Fig. 4. Changes in vital capacity (VC), maximum insufflation capacity, and glossopharyngeal maximum single breath capacity over a 20 year period for a patient with Duchenne muscular dystrophy. The GPB, added to his autonomous tidal volumes, permitted the patient to breathe without requiring full ventilatory support until 43 years of age despite having a VC of 20 mL from age 42. VC, vital capacity; MIC, maximum insufflation capacity; GPmaxSBC, glossopharyngeal maximum single breath capacity.
