Researchers from Stanford University in the United States are developing the first pain detector that will be able to measure pain physiologically, a breakthrough in pain medicine which currently relies on patient's self-reporting of pain.

The detector consists on a computer that scans the brain and captures "brain patterns of pain" to give an "objective physiologic assessment" of whether someone is in pain. The computer made accurate predictions 81 percent of the time, according to a study published Sept. 13 in the online journal PLoS ONE.

“People have been looking for a pain detector for a very long time,” said Sean Mackey, MD, PhD, chief of the Division of Pain Management and senior author of the study. “We’re hopeful we can eventually use this technology for better detection and better treatment of chronic pain.”

The new tool would help to measure the presence or absence of pain on a large number of patients -particularly among the very young and the very old- that can't communicate their pain levels, according to Mackey.

More than 100 million Americans suffer chronic pain, costing around $600 billion each year in medical expenses and lost productivity, according to a study released by the Institute of Medicine in June

Future studies are needed to determine whether these methods will work to measure various kinds of pain, such as chronic pain, and whether they can distinguish accurately between pain and other emotionally arousing states, such as anxiety or depression, researchers said.