Patients with a de novo diagnosis of positional sleep apnoea on a polysomnography performed in our sleep lab will be asked to participate to the study. They should fulfill the Mador definiton of POSA.

A home recording of sleep position with Somnibel Pro will be conduted for 2 consecutive nights. In case of confirmation of supine sleep at home (Mean supine sleep >30% of total sleep time) the patient will be asked to use two different positional therapy devices consecutively (Positional pillow and vibrating belt), 3 nights each, in a random order, with concomitant recording of sleep position with the Somnibel Pro. Global satisfaction questionnaire will be assessed by a simple visual analogic scale (is it easy to use? Is it confortable? Is it efficient on snoring? Is it efficient on sleep apnea? Would you pay for such treatment? Willingness to use it on a long-term basis?) The subjective sleep quality will also be assessed by means of "Sleep quality questionnaire", prior to commencing treatment, and consecutively after 3 nights on each individual therapy.

Statistical analysis:

Efficacy of Positional pillow (Posiform) and vibrating belt (Somnofit) Percentage sleep on back on treatment will be compared to mean percentage sleep on back without treatment, at home, for both devices. Comparison on surrogate AHI based on diagnostic polysomnography, with and without each device. Global satisfaction with the devices will also be compared between devices.

The sleep quality will be compared on the two devices using the "Sleep quality questionnaire".

The sample size of 52 subjects (26 in each arm), has been calculated to obtain a power of 90% and allow a drop out rate of 10%.