Using wireless bio monitoring in studies

Tool proves popular in obesity research

Investigators at the University of Southern California in Los Angeles, CA, have found an electronic solution to the problem of collecting accurate data about subjects' daily activities.

They developed the wireless network sensor solution to use in research involving preventing and treating obesity among minority youth. But it has a variety of potential applications, including being used in research involving rehabilitation patients or disabled people.

"It's a set of wireless network sensors that kids can wear," says Donna Spruijt-Metz, MFA, PhD, an associate professor in the department of preventive medicine at the Keck School of Medicine of USC.

The electronic device holds a great deal of potential for research, as well as clinical use. It has the potential of gathering greater amounts of information and more accurate data than self-report diaries and other types of automated devices. It also can be used as part of the intervention.

For instance, it can be programmed to provide automated alerts to subjects. These are in the form of text messages.

The youth wore an unobtrusive set of Bluetooth-enabled wireless sensors and carried a mobile phone. The sensors can detect motion and transmit their data to the mobile phone, which is GPS enabled.

Study subjects wear the bio monitoring device throughout their typical daily activities, and the device sends immediate electronic feedback to researchers about how much and where subjects are moving around. This would make it possible to provide immediate interventions based on what is going on with the subject at any particular moment.

For instance, the device's data sent to a lab researcher who is monitoring it might indicate that the subject is walking by a fast food restaurant. The researcher could text the youth a message about how the restaurant's choices are unhealthy and counterproductive to the goal of losing weight.

In another example, the device could indicate that the youth has moved to a home near a park where he or she might benefit from a regular walking routine.

"Eventually, we'll be able to know where they are, and we'll monitor them on a website," Spruijt-Metz says. "We'll see that someone was sedentary for two straight hours, and we can call the person and tell him or her to get up and move around."

While researchers already can use small motion loggers that will store data about subjects' activities, these are less useful than a real-time wireless device, she notes.

"The small motion logger will store data, and when I come back to my lab I can download the data," she says. "But I might find that the person returns the motion logger and has not worn it."

Kids liked to wear it

Research subjects can turn off the wireless device too, but the 12 youths introduced to the technology in a recent pilot study liked it so much that they wore them frequently.

"The kids were responsive in an exciting way," Spruijt-Metz says. "We used the devices in a dry run to see if they would wear them and if we could deal with the monitors over a long distance and to see if the youths would change the batteries on time and receive the text messages all right."

Investigators found that everything worked very well, she adds.

They also obtained information about the subjects' lifestyles that has resulted in their changing the intervention goal.

"The youth were incredibly sedentary," she notes. "We were going to intervene by encouraging physical activity, but we changed our mind after seeing them sit around."

Now the intervention goal will be to have the youth engage in less sedentary behavior rather than pushing them to actively exercise, she adds.

Researchers also found that the youth were very engaged with using the electronic devices. They'd actively communicate with research staff throughout the day.

"One person said, 'I really like the texting back and forth,'" Spruijt-Metz says. "They'd text us nine times a day — it was like they had a doctor in their pocket."

The brief messages often were of the nature of saying, "Hi — I'm awake," or "I took it off because I'm going to play soccer," she explains.

"They keep us posted during the day," she adds. "These are kids with parents holding many jobs, and they like the attention."

Key questions

The trial run gathered information on the bio monitoring device's strengths and limitations, answering these kinds of questions:

— How well is the device working?

— What can and cannot be automated?

— How much work is it to monitor the subjects daily?

— What is possible with the device?

— To what extent does the intervention need to be personalized so that the messages that each subject receives relates particularly to that person's circumstances and activities ?

Investigators had plans to start the first intervention in November 2010. The first intervention will be a simple application of the device, using general text messages, such as telling subjects at 3 p.m. that it's time to exercise.

In future trials, researchers could personalize the device to give an intervention that is event-based, such as telling a subject who has been sedentary for hours to do something different, she says.

"If I know that every time you come home from school you pass a McDonald's and buy french fries, then I can text a message that says 'Don't do it,'" she adds.

These events are time-based and fit in with some researchers' goals of finding random moments for collecting data about subjects, she says.

The device has caught the attention of rehabilitation clinicians, who would like to apply it to physical therapy and other rehab activities. So it likely will be applicable to more than the obesity and youth research, she says.

"We started development of the device out of my complete frustration with current technologies," she says. "Every kid has a mobile phone, so we started amassing a backlog of off-the-shelf monitors that are Bluetooth-enabled," she explains. "At the same time we were developing these patterns of recognition algorithms."

Then researchers recruited youths and their parents to participate in a trial that was designed to see how youths would use the devices. These subjects also performed various activities and exercises while wearing the devices so investigators could gather data on the monitors and use these to develop algorithms that would recognize patterns of behavior, Spruijt-Metz says.

"Then we did some qualitative work with kids to talk with them about wearing monitors and to find out what their parents thought about it," she adds. "Their parents also wanted to wear KNOWME, and that was interesting."