Evaluation of Mixed Reality Cardiopulmonary Resuscitation Training

\<Study Design\> This study is a cluster-randomized, stratified, non-inferiority trial designed to evaluate the feasibility, efficacy, and educational effectiveness of HEROS 4.0, a mixed-reality (MR)-based cardiopulmonary resuscitation (CPR) training system, compared with conventional instructor-led CPR training. \<Objective \& Hypothesis\> The primary objective is to determine whether MR-based HEROS 4.0 CPR training is non-inferior to standard video- and instructor-based CPR training in improving CPR performance quality. The central hypothesis is that participants trained using HEROS 4.0 will achieve comparable CPR quality to those trained using traditional methods, while benefiting from enhanced immersion, scalability, and accessibility. \<Participants\> A total of 120 adults aged 18-50 years who have not received CPR training within the previous 12 months will be recruited. Participants will be assigned to one of two clusters and randomized in a 1:1 ratio to either the HEROS 4.0 MR training group or the conventional CPR training group. \<Intervention \& Control\> Participants will undergo CPR training according to their assigned group: Intervention group (HEROS 4.0): Participants will receive a two-stage CPR training program consisting of pre-training and on-site MR-based training. As pre-training, participants will be instructed to watch a 40-minute instructional video (conventional CPR training group video) at home prior to their visit. After completing the pre-training, participants will undergo 20 minutes of MR-based CPR training using the HEROS 4.0 system in a dedicated CPR training booth. Control group (Conventional CPR training): Participants will receive 60 minutes of standard CPR education delivered through instructional videos and in-person instructor guidance, reflecting current community CPR training practice. \<Outcomes\> Immediately after training, all participants will undergo a standardized cardiac arrest simulation using a CPR quality-measurement manikin. This simulation will assess objective CPR performance metrics as well as subjective outcomes through questionnaires. To evaluate knowledge retention and skill durability, all assessments will be repeated 6 months after training using the same simulation scenario and outcome measures. The primary outcome is chest compression fraction measured during the standardized simulated cardiac arrest scenario. Secondary outcomes include quantitative measures of CPR quality and participant-reported outcomes based on survey.