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Articles from 2010 In September


Artificial Cilia Could Revolutionize Sensor Technology

Newly engineered artificial cilia that respond to changes in heat, electromagnetic radiation, and acidity could eventually form the basis of medical device sensors used in such applications as glucose monitors. (Image by Zina Deretsky, National Science Foundation.)

Scientists at the University of Southern Mississippi (Southern Miss; Hattiesburg) have developed a thin molecule-based material that resembles cilia, the tiny, wavy, hairlike structures that protrude from organs and through which organisms derive smell, vision, hearing, and fluid flow. While the new material isn't exactly like cilia, it responds to thermal, chemical, and electromagnetic stimulation, enabling researchers to control and perhaps wield it for a range of future applications, including medical device ones.

Supported by the division of materials research at the National Science Foundation (Arlington,VA), the scientists at the Materials Research Science and Engineering Center for Response-Driven Polymeric Materials at Southern Miss created a thin copolymer film featuring whisker-like formations that mimics Mother Nature.

Employing a process used for years to produce latex paints, the researchers formed thin copolymer-based films with a chemical composition that enables them to produce filaments with built-in molecular sensors. These sensors, in turn, can respond to temperature, acidity, and ultraviolet radiation. Moreover, the filaments are capable of locomotion, waving, shrinking, and expanding in response to stimuli. They also are capable of fluorescence, enabling them to absorb and emit light and changing colors in response to ultraviolet rays.

"Our interest is in developing materials with multilevel responses at various length and time scales," remarks Marek Urban, professor of polymer science and engineering. "I believe this is the future of science and engineering that will drive future technologies."

In addition to performing a variety of sensing operations in environmental applications, the new cilia may one day find their way into sensors used for testing glucose levels. There is no limit to dreaming up applications for such a material, Urban says. "Many new ideas are being generated as we speak, but it is too early to reveal them."

The research is presented in "Advanced Functional Materials: Colloidal Films That Mimic Cilia," published in the journal Advanced Functional Materials.

Global Progress for Neuro: St. Jude Device Approved in Japan

It is the first spinal cord stimulator to be approved by the Japanese Ministry of Health, Labor and Welfare (MHLW) for use in Japan. Spinal cord stimulators manage chronic pain of the trunk or limbs and pain from failed back surgery by delivering mild electrical pulses to the spinal cord, which interrupt or mask the pain signals' transmission to the brain.

Chronic pain is a largely undertreated and misunderstood condition that affects millions of patients worldwide. The World Health Organization, in conjunction with the International Association for the Study of Pain (IASP), reports that as many as one in five people suffers from moderate to severe chronic pain.

According to the company, the Eon Mini neurostimulator has the longest-lasting battery life of any rechargeable spinal cord stimulation device currently on the market, and it is the only small rechargeable neurostimulator to receive a 10-year battery longevity approval. St. Jude says the device should provide sustainable therapy and maintain a reasonable recharge interval for at least 10 years of use at high settings. The device's battery longevity also may mean that patients require fewer battery replacement surgeries.

Slightly larger than the typical man's watch, the stimulator has a thin 10-mm profile and weighs 29 g (approximately 1 oz). Additionally, the device has the greatest recommended implant depth of any rechargeable SCS device. The thin profile and greater implant depth potentially makes the neurostimulator less noticeable and more comfortable for patients. Its small size also allows for a smaller incision, which gives physicians increased flexibility in selecting the implant location.

"The launch of the Eon Mini spinal cord system--the first rechargeable technology in Japan--is an excellent addition to our growing portfolio of neurostimulation products available from St. Jude Medical Japan." said William Phillips, president of St. Jude Medical Japan.

The MX Q&A: David Rose, Vitality

It’s a safe bet that few chief executives mention Frodo Baggins and his sword, Sting, in their business presentations. As befits a visiting instructor in tangible user interfaces at the MIT Media Lab, David Rose can make The Lord of the Rings connection ring true. The CEO of Vitality Inc., a five-year-old company based in Cambridge, MA, Rose name-checks Frodo to describe the “magical” capabilities of the firm’s new medical device. Called GlowCaps, the healthcare product is a wireless-enabled cap for standard prescription bottles that glows like Frodo’s sword to remind patients it’s time to take their medication. But instead of fighting Orcs, the device is designed to help ward off hypertension, diabetes, heart disease, and other treatable maladies.

At the previous company he founded, Ambient Devices, Rose developed products such as the Ambient Orb, which changes color to track changes in stock markets, weather forecasts, and traffic. Spurred by family-related health concerns, Rose and his serial entrepreneur partner, Joshua Wachman, company president, cofounded Vitality in 2005 to address the multibillion-dollar problem of medication nonadherence through their respective backgrounds in ambient information display and machine learning. In 2008 the pair brought in a healthcare system expert, Patrick Soon-Shiong, M.D., the chairman of Abraxis BioSciences, as an investor and board member.

Vitality launched the first GlowCaps in 2008 and recently released the fourth generation of the device, which lights up and plays a pleasant ring tone to remind a person to take her medication. The device sends a wireless time-stamp to Vitality’s secure network each time the medicine bottle is opened. Reminder calls are sent to the patient or designated caregiver if the bottle isn’t opened within one to two hours of the designated time. The patient or her caregiver receives an e-mailed medication adherence summary each week. The goal is to effect behavioral change through a combination of self-motivation and social networking. The company claims that patients, physicians, payors, drug companies, and pharmacies will all benefit from improved medication adherence.

Calling them “enchanted objects,” Rose specialized at Ambient in embedding Internet information in commonplace items such as light bulbs, umbrellas, and refrigerator doors. Vitality’s first medical device to use the smart-packaging concept won the company a silver 2010 Medical Design Excellence Award in the OTC/Self-Care products category.

In addition to teaching at MIT, Rose speaks at industry conferences and corporate retreats on the topic of product innovation. He received bachelor degrees in physics and fine art from St. Olaf College (Northfield, MN) and a masters degree in education from Harvard University. In this interview with MX, Rose discusses the social dynamics of behavioral change, encouraging clinical study results, the slow rate of innovation adoption within the healthcare bureaucracy, and the therapeutic value of lifting one’s voice in song.

MX: So are GlowCaps “enchanted objects,” too?
David Rose: I do think the GlowCap represents an “enchanted object,” because it’s taking an ordinary, everyday object and adding a little bit of computation and a little bit of wireless connectivity and making it a lot more useful. It’s the same way—and this is a geeky example—that Frodo’s sword in The Lord of the Rings showed him whether he needed to use it when Orcs were nearby. It’s almost the same thing, showing that [your medication] needs to be used so you don’t forget about it.

What’s the genesis of the concept?
Most of my family has suffered from heart disease. My grandfather died of it, and my father is struggling with it. I realized for many of us it’s something we face and that we will struggle with every day for, hopefully, decades. And so, more than just being a reminder device, it was seen more as a helping hand or a coach, where if the data about my hopefully good behavior is shared with someone in my life that cares about me, I’m much more likely to do the right thing. It does remind me, but I think more importantly it offers a little visibility into my social network and allows others to celebrate my success or my interest in keeping up with my medication regime.

As we looked at the literature, we learned almost every successful example of behavioral change uses social dynamics. Whether it’s smoking cessation programs or Alcoholics Anonymous or weight-loss programs, the recipe for success is all about opening windows of connectivity between you and the people that care about you so that they can support you and try to help you change your behavior. And behavior change is incredibly hard. It doesn’t happen without that social nudge.

There are two types of social nudges that we’ve designed into the product. One is where you select one or more people in your social network, like a family member, in order to see the data about how you’re taking your medication on a weekly basis. And so it gives you a little calendar of which days you did or did not take your medication and how you’re tracking against a goal. And the second type is really a product for…sharing your data with a physician. There are certain personality types—people who respect their doctors and have a high respect for authority—that really respond [to this approach.]

How long did it take to develop the GlowCap?
It’s had a long developmental period. We’ve been working on the product for about three years. This is the fourth-generation product we’re launching now. The fourth-generation product connects over an AT&T cellular network. You don’t need a computer, you don’t need broadband, and you don’t need WiFi. You just need to be able to plug the nightlight in, and it creates connections to the AT&T network. Previous versions relied on a home phone line or a broadband connection. The new version is easier to install, and it’s just magical. It just connects to the Internet on its own.

I imagine that’s a plus for elderly people who may not be technologically savvy—that ease of use, wouldn’t you say?
Yes, absolutely.

Just as a follow-on to the ease-of-use point, one of the advantages in embedding technology in everyday objects like a pill [bottle] cap is it doesn’t look like technology. It’s not a computer program or a Web site or an iPhone app. It’s a dedicated, very inexpensive microprocessor just for that one app. As the cost of wireless and computation falls, I think you’ll be seeing this more and more. You can afford to create a $5 pill cap that people use every day. And that people can throw out.

Are you at liberty to tell us your start-up costs?
No.

Okay, but has it been difficult then to find investors for the device in this economic environment?
No, the problem of medication adherence is such a well-understood one that lots of people have been interested in coming and funding it. Especially if you have a product that breaks new ground in terms of simplicity, and also if you get the sort of blue-chip research evidence we’ve gotten.

Speaking of that, what’s your latest research news?
We worked with Massachusetts General Hospital, which is part of Harvard Medical School, and we did a study over the last year specifically for hypertension, which is one of the hardest things for people to solve. With hypertension you don’t feel sick and you don’t feel the medication working, so it’s very easy to not take the medication.

Half of the population used the GlowCap with all its services turned on, which were reminders, social support, doctor accountability, and refill coordination. And we gave the other half GlowCaps that just collected data. And then we looked at the difference between those two populations every day for about nine months now. The difference in the people’s medication-taking behavior is about 30% between those groups. Meaning that 70% [were not taking their medication in the second group] and 98% were in the first. The group [adherence] where we had the GlowCaps turned on, where they were doing all the things they do to take medication, was much higher than we expected.

This is a much better result than anybody else who has been working on this problem has gotten. A 30% lift [represents] about 100 days a year. The current best-of-breed on the market is [an increase of] about 10 days per year. With the current best-of-breed you send somebody a letter, and you call them if they haven’t picked up their script. Those services buy you about 10 more pills taken per year, so we’ve really done the classic type of innovation by improving the state of the art by a factor of 10.

Did you have any manufacturing or design challenges, say with overseas production, for instance?
Well, my previous company, Ambient, has been manufacturing in China for about eight years. I think the hardest part is designing a product that is polite enough that people want to live with it every day. You can’t make it [sound] like a smoke detector, because people would toss it out the window.

Your previous position involved selling consumer products. Did you face new regulatory concerns in designing a product for the healthcare market?
We passed all the standard regulatory issues. There are at least six tests we had to pass. We had to use food-safe plastic, the device had to pass the “light-and-tight” test, which means that no moisture can penetrate the bottle that can change the absorption rate of the drug. We had to pass childproof testing, and we independently had to pass AT&T FCC wireless certification.

Your previous question is really good, I think. What’s surprising is just the pace of adopting even innovations that have overwhelming evidence that shows they work. It’s still quite slow. Everybody wanted to do…their own little studies. Here we have evidence for a device that has been shown in a clinically controlled and randomized trial to change people’s behavior by an incredible amount. And other people have already written studies. There are 30,000 studies about medication adherence and the problems and the cost of medication non-adherence. People have already documented what happens with people not taking medication: getting put right into the hospital or a rise in nursing home admissions due to non-adherence or the cost of increased ER visits for diabetics who are non-adherents.

There are already thousands of studies that have documented the financial ramifications of low adherence versus high adherence, and we show we have a product that increases adherence more than any product we know of. And we have a price-point of less than $20 per month for a Blue Cross, a Blue Shield, a Humana, or self-insured employers to distribute the product. What else should we have to do?

But instead, if you talk to United Healthcare or Humana or Kaiser, they say, “this is very interesting; we want to buy a 1000 units and do a six-month trial and see if we get the same result with our population.” How is their population any different than the population recruited by Harvard?

Your point is: here’s a well-established and identified healthcare problem and here’s a solution.
I would expect a large employer or large insurance company to start with 10,000 units or with 50,000 units, not to start with 500 or 1000 units. It’s: “Let’s start slow.” They should not do these minuscule studies that take 1000 people at a time. [Laughs]. That’s my soapbox [speech.]

Does Vitality have any new medical devices in the pipeline?
We’re working on a couple other ones that we can’t talk about. They are very simple. They are wireless. They are things that create positive feedback loops for good behavior and things that you wear all the time.

What’s the timeline for introducing them?
We’re doing in-house tests over Q4. We hope to announce something in [calendar] Q1.

In developing the GlowCap, did you consult with pharmaceutical companies?
We consulted with pharmaceutical companies and with pharmacies. One of the reasons we made a cap rather than a box is because pharmacies say boxes are illegal. They can’t put medication in a box for you. They can’t use the box even if you’re on 10 meds. It would be a [problem] if the box separates the medication from its instructions, or it may cause interactions between drugs sitting next to each other. Also, it’s not childproof.

That’s why we did an incremental innovation. We just reengineered the cap. The vial is the existing Walgreens vial.

Your business model assumes that drug companies and insurers will see the financial benefit of using GlowCaps. How would you describe the acceptance rate?
Our [business] model is that it’s just given away through the pharmacy. We have an almost 100% acceptance rate. When your pharmacist gives it to you or mails it to you, it’s “oh, look, you get one of these free GlowCap things; it’ll call you if forget to take your pills.”

Right now we’re working with Express Script, which has a national footprint. They’re the second largest pharmacy benefits manager. They mail you your script. You may be mailed a script with a GlowCap. Right now our model is for people taking specific meds who have adherence challenges. Patients can also go to Vitality.net. They can put their names and medications in [the site.] If we have a program with that medication, we’ll let them know.

What’s the level of acceptance for individual patients?
The acceptance level among individuals who are given the product is nearly 100%. The acceptance level among pharmaceutical companies is faster than it is among insurers, because insurers are even larger bureaucracies that should accept innovation faster.

Of the different pricing strategies such as loss-aversion pricing and pharmaceutical reimbursement, which one appears to work best?
I’m intrigued by the idea of giving people a discount on their co-pays, for example, if their adherence rate is high. But I don’t think that’s required in order for the product to be really successful. Value-based pricing insurance plans are very interesting to me. Certainly, it helped to have a tool like GlowCaps in order to be able to calculate [adherence rates]. If your adherence is over 80% then you get a discount on your co-pay or your health savings accounts gets more money added. You can certainly do that, although I prefer not to do an extrinsic reward if an intrinsic reward [is possible].

You’d like to believe that people would change unhealthy behavior because it’s inherently a good idea.
Ideally. There are certain persons who are susceptible to a financial reward—people who are scratch-card lottery players, for example. Those people might be open to a financial reward. I don’t think it’s needed in order to get people to change.

This question is tangentially related to healthcare, but I read in your bio description that you sing in the Tanglewood Festival Chorus. I’m a former choirboy and church cantor myself. How important is it for executives to have creative outlets?
(Chuckles.) I don’t know about others, but for me it’s inherently therapeutic. Business is so engaging that I have to concentrate on it 100%. When I’m singing I can’t stress about my business or concentrate on anything else during concerts. I’m sure for many people it might be all kinds of different hobbies.

If you’re in an intense start-up situation you’ve got to do something to get out of thinking about [business] all the time. For instance, you wake up in the middle of the night and you’re making lists. You’ve got to schedule something so that you [can relax].
 

Revisiting a Smart Device (with a little Lord of the Rings thrown in)

Fiber-Optic Link Could Be Key to Realistic Prosthetics

Two-way fiber-optic communication between prosthetic limbs and peripheral nerves could enable amputees to 'feel' such sensations as pressure and heat, according to researchers at Southern Methodist University (SMU; Dallas). This technology could allow for more-natural movement of prosthetics as well.

Funded by DARPA, engineers at the SMU Neurophotonics Research Center are developing a two-way fiber-optic interface that would facilitate the seamless delivery of signals from the brain to a robotic limb. Current prosthetics use cables that connect the device to other parts of the body to prompt operation. This method, according to the engineers, is cumbersome and does not mimic natural movements.

The SMU team, in contrast, is attempting to create a fiber-optic link that is compatible with living tissue and will connect computer technologies directly to a patient's nervous system through the use of hundreds or possibly thousands of sensors embedded in a single fiber. This approach, it says, will also be superior to metal electronic nerve interfaces that are currently under investigation because the fiber-optic technology will not be attacked or rejected by the body's immune system.

"Enhancing human performance with modern digital technologies is one of the great frontiers in engineering," says Marc Christensen, the center's director.  "Providing this kind of port to the nervous system will enable not only realistic prosthetic limbs, but also can be applied to treat spinal cord injuries and an array of neurological disorders."

As Christensen notes, the fiber-optic technology could potentially factor into the development of brain implants for tremor control, neuromodulators for pain management, and implants for patients with spinal cord injuries, along with the improvement of prosthetics.

FDA: Sleep Positioners Harmful to Babies

Federal officials say that there have been 12 known infant deaths associated with sleep positioners in the past 13 years, including two recent fatalities. In addition, the Consumer Product Safety Commission has received "dozens of reports of babies who were placed on their back or side in the positioners only to be found later in hazardous positions within or next to the product."

Using ‘White Box’ Workstations with Medical Devices Does Not Compute for This IT Company

The practice puzzles IT experts like Edwiges Demello of Momentum Microsystems, a software and hardware systems integrator based in Fremont, CA. “Manufacturers need to take the same consideration when selecting the computer system that they do for making the device,” says Demello, the chief technical officer for Momentum. “They will go to great lengths to find the perfect tube, with the perfect bend and materials, for a medical instrument. Then they put a white box there, and they don’t do the research, while companies like HP do.”

A white box is the term Demello and others use for a non-branded computer that is assembled from a motherboard and other purchased parts. The device manufacturer then either integrates the assembled computer with the actual medical instrument or connects it as a standalone component. Using white boxes can lead to both hardware and software problems, according to Demello. For example, “a lot of software had major issues when hyperthreading was introduced in a CPU. Sometimes, hyperthreading may work well on dual-core and not quad-core processors.” She adds that video images may also suffer “because the graphic cards have different amounts of memory that could impact the display of crucial medical information.”

Momentum Micro launched in 1991and signed its first device client about 10 years ago, Demello says. The company has been working with Hewlett-Packard since 2003 to supply standalone workstations for medical devices made by customers such as Heidelberg Engineering and BD Biosciences.


Stability and Control


Manufacturers have one overriding reason for using a custom-built computer, says Dan Olsen, marketing and business development manager for Hewlett-Packard’s workstation global business unit in Fort Collins, CO. “A lot of healthcare OEMs have historically ‘gone white-box’ because of the desire to keep things stable and to maintain control of their configuration.”

The need for stability is tied to FDA approval. The microelectronics industry and the device industry are world’s apart in terms of product development speed. FDA’s device approval process can take several years, while computer manufacturers and chipmakers introduce new models and faster microprocessors every year or so. “The computer is part of the instrument, and the instrument goes through the FDA process. Everything has to be closely monitored,” Demello says.

Roger Smith, a 21-year veteran of the medical device industry, says that his company had to take into account the contrasting paces of technological change and the regulatory process when designing its blood diagnostics instrument. Given the need for FDA approval, the device manufacturer noted the computer’s “very short lifetime” versus the instrument’s “fairly long lifetime,” says Smith. “We decided that our regulatory process would be easier if the computer was separate from the instrument.” The company simply “didn’t have the staff, the warehouse, the floor space. And it wasn’t our main focus to be doing computer integration,” he notes.

Smith says his company’s chief competitor “made its first desktop instrument, more or less equivalent to ours, with a built-in computer. That was really a big nightmare for them.” As a result, the competitor decided to use a separate workstation and “went the white-box route.” Smith says his company “didn’t want to go that route,” believing it was more cost efficient to find an outside computer supplier.


Real Benefit Is Service

There are advantages to both approaches, according to Smith. “The advantage of having an OEM box is that the customer doesn’t know what’s in it. And in some ways you don’t want the customer to know because it doesn’t make any difference whether it’s the latest and greatest hardware or not.” Having decided to tap an outside supplier, Smith’s device company initially used Apple Macintosh computers, which created problems when rapid technological churn clashed with the diagnostic instrument’s life cycle.

“One of the problems we had with the Mac was the customers wanted the latest and greatest,” Smith says. “It became a selling problem, because we were still selling older computers, which were perfectly fine for the application, but they wanted a newer product.”

Smith’s company had been using a Texas-based systems integrator, but the long-range nature of the business arrangement made it difficult to sustain, he says. Around 2000 the company decided to dispense with the Mac and find a local integrator, “and we came across Momentum. It turned out to be a very good fit for the company. It was local, and we could have weekly meetings with them in person.”

Smith pinpoints one key benefit that device manufacturers derive from using a systems integrator and a brand-name computer vendor. “The real issue is service,” he says.” Post-sales maintenance for white-box computers wasn’t a problem for customers in the United States, he says. “But if you’re selling a computer worldwide like our company is, then service became a real issue. If you were in, say, Czechoslovakia and the box broke, nobody could fix it. We ended up having to ship the box back, or the company had to keep spares.

“So, your service became a hassle,” Smith adds, “and ultimately it cost more in the long to use a white box because of the service hassle than it did for us to use, say, an HP computer.” In fact, he says the company “had really good luck” with the HP workstations. “They’ve been really reliable, the life cycle’s been good, and service has been good. Even in Europe out in the boonies we can get good service from HP. That saved us more money in the long run by going with the name brand.”

HP’s Olsen says the computer manufacturer is aware of the distinctive challenge posed by working with healthcare providers. “Regulatory certification, whether its FDA in the U.S. or agencies in other countries, is one of the biggest issues for the medical device manufacturer, and that flows on down to us, the workstation manufacturer,” he says.

‘Stability of Configuration’

HP addresses that challenge by offering “stability of configuration,” Olsen says. Changes to a workstation that could affect the software image “generally means a recertification with FDA. That’s a lot of pain for the medical device manufacturer. So HP has developed what we call ‘stable and consistent offerings.’ That’s an official program HP has developed.”

Olsen says the company’s Z400, Z600, and Z800 series workstations have three-year life cycles. Introduced in 2009, the line will be for sale into 2012. “But inside of that three years, for instance, Intel will have three different revisions of their processors. So to medical OEMs that now looks like three one-year life cycles, and one year is a pretty short period in their world. The stable-and-consistent program is where HP has chosen a subset of the major components in the workstation that could impact the software images—like the microprocessors—and we basically freeze those and make them available all the way to the end of the workstation’s life.”

As a result, Olsen continues, “a medical OEM can choose a configuration of one of our workstations, and it will now get that same configuration all the way till the end of life.” Manufactured for high-end third-party use, the workstations are designed for 2D and 3D medical imaging and picture archiving and communications systems (PACS) in radiological, surgical, and diagnostic applications.

Jim Niemi, partner business manager for HP, started working with Momentum in 2003, when the computer manufacturer and systems integrator began calling on specific medical device customers. Together, they developed a turnkey solution for Momentum’s first medical device client, which manufactures diagnostic machines for blood analysis. “Momentum was able to work with HP and get the right configured machine, sell and implement it, and have an order track and a turnkey solution within 24 hours,” Niemi says. “HP doesn’t have that kind of speed for a custom-configured machine. That’s why it was a good thing that we work with a company like Momentum, because they have the speed and flexibility to deliver the solution within a 12- or 24-hour time frame. They have it available in their warehouse ready to go.”

As a systems integrator, Momentum specializes in managing a product’s entire life cycle, acting as a single point-of-contact for IT assets. The company installs standard and customized operating systems, including back-up programs and server management software. The company consolidates end-of-life information in one electronic mailbox in order to enable suppliers to notify Momentum of product changes, and its sales team identifies any affected customer orders. Momentum is in the process of adding to its ISO 9001:2008 status to the ISO 13485 certification, Demello says.

“An integrator can help you keep the life cycle of the computer and keep you informed of when components are going out of life and when you might have to go into another development cycle,” Smith says. “That’s a real advantage.”

Having worked with several device companies in the last 10 years, Demello says the company has gained valuable experience that can help manufacturers lower costs and improve their ability  “to take care of the business they’re in, which is medical devices, and not the computer integration business.”

Lesson Learned from the DePuy Recall: It's All Material

Metal-on-metal implants are getting quite the bad reputation. Could a platform of easily cross-linkable diene-copolymers by DSM Biomedical offer an alternative?

Let the litigation begin: This week, plaintiff litigation law firm Burg Simpson Eldredge Hersh & Jardine filed a class-action lawsuit in Ohio against DePuy Orthopaedics (Warsaw, IN) on behalf of all U.S. citizens implanted with the ASR XL acetabular head system. The lawsuit follows last month's voluntary recall of DePuy's metal-on-metal acetabular head system attributed to a high failure rate associated with the hip implant. In the wake of the recall and as the suits likely continue to roll in, what can medical device manufacturers learn from the DePuy debacle? Materials matter!

Metal-on-metal hip implants have drawn fire for years owing to their tendency to produce metallic ion debris generated by the friction of the two metal bearing surfaces. This metal debris has been blamed for inflammation of the tissue surrounding the implant, which can result in early implant failure, discomfort, and the subsequent need for risky revision surgery.

The DePuy recall, however, appears to be the culmination of frustration and outcry against metal-on-metal implant designs, which has been especially prevalent in recent months. Back in March, for example, Medtech Pulse highlighted how the New York Times addressed the complications associated with metal-on-metal designs in an article that brought the issue to the attention of the masses. Then in May, reports circulated that all-metal hip implants might also be linked to tumor formation.

Simply put: Evidence is mounting against metal-on-metal implants. Sure, they boast mechanical strength and biocompatibility, but faith in their design is floundering. And that doesn't bode well for other manufacturers of metal-on-metal hip implants.

Luckily, there are other proven options. As noted in MPMN's April cover story, "What's Hip in Orthopedic Implant Design," ceramic-on-ceramic and even an emergence of ceramic-on-metal systems seem promising. Tried-and-true metal-on-polyethylene bearing surfaces are among the most popular combination. Plus, materials specialist DSM Biomedical, for instance, is researching how to optimize materials for these applications. The company offers a platform of easily cross-linkable diene-copolymers, and claims to be the first one to apply the technique to UHMWPE. The platform minimizes the loss of critical properties that can occur during conventional cross-linking processes and uses significantly lower doses of radiation, according to the company.

But those aren't the only options, either. Materials companies are researching new formulations and compounds that can withstand the stringent requirements of these hip systems. The time to change is now.
 

The Future of Stent Design

Biodegradable polymers represent the future of stent design, according to Yaling Han, director of the department of cardiology at Shenyang Northern Hospital (China). Han's hypothesis follows her presentation of three-year data that demonstrated satisfactory clinical and safety results for a sirolimus-eluting stent featuring biodegradable polymers.

Data from the three-year CREATE study were recently presented at the Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium. The Chinese-led study was a postmarket surveillance muticenter registry examining the outcomes of the implantation of Excel sirolimus-eluting stents in 2077 patients. The Excel S-shaped stent features a stainless-steel construction to which a sirolimus coating is bound using a biodegradable polymer.

"This study demonstrates sustained clinical safety and efficacy of biodegradable polymer-based sirolimus-eluting stents when used with six months of dual antiplatelet therapy in a 'real-world' setting," Han states. Major adverse cardiac events were 4.5% at three years, while the rate of stent thrombosis was 1.53% at three years.

As Han notes, biodegradable polymers will most certainly play an important part in future stent design. In addition to their use in facilitating controlled drug delivery, biodegradable polymers may also be the key to next-generation fully bioabsorbable stents, exemplified by Abbott Vascular's endeavor into this area. Although the viability of fully bioabsorbable stents has sparked debate, the future of biodegradable polymers in next-generation stent design, at least in some capacity, is secure.

October 2010 Contributors

  Arathi Asthi is an intern at Patni Medical Solutions. She has a master’s degree in biomedical devices. ?
Don Berndt is owner of Mapletech Productions LLC (Maple Glen, PA). He an independent consultant who has more than 25 years of experience designing embedded systems software for the medical device industry. Contact him at info@mapletechproductions.com.
  Monika Bhatt is an attorney in Hodgson Russ LLP’s Intellectual Property & Technology and Health Law Practice Groups. She has experience in national and international business law, commercial litigation, and asset protection. Contact her at mbhatt@hodgsonruss.com.
  Marcia Coulson is president of Eldon James Corp. (Loveland, CO). She introduces customers to new and innovative materials that offer safe and effective medical solutions. Contact her at m.coulson@eldonjames.com.
  Sudhi Gautam, PhD, MD, is head of medical solutions at Patni Americas (Milpitas, CA), as well as a surgeon and biomedical engineer. He has more than 15 years of experience with cardiovascular, blood processing, medical imaging,and diabetes monitoring devices. He teaches cardiovascular engineering and physiology,  at the University of California (UC), Irvine and medical device design and& development at the UC, Santa Cruz. Reach him at sudhi.gautam@patni.com.
  Yahia Gawad, MD, is CEO and director of CardioGenics Inc. (Mississauga, ON, Canada). He has nearly 20 years of experience with cardiac diagnostic test products and has taken such products from concept and bench development to commercialization. Reach him at ygawad@cardiogenics.com.
 
Bethany J. Hills is an attorney at Hodgson Russ LLP. She assists life science companies with regulatory and compliance matters and represents them in all aspects of business, from regulatory submissions to collaborative agreements for research, supply and distribution, or joint product development. She advises clinical trial sponsors, investigators, institutional review boards, and contract research organizations, and others on clinical research compliance and reimbursement. Reach her at bhills@hodgsonruss.com.
 
Ed McCauley is vice president of business intelligence and sourcing at GHX (Louisville, CO). He holds sales, product management, technology, and operations responsibilities for GHX market intelligence and channel intelligence. He oversees these divisions’ efforts to provide visibility into the medical and surgical marketplaces to help manufacturers turn market opportunity into market share. Reach him at emccauley@ghx.com.
  William Spees is a forensic software engineer at CDRH. He is a longtime educator and a career software developer in medical devices, control systems, and robotics. He holds a doctorate in computer science. Contact him at william.spees@fda.hhs.gov.