Positional therapy encourages side sleeping to reduce apneas that worsen when lying on the back

https://www.slideserve.com/nuallaqqkj/does-insurance-cover-a-sleep-apnea-test-online-costs-and-coverage-explained

Positional therapy encourages side sleeping to reduce apneas that worsen when lying on the back, using specialized pillows, belts, or vibrating sensors.