Measuring human stress more accurately than ever before – it is the goal of the ICARUS ARMOR project funded by the European Space Agency (ESA). Last week, a team of researchers from the Brno University of Technology, led by Uptimai, tested volunteers in a climate chamber of the Faculty of Mechanical Engineering. Lending his expertise to the critical test was ESA's own reserve astronaut, Major Aleš Svoboda.

"At the moment, we can see our colleague in the climate chamber. Now, he needs to sit still for ten minutes to get used to the environment. After a while, I will bring him a tablet which will perform a cognitive function test," explains the head of the research, Vratislav Šálený of the Faculty of Mechanical Engineering. This is not just any test, the same one is used in NASA's Twins Study to test the cognitive functions of astronauts on the International Space Station. "It's about exposing the test subject to a very intense cognitive load. Which is exactly right for us, because the goal of our research is to measure stress. As part of the test, we, in cooperation with Deloitte, whole also explored the introduction of cognitive loads using virtual reality devices," adds Šálený.

The test subjects will spend a total of two stays in the climatic chamber. The first test is performed under normal conditions at the room temperature, the second at an elevated temperature reminiscent of a rather unpleasant tropical climate. In both cases, the battery of demanding neuropsychological tests, which have been specifically designed for high-performance astronauts, is intended to increase the mental load and thus the stress response of the test subject. In the latter case, the aforementioned high temperature and humidity are added as a stressor. Or in other words, the second tests attempts to overheat the brain, and see how the test subjects will perform. You can imagine this as doing your regular tasks in a sauna, everything is physically possible but test subjects are pushed closed to the limit where mistakes happen more often.

While engineers of the Faculty of Mechanical Engineering create the necessary conditions in the climatic chamber, the actual measurement of bodily functions is performed by biomedical engineering experts of the neighboring Faculty of Electrical Engineering and Communication (FEEC). "During the measurement, we use a single-lead ECG, and we monitor the respiratory rate using a sensor located in the chest strap, on which we positioned body temperature sensors. The test subject also uses a MetaLyzer measuring mask, thanks to which we obtain data on exhaled CO2, which is one of the important parameters for calculating the stress load," says Jana Kolářová of the Department of Biomedical Engineering. She adds that the course of the entire measurement was approved in advance by the ethics committee and all the test subjects were familiarized in detail with the entire course of the measurement before the start of the experiment.

One of the devices is operated by Dominik Bachratý, a student of the Sports Technology program at BUT. "In the second and third years, we have to complete 480 hours of professional practice as part of a professionally oriented study program. I was intrigued by the measurements of the physiology of physical exertion, which are done at our Sports Activities Centre. I had myself trained and now I help with measurements in the laboratory," explains Bachratý, who thus got a chance to take part in a real research during his studies. During the test in the climatic chamber, he is in charge of operating the aforementioned "mask", which is actually a very sophisticated complex tool enabling analysis of gas as human inhale and exhale. "We are interested in oxygen consumption and CO2 production, or ventilation quotients, respiratory exchange ratio and heart rate," he explains while preparing the device for further measurements.

The Limits of (Un)Healthy Stress

To certain extent, stress is natural for humans and we know how to deal with it. "The human body is a closed system. When we are exposed to stressful conditions, our body immediately reacts and triggers mechanisms that try to keep our body in optimal conditions," explains Kolářová. While all the previous tested persons represent a sample of the standard young population, the last tested person was Major Aleš Svoboda. "In pilots or athletes – generally trained individuals – the organism reacts faster to changes and does not allow the body conditions to change as dramatically as we can see in an untrained person. For this reason, we found Major Svoboda's participation in the test very interesting. We have the opportunity to compare the measured physiological changes in a group of young untrained individuals with a pilot in whom we expect a different reaction speed," adds Kolářová.

A fighter pilot and, since last autumn, also a member of ESA's reserve team of astronauts, he has all the prerequisites to stand out from the results of other measurements. The first impressions after the test confirmed that he is used to similar conditions. "Thermally, it was fine, I enjoyed the tests. So I guess I wasn't completely stressed," he says with a smile, adding that he often undergoes similar tests as a pilot. "At a recent conference, we were talking about the fact that stress – as long as it fails to exceed a certain limit – is actually useful. It is a compensatory mechanism of the organism and preparation for a stressful situation. So being slightly stressed is basically good," Aleš Svoboda sums up.

The measurement data obtained will be processed by Uptimai, a Czech start-up involved in probabilistic modelling, both for the needs of upcoming civilian users and space research. The result of the development is to be a wearable device that can alert the user that their stress level is approaching a problematic level. The technology is to use advanced algorithms and machine learning methods to process physiological data to measure stress markers in the human body. "The goal is to create a comprehensive real-time stress monitoring system that can be used in a number of areas: from paramedics, through firefighters, to civilian employees in high-stress situations," explains researcher Šálený. If the research is successfully completed, it will be another example of how people on the ground can also benefit from what was originally a space research.

Aleš Svoboda has no doubts that space research brings benefits to everyday life as well. "I think it's not just a question of whether we will have our own Czech satellite or an astronaut. Investment in space research also impacts business here on earth. That is why we should have slightly bigger goals as a country, or we will miss the boat, because even countries like Poland or Hungary are pushing it much harder than we are. So far, we are at least trying to return to where we were in the 1970s. We should be much more ambitious," concludes Svoboda.