A continuous-testing device was developed that samples sweat as effectively as blood but in a noninvasive way and over many hours. After examining the use of saliva, tears, and interstitial fluid, researchers concluded that sweat holds the most promise for noninvasive testing because it provides similar information as blood and its secretion rate can be controlled and measured.
The device consists of sensors on a wearable patch the size of a Band-Aid® that stimulates sweat even when a patient is cool and resting. The sensor measures specific analytes over time that doctors can use to determine how the patient is responding to a drug treatment. The sensors can be tailored to measure anything from drugs or hormones to dehydration.
The continuous sensor allows doctors to track health over time to see whether a patient is getting better or worse. And they can do so in a noninvasive way with a tiny patch applied to the skin that stimulates sweat for up to 24 hours at a time.
For medications, sweat can be used to get an exact measurement of concentrations in the blood. Once concentrations of therapeutics in blood are measured, drug dosing can be tailored based on things such as liver or kidney failure, or how quickly someone metabolizes a drug.