This part of ISO 20342 specifies conditions and test methods for the durability of assistive products for tissue integrity (APTI) when lying down additional to ISO 20342-1.  This document is applicable to APTIs, such as mattresses and overlays, and includes single patient multiple use products. This document does not apply to single use products. NOTE                        It is intended to help differentiate the durability characteristics between APTIs.  It is not intended for determining overall performance or for ranking or scoring of such APTIs.