The measurement of respiratory flow in tandem with the measurement of the abdominal chest movements provides a significant parameter in polysomnography: the breath
study, which allows to distinguish between obstructive sleep apnea (absence of flow with the presence of respiratory effort) or central apneas.
The plethysmography, defined as the change in abdominal and thoracic volume, can be measured by:
- variation of an elastic band
- variation of electrical inductance