Relaxation and Wound Healing: A Randomised Controlled Trial Evaluating the Effectiveness of Virtual Humans in Delivering Relaxation to Improve Skin Barrier Recovery and Reduce Stress

Abstract

Virtual humans are a form of artificial agent that is starting to be used to deliver e-health interventions. Several early studies show promising feasibility, but research designs have been preliminary to date. Therefore, more randomised controlled trials (RCTs) are needed to evaluate their effectiveness in delivering psychological interventions and improving health outcomes. The aim of this study was to evaluate the effectiveness of a brief relaxation intervention delivered by a virtual human recording compared with a real human audiotape and a control group on wound healing and stress in a healthy community sample. An RCT with a mixed factorial design was conducted. One hundred and fifty-nine healthy adults aged between 18 and 60 years (M =26.04) participated in a 90-minute session, during which they completed questionnaires and underwent a non-invasive tape-stripping procedure to disrupt the skin barrier, followed by a 20-minute recovery period. Participants were randomised to (1) relaxation delivered by a Digital Human, (2) relaxation delivered by human audiotape (3) reading magazines during the recovery period. A series of psychological questionnaires collected self-reported stress, relaxation, anxiety and pain, satisfaction, engagement, and open-ended responses; a wrist sensor wrist measured heart rate (HR) and electrodermal activity (EDA) and saliva samples collected stress hormones salivary cortisol (sCort) and alpha-amylase (sAA). Results indicated no significant differences in skin barrier recovery (SBR), psychological or physiological stress measures between the delivery methods. However, the Digital Human and audiotape groups had significantly greater relaxation following the relaxation session, superior to the control group. Anxiety was significantly more reduced, and satisfaction and engagement levels were greater in the audiotape group. Additional open-ended responses indicated that the appearance and mismatch in lip-syncing of the Digital Human made some people feel uneasy and could be improved. The findings demonstrate a virtual human’s ability to relax people, comparative to traditional audiotapes in an RCT. The study provides suggestions to improve virtual humans’ delivery of relaxation interventions and provides future experimental design recommendations. Ultimately, these findings encourage future studies to explore further the effects of an interactive virtual human to deliver relaxation and improve health outcomes, particularly in highly stressed or clinical wound samples.