A new method of assessing the mechanical properties of patient support systems (PSS) using a phantom. A preliminary communication

Pressure ulcers are a major problem worldwide believed to affect over 5% of all hospital in-patients, and countless others in the community at large. Many types of Patient Support Systems (PSS) are sold as pressure ulcer prev ention equipment, but no consensus exists as to their mechanical efficacy. The use of human volunteers to assess the mechanical properties of PSS intr oduces nonrepeatability and variability in results which cannot give a stat istically significant difference in performance between systems. Mechanical testing without human volunteers provides faster evaluations of PSS, with improved precision and repeatability. An instrumented articulated anthropom etric phantom has been developed to investigate the distortion of simulated soft body "tissues" of the buttock and sacral areas due to precise and rep eatable static loading on a PSS. The weight of the phantom can be adjusted to 50, 70 and 90 kg and can be applied with the torso inclined at 0 degrees , 45 degrees and 80 degrees. Validation of the phantom by measuring interfa ce pressure using a force sensing array mat indicates that the phantom repr esents realistic physiological loading conditions. The new method of measur ing the distortion of the "artificial tissues" provides a highly selective ranking of PSS. (C) 1999 IPEM. Published by Elsevier Science Ltd. All right s reserved.