UBC Reports | Vol. 51 | No. 1 | Jan. 10, 2005

Rest Easy: This Bed Can Save Your Life

By Michelle Cook

A patient in a busy hospital ward has a seizure. Violent convulsions prevent him from calling for help. It’s a scenario that nurses dread, but they also know it’s impossible to watch patients every minute.

Now a group of UBC engineering students has developed a new bed monitoring system that lets health-care workers check on patients from a remote location. What started as a three-month class project has gone farther than any device on the market today to help keep track of patient movements.

“There are currently products out there that can detect a patient out of bed but nothing to detect whether a patient has been still for too long or is suffering from a seizure. Our device is based on cheap components and is extremely simple but it can do these things,” says Hassen Karaa.

Karaa and fellow team members Shadi Safarkhah, Benjamin Chen, Matthew Wilder, Harjinder Gill, and Ahmed Abdi are all fourth-year undergraduate students. None of them knew each other before starting the project, an assignment for electrical and computer engineering professor Lee Iverson’s instrumentation and design lab course.

The medical bed monitor is a thin pad that can be laid on top of a mattress. Health-care professionals can program it to check for a variety of conditions including epileptic seizures, attempts to leave the bed and prolonged periods of inertia in bedridden patients.

The waterproof pad is embedded with 24 sensors that send information via an Ethernet connection to a computer at the nursing station. The team designed a computer program to analyse the data being sent and developed a user-friendly interface for health care staff.

All a nurses have to do is input the patient’s name and the condition they want to monitor. To monitor for bedsores, for example, they can input the time interval (e.g., every five minutes, 15 minutes) between alerts. The computer uses a time / date log to keep track of each patient’s movements and can monitor several patients at the same time. Nurses can even choose how they want to be notified, and the computer will send them pop-up message on screen or an audible message such as “John Smith is having a seizure.”

The team consulted with a biomedical engineer and several health-care professionals in B.C. and Ontario in order to come up with a product to meet their needs. They also studied video footage of people having seizures. To prevent false alarms the team incorporated a multiple detection function into the computer program.

“One of biggest challenges was getting the monitor to distinguish between seizures and normal movement in bed,” says Matthew Wilder. “If someone is having a restless night, the bed monitor won’t register this.”

The team’s other big challenge was cost. With a $400 budget, they quickly realized they would have to settle for simple, easily available materials like carpet underlay and 50-cent tactile switches to use as sensors. They estimate their prototype cost about $200. Most commercially available medical bed monitors cost between $800-$1,900.

Iverson says the group’s key to success was a combination of good teamwork, keeping the project simple and an ability to listen carefully to what medical practitioners had to say.
After seeing a demonstration of the prototype, Alison Phinney, an assistant professor in UBC’s School of Nursing, says there is a definite need for such a device in hospitals, geriatric and long-term care facilities.

“Nurses are always concerned about their ability to watch patients closely, and about patients crawling out of bed and then falling. Some health-care workers even move high-risk patients into the halls near nursing stations in order to keep an eye on them,” Phinney says.

“In acute care, where patients are at high risk of seizure and in a setting where they are closely monitored already, having something like this in place would be a bonus. If there was something in the same price range as products now available but that did more and had a simple interface easy for nurses to learn and use, I think the health care community would welcome that.”

What interested her was the monitor’s ability to alert nurses when a patient is just starting to get out of bed.

“There are products out there, but these only tell the nurse that a patient is already out of bed and they have alarms that are loud and disruptive,” says Phinney.

For her, the monitor’s other important feature is that it can be set to alert nurses at specific intervals. This is important when people are sitting or lying for long periods and at risk of bedsores.

“You don’t need to be sitting or lying for long for this to have an effect -- even five to 10 minutes -- and people die from these things,” Phinney explains, adding that actor Christopher Reeve, who died earlier this year, died from an infection from a pressure wound (bedsore).

Encouraged by feedback from health-care professionals, Wilder says the team would like to see the device in use in hospitals some day but, he adds, “for us, the main success was not so much the innovation but proper consulting. When you’re a consulting engineer, you need to listen to the client and that’s what we did.”