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Articles from 2010 In November


LDRA speeds medical device design with IEC 62304 compliance

Medical devices have become increasingly sophisticated, employing software-controlled applications whose failure to function correctly could result in death or serious injury. Despite this increased complexity, medical software standards have continued to reflect only the rigor of software quality typical of applications with low levels of risk. IEC 62304 introduces a risk-based compliance structure—Class A through C where the failure of Class C software could result in death or serious injury—that ensures that medical applications must comply with the standards suitable for their risk assessment.

The safety classification of IEC 62304 has a tremendous impact on the code development process with requirements outlined from a software development plan and requirements through verification, integration and system test. While in practice all companies developing medical device software will carry out some level of due diligence on all software classes, the higher risk Class B and C code requires more formal detailed documentation along with cross-referencing and verification of requirements. By integrating compliance to IEC 62304 into its entire tool chain, LDRA ensures that medical device developers can automatically trace requirements from design through system test and verification, saving a great deal of time and money in software development.

Highlights of RSNA

For its radiological devices that work with X-rays or radioactive tracers, Siemens has developed a range of technologies – Combined Applications to Reduce Exposure (CARE) – that enable the dose to be reduced without compromising the image quality. These technologies include IRIS (Iterative Reconstruction in Image Space), a  method for the reconstruction of CT images, High Definition PET (HD-PET), a high-resolution positron emission tomography technology for molecular imaging, and a comprehensive package of dose-reduction features for interventional imaging, which are now available free of charge for customers.

GE Healthcare's approach is adaptive statistical iterative reconstruction (ASiR). ASiR is a low dose reconstruction technology that the company claims can reduce dose by up to 40–50% while maintaining image quality. The technology can be used on both helical and axial scans asnd is available as an upgrade to many CT scanners.

Other technology advances at the show are a bit more fun. For example, Matthew R. Amans, MD, of Weill Cornell Medical College presented his study on using a Wii video game remote (Wiimote, Nintendo) to access and view radiology images could be a viable alternative to the mouse and keyboard and may help alleviate the repetitive stress injuries radiologists so often report.

Object Research Systems (ORS; Montreal, Canada) also showcased its advanced visualization software ORS Visual, which provides a glasses-free 3-D experience. 

Staying Cool, Calm, and Collected While Milling Challenging Metals

Emuge's TiNox-Cut end mills machine the heat-resistant metals commonly used in such applications as orthopedic devices.

Stainless steels such as Super Duplex, nickel alloys such as Inconel and Stellite, and all grades of titanium can be difficult to machine because they offer high heat resistance. When faced with these materials, standard end mills often don't make the cut. But help is on the way from Emuge Corp., whose TiNox-Cut end mills are designed to machine the heat-resistant metals commonly used in such applications as orthopedic devices.

"The design of our new end mills follows a three-pronged approach," states Stephen Jean, Emuge's milling product manager. "They are specially ground to handle challenging metals, they are made from a tough grade of carbide to maximize wear resistance, and they feature a coating that resists high heat levels." Consisting of titanium and aluminum nitride, this lubricious coating is deposited in many nanothin layers. It has an overall thickness of 3 µm, can withstand temperatures of more than 1800°F, and resists the friction-generated heat caused during the milling process, according to Jean.

"Milling and machining are essentially destructive processes," he comments. "On a microscale, they're destructive to the cutting tool as well as the workpiece." All of the elements of Emuge's TiNox-Cut end mills, including their carbide material and their coating, help minimize tool wear. This, in turn, enables the tool to maximize material removal, Jean notes.

Ranging in diameter from 6 to 20 mm, the mills have an optimized cutting-edge design and reduced neck diameters, enabling them to achieve maximum effective cutting lengths. They also combine tight ISO H5 shank tolerance with a roughened surface finish to increase tool holder clamping potential.

"The mills are suitable for roughing and finishing operations," according to Jean, "and they come in three designs: two four-flute roughing and finishing models and an extralong five-flute finishing model." Available with flat ends or with a selection of corner radii, the roughing and finishing mills have internal coolant and lubricant capability and also feature a serrated profile for chip breaking during roughing operations. Offering added stability and minimal deflection in long-reach applications, the five-flute finishing end mills are also available with various corner radii and feature length-to-cutting diameter ratios of 3 × diameter and
4 × diameter.

"Our end mills feature favorable geometries and novel cutting dynamics, enabling them to convert challenging materials and form rake angles," Jean says. "But what really makes them cutting edge are their advanced construction materials and heat-resistant dual coating, which prevent them from cracking under stress."

Emuge Corp.
West Boylston, MA
www.emuge.com

Ceramics Process Enables Complex Shapes, Controlled Porosity in Implants

The Fast Ceramic Production (FCP) process yields complex geometries for orthopedic implants that are not achievable by other ceramics manufacturing methods.

During the past 25 years, medical-grade ceramics have enabled tremendous progress in the design and development of medical implants. But limitations in current ceramics manufacturing processes may have hampered the development of difficult-to-manufacture shapes and innovative parts. With its fast ceramic production (FCP) process, however, 3DCeram is looking to eliminate these restrictions by producing complex geometries that it claims are not achievable by other ceramic fabrication methods.

Drawing from additive manufacturing methods, FCP employs laser stereolithography (SLA) technology for the rapid manufacture and medium-volume production of ceramic parts from 3-D CAD files. "However, the difference between plastics prototyping and this technology is that we achieve what we call 'good material,' which means it has the required final ceramics material properties that are equal to those produced using ceramic injection molding or other traditional ceramics processes," explains Richard Gaignon, cochairman of 3DCeram.

Using laser SLA, the process entails building a component in successive layers by polymerizing a paste composed of photosensitive resins and a high load of ceramic powders such as hydroxyapatite, zirconia, or alumina. The part is then cleansed of excess resin, placed in a UV chamber for postcuring, and sintered to obtain the desired density, hardness, and other properties.

"With FCP, you are building the product layer by layer, which means you can produce designs that are impossible to produce by any other method, even by spending a lot of money," states JB Lafon, president of Euro Industries Inc., the U.S. sales representative of 3DCeram. "These are shapes that you just cannot produce with ceramic injection molding or machining." Furthermore, the process does not require the production of any tooling and can reduce manufacturing times--and thus overall costs--as well, Gaignon adds.

In addition to achieving complex geometries, FCP promotes osseointegration in ceramic implants by enabling controlled porosity. This capability yields more-wear-resistant ceramic components and, thus, less hazardous debris, according to Gaignon. "There are other processes where you can produce porous parts to promote bone growth with ceramics; but you can hardly control some key parameters," Lafon says. "With the FCP process, you can actually control the size of the holes, their location, how they are connected, and so on. That makes the product a lot stronger, less brittle, and more desirable from a purely medical standpoint in terms of bone-growth promotion."

Seeking to support implant markets in which there is an unmet need for complex ceramic parts, 3DCeram is targeting such applications as tibial osteotomy wedges, intervertebral cages, and cranial, jaw, and eye implants.

"From a cost standpoint, if you can make a simple ceramic shape from extrusion, for example, keep extruding," Lafon says. "But if you want something with controlled porosity or sophisticated shapes, volume production, and speed, you just can't do it any other way."

3DCeram
Colorado Springs, CO
www.3dceram.com
 

Roundtable: Evolution, Not Revolution, Drives Biomaterials Development

Marcus Jarman-Smith, technology leader at Invibio
Andrew Nield, director of sales and marketing at C5 Medical Werks
Robert Raess, medical market manager and Midwest regional manager at Titanium Industries Inc.

Recently, MPMN assembled a panel of biomaterials experts to discuss the exciting developments in the field over the past 25 years and to predict what lies ahead. Moderated by MPMN editor-in-chief Shana Leonard, the roundtable included panelists Marcus Jarman-Smith, technology leader at Invibio (West Conshohocken, PA); Andrew Nield, director of sales and marketing at C5 Medical Werks (Denver, CO); and Robert Raess, medical market manager and Midwest regional manager at Titanium Industries Inc. (Rockaway, NJ). They specialize in biocompatible polymers, ceramics, and metal alloys, respectively.

MPMN: In honor of MPMN's 25th anniversary, what do you cite as the most significant breakthrough in biomaterials for medical device applications in the past 25 years?

Jarman-Smith: What constitutes something significant? You can consider things like the size of the patient population, or how widespread the benefits of something would be, or what clinical advancement the material development would bring and, ultimately, what the impact is for the patient. Two things come to my mind immediately: The Medtronic Infuse bone graft being used in combination with things like PEEK-Optima polymer cages has had a significant impact. There are now more than 2.5 million devices with PEEK Optima in them, so it's pretty significant. Another example would be the arrival of drug-eluting stents over the past 25 years. Metal stents in combination with drug-eluting polymers have really been a massive breakthrough.

Nield: The most important breakthrough that I've seen in the last 25 years is ceramic being used in hip joints. If you go back 20 years, you'd typically see a patient getting a hip joint replaced when they were maybe 65 or older and being happy to just walk again. But what we're seeing now is ceramic being used in maybe a 31-year-old cyclist that wants to be able to do the Tour de France again. The shift is in these lifestyle changes--people wanting to lead an active life again after they've had the surgery. They want to be able to do an Ironman, cycling, skiing. If you just look at the success rate of ceramics in hip joints, there is a less than 0.1% revision rate for fracture on these surgeries.

Raess: For me, it's what has happened since Type 316 stainless steel was developed to be implantable in the body and how it has progressed through all of the other materials mentioned.  I've seen the natural progression of metals and polymers and ceramics over the years, but I guess it all comes down to biocompatibility. Is the material compatible with the body? Is it corrosion resistant? What kind of strength does it have? What kind of modulus of elasticity does it have? In certain applications, a basic Type 316 implantable-grade stainless steel might be the right choice. In other cases, titanium might be the right material where it gives you the right strength-to-weight ratio. In certain applications, PEEK and ceramics might be the right fit. It's just an ongoing natural progression of medical technological advances and materials science developments.

MPMN: A number of medical device designs have replaced metal with other materials, including polymers such as PEEK, for example. Do you think medical device design engineers will continue to find alternatives to metal, or do you think that metal alloys will always have a prominent place in medical device design?

Raess: I think there will always be a place for metal, especially titanium. Its physical properties, as well as its density, strength, and serviceability characteristics, are so closely matched with that of bone. There will always be a place for the mainstays, but there will be unique and new applications. There's still a growing population, and there will always be new procedures, but I think there's a market for everything.

Jarman-Smith: I would echo all of Bob's points. Metals make a phenomenal contribution to medical devices and they're always going to have a place. In trauma, metal has been in use for over a century and continues to be excellent in patient care. As we look at more-specific patient populations and their particular needs, it may be that new materials bring with them new benefits that outweigh those of metals or indeed other existing material solutions. From experience, we've seen instances in younger patients where minimal stress shielding at the bone is desirable. This could benefit from a material that can connect to a structural bearing material but can still also transfer the stresses through to the acetabulum. I suppose it's bringing something new that isn't present at the current time for a particular niche application. Sometimes, it might not just be about the mechanicals, but other benefits as well. Polymers can bring their own benefits, ceramics others, and metals others. Really, we have to just consider the best solution for a patient and offer more high-quality choices to the engineers to hopefully encourage them to innovate either with a different material that allows them more freedom or with combinations of materials. I think we're going to see more combinations of materials coming in the future as well.

Nield: And I would echo that last point: The most important thing I see is integrating different materials together. There is no device that only uses a ceramic; it is integrated with polymer or a metal. That becomes much more important as you start to get smaller and smarter devices and you want to increase their reliability. You need to get more out of a material and get synergistic materials by putting two materials together.

MPMN: Materials have been at the center of an escalating controversy in terms of growing concern over metal-on-metal bearing materials for hip implants. As a medical materials supplier, what is your take on this hot-button issue?

Ceramic hip joints have a less than 0.1% revision rate for fracture, according to C5 Medical Werks.

Nield: I can really only look at it from the ceramic perspective, but we're still learning a lot there. The benefits of ceramic in that application are low wear compared to a polymer or metal alloy and you also get smaller particles. Ceramic materials that are used in orthopedic implants are bioinert, so the body doesn't react to the particles. We've seen applications for ceramic where it can be used in a total disc replacement in the spine and as a bearing surface in the hip joint and the knee joint. It's a really good material that lasts longer and causes less or no harm to the patient than perhaps other materials.

Jarman-Smith: It's important to get perspective on any of these headline-grabbing stories. Metal-on-metal implants have been in use since the 1950s and continue to work well in certain applications. We're still learning about the impact of the correct positioning and how metal-on-metal constructions work in certain applications and patient types. It's probably clear that we need to be more selective in its use, but I don't think the entire story is in yet. From the polymer side, Invibio has helped to provide alternative options for certain applications. We try to evidence this through screening, simulating studies, wear-particle-debris analysis, that kind of thing. Consequently, we're seeing certain hip, knee, and spine applications come through using PEEK Optima materials. But I guess it's horses for courses and understanding where the best fit is for the purpose. We're seeing FDA asking more and new questions and requiring new data on wear particulates, and we're even seeing that in nonarticulating applications. The only thing to do is keep providing the research and clinical data. Invibio is lucky in that we have an extensive Master File and a decade of clinical data, but there are still so many unknowns. So, we keep doing development work and hopefully choose the right materials for the right applications.

Raess: The other factor you must keep in mind is the design of the implant. There have also been issues with squeaky hips, for example, and sometimes it's material selection, sometimes it's design, and sometimes it's installation techniques. All materials have limitations, and if you take them past what they can perform or do, problems can't be prevented by the materials themselves. Design and installation are major factors.

MPMN: There's also a lot of buzz around bioabsorbable materials and their future in a variety of implantable devices, including stents. Do you think that bioabsorbable materials can live up to the hype in implantable devices, and what does this mean for more-traditional materials?

There are now more than 2.5 million devices that incorporate PEEK Optima, according to Invibio.

Jarman-Smith: It's about need, really. The current PLLA resorbables are good in certain areas--sports medicine, suture anchors, and those sorts of things--but they lack high strength for more-demanding applications. There are concerns about the resorption profile, the consistency, and the degradation of the materials. Creating resorbables that can serve some of the more-critical application areas is quite a steep technical climb. Probably lesser known, Invibio is currently looking beyond PEEK Optima polymers and has been conducting R&D into a high-strength resorbable with a surface-degradation profile that strives to address the gap in needing something with high strength and surface degradation. We've recently published two studies at the European Society of Biomaterials. But again, I would say it's about selecting the right materials for the device. Rather than viewing it as a question of displacement, resorbables are widening the choice in the medical device designer's toolkit, but I don't think they're going to be the answer to everything. They've been around for some time now, but the technology is limited with the existing materials that are out there.

MPMN: I'm noticing a theme in all of your diplomatic answers that there's a place for everything. As emerging, optimized, and composite materials enter the market, are you seeing opportunities dwindle or are you creating new opportunities?

Nield: I think it comes back to that integration. When something like bioresorbable materials comes into the picture, it's figuring out how to use that along with the device we have now to make a better device that capitalizes on the synergistic benefits of both materials.

Jarman-Smith: I totally agree. As we're getting into new sectors and application areas, it's definitely about being complementary. Whether a new material's benefit is manufacturability or a difference in cost or bigger head sizes or thinner parts or bone conservation, the end device still needs those other biomaterials as components in the bigger picture. Things are becoming more complementary as you step into new application areas.

MPMN: It seems like every day there's an announcement from university research labs and companies about a superlative new material that could revolutionize the medical device industry. What do you think will be the 'next big thing' in terms of materials for medical applications?

Raess: I think stem cells will be the biggest breakthrough if they can ever figure them out.

Jarman-Smith: When medical device development news hits the headlines, you always hope the product will be out a few months later, but it never works out that way. I come from a tissue-engineering background originally, and we're still looking at tissue engineering 25 years after it was touted as the next big thing. I suppose stem cells are the next significant area, and these sorts of innovations will require, in some cases, biomaterial delivery vehicles to localize them. One of the great things about polymers is that you can combine them with compounds or coatings, so there are opportunities there. Another key clinical problem to address would be infection, and in our sector, we've seen silver-based technologies picking up momentum and being incorporated into PEEK and metal biomaterials. But we should look at things that are evolutionary rather than revolutionary--improvements that are more incremental and shorter term. The gulf I noticed when I stepped into this marketplace was the gulf between blue-sky developments and the actual reality of there being a metal or ceramic or polymer part in your body. There's going to be buzz about these longer-term blue sky things, but I think there's a technical challenge to just doing the incremental improvements.

Nield: I agree that evolution is the way to go in the medical market. If I go to one of our customers and say that we've got something groundbreaking, I hear a few murmurs of interest and a promise that they might take a look at it. But if I say we have something that is an incremental improvement that will improve the reliability, improve the life, reduce the cost, or reduce time to market on an existing device, then there's a lot of excitement around that. About 10 or 20 years ago, for example, ceramic started to be used in medical devices, and what you started to see was a migration and evolution in using specific materials for specific applications. Certain ceramics were developed for hips and knees, others for spinal, and others for pacemakers or dental applications, and you start to see evolutions.

Jarman-Smith: Referring back to what we just talked about with evolution rather than revolution, I would say a lot of that approach is made even more real by the regulatory environment that has changed over the past year and the diligence and scrutiny that has come in from the FDA. I think certainly in terms of the risk, the room to bring revolutionary products to market is limited, or the number of people willing to tackle that hurdle is reduced. So, it's about incremental stuff, making sure the product is safe, proven, evident, and secure.

Select the most effective wavelength for an LED system

  1. Lower running costs: a properly designed UV LED curing system can provide over 20,000 hours of lamp life as compared to about 3000 hours for lamp systems, significantly reducing running costs of a process.
  2. Low heat curing: the narrow bandwidth of LED light sources reduces the amount of heat generated in the curing process, making them ideal when assembling heat sensitive components.


Other benefits of LED which may also be a consideration include: they are environmentally friendly as the UV LED systems use about 80% less power versus a comparable lamp system and contain no mercury; the instant on/off nature of LEDs eliminates the need for a shutter; and, the electrical connection to the UV LED heads makes it easier to place the controller remote as compared with using a light guide to a lamp system.



1. UV LED systems offer multiple wavelengths: 365, 385, and 400 nm.

As with any technology, there are limitations to using a UV LED system, such as smaller spot sizes, lower optical power, and limited depth of cure. Also, due to narrowband spectral distribution and narrow beam pattern of LEDs with lenses, it’s more difficult to get an accurate measurement from a radiometer. Testing remains the best method for determining if LED technology is well suited for your application.

There are many variables to consider when developing a UV curing process, such as the adhesive, substrates, curing conditions, and environmental conditions, all of which will affect the cured product’s physical properties. The variables which are controlled by the UV spot curing system are:

  1. Time
  2. Irradiance
  3. Spectrum
  4. Heat


In most good quality UV spot curing systems, the first three factors can be directly controlled. Heat is a byproduct of the curing process resulting from the combination of the first three factors along with the substrates being joined. Although it’s not directly controlled, managing heat during the curing process can be an important consideration when dealing with plastics or other components which are sensitive to heat.

With a maximum irradiance reaching up to 9.5 W/cm2, UV LED systems can likely offer a sufficient irradiance level, in small spot sizes, for most curing processes. However, there’s often a significant difference in the peak irradiance available from the LED system, depending on the wavelength being offered. In general, 365-nm LED systems offer the lowest peak irradiance, with available peak irradiance increasing as the wavelength increases. In some cases, a 385- or 400-nm LED system can have significantly higher irradiance as compared to 365 nm. Therefore, the question will often arise as to which is more important in an LED system, wavelength or peak irradiance.

A light-cured adhesive must receive a sufficient exposure of the correct spectrum of light to be fully cured. Because of the narrow spectral bandwidth of LED output (10 nm), it’s critical that the UV LED system’s wavelength matches the absorption spectra of the adhesive’s photoinitiator. If the spectral output of the UV LED system doesn’t match the spectral absorption of the photoinitiator, then regardless of the irradiance level or exposure time, the adhesive won’t cure. However, increased peak irradiance can be of benefit in decreasing curing times or improving depth of cure for some applications.

The adhesive spec sheet specifies a spectrum of light required for curing, based on the photoinitiators contained in the adhesive. Many of the current light-curable adhesives specify 365 nm energy as a requirement for curing. This is designed to match the 365-nm peak output of mercury lamps which have been the standard for UV curing.

However, the limited information provided on some adhesive spec sheets may not always tell the whole story. It’s the range of spectral absorption of the photoinitiator which will determine the wavelengths suitable for curing. This range will vary between adhesives, but is always more than a single wavelength. If there’s only a single wavelength specified, such as 365 nm, then this may unnecessarily limit the wavelengths available for curing the adhesive.

Results of our testing on a select number of adhesives where 365 nm was specified as the required wavelength showed that our 365-nm source, at the irradiance level tested, works well with all the tested materials. Our 400-nm source also worked well on many of the materials. However, it failed to provide adequate curing on several occasions. Although the irradiance of the 400-nm source is higher than the 365-nm source, for a number of materials, the wavelengths were not a good match which resulted in inferior curing ability. While the lower irradiance of the 365-nm LED source may affect the efficiency of the curing, it was able to cure all of the adhesives by extending the exposure time where required.

This initial testing confirms that 365-nm LEDs are suitable for curing many adhesives where 365 nm is the specified wavelength. However, there are other considerations to the curing application which could affect the wavelength selection. This includes cure time; depth of cure verses surface cure; and transmission through parts.

Cure time
A light cured adhesive requires a sufficient exposure before it’s fully cured. An exposure is made up of the irradiance multiplied by the cure time. Therefore the higher irradiance of a 400-nm LED may allow for a decrease in the cure time. The time required for the UV adhesive to cure can be directly controlled by the irradiance level of the light source as given by:



The Rp (polymerization rate or curing speed) is proportional to (I0)0.5 where I0 is the UV irradiance being absorbed by photoinitiators in the adhesive formulation. As long as the UV source’s wavelength matches the absorption spectra of the photoinitiator, then increasing the peak irradiance will have an effect of accelerating the polymerization rate. By accelerating the polymerization rate, it’s possible to reduce the curing time, resulting in increased throughput for the process. However, if the UV source’s wavelength doesn’t match well to the photoinitiator absorption peak, large portions of the UV are wasted and sometimes could be harmful.



2. Penetration into the adhesive depends on the optical density of the material and is also controlled by the peak irradiance and wavelength of the UV source. Longer wavelengths (400 nm) will provide better penetration than shorter wavelengths (365 nm). Higher irradiance will provide better penetration through the material.

Depth of cure vs. surface cure
For transparent UV-curable adhesive formulations, the penetration of the UV from all LED systems (365 nm and up) was found to be sufficient to cure the adhesive to a reasonable thickness. Applications using adhesives, which include some tint or filler or where depth of cure is important, would benefit from the higher irradiance and longer wavelengths of a 400-nm UV LED, if the adhesive is compatible. Conversely, in applications where the adhesive is open to the atmosphere, testing showed that in general, the lower irradiance, shorter wavelength 365-nm LED provided a better surface cure of the material as compared to the higher irradiance 400-nm LED.

Transmission through parts
A light-cured adhesive must receive a sufficient exposure to be fully cured. For many applications where two parts are being joined together, this means that the light must travel through one of the parts being joined to reach the adhesive surface. In these cases, the transmission or absorption spectrum of the parts through which the light must pass is a key consideration when selecting the wavelength of LED for curing.

In one of our test examples, the adhesive datasheet specified a 365-nm light source for curing. Testing showed that both systems were able to cure the adhesive, but the 400-nm example was able to cure much faster and with lower heating of the parts. In this case, following information from the spec sheet alone would not have shown the most effective wavelength for assembly of the parts.



3. Testing of the plastic parts being joined showed that they had significantly higher absorption at 365 nm as compared to 400 nm. As a result, about 60% more of the light energy at 400 nm would make it to the adhesive as compared to the 365nm light.

We’ve focused on the importance of matching the narrow band wavelength of the LED with the absorption spectra of the adhesive’s photoinitiators. This is a minimum requirement for curing the adhesive. However, it should be noted that many of the currently available light-curable adhesives have been designed to work with broadband light sources and as such may include multiple photoinitiators with different spectral absorption ranges. It’s also important to remember that light outside of the spectrum required by the photoinitiators will also have an effect on other components of the adhesive as well as the substrate. It’s the combined effect of the full light spectrum on all components of the adhesive, as well as the substrate, which results in final physical properties of the cured adhesive.

In some cases, it may be found that using a narrow band light source such as an LED on an adhesive that’s designed to work with a broad band light source may not provide the optimal physical properties in the cured materials. Unfortunately, a number of adhesives have not been able to match the physical properties of curing with a broadband curing system such as when a UV LED system is used. It may be found through testing that using multiple wavelengths of LEDs has some benefit to the adhesive’s final cured properties. However, it may be determined that a UV LED light source isn’t appropriate for the adhesive being tested.

Mike Kay, a senior marketing analyst, has been with Lumen Dynamics Group for 10 years. He has extensive experience developing UV curing solutions for medical, electronics, and optoelectronics manufacturing. He holds a Bachelor of Science degree from McMaster University in Hamilton, Ontario.

Genesis Plastics Welding, PolyOne Develop RF Welding Breakthrough for TPEs

A new RF welding technology enables nonhalogenated and nonplasticized TPEs to be RF welded into any 2-D shape or configuration.

Facing environmental and health concerns with the use of traditional materials, manufacturers of medical fluid-delivery products are looking for alternatives that avoid the use of halogens and plasticizers. Claiming that it now offers a breakthrough technology, Genesis Plastics Welding (Indianapolis) has developed an RF welding method in conjunction with PolyOne GLS Thermoplastic Elastomers (Cleveland) that enables nonhalogenated and nonplasticized GLS Versaflex thermoplastic elastomers (TPEs) to be RF welded into any 2-D shape or configuration, including mandrels.

Collaboration between the companies expands the portfolio of Versaflex grades that can be welded using the ecoGenesis technology, improving the flexibility, mechanical properties, clarity, and aesthetics of fluid-delivery products, according to the companies. Previous RF welding techniques were restricted to handling high-dielectric-loss materials. TPEs could only be heat sealed, limiting configurations to straight lines. In contrast, the ecoGenesis technology enables nonphthalate, low-dielectric-loss materials to be RF welded. Applications include infusion kits, blood transfer and drainage bags, and urinary bags.

Screening Carbon Nanotubes for Nanocircuit Applications

Metallic and semiconducting single-wall carbon nanotubes are distinguished using a new imaging tool for rapidly screening the structures.

Semiconducting nanostructures might be used to revolutionize electronics by replacing conventional silicon components and circuits. However, an obstacle to implementing the use of semiconducting single-wall carbon nanotubes is that metallic versions form unavoidably during the manufacturing process, contaminating the semiconducting nanotubes. But now, researchers have demonstrated a new imaging tool for rapidly screening these nanotubes that could hasten their use in electronic applications.

Developed by Ji-Xin Cheng, an associate professor of biomedical engineering and chemistry at Purdue University (West Lafayette, IN), the imaging technology uses a pulsing laser to deposit energy into the nanotubes, changing the nanotubes from a ground state to an excited state. Another laser, called a probe, senses the excited nanotubes and reveals the contrast between metallic and semiconductor tubes. Known as transient absorption, the technique measures the "metallicity" of the tubes. The detection method might be combined with another laser to zap the unwanted metallic nanotubes during manufacturing, leaving only the semiconducting tubes.

Working with nanomaterials for biomedical studies, researchers in Cheng's group were puzzled when they noticed that metallic nanoparticles and semiconducting nanowires transmitted and absorbed light differently after being exposed to the pulsing laser. Then researcher Chen Yang, a Purdue assistant professor of physical chemistry, suggested that this phenomenon could possibly be used to screen the nanotubes for nanoelectronic applications.

Measuring about 1 nm in diameter, roughly the length of 10 hydrogen atoms strung together, the nanotubes are far too small to be seen using a conventional light microscope. "They can be seen with an atomic force microscope, but this only tells you the morphology and surface features, not the metallic state of the nanotube," Cheng explains.The transient absorption imaging technique represents the only rapid method for telling the difference between the two types of nanotubes. A "label free" technique, the imaging method does not require that the nanotubes be marked with dyes, making it potentially practical for manufacturing applications, Cheng adds.

Medical Device Numbers 101

  • $94.9 billion: Estimated value of U.S. medical device market in 20101
  • 17.7%: Healthcare's percentage of GDP2
  • The United States’ health expenditure is projected to reach $2.6 trillion for 2010, which is about 17.7% of the GDP.2
     

1. Espicom Business Intelligence; 2. CMS Office of the Actuary

Regulatory

It’s been a tough year (or two) for FDA, especially where the 510(k) process is concerned. And industry didn’t make it easier, submitting more 510(k)s than it has in at least five years.
 

  • 1300: Approximate number of current part- and full-time CDRH employees
  • 100: Approximate number of times FDA has ever rescinded a 510(k) clearance
  • 1: Approximate number of 510(k) rescissions in which FDA admitted making an error

FY 2009 Submissions to FDA3

  • 510(k)s: 4153
  • PMAs*: 512

** includes original PMAs, panel-track PMA supplements, premarket reports, expedited original PMAs and panel-track PMA supplements, 180-day PMA supplements, and real-time PMA supplements

3. FY 2009 Performance Report to Congress

Imaging

Imaging was one of the dominant medtech headlines for 2010, whether for controversial mammography guidelines (click here for a bonus section on mammographies) or excess radiation doses. Here are some of the numbers behind the fuss.

Annual Spending on CT Imaging4

2000: $975 million
2007: $2.17 billion

Roughly 80% of the ionizing radiation most people get in their lives comes from radon gas, cosmic rays, and other natural sources—even bananas.5

4. Government Accountability Office; 5. Los Angeles Times
 

Battelle Moves Needle on Innovation

Battelle is leading a team called the Battelle Woman and Children's Healthcare Partnership, which is comprised of 11 organizations, including members from Ohio State University, the University of Arizona, Duke University, and Nationwide Children's Hospital.

“We can move the needle on AHRQ’s understanding of innovative healthcare delivery,” according to Tim Pivetz, a program manager for Battelle’s Health and Life Sciences Global Business. “We’re able to deliver scientifically defensible results that are vital for the acceptance of innovation, which is of critical importance at this juncture of the development of America’s healthcare system. Because of our group’s breadth, we’ll be able to engage the diverse clinic population and access the supporting databases that are required to effectively bring innovations to scale.”

The key to this initiative is that they're talking about bringing evidence-based improvements into routine healthcare practices, and the Battelle group provides healthcare access to more than 3 million patients--including more than 1.7 million children. The group also reaches rural, low-income, and minority patients. According to Battelle, the ACTION I I program could be funded for up to five years with as much as $100 million. The funding is being provided by the HHS Agency for Healthcare Research and Quality (AHRQ).

-Maria Fontanazza