Drowsiness detection in the era of Industry 4.0: are we ready?

Interconnectivity and smart automation of Internet of Things in recent times have led to the concept of Industry 4.0. Employment conditions should take advantage of these new technologies. Safety in workplace is one of the most sensitive topics on matters. The safety can be guaranteed by investigating the attention states of the workers and, in particular, their drowsiness levels. Several technologies have faced this problem by using biometrics, but how many of them are applicable in a real-case-use scenario of Industry 4.0 This work aims to answer this question by discussing available data and methods that can be used in specific workplaces. We highlight their limitations and accuracy to sketch out the recent literature which may contribute to worker safety in Industry 4.0. Finally, we point out a gap that needs to be filled in order to implement these strategies on a large scale.