Originally Published MDDI April 2005

MDEA 2005

Prescription for Award-Winning Design: Go to the Doctor

Sherrie Conroy

An award-winning medical device is one that is easy to use and promotes error-free operation, bringing together all of the components needed to do a particular task. In the Medical Design Excellence Awards competition, the judges look for attributes such as easily visible displays and controls. The judges also look for usability, human factors, and technical competence. Moreover, a device must be "safe in the clinic, not just in the conference room," says juror William A. Hyman, professor and interim head of the department of biomedical engineering at Texas A&M University (College Station, TX).

"Devices must show a clear benefit, preferably to both the patient and the clinician," says juror Matthew B. Weinger, MD, professor of anesthesiology, biomedical informatics, and medical education at Vanderbilt University School of Medicine (Nashville, TN). In some cases, the benefit to the user—usually a clinician—is the most significant aspect of a device and what makes it stand out above the rest. The following devices fell into that special group.

RelyX Luting Plus Cement Dispenser

The RelyX Luting Plus dispenser, manufactured by 3M ESPE Dental Products (St. Paul, MN), is a clicker dispenser of fluoride-releasing dental cement for permanently affixing crowns and bridges. The clicker ensures a precise 1:1 volume ratio of the two-part cement.

"The cement is provided in a ratio of 1:1. That's an advantage because it's a specific delivered dose," says juror Eliot Lazar, MD, principal of ElCon Medical (Buffalo, NY). "The delivery device has been designed so that the two sides are different, one allowing oxygen and one not allowing oxygen, which makes it a convenient storage and delivery device for the cement at a particular point in time. That makes it very easy for the dental assistant," he explains.

The jurors noted that the dispenser is fast and efficient for the dental assistant. The dispenser and cement are designed to replace a more complicated, less accurate powder-liquid combination. "It allows the dentist or dental assistant to easily get the amount required," says juror Jay R. Goldberg, who serves as director of healthcare technologies at Marquette University (Milwaukee). "This is important because if the proportions are not right, a patient's crown could fall out prematurely," he says.

"Before we developed the Relyx luting cement, the dental assistant was required to scoop out powder, place it on a pad, and drop liquid out of a vial," explains Bruce Broyles, senior product development specialist for 3M. "That is a fairly inaccurate way of dispensing a cement that needs a fairly consistent viscosity when all is said and done," notes Broyles. "The powder-liquid systems would provide such a wide range of viscosities that the cement was either too thick or too thin. When applying it to a crown, the dentist would often ask the dental assistant to remix it because it was too far from a reasonable viscosity."

Achieving a consistent viscosity easily and accurately became the goal of the design team. If the viscosity is too high, says Broyles, the dentist can't force the crown down on the stump because the material won't flow out. When it is curing, the crown will be sitting too high, and when the patient bites down, the crown will hit the opposing teeth. A too-thin viscosity, he
says, results in too much resin, which can affect the mechanical and physical properties of the material.

"We heard our customers, and we realized this was a problem," says Broyles. "We came up with a paste-paste version of this liquid-powder cement that we could dispense from an accurate dispensing system." Broyles says the design team developed the clicker dispenser system so that it would ensure an accurate ratio each time and be easy for dental assistants to use.

The users had input in the design early on. Broyles says that each quarter, 3M brings in a large group of dental assistants and, twice a year, the company brings in local dentists for their feedback. "We had a lot of input on the design of the dispensing system from the dental assistants and the dentists to help ensure that the cement is easy to use and fairly easy to clean up," he says. "You get the 1:1 ratio each time, so that the physical properties of the material are always right."

The company chose formulations that allow the two pastes to sit on the shelf for up to two years without polymerizing. "Some thought was definitely given to this aspect of the product, and it is clear that the necessary testing was done to give it a sufficient shelf life. The designers clearly appreciated that the shelf life was another important feature," says Goldberg.

Intelect Advanced and Mobile Electrotherapy Range

The Intelect Advanced and Mobile Electrotherapy range, manufactured by Chattanooga Group (Hixson, TN) is a fully integrated suite of clinical electrotherapy equipment used to administer a wide selection of physiotherapy treatments.

For clinical electrotherapy, all devices—such as ultrasound, vacuum stimulator, and patient data system—come in a single unit for the therapist. The jurors noted that the innovation of the device is its nice workstation and applied state-of-the-art industrial design. "With multiple modalities in one workstation, it creates task flow," says juror Goldberg.

Task flow, as it is known, was a critical element in the design," says Ed Dunlay, vice president of marketing for the Chattanooga Group. "Our vision of the product was of a modular design to allow clinicians to select the modalities they use clinically from a single operating screen. At present, we have six modalities that can be selected from one screen, and we are working on additional modalities as well," he says. "What stands out is that it has the devices all in one place," notes Goldberg. "It has several modalities, whereas before, the physiotherapist had to use six different pieces of equipment."

Dunlay says the company conducted extensive global surveys of clinicians in the world of rehabilitation as to the value and benefit of integrating multiple clinical modalities into one unit. "Those outcomes determined our direction," he says.

F.A.S.T.

The F.A.S.T. (facilitated aspiration/suction thrombectomy) device, manufactured by Genesis Medical Interventional Inc. (Redwood City, CA), employs a funnel catheter and suction to remove blood clots from the access grafts of dialysis patients, reducing the possibility that clots might move elsewhere in the body where they could cause death.

"The device brings together unique components literally in a kit so that you have a consistent and logical methodology," says juror Hyman. "It is presented as a whole, as opposed to standard methods that require the surgeon to assemble the parts needed for the procedure," he says. "But to determine what pieces are needed to effect the technique safely is as
critical as finding the pieces. The product also represents a technique, and addresses both of those uses."

Hyman says it's the broad principles that contributed to the successful design of the system. "It is not particularly easy to use because it's a challenging technique," says Hyman. "In this case, the user benefit that was created certainly leads to patient benefit."

"Developing the device was all about the team. It was their love of the technology and their desire to increase patient safety," says William Dubrul, CEO of Genesis.

The real clinician benefit, he says, is that the doctor is now "pulling the clot out instead of sending it elsewhere in the body." Dubrul explains that most physicians use lytic drugs, which can be dangerous for high-risk dialysis patients. These patients are six times more likely than nondialysis patients to have a pulmonary embolism, he says.

"Our device does not get rid of the clot faster. We are just allowing the doctors to remove the clot instead of sending it downstream," says Dubrul. The initial target for the device will be those physicians who are currently using mechanical thrombectomy. The doctors who use lytic drugs are more skeptical, he says. They want proof that the drugs do cause problems. Genesis is planning side-by-side trials over the next couple of years to address this issue.

"We are still addressing some ease-of-use issues as well. The procedure is different, so training is going to take some time. Physicians do love the idea of removing the clot," he says.

Axxess Neurostimulation Leads

Axxess neurostimulation leads, manufactured by Advanced Neuromodulation Systems (ANS, Plano, TX), are designed to provide surgeons with better control and more placement options, resulting in less-invasive insertion.

Used for pain electrostimulation (e.g., epilepsy), the leads are the smallest-diameter electrodes available for surgery that is guided under fluoroscopy (0.8 mm). The leads, which have a 1:1 torque ratio, have inner guidewire bipolar leads that go through the tissue.

"When using neurostimulation to treat chronic pain, the primary goal is to position leads (and ultimately, platinum conductors) over specific regions of the epidural space in order to achieve effective coverage of the patients' pain," explains Brad Maruca, marketing director for ANS. "However, lead placement can be difficult because a large portion of patients have scar tissue and adhesions, often as a result of prior surgery, which create an impediment for physicians. While navigating leads into position around such impediments, the technical challenge for physicians is to control the distal tip of the lead through manipulation of the proximal end, which can be 30­60 cm away," he says. Maruca says that with its small size and 1:1 torque transfer, Axxess allows physicians to move the lead in precise, fine movements, helping them place it into proper position even when patients have restrictive anatomical structures. "We believe this feature will have advantages as the locations and the indications treated through neurostimulation evolve," he says.

"This is the equivalent of Œwhat you see is what you get' in visual user-interface design, or perhaps Œwhat you feel is what you get,'" says juror Weinger. "These leads allow for more rapid and more effective positioning."

According to ANS, the lead's small size and steerability facilitate placement into restricted spaces, which results in a less-invasive procedure. "The unibody design is the result of a process whereas the lead strands became incorporated into the inner wall of the lead," says Maruca. "Essentially, the lead feels like Œone-piece' to the physician. The clinical result is better rotational control of the lead. The more responsive the lead, the better equipped the physician to maneuver the lead into confined anatomical spaces," Maruca explains.

Cassi Rotational Core Biopsy Device

The Cassi rotational core biopsy device, manufactured by Sanarus Medical (Pleasanton, CA), is an automated large-core biopsy device used in the diagnosis of breast disease. Cassi's patented Stick-Freeze technology is used to immobilize the target tissue, making it unnecessary to purchase costly capital equipment.

The beauty of this device is that it enables a breast biopsy to be done in the doctor's office. "It is a disposable, self-contained device that provides a large-core biopsy. It is an office-based procedure that requires no capital equipment," says juror Michael Wiklund, a human-factors engineering consultant based in Concord, MA.

"Breast surgeons tend to work in small practices where cash flow is a big concern. They get very worried about spending money to buy new technology when they aren't sure how often they will use the equipment," says Russ DeLonzor, vice president of research and development for Sanarus. "We knew that we'd have a huge hit on our hands if we could deliver the same reliable cores with no worries about amortizing the cost of the equipment over a lot of procedures."

"We really like the engineering design, including the use of the CO2 to freeze (or hold in place) the tissue to be biopsied," says juror Weinger. The CO2 unit also drives the biopsy mechanism pneumatically, pushing the core piston forward and then retracting it later to extract the obtained specimen. "It doesn't require a huge up-front capital expense, so it is easy for a small clinic or individual clinician to purchase and use," he says.

DeLonzor says the company's goal was to deliver a product at the same cost per use that other companies were charging for their disposable components, but with no capital equipment. "Delivering the sophistication of an automated biopsy device at the lowest possible cost was a tough goal," he says. "To hit it, we knew we would have to borrow from the high-volume consumer world for some of our basic building blocks. From the gearmotors used in ATMs to the safety mechanisms used in paint-ball guns, to general-purpose programmable integrated circuits used in about everything, we designed using off-the-shelf solutions wherever possible."

By taking advantage of these economies of scale, DeLonzor says, the company was able to produce a highly sophisticated, completely disposable device. "This device will make the clinical advantage of large-core biopsy devices accessible to many more physicians," he says.

The reason automated large-core biopsy devices are worth the investment is because they provide much more reliable tissue specimens than the spring-loaded devices that are designed to essentially harpoon the target lesion. "One of the downsides to previous large-core devices is the cost of the capital equipment," DeLonzor explains. Another problem is that the devices are fairly complicated and require the time of a trained technician to set the equipment up before a procedure, then take it apart and clean it after the procedure. "At the beginning of the project, physicians told us what they really wanted was a device that worked as well as the current automated biopsy devices, but in a single-patient-use form that doesn't require setup or maintenance," he says.

"We've heard from several clinicians that we have met that goal and have truly changed their practice of medicine," he says. He explains that, in the past, if a woman came in for an appointment because she felt a lump in her breast, the doctor would verify the lump under ultrasound, then schedule another appointment for a day when they could set aside the time that it takes to set up the automated biopsy device. "Because Cassi doesn't require any setup, these clinicians are now doing the biopsy procedure during the woman's first appointment."

There is another, subtler factor that he says drove the company to provide a self-contained, disposable design. "The current equipment uses a large piece of capital equipment sitting on a cart hooked up to a disposable handpiece via a set of tubes and cords. The sheer size and weight of the equipment is very intimidating, and many doctors prefer not to have the patient see the
device prior to use.

Our goal was to minimize the patient's anxiety by providing an unintimidating, quiet-functioning device that requires no tubes or cords. "Something we didn't think to write in our product specs up front, but something we've heard from many of our physicians, is that Cassi's presentation to the patient is far superior to the competitive devices."

ClozeX

The ClozeX wound-closure device, manufactured by Clozex Medical LLC (Wellesley, MA), is a coaptive wound-closure device that replaces sutures, staples, and glues. The closure, which comes in many sizes, uses adhesive films and mechanical action to draw a wound together in 7­10 days. The color-coded device uses red, white, and blue to indicate the order in which to apply the device. "Suturing takes 10­14 minutes. Using our product to close a wound takes 2 minutes," says Ray Barbuto, vice president of manufacturing for ClozeX. Glues take 3­4 minutes and require the hands of another technician to align the tissues," he says.

Barbuto explains that it is difficult to get a straight line with sutures. The physician must estimate what the wound will look like when it is done swelling. If it begins to pucker, he says, the physician must cut it open and start over, resuturing or stapling it, which causes additional injury to the skin. The idea behind the ClozeX device was to eliminate those issues. The device brings the margins of the wound together and "lets the body do its job. Its simplicity is why it works well," he says. It improves wound-closure speed, and if a clinician makes a mistake, the ClozeX can be removed with no injury to skin. "We see this device as a paradigm shift in the making," he says, noting its appeal to physicians and patients.

"The ClozeX wound-closure device is the first device that approximates the edges very cleanly and neatly," says juror Lazar. "It is very efficient for the physician."

The device was invented by ClozeX Medical's president, Michael Lebner. Just two years ago, Lebner and Barbuto met with potential suppliers at MD&M East in New York. "We had a wound-closure device concept. We just had to find the
right raw materials."

Key to the device's success in the marketplace is the significant time savings, which offers great benefits to both the physician and patient. "For doctors and institutions, time savings can improve patient satisfaction, increase efficiencies and revenues, and reduce overall costs," says Barbuto.

"The local injection of anesthetics and the patient trauma associated with needles can be avoided in many emergency department cases, enabling doctors to more quickly treat patients," adds Barbuto. The ClozeX's topical design "forgives errors" because the device can be easily removed without skin damage. "The device is not secured until the alignment is satisfactory," he says.

"A good design or new method of treatment should provide one of five benefits," says juror Goldberg. "It should provide a less-invasive tool, offer a safer alternative (or have less risk associated with it), reduce pain and discomfort, make an existing procedure easier, or offer a time savings," he says. "It's important to know that less time for a procedure usually means that it is safer for the patient and that it can be done at a lower cost."

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