Portable sweat sensors can detect what's in your blood

The needles could be a thing of the past with the development of new sweat sensors that can tell what's in our blood.

Medical technology has evolved considerably in recent years. A recent medical technology development comes from a team of scientists from the University of California at Berkeley. The team is developing portable skin sensors in the hope that someday, sweat monitoring could help avoid more invasive procedures such as blood sampling and providing updates. real-time day on health issues such as dehydration or fatigue.

The team has designed new sweat sensors that can be manufactured quickly using a "roll-to-roll" treatment technique that essentially consists of printing the sensors on a plastic sheet, using the words newspaper.

They used sensors to monitor sweat rate, electrolytes and metabolites present in sweat from volunteers doing exercise, as well as other people with chemically induced sweating.

The secret is in sweat

The sweat sensors developed by the team contain a microscopic spiral tube, or microfluidic, that wicks sweat away from the skin. By detecting the rate of perspiration through microfluidics, sensors can indicate a person's level of perspiration or its transpiration rate. Microfluidics are also equipped with chemical sensors capable of detecting electrolyte concentrations such as potassium and sodium and metabolites such as glucose.

Berkeley, professor of electrical engineering and computer science, and senior author of the newspaper, Ali Javey, said, "The goal of the project is not just to make sensors but to start studying many topics and to see what sweat tells us – I always say "decoding" composition of sweat.

"For this, we need reliable, reproducible sensors that we can scale to fit multiple sensors in different parts of the body and apply them to many different subjects."

During the study, the team found that the local transpiration rate could indicate the overall body fluid loss during the exercise, which means that tracking the transpiration rate could be a way to tell the athletes when they could push themselves too hard.

Develop sweat sensors

Working alongside researchers at the VTT Technical Research Center in Finland, the team found a quick way to make perspiration sensor patches in a roll-to-roll process similar to screen printing.

Jussi Hiltunen of ATV said, "Roll-to-roll processing enables the production of large volumes of low-cost disposable patches. Academic groups gain a significant advantage from roll-to-roll technology when the number of test devices does not limit the search. In addition, large-scale manufacturing demonstrates the potential of applying the concept of sweat detection in practical applications.

"Traditionally, people collect sweat for a while, then analyze it. You could not really see the dynamic changes very well with good resolution. With the help of these portable devices, we can now continuously collect data on different parts of the body, for example to understand how local loss of perspiration can estimate fluid loss throughout the body.

No correlation between sweat and blood glucose

Sweat sensors have also been used to compare glucose levels with sweat and glucose in the blood in healthy and diabetic patients. In doing so, the team found that a simple measurement of sweat glucose could not necessarily indicate a person's blood glucose level.

Mallika Bariya, co-author of the article, said: "There was great hope that noninvasive sweat tests could replace blood-based measures for the diagnosis and monitoring of diabetes, but we have shown that There is no simple solution, universal correlation between sweat and blood sugar. This is important for the knowledge community, so that in the future we can focus on finding individualized or multi-parameter correlations. "