the regional ventilation. B1/2 is useful to evaluate regional ventilation under different conditions.
Loading of the expiratory resistance improved the regional ventilation in patients with chronic pulmonary emphysema but to varying degrees in different patients.
Improvement of regional ventilation with expiratory resistance had little relation to changes of chest and abdominal wall movement. Therefore it was considered that PLB and abdominal breathing had different effects on regional ventilation.
It was thought that dynamic airway compression during expiration decreased due to a decrease of expiratory flow rate and increase of ultra-airway pressure, resulting in improved regional ventilation.
