An assistive device for congenital central hypoventilation syndrome outpatients during sleep

Congenital Central Hypoventilation Syndrome is a genetic disease characterized by alveolar hypoventilation and autonomic dysregulation. Patients have hypoventilations, especially during sleep, conditioning hypercapnia which can lead to neurological damage and death. They therefore need mechanical ventilators, that provide sufficient gas exchange, and pulse-oximeters that monitor oxy-hemoglobin blood concentration. Due to the restrictions regarding domiciliary assistive devices, the presence of a caregiver is required all night long. Currently, the only alarm systems available are the ones integrated in the ventilators and monitoring systems. During the night, multiple false alarms may occur, interrupting the sleep and causing anxiety. In this work we describe an assistive device that acquires real-time data from a pulse-oximeter, provides a multisensory stimulation if oxygen saturation falls under a certain threshold, and wakes up the patient if the hypoxia is severe. Tests on healthy subjects have shown that the device guarantees rapid awakenings, with a stimulator-dependent efficacy, and that it does not affect sleep efficiency. The purpose of the device is to determine a gentle awakening if mild hypoxia conditions persist, and to assure rapid awakening when a severe hypoxia occurs, reducing false alarms, improving the quality of sleep and increasing the self-sufficiency of the patients.