Originally Published MDDI February 2003
COVER STORY: DESIGN AND DEVELOPMENT
The trends and technologies that are influencing the design of today's medical devices reflect an increased focus on
the end-user and home healthcare.
|PediSedate, an anesthesia delivery device developed by Design Continuum, relaxes children during medical procedures.|
Stacey L. Bell
The way product developers approach medical device design is changing. “Five years ago, device manufacturers tended to focus on feasibility when thinking about product design,” says Tad Simons, director of healthcare and life sciences for IDEO (Palo Alto, CA). “Now, they're taking a more holistic view of product design—thinking about how the product looks, how it affects work flow, and how healthcare workers and patients use it.” Every product in every class is experiencing increased competition, so manufacturing is “a big issue for everybody,” Simons says. “Everybody wants to know: How do we create a product that stands out in the marketplace but is also cost-effective to produce?”
Making Products Faster, Cheaper
There's no denying that product development is expensive. It's estimated the concept and creation of a new device can reach upward of $500,000 before even one product is made and sold.
“The biggest challenge we see is that budgets are a lot tighter than they were two years ago,” says Doug Hiemstra, president of Hiemstra Product Development (San Francisco). “Across the board, medical device companies are looking for design firms to be more efficient and more cost-effective.”
Take Respironics Corp., for example. Its CPAP nasal mask for sleep apnea sufferers had won a design award, but the high per-unit cost to manufacture the device's housing was prohibitive. When Respironics approached WhiteLight Design (Lawrenceville, GA) for help, the latter used miniaturization and parts consolidation techniques to reduce the manufacturing costs by more than 50%.
“We created an injection-molded clamshell housing with many integrated internal mechanical features, including ribs, venting, noise management, and a convenient handle. The housing was redone into two pieces, rather than the previous four, and the size was reduced,” explains Willis Whiteside, president of WhiteLight Design. “We saved a lot on materials, and cut assembly time and cost. The new design significantly improved market adoption and thus, sales volume,” he adds.
Whiteside notes that CAD and rapid prototyping (RP) technologies were instrumental in the redesign. Together, these two technologies allow a company to see how a product fits together and works on-screen, and to create a working prototype in just a few days, before investing in high-cost tooling and manufacturing. Although both CAD and RP have been around for years, they have matured, helping to shorten development time and increase productivity and quality while improving a company's bottom line.
|Medical devices are increasingly functional, stylish, and high-tech, like the CoolGard 3000 designed by Stuart Karten Design for Alsius Corp. (Irvine, CA).|
For example, a few years ago, prototypes could be made from only a few resins. Today, additional resins and powdered metals are among the options, making possible more-durable component manufacturing. “Today's resins allow for much better controlled and defined features and have higher heat resistance, so manufacturers can do more functional testing and expose the parts to actual use conditions and harsher environments, such as sterilization cycles,” explains Len Czuba, president of Czuba Enterprises Inc. (Chicago). “The laser beams are also more sensitive. Therefore, the industry can make smaller and smaller parts with better-defined features and get better feedback on product functionality.”
Whiteside sees RP as a revolutionary technology that is here to stay. “Rapid prototyping technologies that create durable, usable parts could eventually render injection-molded parts obsolete,” he predicts, noting that for processing to be cost-effective, manufacturers typically need to produce at least 50,000 parts in an injection mold. Instead, he says, manufacturers are looking to lower-cost processes, including thermoforming or pressure forming, to consolidate parts and cut costs.
Czuba notes that a recent development in RP may speed the process and make it even less expensive. “One company is now taking a novel approach to RP,” Czuba says. “Rather than producing a part from a part file, Met-L-Flo makes a mold. So instead of creating an aluminum mold later, they are saving a step and creating a mold that can then produce parts by injection molding—often using the actual resin that will be used for the final product.” He points out that this capability also allows for better part definition and more-direct design evaluations.
CAD also may see a new, important iteration in the next year. Cesaroni Design Associates Inc. (Glenview, IL) is developing a three-dimensional digital man (think of the animated Shrek character) to test products in three dimensions. “We're creating digital images of anatomically different people that we can download on-screen. We then use them to locate potential problems with product concepts before we give a file to the model shop to produce a prototype,” says Bill Cesaroni, president of the design firm. One continual drawback of the design process, he says, is finding that a product concept doesn't work for some reason once a person is factored into the equation. “That's why we're trying to integrate digital users into the design stage. If we are designing a therapy or fitness product, we want to be able to watch how our ErgoMan's muscles are flexing as the product is working.”
Although 2-D users are already incorporated into current software offerings, Cesaroni says he wants “a Superman.” Two-dimensional adaptations move stiffly and are very limited, he explains, and designing and building a prototype is expensive. “Real people are the ultimate test. If we can test a new product on a digital person before we make even the first prototype, we will weed out 90% of problems and save a lot of time and money in the end.”
Work Flow Matters
|Aspect Medical Systems's A-2000 BIS Monitor features a new enclosure that can be mounted on a pole with other equipment.|
While device companies are taking a closer look at costs and speed in manufacturing, another of their concerns is making certain that users, primarily healthcare institutions and professionals, literally buy in to a device. It's well-known that the healthcare system is strained. Worker shortages are resulting in longer, busier workdays for those in the sector, and patient loads are increasing as the population ages—innovative medical device manufacturers are keeping these facts in mind as they design products.
A redesign project often meets several goals, improved work flow included. When IDEO redesigned the manufacturing process for the Dermagraft dermal skin product, manufactured by Advanced Tissue Sciences Inc., the result streamlined costs and made physicians' lives easier.
“In the past, designers may have looked simply at how to get a product to work,” explains IDEO's Simons. “Today, we're looking at the process, at work flow, and asking, ‘How can I shape this product to make it easier or faster for the physician to use?'”
Dermagraft previously was grown in 4 ¥ 6-in. sheets that required manual seeding of the cells, rotation of the large growth containers, and injection of a growth culture. The redesigned growth environment, on the other hand, features a bioreactor system with stackable growth manifolds. Each manifold holds eight 2 ¥ 3-in. pouches containing matrices that can be automatically seeded, rotated, and fed. When the matrices have grown to a size that fits 80% of foot ulcers, each pouch is sealed and separated. The new Dermagraft is simpler to use, and the potential for product damage has been reduced.
Similarly, more manufacturers are creating products that have easier-to-remove packaging and disposable elements to ease overstressed nurses' and other caregivers' workloads. (Disposables are facing a new design challenge of their own. See “Medical Devices Go Green,” this page.)
Further, designers are looking at technologies being adapted to consumer markets, which, with their high product volumes, tend to lead the way in technological innovation. Many of these technologies could possibly improve medical product design. One example of a consumer-market crossover is the double-sided tape now being used to secure ECGs. Although ECGs have been used for decades, they historically had poor leads; the adhesive did not stick well to patients' chests, nor did the leads provide good measurements. When double-sided tape entered the consumer marketplace, it provided a solution to the ECG lead problem as well.
Similarly, while bar codes have been a part of consumer products for decades, it is only in recent years that they've become common in the medical arena. “Hospitals are using bar codes as a check-and-balance system,” Czuba says. “Scanned bar codes simplify recordkeeping, as in the case of implanted heart valves. The government requires tracking of such devices in case there's need for a recall, and scanning a bar code into a patient's on-line chart streamlines any potential notification process.”
“We're seeing a lot more bar code labels and radio-frequency identification chips in products now, so that the products can be scanned,” agrees Hiemstra. The practice helps track inventory and can reduce data-entry errors as well as mix-ups. “Nurses used to have to put a hand-written label on a vial to identify which patient provided a sample. Now hospitals or clinics may use a preprinted, adhesive-backed label from the patient record to make sure the sample is labeled properly, and so the diagnostics technician (or machine) can automatically read the label,” Hiemstra says.
Miniaturization is also a focus for manufacturers trying to please healthcare professionals. There is only so much real estate available at the bedside or in the emergency room, so devices are becoming smaller and more portable to allow professionals more room to work.
Aspect Medical Systems's A-2000 BIS Monitor, which measures the effects of anesthetics on the brain and consciousness, used to consist of a tabletop box and a cable that the patient wore, which occupied a lot of space in the operating room. To reduce the bulk, Design Continuum Inc. (West Newton, MA) designed a new enclosure that would mount on a pole with the anesthesiologist's other equipment and show data on a computer screen, also attached to the pole. The changes freed up space in the operating room and also increased market share. The monitor is now used at 60% of the nation's top hospitals, according to Aspect Medical Systems.
“Sometimes [a product redesign project involves] taking the user interface off a medical product and putting it someplace else, combining the medical product with wireless technology to free up space,” notes Stuart Perry, director of electrical engineering for Design Continuum.
Medical device designers also are adopting smaller but higher-powered, longer-lasting batteries and sensors from the cellular phone and electronics industries to fuel smaller, mightier designs.
“As products get smaller, an important challenge becomes keeping the displays crisp and clear,” Perry says. “A wide viewing angle is necessary, as are power management strategies.” There's a trade-off between how often a backlight can be used to light a display versus how long its battery can last, Perry explains. “In the next few years, we'll see more organic LEDs being used because that display technology has deeper color saturation, an extremely wide viewing angle, and remarkable clarity, and uses little power. The technology is being refined on cell phones, and once it becomes more pervasive in high-volume areas, we'll see it used more in medical device design.”
|Dental View's DVA Perioscopy System,
designed by Stuart Karten Design, provides real-time visualization enhanced by intense
illumination and magnification.
Patients Have Their Say
In addition to considering how a product will be used, designers also think about how patients will respond to a device. “In the past, lots of manufacturers focused on the technology and idea for a device, and the user experience was secondary. Now, those factors are running neck and neck. It's a significant shift in the paradigm,” says Allan Cameron, industrial design principal and leader of Design Continuum's health and medical practice.
Sometimes a user's needs are interpreted incorrectly, and the resultant final design is counterintuitive. For example, one manufacturer, trying to develop a toothbrush that would appeal to children, made a smaller version of an adult brush. Sales were flat. IDEO observed children brushing and found that a large, thick-handled toothbrush—rather than a miniature adult version—that children could hold easily in a closed fist won the favor of youngsters.
Certainly, manufacturers have thought about human factors for years, but Cameron says there's a need to reframe the criterion. “We refer to ‘targeted' design,” Cameron explains. “There was a time when people wanted things to look pretty. Now we're concerned about the emotional response when people look at a product. Manufacturers now tell us what message they want consumers to get when they look at a product, and we create characteristics to reinforce those attributes.”
For example, Design Continuum and Geoffrey A. Hart, MD, were trying to create a “playful, nonthreatening” pediatric sedation device when they developed PediSedate. The colorful, toy-like headset lets children play with a Nintendo Game Boy system or listen to music on a portable CD player while a snorkel delivers nitrous oxide into their nose. The device relaxes children during medical procedures, easing the minds of their parents and the task at hand for healthcare professionals.
Of course, adult patients' concerns tend to be more complex. Numerous devices are being designed to look like anything but a medical device to protect their users' privacy. For example, one blood glucose monitor for diabetics that checks the wearer's blood sugar level every 20 minutes is designed to look like a wristwatch.
In many instances, manufacturers are developing different models of devices depending on whether they're intended for clinical or at-home use. Home-use medical products are a rapidly expanding market; in a 2001 FDA Consumer magazine article, William Herman, director of the division of physical sciences for CDRH, called home-care systems “the fastest-growing segment of the medical device industry.”
“IT [information technology] is making it all possible,” says Hiemstra. “Communication is key to device advancement. The IT sector is now merging with the medical sector, and that—coupled with advances in sensors, software, and other monitoring equipment—is allowing us to capture patient data outside of traditional settings.”
At-home devices record such patient information as blood pressure measurements, then transmit that information either over a computer line or wirelessly to the patient's healthcare provider, making device interface capability an increasing priority. While industry experts say that technologies like Bluetooth still haven't had much impact on medical device design, they believe such protocols will play an increasing role in coming years as the technology becomes more affordable and mainstream.
In the meantime, designers are focusing on how to make products easy for patients to use and understand. “Outpatient care is being driven by PCs, and I believe flat-screen technology will permeate all medical products in the future because it's the most explicit way to deliver instructions, and it's becoming cheaper,” Cesaroni says. “In the old days, you would give patients printed instructions, but who knows how thoroughly they read them. With a flat-screen display, they'll reference the screen to get feedback on how to use the product, or what the results of a blood analysis are. It's like the old saying, ‘a picture is worth a thousand words.'”
We live in a society where people are obsessed with the looks and stylishness of their homes, their cars—nearly everything. That same perspective applies to medical devices, says Stuart Karten, principal and founder of Stuart Karten Design (Los Angeles). “Actually, it probably is even more important that a medical device look stylish and high-tech, because consumers want to have confidence in its ability to function the way it should. Often, a product's value is closely related to its appearance.”
Karten says his company sometimes will use metal finishes rather than plastic to give devices a higher perceived value, which often translates into higher sales.
WhiteLight Design's Willis Whiteside agrees. He also uses metal sheeting occasionally, rather than plastics, to increase a product's appeal. “You're trying to create something that stands out in the market and creates a brand for a new product, giving it a competitive advantage,” Whiteside says. “Technology becomes a tool in achieving that goal, and our knowledge of design and engineering principles lets us use manufacturing processes in creative ways to design a device that looks expensive, but isn't.”
Today's definition of good design encompasses many components, including cost-efficiency, eased work flow, consideration of the end-user, a compelling look, and one more element that often separates good from great design: the so-called “wow” factor.
“Great design all comes down to cleverness,” Karten concludes. “Technologies get you only so far. Engineering horsepower and creativity will find new ways to mix older and emerging technologies to create devices that are functional, user-friendly, and inspired.”
Copyright ©2003 Medical Device & Diagnostic Industry