Researchers have developed a small, touch-based sensor that can detect the level of lithium in a person’s body using their sweat. The device can give out results in less than 30 seconds and does not require a visit to a clinic.  The right level of lithium in the body can help in controlling the symptoms of mental health issues including bipolar disorder and depression. Updates on the lithium level in the body allow health care providers to keep a track of whether a patient has been taking the medication as prescribed or not.

The presently available methods of keeping a track of medication are invasive and have their own drawbacks. While blood tests offer a picture of the progress of medication, the process is invasive and time-consuming. Pill counters, on the other hand, can’t assure the measure of actual medication intake. However, with this new device, researchers attempt to address this limitation using sweat.   

The results of the device’s performance were presented at the fall meeting of the American Chemical Society (ACS) on August 21

The electrochemical sensing device uses a water-based gel containing glycerol to detect charged particles of lithium in the sweat which usually is present in minute amounts.

“Although it may not be visible, the human body constantly produces sweat, often only in very small amounts,” said Shuyu Lin, PhD, a postgraduate student researcher who co-presented the work with graduate student Jialun Zhu.

The gel created a controlled environment for the electronic portion of the sensor. To trap the lithium ions after they passed through the gel, the researchers used an ion-selective electrode. The accumulating ions generate a difference in electrical potential compared with a reference electrode.

This difference was then used to ascertain the concentration of lithium present in sweat.

The device has already been tested on people, including one person on a lithium treatment regimen. The researchers recorded this person’s lithium levels before and after taking the medication. The results showed that the measurement fell were close to those derived from saliva, which prior research has shown to accurately measure lithium levels.

Though the sensor is still in the preliminary testing phase, the researchers aim to incorporate it into a larger, yet-to-be-designed system that provides visual feedback to the provider or the patient.