  Wearable devices have revolutionized healthcare monitoring, allowing us to
track physiological conditions without disrupting daily routines. Whereas
monitoring physical health and physical activities have been widely studied,
their application and impact on mental health are significantly understudied.
This work reviews the state-of-the-art, focusing on stress and concentration
levels. These two can play an important role in workplace humanization. For
instance, they can guide breaks in high-pressure workplaces, indicating when
and how long to take. Those are important to avoid overwork and burn-out,
harming employees and employers. To this end, it is necessary to study which
sensors can accurately determine stress and attention levels, considering that
they should not interfere with their activities and be comfortable to wear.
From the software point of view, it is helpful to know the capabilities and
performance of various algorithms, especially for uncontrolled workplace
environments. This work aims to research, review, and compare commercially
available non-intrusive measurement devices, which can be worn during the day
and possibly integrated with healthcare systems for stress and concentration
assessment. We analyze the performance of various algorithms used for stress
and concentration level assessment and discuss future paths for reliable
detection of these two parameters.
