Medical Device Link.

Originally Published IVD Technology May 2004

Medical Design Excellence Awards

Top honors in the annual Medical Design Excellence Awards (MDEA) competition go to medical devices that exemplify the highest standards for healthcare products. This year’s four winners in the IVD category are no exception. 

The MDEA competition is the premier awards program for the medical technology community. Winning products in this year’s competition will receive gold or silver recognition at a ceremony held June 16 during the Medical Design & Manufacturing East 2004 Conference and Exposition at the Jacob K. Javits Convention Center in New York City. But to get to the winners’ circle, this year’s entries had to satisfy a demanding set of criteria applied by the competition’s judges.

One of the most important criteria considered by the jurors was whether a device has obvious utility for patients. In other words, the jurors needed to see what a product has to offer to end-users. The criteria involved evaluating a number of factors, such as quality of the test results, ease of obtaining the results, savings that could accrue from using the device, and safety considerations.

In addition to utility, the jurors were looking to see whether a device possesses any novel features. Compared with previous products, a novel device demonstrates improvements that would benefit end-users. Such a device shows that a manufacturer and its designers looked at and identified end-user needs, developed a product that meets those needs, and then refined that product to the degree that it would be attractive in the marketplace.

“There are already a lot of IVD products in the market. So a device has to have something that is a substantive improvement, offering a novel solution to a difficult problem. Those are the kinds of features that grabbed our attention,” says Craig M. Jackson, a member of the juror panel and president of HemoSaga Diagnostics Corp. (San Diego).

This year’s winning IVD devices impressed the jurors with their utility and novelty. The distinguished honorees in the IVD category include a revolutionary blood glucose monitor for diabetics; an automated microbial-detection system that accommodates multiple applications in a single platform; a fully integrated, interactive computer system for cervical cancer screening; and an instrument that reproducibly isolates rare circulating tumor cells. 

While different in terms of their intended use, the winning devices share key attributes. Each boasts well-thought-out design and engineering, technical innovation, and human factors to the ultimate benefit of patients. Improvements to healthcare and to patients’ lives are indeed the results. 

Diabetes Management

Figure 1. The Paradigm Link blood glucose meter.

Thanks to a breakthrough product called Paradigm Link, diabetics can forget about sending blood glucose results manually to their insulin pumps (see Figure 1). Paradigm Link does it for them automatically. 

The Paradigm Link blood glucose meter is the world’s first untethered wireless glucose meter that provides bidirectional communication between a glucose meter and an insulin pump. It was developed jointly by BD Medical, Diabetes Care (Franklin Lakes, NJ), Medtronic MiniMed (Northridge, CA), and Nova Biomedical (Waltham, MA), and manufactured for BD Medical, Diabetes Care, and Medtronic MiniMed by Nova Biomedical. 

The Paradigm Link monitor automatically transmits a patient’s glucose value to a pump using a radio-frequency link, as described on the Medtronic MiniMed Web site (www.minimed.com). The pump’s Bolus Wizard calculator then uses that value to recommend the right insulin dosage. 

Patients with diabetes who use Paradigm Link reap significant benefits according to Jeffrey A. DuBois, vice president of business development for Nova Biomedical. That the Paradigm Link glucose monitor and the insulin pump communicate with each other bidirectionally “reduces the potential of a data-entry error, improving the accuracy of dosing and providing convenience for patients,” DuBois says. The elimination of manual data entry also makes managing diabetes simpler and more convenient. 

Developing the system required that Nova Biomedical “embed electronics to affect communication between the pump and the meter so specific algorithms for insulin dosing in the pump would have accurate and up-to-date glucose levels,” DuBois says. “This type of integration had never been accomplished by another company. That’s what’s unique—we were the first to do that.” Critical to the success of the embedded electronics, he adds, was “understanding how Medtronic developed its pump electronics for communication and how to modify our meter accordingly.”

Development of the integrated system was fast. “Because the initial glucose meter and strip went from breadboard to a manufacturable product, as the BD Logic, in 9 months and into distribution within 18 months, we were able to fast-track the development of the Paradigm Link in a record 5 months,” DuBois says. The fact that the meter and strip portion of Paradigm Link were already in place sped time to market. “It was just a matter of redoing the electronics for the communication between the meter and the pump, and getting that new product through FDA.”

Together, Paradigm Link and the Paradigm pump provide a user-friendly design. The monitor has an easy-to-read display, and tests blood glucose fast, generating results in just 5 seconds. According to BD, the monitor uses a 33-gauge lancet, the thinnest on the market, and requires a test-strip blood volume of only 0.3 µl.

Supply and design credits go to Herbst LaZar Bell Inc. (Chicago), a provider of turnkey design and development solutions, as well as to Nova Biomedical and Medtronic MiniMed. Among Herbst LaZar Bell’s charge was “field research to determine the needs, wants, and desires of insulin-dependent patients; their life-styles; and their preferences as they relate to maintaining their regimen,” says Charles Keane, senior vice president and general manager at the firm’s Boston office. “Paradigm Link breaks new ground in offering exceptional freedom to active diabetics,” Keane says. It was, he adds, an “opportunity to define innovation in the context of positive change to people’s lives.”

Automated Microbial Detection

Figure 2. The VersaTrek automated microbial detection system by Trek Diagnostic Systems Inc. (Cleveland). VorTrexing (see inset) is an agitation method that facilitates growth of organisms in culture media by delivering oxygen to those organisms.

To clinical laboratory professionals, VersaTrek means ease of use and overall process efficiency (see Figure 2). For patients, the clinical lab instrument may well mean that appropriate treatment is determined more quickly and started earlier. 

The automated microbial detection system combines blood culture, sterile body-fluid culturing, mycobacterial detection, and Mycobacterium tuberculosis susceptibility testing in a single platform. Trek Diagnostic Systems Inc. (Cleveland) manufactures the VersaTrek system. 

“In blood culturing, the prognosis of a septic patient is greatly improved when appropriate treatment is initiated quickly,” says Nadine Sullivan, Trek Diagnostic Systems’ chief science officer. “When you perform antibiotic susceptibility testing, you have a very good answer for the best treatment of the pathogenic organism. If the organism is detected faster, the time to obtain the antibiotic treatment information is also faster, since one must detect the organism first before subsequent testing can be done.”

VersaTrek’s faster times to detection are due to the culture media (the same media used in the instrument’s predecessor, the ESP Culture System II) and an agitation method called VorTrexing. “To optimize oxygen getting into the aqueous solution to optimize the growth of the organisms that need oxygen, we’ve put a stir bar in all of the aerobic bottles. A magnetic motor at each test location in the instrument causes the stir bar to mix the solution,” Sullivan explains. Other instruments that rock or rotate are not as efficient in mixing oxygen into the aqueous solution, she adds. 

Having that magnetic motor at each test location means that any bottle, whether aerobic or anaerobic, can be placed anywhere within the system. This addresses issues of ergonomics, reliability, and work flow, thereby simplifying test management. 

Trek Diagnostic Systems’ codeveloper for the project, Plexus Technology Group (Neenah, WI), designed VersaTrek in its entirety. Contract manufacturer Mayville Engineering Co. (Mayville, WI) worked concurrently with Plexus, providing input on mechanical design and process tolerance. 

One of the design obstacles Plexus faced involved the test location and magnetic motor. “We needed a certain rpm range for the stir bar to perform optimally. When we received our prototype, it didn’t work—that is, the maximum rpm we could achieve in the instrument was not adequate,” Sullivan says. It was then discovered that the distance between the magnet and the bottom of the bottle holder was too great. Consequently, the coupling of the magnetic stir bar was insufficient and the stir bar mechanism was not effective. Moving the magnet closer solved the problem. 

There were challenges on the mechanical side as well, according to Tom Verbos, director of sales and marketing for Mayville Engineering. “One significant challenge was that of weight versus strength, to ensure the robustness of the design,” Verbos says. “A resolution was obtained by using heavier carbon-steel construction for the cabinet and lightweight aluminum for the drawer assemblies.”

Cervical Cancer Screening

Figure 3. The ThinPrep imaging system by Cytyc Corp. (Boxborough, MA).

The ThinPrep imaging system, manufactured by Cytyc Corp. (Boxborough, MA), is a fully integrated, interactive computer system that assists cytotechnologists and cytopathologists in the primary screening and diagnosis of ThinPrep Pap test slides (see Figure 3). Because the system boosts productivity in the laboratory, patients can receive more-accurate and -timely results.
“Prior to the arrival of the ThinPrep imaging system, cervical cancer screening was accomplished primarily using manual screening,” says Matthew Zelinski, director of operations for the product development solutions division of Battelle Healthcare Products (Columbus, OH), which provided development support for the imager. ThinPrep, he says, is “the first imaging-based system developed to augment human screening instead of replacing it.” 

Total integration of the system throughout the screening process enables the cytotechnologist to concentrate on the most important areas of each slide. In essence, the imaging technology combines a conventional microscope with automated stage control to pinpoint 22 fields of interest for the cytotechnologist’s review and determination. “This approach allows technology to reduce significantly a cytotechnologist’s work load while maintaining the human element, with experience, training, and judgment skills, to make a determination of disease,” Zelinski says. “The imager has the potential to greatly increase screening productivity while maintaining or improving sensitivity and specificity at all diagnostic levels.” 

Various ergonomic features help to optimize efficiency. In many cases, Zelinksi says, they double the number of slides that can be reviewed in an eight-hour day. Among them are positioning of the eyepiece to accommodate individual screeners; changing of the optical magnification and electronic marking of slides while maintaining a view of the actual cells; and automated physical marking of the slide. 

To make the ThinPrep imaging system a reality, several technical challenges needed to be overcome. One key hurdle was producing sufficient light to image the slide in a reasonable period of time. So Cytyc and Battelle came up with a twofold solution. “First, Cytyc developed a custom stain that combined the visual characteristics of a traditional Pap smear stain, to accommodate manual review, with spectral characteristics and reproducibility needed for monochromatic imaging of cell nuclei,” Zelinski explains. 

Figure 4. The CellTracks AutoPrep system by Immunicon Corp. (Huntingdon Valley, PA).

Then Battelle developed a custom, high-efficiency, high-intensity light-emitting-diode (LED) module for the light source. “Instead of a traditional light source, LEDs are used to generate a narrow band of light that eliminates the need for filters,” adds Zelinski. The result, he says, is a dime-sized fractional-watt light source consisting of low-cost optics that eradicates heat dissipation problems and facilitates packaging. 

Slide vibration and focus were also addressed to ensure high-quality images. This was particularly important, since proper evaluation of each slide depends upon as many as 2600 images being taken in a four-minute span. Thus, external vibration isolation and slide motion techniques were employed, and a piezoelectric linear drive was incorporated for a start/stop motion profile that immobilizes the slide for each image. 

Rare-Tumor-Cell Isolation

Carrie Mulherin likens isolating rare circulating tumor cells (CTC) to locating a grain of salt in a five-pound bag of sugar. Immunicon Corp. (Huntingdon Valley, PA), where Mulherin is vice president of marketing, has produced a general-purpose laboratory instrument that automates the process (see Figure 4). It not only enables CTC analysis in a clinical laboratory setting for the first time, but also aids oncologists in selecting and monitoring cancer therapy. 

The CellTracks AutoPrep system is used with immunomagnetic reagents that capture and enrich target cells, and labeling reagents that differentiate them. Immunicon has developed reagent kits and an analyzer for the system, for its first application in the field of cancer. Rare CTCs are isolated by the CellTracks AutoPrep system from 7.5 ml of blood and concentrated to a final volume of roughly 300 µl.

Isolation is accomplished via magnetic tagging. A magnetic field applied to the sample tags cells of interest and immobilizes them while the nonmagnetic portion of the sample is removed. Fluid is then added for continued processing of the targeted cells. 

The system’s MagNest presentation device is critical to preventing cell loss. “It’s basically two angled rare earth magnets held together by a piece of steel,” Mulherin says. “The angles, the spacing, the length—the design of the magnets—are relative to the analysis cartridge itself.” The result is a completely vertical magnetic field inside the chamber. The immunomagnetically labeled target cells “move straight up and distribute CTCs randomly across the surface of this device, putting all of the cells into one plane, ready for analysis by the system’s CellSpotter analyzer.”

Lori Bryan is a freelance writer in Santa Monica, CA. She formerly  was editor of  IVD Technology’s sister publication, Cosmetic/Personal Care Packaging.

Designing the complex system posed challenges. “Dealing with the precision fluidic handling and exact dispensing requirements was the largest challenge on the unit,” according to Tom Harbart, director of engineering for Astro Instrumentation LLC (Strongsville, OH). The company provided the unit’s mechanical and electrical design, and does the manufacturing for Immunicon. “We were able to keep the design flexible enough so that Immunicon could continue to develop its protocols while keeping to the development schedule,” Harbart says. 

Also a contributor to the CellTracks system, HS Design Inc. (Gladstone, NJ) lent its expertise in such areas as user research, industrial and mechanical design, and human factors. Making the system intuitive and easy to use for the clinician was a top priority. Focused interface points, a simple user interface, and maintenance doors are designed to reduce potential errors and system downtime. “The design has complicated surface geometry,” says John Studier Jr., a principal. “It helped us push our internal capabilities in this area.”

Conclusion

This year’s MDEA-winning diagnostics show mastery of automation, ergonomics, and technical ingenuity. Whether for laboratory use or for patient use directly, the products have in common their significant contributions to improving patient care. Speedier detection of disease and the ability to more precisely target and monitor therapies rank among the top benefits. For the companies that brought these products to the healthcare marketplace, those benefits are the ultimate rewards. 

Copyright ©2004 IVD Technology