Development of a system for the evaluation of external ear sounds for use in sleep apnea studies

the monitoring of respiratory events during sleep is important in the diagnosis of sleep apnea. The methods used to accomplish this task, however, are invasive or inaccurate. The aim of this work is to investigate an alternative method based on the respirator), sounds measured in the external ear. The development of a system able to measure the cited sounds is described, as well as results associated with simulated conditions usually found in respiratory sleep diseases (hyperventilation, tidal breathing, hypopnea and apnea). In these simulations, the sounds at the external ear were compared with the respiratory flow measured by a pneumotachometer. These experimental results revealed a correlation around 0.90, confirming the high scientific and clinical potential of this system.