Night Balance for Positional Obstructive Sleep Apnea Syndrome (POSAS)

Inclusion Criteria: * AHI supine ≥ AHI non-supine x 2, * AHI supine ≥ 10 * AHI non-supine \<10 * 10 -90 % sleep time in supine position * Daytime tiredness and/or disturbed sleep and/or snoring Exclusion Criteria: * Not able or willing to cooperate * Age \<18 years * Central Sleep Apnea * Night or shifting work * Severe chronic heart failure or severe COPD * A medical history of known causes of tiredness by day or severe sleep disruption (insomnia, PLMS, Narcolepsy) * Seizure disorder * A known medical history of mental retardation, memory disorders or psychiatric disorders * The inability to provide informed consent * Pacemaker * Pain in joints or shoulder * Other reasons unable to sleep in lateral positions. * Pregnant females or females that plan pregnancy in study period (problems sleeping supine) * Breastfeeding females in study period (other reasons for disturbed sleep) * Plan weight reduction in study period * Plan to quit smoking in study period