12 participants wore 3 different connected heart rate sensors during sleep (i.e. electrodes, chest belt, smartwatch). They consult the respective reports and filled a questionnaire to help us to identify which one is the most acceptable device to monitor sleep. Chest belt was perceived as the easiest device to use and was considered as reliable as electrodes. Taken together and in line with the Technology Acceptance Model, these preliminary results suggest that the chest belt is the most acceptable HR sensor device.