A mattress-like device consisting of an arrangement of alternating-pressure air cells designed to be placed on a bed mattress support platform to provide a comfortable surface on which an occupant can lie, rest, and sleep, and intended to distribute body weight over a large surface area typically to help relieve pressure points for comfort and improve blood circulation to prevent pressure sores. It is connected to an alternating-pressure pump (not included) which provides the inflation/deflation control. It is commonly used for elderly immobilized (especially in cases of decubitus ulcers) patients, patients with disabilities, or patients with low body fat.