Global ageing is leading to an increase in cardiac arrest incidents among senior citizens, posing a significant societal challenge. Most out-of-hospital cardiac arrest (OHCA) incidents occur at patient’s domestic residences, limiting their immediate access to professional help and Automated External Defibrillators (AEDs). In such instances, Cardiopulmonary Resuscitation (CPR) performed by caregivers, often the patient's family with no expert knowledge of emergency care, becomes crucial. Compared to professional rescuers, non-expert rescuers such as caregivers could face challenges in executing effective CPR due to skill gaps and potential emotional barriers in performing such procedures on family members. This study investigates the experience of caregivers in cardiac arrest scenarios, a critical but often overlooked aspect in the design of emergency care devices.

We aim to understand 1) how emotions affect caregivers' performance and experience during domestic cardiac arrest incidents and 2) how design can support their practical and emotional needs, enhancing their performance. Semi-structured interviews with professional rescuers and caregivers reveal both emotional and skill-related challenges that caregivers might confront before, during, and after cardiac arrest incidents, such as unfamiliarity with rescue procedures, unskilled in CPR, physical strain, fear of approaching a collapsed person, anxiety about causing harm, lack of confidence, and moral pressure from social ties. These challenges can lead to adverse reactions that further hinder their CPR performance. The study highlights the importance of including emotional support for non-expert rescuers in OHCA incidents. By incorporating human-centred design principles, we propose an inclusive design guideline for emergency care devices and practical design recommendations to mitigate emotional barriers and assist operational performance for non-expert rescuers. Under these design guidelines, we conducted two follow-up interviews to engage non-expert rescuers in co-design sessions to propose an emergency care device concept. With the co-design results, this study established the final design concept for this device and created a digital prototype demonstration of our final design concept. Finally, we invited two non-expert participants to evaluate the demonstration through an experiential evaluation. This study contributes to the field by presenting a design demonstration of an emergency care device, emphasising the emotional and practical support to enhance the experience of non-expert rescuers in domestic OHCA incidents.