According to New Atlas, it's important for people with conditions like depression and anxiety to know when they start to feel stressed so they can initiate coping strategies. An experimental new smartwatch could one day warn them by detecting pressure hormones in sweat.
When a person feels stressed, their body produces a hormone called cortisol — and the greater the pressure, the higher the concentration of cortisol in their blood. While these concentrations can be measured by analyzing blood samples, doing so is clearly not an effective way to continuously monitor pressure in real time.
Fortunately, the concentration of cortisol in sweat is consistent with the concentration of cortisol in the blood. That's what the smartwatch prototype does — it's currently being developed by researchers at UCLA, led by a team led by Professor Anne Andrews and Associate Professor Sam Emaminejad.
At the bottom of the device there is a thin adhesive film that utilizes microfluidic channels to draw in trace amounts of sweat from the wearer's skin. The sweat is brought to a sensor containing a designed strand of DNA called an aptamer.
Each cortisol molecule in sweat is attached to an adapter "like a key inserted into a lock". The aptamer thus changes shape, changing the electric field on the surface of adjacent transistors. A microprocessor analyzes these fluctuations in electric fields and uses them to determine the wearer's current cortisol level. These levels are displayed on an LCD screen on the top surface of the watch.
Since each person produces a different amount of cortisol, the watch must initially calibrate each user to establish a baseline for their default cortisol levels. Once the baseline is set, the device can warn them when they become dangerous under stress. In addition, it can track their cortisol levels over time to see when and how often they experience a stress rise.
Andrews said: "I expect that the ability to closely monitor cortisol's changes over different periods will be very instructive for people with mental disorders. They may be able to see something coming, or monitor changes in their own personal patterns. ”
A paper on the study was recently published in the journal Science Advances.