Taking a Licking, but Still Ticking: New “eWatch” Measures Life’s Daily Stresses

Issue Date: 
October 22, 2007

A new device developed by a joint team of researchers from the University of Pittsburgh and Carnegie Mellon University will allow doctors to more accurately measure the amount of stress people are feeling during their daily lives.

About the size of an ordinary wristwatch, the “eWatch” records a person’s skin temperature and activity level, along with ambient light and noise conditions and other data.

Pitt Psychology Professor Thomas Kamarck, director of the University’s Behavioral Medicine Research Group, is leading a team that is developing more effective ways of measuring psychosocial stress exposure during the course of daily life.

Kamarck’s collaborators include Pitt Psychology Professor Saul Shiffman; Barbara Anderson, Pitt senior research associate in psychology; Daniel Siewiorek, a Carnegie Mellon computer science professor who directs that university’s Human-Computer Interaction Institute (HCII); and Asim Smailagic, Carnegie Mellon research professor of electrical and computer engineering.

Previous studies have determined that people who report highly stressful lifestyles may develop higher rates of a variety of illnesses, ranging from viral infection to heart disease. But quantifying exposure to stress has been difficult, Kamarck says.

“Some say we’re exposed to stress when demands we face exceed our resources for dealing with them,” says Kamarck, adding that traditional methods of measuring life stress don’t quantify the duration or intensity of exposure effectively.

“A husband and wife may react to the death of the same relative very differently,” he says. “Furthermore, stress is an ongoing fluctuating process. At what point does a stressor begin or end?”

Kamarck and his collaborators will outfit several hundred participants, five at a time, with eWatches.

Every 45 minutes over the course of five days, participants will be prompted to take part in a 2-to-3-minute interview administered by the eWatch. It will ask their response to current activities. Are they working? Is the work hard?

Previous research has shown that responses to such interviews help predict who will show higher rates of plaque development in the arteries, a risk factor for heart attack or stroke.

Using interviews in real time allows researchers to quantify how stressors affect one’s daily life, as well as to pinpoint when these effects begin and when they end.

Use of the eWatch technology, developed at HCII, should assist researchers in finding the optimal method for responding to such interviews during daily activities, whether by pressing a button, moving the wrist, or speaking into a wireless device nestled in the user’s ear.

Environmental data collected by the eWatch also may assist the researchers in characterizing the types of environments people find most stressful, so that their location may automatically be recorded (for example, whether at home or work) in a manner that will not require the participant’s response, potentially reducing the number of interview questions required.

“We want to capture a slice of life in people’s daily routine,” Kamarck says. “We hope that these new tools will allow us to do so while minimizing disruptions imposed by the act of measurement.”

Kamarck also wants to work toward making the measurement very user-friendly for a study participant such as a bus driver, who can’t necessarily stop what he is doing to answer questions.

Another part of the project is aimed at improving face-to-face interview measures of chronic stress as well, he says.

Kamarck and his colleagues have received a $426,000 National Institutes of Health (NIH) grant for the first year of their four-year project, which is part of a larger NIH initiative to study environmental factors that people encounter every day that may increase their risk of certain diseases.

The study is part of the NIH Genes, Environment, and Health Initiative, a collaboration between geneticists and social and behavioral scientists that will give researchers an unprecedented look at gene-environment interactions and effects on disease across large population samples.