A patient transfer device includes a mat, with an upper side and a gas permeable lower side. The mat includes a chamber between its upper and lower sides, which is operable to be in fluid communication with an air source such that when air flows into the mat, the air will flow into the chamber and through the gas permeable lower side to form an air film between the mat and a surface on which the mat is supported at its lower side. In addition, the lower side of the mat is substantially planar when the mat is inflated. A system for controlling the inflation of the mat may be used that automatically adjusts for the inflation of the mat during patient transfer.