Three-dimensional shape-conformation performances of wound dressings tested in a robotic sacral pressure ulcer phantom.

Effective exudate retention by dressings requires close and intimate dressing-wound contact, immediately and continuously after the dressing application. Any dressing-wound spaces may allow for build-up of non-retained fluids, causing exudate pooling which forms a favourable environment for pathogen growth. Maceration may follow if the pooled exudates spread to peri-wound skin. Dressings with a claimed 3D-shape-conformation technology are commercially available; however, their effectiveness in minimising dressing-wound gaps has never been scientifically investigated. We present a novel bioengineering methodology for testing the effectiveness of such 3D-shape-conformation dressings, using our recently reported robotic phantom system of a sacral pressure ulcer. By means of 3D laser scanning and bespoke software, we reconstructed dressing shapes after simulated use and calculated the goodness-of-fit between each dressing (swelled to near-saturation) and the corresponding wound geometry. Two dressing sizes (10 × 10 cm and 12.5 × 12.5 cm) and two wound depths (2.5 or 2 cm) were considered. All the tested dressings were far from reaching good contact with the (simulated) wounds: Approximately one-third of the wound volume and nearly half of the wound surface were not in contact with the swelled dressings. Our present findings question whether 3D-shape-conformation dressings are effective, by revealing their swelling behaviour which was previously unknown.