Anyone can witness a cardiac arrest on the street, at work or in the lobby of their building. As we all know, immediate cardiac massage can save lives, whether it is performed by professionals or by citizens. Some call centers have already implemented first aid coaching techniques for those who have never performed CPR. Unfortunately, because of the fear of doing the wrong thing or of hurting the victim, many witnesses remain paralyzed while waiting for the arrival of the emergency services. This is all the more dramatic because only 7-10% of patients (Gräsner et al., 2020) survive an out-of-hospital cardiac arrest. This is why it is necessary to work with citizens and rescue professionals to increase the chances of survival of victims.

It is in this context that the project "Numérique et living-lab : pour un citoyen secouriste" (Digital and living-lab : for a citizen rescuer) has been financed by the MAIF Research Foundation for a period of 2 years in collaboration with the University Hospitals of the city of Geneva and their 144 call center. The project aims at understanding the dynamics between the regulator (operator of the emergency call center) and the citizen during an emergency call and the mediation effect of a digital application (SARA) intended for the actual handling of the victim. It is also about highlighting how these individual behaviors are part of a collective prevention.

Many digital applications already exist for citizens trained in first aid. These applications, Permis de Sauver or Staying alive for example, are known by the 15, 18, 112 call centers. The citizens mobilized by these applications are private citizens: firefighters, volunteer firefighters, or people with a first aid certificate. The SARA application is intended for a wider public without knowledge or competence in first aid. It allows the caller to be accompanied by the regulator through video guidance.

Ophélie Morand, post-doctoral student in Ergonomic Psychology, Stéphane Safin, Senior Lecturer in Ergonomics, specialist in participative co-creation methods favoring the involvement of citizens and in the appropriation of technologies by users and Caroline Rizza, Lecturer in Information and Communication Sciences, specialist in crisis and emergency management and in the digital skills of its actors, collaborate in this project to understand the stakes of such a digital mediation and of the trust it can foster between first aid professionals and citizens.

The three researchers rely on a specific methodology (the living-lab) aiming at bringing together and collaborating with professionals in the field of personal assistance (call center operators/regulators) and informed citizens (first responders) or novices. Stakeholders will carry out simulations of emergency situations based on scenarios co-constructed by researchers and HUG doctors. The living lab is a method that has proven its effectiveness in transferring knowledge and developing a discourse and a common frame of reference for the stakeholders. "Emergency services operators think they are giving clear indications to the citizens who are helping them. But this information is not always understood in the field," explains Caroline Rizza, the project's scientific manager. These days of work will allow the application to be tested, new ideas to emerge, to reflect together on the application's functions and ergonomics, but above all to collectively identify the obstacles and levers relating to the performance of lifesaving gestures in order to encourage the creation of a link and trust. The researchers are particularly interested in the experiences and practices of citizens and professionals in terms of first aid gestures while collectively raising awareness of these gestures.

The Living Lab day will be divided into two parts: simulation workshops and, for the volunteers, participation in photography workshops led by Hortense Soichet, researcher and photographer. These workshops will allow to retrace the exchanges that took place between citizens and rescue professionals. They will be staged using a selection of the situations evoked, recurring gestures, feelings to be highlighted, etc. These photographs will be re-enactments of these actions performed by the participants and envisaged as an extension of the work done in the Living Lab. "It will capture a fear, a gesture and put them back into situation. I would like to reuse these photos to get people talking again, to go further than the interviews we do in this framework," explains Caroline.

This joint work on the simulations, the experiences and the emotions of each person aims to bring out a mutual understanding and a budding collaboration, allowing the development of trust between the two groups working together, which is essential for the success of an intervention. "Mutual trust between the citizens and the emergency services is the key to their involvement in the rescue operation.  In order to be guided by the emergency services and to apply life-saving gestures, the citizens must be confident and conversely the regulator or the operator must be able to trust the caller to perform these gestures thanks to digital guidance" conclude the three researchers.