Evaluation of a Virtual Human in Delivering Relaxation Exercises for Wound Healing and Stress Reduction: A Randomised Controlled Trial

Objective: Relaxation delivered via audiotapes can reduce stress and improve wound healing. Virtual humans are a promising technology to deliver relaxation, but robust research is needed into their effectiveness. This randomised controlled trial investigated whether relaxation delivered by a virtual human could improve healing and reduce stress after an experimental wound. Methods: A total of 159 healthy adults underwent a tape-stripping wounding procedure and were randomly assigned to relaxation delivered by a virtual human, human audiotape, or a control condition. Skin barrier recovery (SBR) was measured by assessing changes in transepidermal water loss at baseline, post-tape-stripping, and post-intervention. Psychological and physiological variables were measured over the session. Participants’ perceptions of the interventions were assessed. Results: There were no significant differences in SBR between conditions. All conditions experienced significant improvements in the psychological variables, heart rate, and cortisol over time. After controlling for the baseline values, the virtual human and audiotape conditions were significantly more relaxed post-intervention than the control condition (p = 0.005), the audiotape condition had lower post-intervention anxiety than the control condition (p = 0.016), and alpha-amylase was significantly reduced in the virtual human group compared with the audiotape (p = 0.041). The audiotape received the highest satisfaction and engagement ratings, with qualitative results suggesting the appearance and lip-syncing of the virtual human could be improved. Conclusions: Relaxation instructions delivered by a virtual human increased participants’ relaxation levels with similar effects to traditional audiotapes. Furthermore, it reduced physiological stress indices. Further work with other wound types and stressed samples is needed. The voice and interactiveness of the virtual human should be improved to promote greater engagement and satisfaction.