Usability Testing of a Hair Apposition Device for Scalp Laceration: A Manikin Simulation Study

The hair apposition technique (HAT) is a method for closing scalp lacerations by twisting adjacent hair strands, which may require more than one operator. The hair apposition device (HADev), a prototype, was developed to enable single-operator use by integrating a comb, hair clips, and an anchoring system. Accordingly, the objective of this study was to evaluate the usability of HADev.

Study participants were medical professionals with prior experience in HAT. Following a 30-min lecture and practice session, participants performed HAT using HADev on manikins with short (8 cm) and long (20 cm) hair. Each participant completed two procedures for each hair type. Participants were randomized according to the sequence of hair length. The success rate and procedure time were recorded. Questionnaires were administered to assess the perceived difficulty and satisfaction.

Twenty participants (13 physicians and 7 residents) completed 40 procedures using HADev, with 20 performed on short-haired manikins and 20 on long-haired manikins. For short hair, physicians and residents achieved success rates of 100% and 85.7%, with median procedure times of 55.1 and 52.8 s, respectively. For long hair, physicians and residents achieved success rates of 92.3% and 100%, with median times of 63.0 and 62.1 s, respectively. The median perceived difficulty scores (1 = very easy, 5 = very difficult) were 2 for HAT and 1 for HADev. The median satisfaction scores (1 = excellent, 5 = very poor) were 2 for physicians and 3 for residents with HAT and 1 for both groups with HADev.

HADev demonstrated feasibility for single-operator use in a simulated environment, with a 95% success rate and procedure time of approximately 1 min for both hair conditions. However, further studies are needed to improve its usability and assess its clinical applicability.