DreamStar™ Duo is designed for the Non-Invasive Ventilation of patients suffering from Sleep Apnea Syndrome or Chronic Respiratory Failure, who are not dependant on ventilatory assistance. The Flow Sens algorithm optimizes patient-to-device synchronization. Summary and usage data, apneas, hypopneas, respiratory rate and patient flow are stored in the embedded memory and are available for downloading, either through a USB link or data card. DreamStar™ DuoST is designed for the Non-Invasive Ventilation of patients suffering from Sleep Apnea Syndrome or Chronic Respiratory Failure, who are not dependant on ventilatory assistance. Equipped with the same features as DreamStar Duo, DreamStar DuoST features in addition a backup rate setting to ensure a minimum minute breathing rate and an I/E ratio setting for the backup breaths.