Figure 1From: Thoracic gas compression during forced expiration in patients with emphysema, interstitial lung disease and obesity Compressed (mouth) and compression-free (thoracic) flow values at different expiratory flow levels. Compressed (mouth flow) and uncompressed airflow (thoracic flow) during forced expiration at peak expiratory flow level (PEF) and at different levels of expired volume (MEF75, MEF50 and MEF25).Back to article page