MPMN: May 1997
PROFILE
Human Factors Dictate
Syringe-Pump Design
Innovative product ideas continue, as always, to lead to the launching of new competitors in the medical device market. Unfortunately, many start-ups discover that the process of turning a good idea into a winning product involves time, capital, and expertise that they simply don't always have.
A Dual Purpose
Harvard Medical Inc. (South Natick, MA) began, like many start-ups, on the strength of a single product idea. Observing that many patients in operating rooms and ICUs receive more than one drug intravenously, the group decided to develop a single device capable of performing the work of two syringe pumps. They realized that the design of such a product would be critical; if it weren't smaller, cheaper, and easier to use than a pair of traditional syringe pumps, there'd be no point in mak-ing it. Moreover, they knew that input from the targeted users would be essential in creating a device that would meet with wide market approval. They had a basic idea of what they wanted, but weren't quite sure how to proceed. They started looking for professional design assistance, and contacted Design Continuum (West Newton, MA), which soon convinced them that a specialized device requires a specialized approach to product design.
Unlike some design firms, Design Continuum doesn't think about a product in an abstract sense, but carefully analyzes all the varied circumstances that could influence its use and usability. "The philosophy that we try to bring to every project," explains Ed Milano, project representative, "is to design the experience rather than the device. It's a subtle but significant difference. If you design the object, you presume that the designer's instincts will properly configure the mechanisms and appearance. But if you design from the user's experience, then that experience will dictate design decisions."
The Human Factor
This strategy brought the design team into a number of ORs and ICUs to get a feel for the requirements and restrictions of the end-use environment. "We wanted hands-on experience as to how these products get used," explains Lewis Pedraza, design engineer. His investigations, he says, revealed "how stressful these environments are. They tend to be very cluttered. There are a lot of devices competing for the immediate space by the patient." Bedside clutter does more than complicate the caregiver's job, he says; it affects the emotional state of everyone in the room. "There's a big perception issue. If you can imagine going to an ICU and seeing a loved one in that cluttered environment, it adds to the stress."
Pedraza examined a host of other devices in use in the field, and concluded that none of them adequately addressed human factors issues in its design. The challenge, as he saw it, was to finalize a design that would take into account the emotional and task-driven needs of everyone who might come in contact with the device. "This was not a product that was driven by the need to get it out to market immediately," explains Milano. "The focus was on doing it right and doing whatever it took to design a truly universal pump that would meet the needs of both the OR and the ICU." With that in mind, the design team began investigating ways to make the device as user-friendly as possible.
Simple Solutions
One of the most important design elements, according to Pedraza, was the simple paddle mechanism for loading syringes. "With other pumps, you have to pull the clamp open while it's mounted on an IV pole, so you end up pulling the pole toward you--it's basically a three-hand operation. With these paddles, the pressure is on the axis of the pole, so the pole doesn't move." It may seem like a small point, he says, but "users wonder why no one thought of it before."
Striving for simplicity, the design team also developed a set of user-friendly control knobs, rather than elaborate keyboards, for data entry and function control. "We managed to have the knobs interface with the software as if they were a computer mouse, so as you rotate the knob, you highlight different items, and you select them by pushing," says Pedraza. The combination of the turn-and-push knob and the computerized library of infusion protocols simplifies the interface tremendously. "The beauty," adds Milano, "is that in the future we can upgrade the product and incorporate new advances without redesigning the pump or front panels. It also means a lot less visual confrontation for the user."
Although Harvard Medical developed the operating software, Pedraza's design team had a hand in integrating it with the device. "We worked with them in reviewing the presentation of the information on-screen, thinking again about the overall experience. We wanted all the information presented in an easy-to-read manner, with the right contrast and emphasis on the appropriate information." Some of the elements the design team chose to enhance data presentation include an LCD, legible at distances up to 6 ft, and a color-coded graphics system--green when the unit is running, yellow for warnings, and red for alarms.
Pedraza and Milano also noted that competing products did not address issues of portability, space conservation, and mounting flexibility. Therefore, they designed a device that could hang from an IV pole or stand vertically on a tabletop, as well as lie flat during transport. The unit can also accommodate a full range of syringe sizes from 1 to 60 cm3, allowing it to be used in pediatric applications.
Conclusion
In the end, the device--named the Harvard 2--proved to be simpler and more economical than competing technologies. "I believe we struck a nice balance in the overall appearance," says Pedraza, emphasizing that the device "comes across as being a friendly, nonthreatening product, yet still projects a serious level of sophistication and reliability." He attributes this success to the close collaboration among all parties involved. "In a lot of product designs, the form can develop somewhat independently of the functional and internal components. In a product like this, the function, the aesthetics, and the user interface really are totally integrated; the only way to achieve that is to develop the product concurrently with engineers, working side by side. There's a constant interaction, a give and take."
