Wearable sweat sensor paves way for real-time analysis of body chemistry
Blood tests allow doctors to peer into the human body to analyze people's health. But in the future, there may be a less invasive way to obtain valuable information about a person's health: wearable sensors that use human sweat to look for signs of disease..
Sweat is a rich source of chemical data that could help doctors determine what is happening inside the human body, scientists explained in a new study. Perspiration is loaded with molecules, ranging from simple electrically charged ions to more complex proteins, and doctors can use sweat to diagnose certain diseases, uncover drug use and optimize athletic performance, they said..
Commercially available wearable sensors, like the Fitbit and the Apple Watch, track users' physical activities and some vital signs, such as heart rate. However, they do not provide data about a user's health on a molecular level. Now, scientists say "smart" wristbands and headbands embedded with sweat sensors could sync data wirelessly in real time to smartphones using Bluetooth..
Previously, studies of sweat largely relied on perspiration collected off the body in containers that was later analyzed in a lab. Now, researchers have devised a soft, flexible, wearable sensor array to continuously monitor changes in four molecular components of sweat and to provide real-time tracking of a person's health..
The invention uses five sensors to simultaneously track levels of glucose, lactate, sodium and potassium, as well as skin temperature. This data is fed to a flexible board of microchips that processes these signals and uses Bluetooth to wirelessly transmit data to a smartphone. All of these electronics could be incorporated into either a wristband or headband..
In addition, the skin temperature sensor helps adjust the chemical sensors to make sure they get proper readings, the researchers said. For instance, higher skin temperatures increase the electrical signals from glucose, which can make it look as if people are releasing more glucose in their sweat than they actually are..
Previous wearable sweat monitors could track only a single molecule at a time, which could generate misleading information, the researchers said. For example, if a lone sensor showed a drop in a molecule's level, it might not be because that molecule's level is actually falling in a person's sweat, but rather because sweating has stopped, the sensor has detached from the skin or the sensor is failing. The inclusion of multiple sensors could help shed light on what is happening to a person and the sensor array as a whole..