Clinical Usability of a Wound Measurement Device

Objective: Monitoring wound size is an integral component to the assessment and treatment of chronic wounds. Conventional methods, such as ruler measures and transparency tracings, for measuring wound size often have low accuracy and reliability. Newer high tech methods, while more reliable and accurate, are often expensive and difficult to use. The objective of the study was to design a wound measurement device (WMD) with the following features: ease of use, low cost, non-contact, time-saving, hand-held, reliable, and battery operated. Design: The performance of the WMD was evaluated in two rounds of bench testing for accuracy and reliability, followed by a single round of clinical testing to assess ease of use. Participants/Methods: Bench testing of the WMD was completed to assess for accuracy over distance from the wound surface, as well as camera angle skew. The performance in terms of interand intra-rater reliability was also assessed. Three clinicians participated in the clinical trial portion of the study. 45 subjects were recruited. General usability and ease of use was measured through the use of written surveys and verbal feedback from the participating clinicians. Results: Intra-rater reliability of presented images for which each clinician was asked to interpret and trace the wound exceeded 0.975. Inter-rater reliability of these same images was 0.966-0.978. Accuracy measures based on two black and white shapes with known areas had an average 2.65% error rate. Conclusions: Both intraand inter-rater reliability proved to be significantly higher than conventional methods, such as ruler measures and transparency tracings. The WMD was easy to use for the clinician. Support: This project was funded by NIDRR Wheeled Mobility RERC#H133030035, IP2Biz and CATEA. Key Words—wound measurement, pressure ulcer, chronic wounds, digital image processing, wound area