Abstract: Intrapleural pressure of a newborn subject is measured by detecting relative movement between adjacently-proximate cranial bones. The preferred device for measuring such bone movements is a surface inductive plethysmographic transducer secured on the subject's head across at least two adjacently-proximate cranial bones. The output signal generated by the transducer may be calibrated to provide a measurement of actual intrapleural pressure by temporarily manually occluding the subject's nose or, if intubal, the endotracheal tube, measuring the airway pressure during such occlusion as the makes an inspiratory effort, and adjusting the transducer output signal to equal the airway pressure measured with the nose occluded.