By Pat Anson, Editor

We’ve written before about wearable medical devices, a fast growing $2.8 billion industry aimed at helping us lead healthier lives. Some devices relieve pain, while others monitor your blood pressure, pulse, body temperature, sleep, or even the number of calories you’re burning.

One device can even be used as a sort of “Big Brother” to monitor your use of opioid pain medication.

A small study published in the Journal of Medical Toxicology followed 30 emergency room patients who were given opioids for severe acute pain. For four months the patients wore a Q sensor, a wristband device made by Affectiva,  a Massachusetts company that specializes in technology that tracks and measures human emotions.

The wristband only monitors skin temperature and locomotion (movement) of the user, but researchers found the data can be used to track and predict opioid use with a fair degree of accuracy.

Researchers say people who take opioids daily for pain or addiction treatment (methadone and buprenorphine) are more likely to fidget or show restless activity when they feel cravings for medication. A sudden decrease in movement and an increase in skin temperature can be signs that they had taken a dose of medication.   

"The patterns may be useful to detect episodes of opioid use in real time," says lead author Stephanie Carreiro, MD, a professor of Emergency Medicine at the University of Massachusetts Medical School. "The ability to identify instances of opioid use and opioid tolerance in real time could for instance be helpful to manage pain or during substance abuse treatment."

Carreiro and her colleagues say wearable devices could help identify pain patients at risk for substance abuse or addiction. They could also be used to remotely monitor patients enrolled in addiction treatment programs to detect whether they are relapsing.

“Wearable biosensors show a consistent physiologic pattern after opioid administration in an ED (emergency department) population,” they said. “This biometric response shows some distinguishing features between heavy and non-heavy opioid users in a controlled ED setting. This pattern may be useful to detect episodes of opioid use in real time. Further study is needed to evaluate the potential diagnostic and interventional applications of these devices in drug abuse treatment and pain management."

The Q sensor was initially developed to monitor children with epilepsy or autism, but they’ve since grown into a tool used in consumer focus groups to measure responses to advertising. They’re also being tested in middle schools as an “engagement pedometer” to measure if students are interested in a particular subject.

Critics say the technology is creepy and the data it generates can easily be misinterpreted.

"In high school biology I didn't learn a thing all year, but boy was I stimulated. The girl who sat next to me was gorgeous. Just gorgeous," Arthur Goldstein, an English teacher and critic of the technology told Reuters.

Affectiva recently raised $14 million in funding to develop facial recognition software for video games.