At low pressures, the vent flow is equivalent to a ResMed open mask system to ensure carbon dioxide (CO2) limits are met. Therefore, ActiveAir should not play a role in resistance at low pressures. As the pressure increases, the ActiveAir vent flow also increases. This however is significantly reduced when compared to a traditional mask vent and therefore if a patient’s peak flow exceeds the ActiveAir flow then some flow will travel down the tube.
Pressure swings serve as an indicator of breathing comfort and AirMini is able to continuously adjust pressure to compensate for the circuit impedance (including the HumidX/HumidX Plus). These mask pressure swings lie within our clinical specifications and do not deviate significantly from AirSense 10. Note that increased resistance may be experienced post apnea. During these episodes, the patient will generally gasp for air which can result in an exhalation so high the AirMini can temporarily struggle to properly control the pressure. After the post-apnea breath, AirMini will return back to normal therapy operation.
