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STUDIES SHOW THAT SOME MEDICAL DEVICES ARE TOO COMPLEX

     COLUMBUS, Ohio -- Sometimes new, high-tech medical devices are too complicated for the doctors and nurses who use them, according to a pair of Ohio State University studies.
     The studies revealed that poor human-computer interfaces can create errors in the set up and use of these devices. The studies also showed how medical professionals work around these difficulties in order to avoid making mistakes that would endanger patients.
Computer technology has enabled engineers to design medical devices that perform many tasks, and hospitals save money when they buy such devices. Too often, though, the cumbersome computer interfaces in these devices hamper the efforts of people who use them.
     The studies appeared in a recent issue of the journal Human Factors, where David Woods, professor of industrial and systems engineering and anesthesiology, wrote, "There is a real risk of error when designers create systems that possess every
conceivable option, multiple modes, and cryptic displays."
In the first study, Woods and his colleagues observed how anesthesiologists interacted with a new anesthesia monitor in the operating room. In the second, they interviewed home nurses who supervised pregnant women’s use of infusion pumps that dispense medication to prevent premature labor.
     In both studies, the researchers saw the same problems over and over again, like the need for medical professionals to remember complicated sequences of commands. Also, the anesthesia monitor and the infusion pump operated in multiple modes, without clearly displaying which mode they were in at any given time.
     "New technology can reduce error, but it can also create new opportunities for error," Woods said. "And sometimes the new errors, though infrequent, may contribute to more catastrophic consequences."
     Woods stressed that the kind of errors he’s talking about don’t result from a malfunction in the medical device.
     "It’s not that the device is unreliable, but rather that the design of the device does not take into account how people need to interact with it. The problem is not a breakdown in the engineering of the device, it’s a human-computer breakdown," Woods said.
In both studies, no patients came to harm, but the medical professionals did have to tailor the devices to meet their needs and to avoid mishaps.
     In the study of the anesthesiology monitor, for example, technicians experimented with the monitor outside the operating room until they figured out how to call up the most useful displays and how to configure multiple windows on the screen. However, when the physicians called up one window during operations, the computer would automatically change to other windows, obscuring important patient information on the computer screen. Users had to discover when the undesired window configuration occurred and develop new procedures and reminders to "undo" the computer’s reconfiguration.
     Because the user interface to the home infusion pump was complex and commands were hard to remember, nurses changed procedures or created new procedures to help the patients avoid or work around trouble. For instance, patients were supposed to change the syringe on the infusion pump whenever an alarm signaled the syringe was nearly empty, which happened in the middle of the night.
     Even for people who are fully awake, the clumsy computer interface makes this a relatively complex task. So nurses told the women to change the syringe at the same time every day even if the syringe wasn’t empty so that they wouldn’t have to fumble with the pump and interface in the middle of the night.
     In both studies, the tailoring that the users had developed worked. But Woods said that the fact users had to tailor the devices at all indicates that the technology isn’t as user-friendly as it should be.
     And one problem remains: because the devices don’t give good feedback, users still can have difficulty detecting errors in the future and correcting them in time.
     Woods said that while error prevention is important, so is error correction. "Safety comes from recognizing that while we try to prevent errors, we also need medical devices to give us time to detect and recover from errors before we get bad consequences," Woods said.
     Woods and his colleagues hope to synthesize these and other results to show medical manufacturers and regulators how poor human-computer interaction in the design of infusion devices can lead to user errors. The goal is to help people understand the importance of human-computer interaction in effective medical products and to begin to apply concepts and techniques from Human Factors.
     Also, the American Medical Association is creating a National Patient Safety Foundation, and Woods is helping the foundation set up its research program. One of his goals is to help people develop user-centered medical systems to improve patient safety.
"If we understand the sources of errors, we can find ways to make good devices even better."

Contact: David D. Woods, (614) 292-1700; Woods.2@osu.edu
Written by Pam Frost, (614) 292-9475; Frost.18@osu.edu