New smartphone tool can track your alertness at work

Researchers wanted to create a way to measure alertness unobtrusively and continuously.

"Since people use their phones very frequently during the day, we were thinking we could use phones as an instrument to understand and measure their alertness," Tseng said.

"And since people's eyes are affected by their alertness, we were thinking that when people are looking at their phones, we could use a moment to measure their alertness at that point," he said.

When people are alert, the sympathetic nervous system causes the pupils to dilate to make it easier to take in information. When they are drowsy, the parasympathetic nervous system causes the pupils to contract.

The tool could be particularly useful in health care, since medical professionals often work long hours doing intricate and important work.

For example, clinicians typically look at devices during surgery, and a front-facing camera on the devices could track their alertness throughout procedures.

Understanding alertness patterns could be helpful to people in many kinds of workplaces, Tseng said.

"If you want to get something very important done, then probably you should execute this task while you're at the peak of your alertness; when you're in a valley of your alertness, you can do something like rote work," he said.