Sensor detects body's stress level

The device will detect changes in cortisol levels that affect anxiety, post-traumatic stress disorder and depression.

Wei Gao, assistant professor of medical engineering at California Caltech Institute of Technology (USA), has built a wireless sweat sensor that can accurately detect levels of cortisol, a natural compound commonly considered a body's stress hormone. In a paper published in the journal Matter on February 26, Gao and researchers demonstrated how they designed, built, and worked the device, and demonstrated that it was effective in Real-time cortisol level detection.

This inexpensive, highly accurate device for measuring cortisol allows for easier stress monitoring. In addition, it can monitor other conditions including anxiety, post-traumatic stress disorder and depression, all of which are associated with changes in cortisol levels.

The sensor Gao developed uses a method similar to another sweat sensor he recently created that can measure uric acid levels in the blood, which is useful for monitoring conditions like cardiovascular disease, diabetes, or diabetes. kidney disease. Both types of sensors Gao and his team have created are made of carbon sheet graphene. A sheet of plastic is laser-engraved to create a three-dimensional graphene structure with tiny holes that can analyze sweat. The pores take up most of the surface area in the sensor, making it sensitive enough to detect compounds that exist in very small amounts in sweat. The tiny pores combine with an immune system molecular antibody, which is particularly sensitive to cortisol, to help the sensor detect the compounds.



In one trial, a volunteer's sweat was collected over six days to analyze cortisol concentration data. In a healthy person, cortisol levels rise and fall on a daily basis. The sensor registers stress levels that are highest upon waking each morning and decrease throughout the day. "Monitoring a patient's daily cortisol cycle may reflect mental health status. Depressed patients have a different circadian cortisol pattern than healthy individuals," says Gao.

In another test, changes in cortisol levels were recorded as they occurred in response to an acute stressor. This was done through two experiments. First, test subjects were asked to perform aerobic exercises because intense exercise caused a sharp increase in cortisol. In the second experiment, test subjects were asked to soak their hands in ice water, a stressor enough to release cortisol. In both experiments, the sensors detected an immediate increase in cortisol levels.

"Normally, a blood test takes as little as one to two hours, and the blood draw causes an increase in stress levels. For stress monitoring, timing is crucial. Our sensor gives results in just a few minutes. minutes," Gao shared.

In October, NASA announced that Gao was one of six researchers selected to study human health during space missions. Gao will receive funding to develop sensing technology into a system to monitor astronauts' stress and anxiety as part of a program, managed by the Aerospace Health Analytics Research Institute. time (TRISH).