Implantable-Grade Fiber Comes in Colors Everywhere

DSM Dyneema's medical-grade UHMWPE fiber can be used to manufacture colored surgical sutures.

Until now, doctors have been hamstrung by the lack of contrast between different sutures used to repair damaged joints during arthroscopic surgery. But help is on the way. DSM Dyneema has developed a 100% UHMWPE fiber available in different colors that can be used to develop high-strength sutures. The advantage of this fiber is that it enables doctors to differentiate among multiple sutures on multiple anchors--the screws placed in the bone during surgery to position the implant.

Prior to the availability of this colored fiber, UHMWPE fiber was offered in white only--the highest-purity grade of the material. To differentiate among sutures, surgeons had to mix the standard white suture material with strands of colored fibers that were not made from 100% UHMWPE. Only within the last year did the FDA approve a pigment that can be added to UHMWPE before extrusion.

"Dyneema Purity Blue does not use colored polyester or nylon strands in its construction, which means it can offer surgeons color variety with the characteristics of UHMPWE," remarks Felice Szeto-Wong, value-chain marketing manager, medical, at DSM Dyneema. "Several different patterns of braid can be developed, offering surgeons bright contrast among the different sutures, including various white-blue combinations and solid blue."

Offering a low profile, softness, and abrasion resistance, Dyneema Purity Blue is 15 times stronger than quality steel, Szeto-Wong says. In addition, the fiber's elongation and fatigue resistance offer surgeons and medical device manufacturers an alternative to traditional materials such as polyester. Exhibiting good local tolerance according to ISO 10993-06 standards, the fiber has lower irritation and inflammatory levels than other implantable materials and has the same biocompatibility as the company's Dyneema Purity, according to Szeto-Wong.

"We are offering the blue UHMWPE material to give surgeons better contrast during the procedure itself," Szeto-Wong comments. "Using this material, surgeons gain more confidence and experience less confusion when tying sutures to their respective anchors." By achieving better visibility, surgeons can accelerate procedure times, reduce the room for error, and increase OR turnaround times. A by-product of using this material is that patients benefit as well, Szeto-Wong states. "Ultimately, by improving visibility during surgery, surgeons perform better operations and also reduce surgical costs,"
she adds.

DSM Dyneema
Stanley, NC
www.medical.dyneema.com

CNT Dispersion Technique Enhances Base Polymer Properties

CNT-enhanced stock shapes demonstrate enhanced performance.

Trumpeted as a significant enabling material for next-generation medical devices, carbon nanotubes (CNTs) are actually already influencing the market. Although several companies have ventured into the area of CNT-enhanced materials, compounder Entegris Inc. claims that its proprietary technique ensures uniform dispersion of CNTs in the base polymer for enhanced performance. Now, a partnership between the company and converter Quantum Polymers has also resulted in the expanded availability of these CNT-enhanced polymers in easily processed stock shapes for use in medical equipment applications.

At the core of Quantano extruded products are Entegris's CNT-enhanced Tego polymers. "These materials have this high aspect ratio where they're very long but they're also very flexible," explains Shawn Cheesman, Entegris general manager, Tego polymers. "What makes our materials different from others is getting the dispersion of this product into the polymer. Think of something that is 15,000 times smaller than the diameter of a human hair and you're trying to get that product dispersed well into the polymer; it's not easy."

Dispersion difficulty often stems from the tendency of CNTs to create bundles or agglomerates. Compared with other compounders, however, Entegris believes that its dispersion process is more effective at breaking down agglomerates into smaller pieces and then distributing them evenly throughout the polymer. This approach, Cheesman notes, helps to optimize the desirable properties of the base material.

CNTs can enhance these inherent properties of the polymer without compromising performance. "In some applications, an additive can actually make the base polymer weaker, for example," Cheesman says. "[Or] a base polymer such as PEEK is well known for its lubricious nature. The nanotubes, because of the [uniform] dispersion, help to maintain some of that lubricious nature of the base polymer, whereas if you put in a carbon fiber or carbon powder, you lose some of that lubricious nature."

Supported by uniform CNT dispersion, the enhanced materials can offer improved mechanical strength, dimensional stability, and homogeneous conductivity for good electrostatic discharge performance. "Carbon nanotubes by themselves conduct electricity better than copper and conduct heat better than diamond," Cheesman states. "They're good thermal conductors to dissipate heat from the polymer, unlike many other additives."

The enhanced CNT-filled polycarbonate, polyetherimide, and PEEK materials are also inherently clean polymers, according to Hemant Bheda, president and CEO of Quantum Polymers. He notes that the lack of debris or particulation establishes the materials as suitable for a variety of parts for medical equipment applications. Supplied by Quantum in extruded rod and plate forms, the easily processed Quantano materials can also replace metal components in some applications.

Entegris Inc.
Billerica, MA
www.tegopolymers.com

Quantum Polymers
Newark, DE
www.quantum-polymers.com

 

Design Improvements in Laparoscopic System Optimize Unit for OR Use

The AirSeal DPS 1000 benefited from KMC Systems' engineering input to reduce the unit's size.

Recognizing the industry's desire for advanced laparoscopic tools, SurgiQuest Inc. (Orange, CT) developed the AirSeal DPS 1000 bladeless optical trocar and cannula system. The patented system employs a single trocar incision in contrast to the three or four trocars used in traditional laparoscopic surgery. It also provides unobstructed access to the abdominal cavity without losing intra-abdominal pressure, thereby enabling surgeons to place a scope and multiple laparoscopic devices through a single port.

As a result of these features, the device allows for better visibility, greater control, and easier access to the abdominal cavity, according to SurgiQuest. In turn, the product facilitates a speedy recovery, coupled with the promise of less pain and better cosmesis resulting from the use of a single incision.  

Creating such a complex minimally invasive system required maximum effort, however. SurgiQuest developed the product to the breadboard stage before seeking out a contract manufacturer. Together, KMC Systems (Merrimack, NH), a provider of engineering and manufacturing services, and SurgiQuest were able to come up with creative solutions to challenges that arose during development of the DPS 1000 system--specifically a needed reduction in the unit's noise and size.

Low noise was crucial to the success of the product, which is designed for use in the operating room (OR) environment. "The noise specifications for the DPS 1000 system were particularly challenging," recalls Dan Donovan, SurgiQuest senior director of operations. "One of the systems' major components is a pump used to recirculate gas and create the required operating pressures; pumps of this type are inherently noisy. In addition, increased system performance features were required after initial marketing feedback required a more-efficient recirculation system."

Because the pump was a necessary component and could therefore not be eliminated from the design, the companies incorporated noise dampening and natural frequency detuning techniques to reduce noise. "Vibration-isolation mounting methods were used to isolate the frequency transmission to the instrument case and structural elements. The utilization of different gas-flow geometries and volumes damped and detuned airflow-induced noise," explains Spencer Lovette, program manager, KMC Systems. "Pumps of this type also generate a fair amount of heat, so a balance of noise dampening material types and thicknesses--which act as an unwanted thermal insulator--with creative air cooling paths were required to achieve the specification levels."

In addition to minimizing noise and vibration, the companies also aimed to reduce the size of the system. They hoped to facilitate user acceptance of the unit by designing a compact system that could help to cut clutter and could fit in designated instrument racks in the OR suite. To do so, the companies applied creative packaging and engineering techniques to maximize internal space. Solutions such as replacing two small pumps with one larger one, using more-compact plumbing between components, and employing a custom manifold contributed to the reduction of the unit's size, according to Lovette.

Throughout development, engineers at KMC Systems and the project management and technical staff at SurgiQuest maintained close contact and met frequently to test the device and discuss challenges, solutions, and next steps. "The resolution of the initial size and noise challenges has allowed SurgiQuest to distribute the DPS 1000 system to the market with broad acceptance and success," Donovan concludes.

Lubricious Coatings Give Minimally Invasive Devices the Slip

SurModics employs a proprietary UV-based technology for applying its Harmony lubricious coatings to medical devices.

Not just a phrase reserved for road signs and an immensely popular 1986 Bon Jovi album, 'slippery when wet' is also the core concept behind many lubricious coatings for medical applications. Because polymers are often inherently hydrophobic, plastic devices such as catheters can experience friction when they come into contact with body tissue. The inclusion of a hydrophilic lubricious coating--terms that are often used interchangeably in the context of coatings--on the surface of such a device, however, renders it slippery when exposed to blood and other body fluids. By reducing friction, lubricious coatings help minimize patient trauma as well as expedite and facilitate device delivery.  

To help navigate the tortuous terrain inside the body, the device coating requires a delicate balance of lubricity and durability. "What everyone wants is a coating that is perfectly lubricious--offers no resistance at all--but at the same time can never come off the catheter in any way, shape, or form, and is completely stable and durable to mechanical forces," states Paul Nowatzki, business development manager for medical coatings at Bayer MaterialScience LLC (Pittsburgh, PA).

Although that's a tall order, providers of lubricious coating technologies are striving to achieve such attributes. And it's not just the coating chemistry that counts; with lubricious coatings, the application method is also a major factor in ultimately determining the slipperiness and adhesion properties of the coating.

As Pure as Water
Within the lubricious medical coatings market, most compounds are fairly similar, says William Lee, director of R&D at AST Products Inc. (Billerica, MA). "It's more about the methods that are different," he states. "In general, there are two types of coating solutions, water based and solvent based, and in order to activate the chemical reactions, heat, UV, plasma, corona, etc. are applied."

As an aqueous-based lubricious coating, AST's LubriLast does not include organic solvents. The use of water for coating attachment can offer several advantages over solvent-based methods, including a more environmentally friendly process. In addition, the lack of organic solvents eliminates the opportunity for residual solvents on the device, which can negatively affect performance or regulatory approval, according to Lee.

Instead of relying on solvents, the LubriLast technology centers on a stabilization technique that involves cross-linking and covalently bonding a non-water-swellable supporting polymer network to the device substrate. Blending hydrophilic molecules with an aqueous polymer dispersion yields a long chain of biocompatible hydrophilic polymer. Upon incorporating the polymer chain into the coating, it becomes partially entangled with the supporting polymer network on the surface to create an anchor of sorts, referred to as an interpenetrating polymer network. The remaining exposed areas of the chain can become hydrated and provide the desired lubricity to the device.

A catheter is dip coated to apply AST's LubriLast lubricious coating to facilitate smooth and speedy device delivery in the body.

Surface modification of the device is executed through a relatively straightforward process, Lee states. "We need to first clean the surface because without cleaning, coatings may not adhere well to the surface," he says. "Depending on the substrate, people might just use alcohol to clean the surface or [they] might use plasma to clean the surface." Following the surface-preparation step, the device undergoes either a dip- or brush-coating process, which is determined by the product. The device is then cured in an oven at 60° to 65°C for a period of time ranging from a half hour to an hour.

When applied to such devices as catheters, guidewires, balloons, and urethral stents, LubriLast technology virtually eliminates the coefficient of friction (COF) in an aqueous environment, according to the company. It claims that tests have demonstrated a static COF of 0.009 and a kinetic COF of less than 0.005 on a LubriLast-coated polyethylene substrate. Furthermore, the company states that chemical cross-linking of the supporting polymer network provides durability and strong adhesion that contributes to a coating life span of more than 100 cycles.

Let There Be (UV) Light
Taking a different approach to lubricious coating application is SurModics Inc. (Eden Prairie, MN). "We have a proprietary UV-based technology, but in the last 18 months or so, there is at least one other company that we know of that is touting a UV-based curing process as well," explains Joe Ventura, the company's director of business development for device applications. Ventura adds that SurModics believes that, based on in-house testing and customer feedback, its coating technology is more durable, however.

The company attributes the durable nature of the Harmony advanced lubricity coatings to the underlying chemistry of its patented PhotoLink process. By exposing the device's substrate to UV light, the process induces photochemical covalent coupling of the coating molecules to the substrate surface. "Our hydrophilic coating is tied to a UV-cure chemistry, and what that allows us to do is achieve strong covalent bonds where the coating and the material substrate meet," Ventura says. "We are also able to achieve those same covalent bonds throughout the coating matrix itself." It is these covalent bonds that ensure firm adhesion of the coating to the substrate during device use.

The PhotoLink platform also promotes flexibility for OEMs. Customizable, the platform can be tailored to accommodate specialty designs, thin-wall construction, and varying geometries. Plus, a range of metal and plastic substrates can be coated. Chemistry flexibility also allows for custom formulations to couple lubricity with antimicrobial or other agents for enhanced properties.

Formulation recipes, along with the substrate material and the device's application, factor into determining the lubricity of a specific Harmony coating. However, the company claims that the technology is typically able to achieve up to 95% friction reduction in a given device. "[Lubricious] coatings are used in applications for the heart, the brain, and the body," Ventura comments. "Companies have leveraged our hydrophilic coating as a natural part of the design engineer's toolbox. Our hydrophilic coating is used to ease the friction forces associated with the initial access into the patient as well as to navigate the delivery device more effectively to the final treatment location."

When There's No Cure
Unlike the thermal- and UV-curing coating technologies offered by other companies, the Baymedix CL 100 lubricious coating does not undergo a conventional curing process. Rather than applying a coating solution to a device and then curing it, the Baymedix technology relies instead on the growth of a rapid-curing polymer to functionalize the device surface.

"Our coating technology is relatively different from what's on the market," says Nowatzki of Bayer MaterialScience. "We first activate the surface of the device with a gaseous activation process that puts functionality on the surface. We then use that to graft or grow a polymer from the surface of the device, [which is] done in an aqueous coating solution." This direct-grafting technique yields strong covalent bonds, Notwatzki notes, which are responsible for firm adhesion of the coating to the device. It also features a low COF of less than 0.03 and is less than 5 µm thick.

Among the most significant advantages of Baymedix compared with competing lubricious technologies, according to Nowatzki, is that it facilitates the coating of device lumens. "We have done on a developmental basis the insides of various tube and catheter-type products and demonstrated that we can make those basically as highly lubricious as we and others make the outer surfaces of devices." He states that other lubricious coating technologies either are not capable of performing this feat or can not do so as easily or quickly as is possible with the Baymedix platform.

As a result, this lubricious coating technology could improve a variety of minimally invasive delivery devices. "By having lubricious coatings, you're enabling less-invasive techniques," Nowatzki concludes. "It's about enhancing the function of existing devices and enabling devices that, without a lubricious coating, would be difficult or impossible to use as intended."

Diversification Efforts Help Drive Michigan’s Medical Device Industry

The industry that has driven Michigan's culture and economy for the past century has run out of gas. As it has been publicly chronicled, the Big Three U.S. automakers, consisting of General Motors (GM), Ford, and Chrysler, have been hard hit in recent years. An economic downturn, plummeting profits, massive layoffs, plant closings, and the bankruptcy of GM and Chrysler have crippled the state's economy. The car companies are in crisis, and, in turn, so is the Automotive State.

But losses in the domestic automotive industry could be the medical device industry's gain. As the state looks to recover from almost a decade of decline--including an especially devastating economic performance last year--it is increasingly seeking new opportunities outside of its comfort zone in order to decrease dependence on the struggling auto industry. Diversification efforts are consequently picking up speed as local manufacturers switch gears from motors to medical devices in the hopes of refueling and pumping new life into Michigan's manufacturing sector.

A Strong Foundation
Although often overshadowed, the life sciences industry has been quietly thriving in Michigan since before the automobile industry became synonymous with the state's economy. One of the fastest-growing life sciences states, Michigan currently employs more than 30,000 people at roughly 542 companies in the pharmaceutical, medical device, instrumentation, diagnostics, and biotech sectors, according to the Michigan Economic Development Corp. (MEDC; Lansing).

Contributing to this strong showing of the medical device industry in Michigan is Stryker Corp., for one. The medtech giant calls Kalamazoo home to its global headquarters as well as a Stryker Instruments facility, while the nearby city of Portage hosts Stryker Medical and Stryker Craniomaxilofacial plants. Together, the company's various Michigan-based divisions employ more than 2000 people, according to the Michigan Manufacturing Technology Center (MMTC; Plymouth).

Also bolstering the local medical device industry is the regional presence of New Jersey-based OEM Becton, Dickinson and Co. (BD) in Detroit. In October 2009, the company further expanded its local presence by acquiring HandyLab Inc. (Ann Arbor), a University of Michigan spinoff and manufacturer of molecular diagnostic assays and automaton platforms.

But Stryker, BD, and a selection of smaller OEMs in Michigan aren't the only ones helping the local device industry to flourish; a slew of suppliers in the state have also played a significant role in laying the groundwork for a healthy medical device industry. Dow Corning Corp. (Midland), for example, has been influential in the area as an established materials supplier specializing in silicone-based technologies, including tubing, adhesives, elastomers, and coatings. "Dow Corning has been a leading supplier in the medical device industry for more than 50 years, so it's not like we're Johnnies-come-lately," notes Steve Wilkowski, new business market development leader. Companies such as Centurion Sterilization Services (Howell), a provider of contract packaging and sterilization services; Orchid Orthopedic Solutions (Holt), a contract designer and manufacturer of implants and other devices; Precision Edge Surgical Products (Sault Sainte Marie), a contract manufacturer of surgical components and cutting tools; and a host of other local suppliers and service providers also serve the medical device industry from local facilities.

A Solid Support System
The success of many local supplier companies coupled with the relative stability of the medical device industry has attracted the attention of various state organizations. And in the search for viable, sustainable markets into which some automotive suppliers can diversify, the state has set its sights on the medical device industry.

Efforts to help automotive suppliers to diversify their business have targeted several industries; however, any industry that could benefit from a service provider's specific skill set is encouraged. That said, the medical device market represents a potentially faster and easier market to break into for automotive suppliers compared with the aerospace, defense, and alternative energy sectors, which often involve government contracts or long-drawn bidding procedures, according to Christophe Sevrain, CEO of the consulting firm CJPS Enterprises LLC (Troy). After all, it's been done before: The German region of Baden-Württemberg, home to prominent automakers Porsche and Mercedes Benz, has concurrently cultivated a bustling medtech industry supported by more than 600 companies.

"The automotive industry is so strong and the manufacturing know-how is so advanced that the medical device industry is a really good place for it to emerge from that basic knowledge of innovation and manufacturing," Sevrain says. "Like they say here, if you can make it in the automotive industry, you can make it anywhere. The margins are so tight, the quality systems so stringent, and the cost structure is so strict that the industry has had to be very good at manufacturing."

Although manufacturing expertise is a start, serving the medical device market requires more than just talent. Luckily, Michigan is dedicated to economic recovery via diversification, committing resources and allocating funds to facilitate the process. For example, the state, through MEDC, gave an exclusive contract to CJPS Enterprises to assist automotive suppliers in leveraging their capabilities to cater to the medical device industry. With the state picking up a portion of the tab, suppliers can benefit from the consulting firm's advice at a discount rate.

"The very first thing we do is tell them right off the bat if we don't think they're candidates for the medical industry," Sevrain states. "We don't want them to have to buy new equipment or get new skills to get into the medical device industry. If the skills they have don't fit the medical device industry, then forget it. For the ones that do survive the reality check, we help them focus on market segments of the medical device industry that leverage their core competencies." He notes that companies specializing in such areas as machining, assembly, electronics, and software are often good candidates; molding companies, however, comprise the largest portion of the firm's current Michigan-based diversification clients.

In addition to consulting, state incentives and benefits for diversification can include tax rebates when jobs are created as well as various loan programs, grants, and other funding for qualified manufacturers. The state and various organizations are also supporting manufacturers through extensive training, workshops, and seminars. Among them was an MEDC-hosted Automotive Supplier Diversification Summit in 2008 that focused on alternative growth opportunities and drew 150 automotive suppliers and manufacturers. A daylong Automotive Manufacturing Diversification event last year hosted by the economic development group The Right Place Inc. similarly attracted more than 300 eager automotive suppliers.

"It's tough for a state that has been hit so hard with the automotive downturn to have enough cash to go around," Sevrain says. "But I would say given the little we have, the state is very aggressive in trying to find money for training as well as if you hire people, having some tax breaks and good loan programs, too."

A Commitment and Creativity
Applying a state grant, training programs, and the input of CJPS to broadening its business, molder and manufacturer Omega Plastics represents a local diversification success story. Last year, the company launched a dedicated medical device unit, Omega Plastics Medical (Clinton Township). Although Omega had been involved in medical device manufacturing for roughly a decade, it opted to fully commit to growing that side of the business; it now accounts for roughly 35% of the company's business, according to Jeff Kaczperski, company president.

"A key point for us was saying that we were committed for the long haul with time, energy, and investments to make this work," Kaczperski notes. "I think that is the biggest concern that medical device companies have when they look at Michigan and say: 'Okay, the automotive industry is down, but it's going to come back up. Are you going to be there in the long run?' It's really a challenge for the Michigan manufacturers to show that commitment to the long term, regardless of whether automotive comes back or doesn't."

Another area about which some OEMs are skeptical of Michigan manufacturers is quality systems. Because quality is of the utmost importance when dealing with life-saving devices, some OEMs and competing suppliers have questioned automotive companies' ability to meet the exceptionally high standards required by the industry. Kaczperski confirms that achieving necessary quality standards is one of the most important aspects of diversifying into the medical device industry. However, it is by no means an impossible feat, he says.

"Even though they're different, the quality systems they have to create cars are incredible. They have to have full traceability and very tight requirements and are used to very high volume with a very low failure rate," Sevrain adds. "It is different, but the quality is here. We make [suppliers] understand that FDA quality system requirements are a federal law; they're not just a good idea. As long as they understand the rules, they'll play by them. They have a lot to bring to the medical device industry in terms of looking at things differently when it comes to quality."

Michigan auto manufacturers may also bring fresh perspective to the medical market. Wilkowski of Dow Corning notes that the company has gained expertise and opportunities from vendors that have traditionally supplied exclusively to the automotive industry. Furthermore, automotive technology has advanced by leaps and bounds in recent years. Impressive sensing, safety, and user-friendly features currently employed in cars could potentially lend themselves to enhancing current medical products or enabling new ones. "Technology in cars has advanced so much compared to what it was 10 years ago, but the cost has not moved proportionally," Sevrain comments. "There's an opportunity for the automotive industry to be a driver for lowering the cost of healthcare--to enable technologies that will lower the cost of healthcare. I think they're going to give some creativity and aggressive cost structure that could benefit the medical industry."

With promises of cost-competitive services and creativity, Michigan manufacturers are hoping that their diversification efforts pay off as they try to get a foothold in the lucrative but challenging medical device industry. These new suppliers are, at the vey least, shaking up the traditional medical device manufacturing landscape. "I've seen suppliers to the medical device industry leverage some of that knowledge from the automotive industry to actually improve their own ways. Also, some strategic alliances are happening; some Tier I suppliers are also moving up the food chain a bit and becoming closer to an OEM than a supplier in the process, which I think is healthy," Sevrain says. "It's going to push some [established medical device suppliers] to be more competitive, but I don't see a down side to that. Let the best companies and the best technologies win. Let the market decide."

Although the diversification of auto suppliers into the medical market is big news, there's a lot more contributing to Michigan's medical device industry. Read a Web-exclusive companion piece at qmed.com/mpmn/michigan.

Channeling Microfluidic Devices into Point-of-Care Diagnostics

Channeling Microfluidic Devices into Point-of-Care Diagnostics
A selection of Dolomite's microfluidic chips are optimized for various types of reagent handling in biomedical applications.

Microfluidic devices have long been a staple in research settings for performing a variety of cell manipulation applications or for determining such material characteristics as viscosity, pH, and chemical binding coefficients. However, university research groups and companies alike are struggling to adapt microfluidic technology to portable diagnostic devices.

Featuring one or more channels containing at least one dimension less than 1 mm in width, microfluidic products are used to move common fluids such as whole blood samples, bacterial cell suspensions, protein or antibody solutions, and various buffers. Their advantages are manifold. Because the volumes of fluids within microfluidic channels are generally in the nanoliter range, this technology minimizes the accompanying use of reagents and analytes—substances or chemical constituents that are determined in analytical procedures. In addition, microfluidic devices can be fabricated using relatively inexpensive production techniques capable of producing elaborate, multiplexed devices. Finally, microfluidic technologies enable the fabrication of highly integrated devices that can perform several different functions on the same substrate chip.

Microfluidics is a mature technology, but its use in medical applications is still evolving. Thus, while the development of microfluidics for point-of-care diagnostics remains a work in progress, new and promising approaches are in sight.


From the Lab to the Living Room

Among the research groups working to transform microfluidics into a core technology for point-of-care portable devices is the Center for Microfluidics and Medical Diagnostics at the University of Notre Dame (Notre Dame, IN), headed by engineering professor Hsueh-Chia Chang. “Microfluidics is particularly useful for global health and epidemic control because it offers portable diagnostic kits,” Chang comments. “These kits may not have the sensitivity of a lab-bound device, but they could be carried around in the field and could be used by nonprofessional personnel.” The team believes that the chip could aid in controlling such infectious diseases as tuberculosis, malaria, and AIDS in the Third World.

The group's nanosensor-based microfluidic chips feature hard-polymer substrates that contain embedded microelectrodes fabricated using standard microcircuit manufacturing methods. The technology employs ac electric fields to separate, concentrate, and detect molecules such as DNA, RNA, and peptide biomarkers on the chip. “Our chip technology is suitable for global health and epidemic control applications because it does not require laboratory-based fluorescent labeling or optical detection techniques,” Chang says.

One of the main challenges facing researchers is developing methods for pumping fluids through microfluidic chips. To that end, the chip produced by Chang's group transports fluids using either an internal or external pump driven by a small battery. “The fluid sample in my chip is often pumped by an ac electroosmotic-flow (EOF) pump developed by us at Notre Dame,” Chang states. “Hence, the chip does not require an external pump. However, it is designed so that a handheld syringe can also pump the sample.”

Another research group devoted to expanding the application range of microfluidic technology is centered at the University of Washington (UW; Seattle). “At heart, the common factor among microfluidic devices is small channels and small volumes of liquid being moved around,” remarks Paul Yager, professor and chair of UW's bioengineering department. “That sounds completely simple-minded, but lots of technologies have been developed in the last 16 or 17 years for really making that come true.”

In the biomedical sector, microfluidics first came into its own as a drug-development technology. But the UW group is focused on developing it for use in devices that will enable patients to perform their own tests, send results to their doctors, and bypass centralized laboratories for many routine diagnostic procedures. “The aim is to use microfluidics as a set of technologies that could allow people to make complicated tests that normally require a lot of equipment and expert people and move them out of the periphery,” Yager says. “And I think that’s the area in which they have the greatest long-term potential.”

Early microfluidic-based point-of-care diagnostic devices included glucose monitors, which have become a standard commodity because they are inexpensive to make and they work well, according to Yager. But his team's aim is to enable microfluidics to perform a greatly expanded range of tests for everything from infectious diseases to drug monitoring. “Pretty much anything you can make into a fluid without big chunks in it is suitable for microfluidics,” Yager says. “We’ve worked on a variety of samples, ranging from saliva, blood, cerebral spinal fluid, tears. Anything you can liquefy you can monitor using microfluidics.”

While early microfluidic prototypes were based on silicon and glass, the UW group is working on a technology that is based almost entirely on polymeric laminate technology. The team has experimented with nitrocellulose membranes and a variety of other materials for the primary liquid movement, but its current focus is the use of polymethylmethacrylate and Mylar for the contacting material, which is held together using pressure-sensitive adhesives. These technologies form the basis of what the research group calls the Dx Box, a microfluidic device designed to work with plastic cartridges for performing aminoassays and nucleic acid amplification assays.

To perform assays, you’ve got to convert some physical quantity into a number, or a signal, Yager notes. This can be done using an electrical or physical sensor. An alternative method is to use different colors to reflect quantitative changes and read the changes using an external instrument. That’s the primary method that Yager’s team has focused on: to convert chemical concentrations into a pattern of color intensities that can then be easily measured using some type of external camera. “It’s not quite the same as having a sensor,” Yager says. “There may be a place in the device where color changes occur, and I guess you can call that a sensor, but you don’t need to have wires, and you don’t need to have a meter.”

Like Chang’s group at the Center for Microfluidics and Medical Diagnostics, Yager 's team is also concerned with optimizing fluid movement in microfluidic devices. “We achieve fluid movement using two pressures and a vacuum generated by small quarter-bolt vacuum and pressure pumps,” he explains. Like other microfluidic devices, the UW group’s device incorporates valves that rely on an external power source. However, the researchers are trying to transcend the need for external power, enabling the fabrication of a completely disposable chip that needs nothing more than a piece of commonly available technology to make it fully capable of performing quantitative measurements.

Small Devices, Big Challenges

Although many universities are engaged in microfluidic research, manufacturers such as Dolomite Microfluidics (Royston, UK) are turning research into reality. Dolomite’s chips are used in point-of-care applications such as drug-delivery and clinical diagnostic devices, but the company is also interested in developing chips for devices that perform therapeutic effects similar to dialysis.

Micronit's glass microneedle arrays have locally insulated electrodes for neural signal recording and stimulation. Equipped with needles up to 7.5 mm long, this array has a cross-section measuring 200 to 300 × 100 ?m.

Fabricating microfluidic devices from glass, quartz, and polymers, the company's chips have a good surface finish and accurate feature alignment, according to Richard Gray, the company’s head of sales. They can also be fabricated with both shallow and deep features ranging in size from 250 nm to 1 mm. For customers that desire complete instruments, Dolomite also builds in pumps, sensors, and valves and can develop full systems. “Imagine a series of concentric circles of microfluidic functions around the chip itself,” notes Gray. “We can do as few or as many of those circles as our customers need.”

In addition, Dolomite makes connectors—otherwise known as macro-to-micro interfaces—and integrates electrodes and sensors into the chips. “We put a lot of attention into the interface—particularly the electrical and fluidic interfaces,” Gray says. “So, we think about the connectors, which I think can be a weak spot in other systems where you end up with a relatively ungainly or impractical interface. In contrast, we have technologies that make that a fairly straightforward process.”

Many of Dolomite’s chips have edge connections; instead of containing a hole in the surface for fluid inlets and outlets, the chip has channels that are fabricated right to the chip’s edge. This configuration is advantageous because it can help to reduce costs by eliminating the need to create holes at right angles to the channel direction. It can also reduce the shear stress on the fluid, which could be useful for handling such fluids as blood. In addition, edge connections enable the company’s chip designers to make straightforward connections to multiple channels simultaneously.

Optimizing pumps and valves is as much a challenge for Dolomite as for other microfluidics companies and university engineering departments. Hence, the company is collaborating with university researchers to commercialize novel miniature pumping technologies based on thermal or electroosmotic techniques, Gray states. And to overcome problems with fluid flow in microfluidic channels, the company is working to develop internal valves using a sandwich of rigid and flexible layers made from glass, elastomer, and rigid plastic in a diaphragm arrangement. “We use that configuration for valves, but you can also use it for a diaphragm pump as well,” Gray adds. “We also offer a range of EOF and miniature peristaltic pumps, which, while not in-chip, are very small and can then be placed on-chip or near-chip.”

A Little Goes a Long Way

Scientists and manufacturers are interested in microfluidics because it consumes small quantities of fluids and can be automated, reducing test costs. It also enables the analysis of tiny samples, allowing tests to be performed with the same or less fluid than other diagnostic methods. In addition, it offers rapid analysis times, improved data quality, multiparameter testing, and reliable parameter control.

Capitalizing on these features, Micronit Microfluidics (Enschede, Netherlands) designs microfluidic products for portable medical devices that can perform near-patient testing. The company’s chips, explains Harmen Lelivelt, manager of marketing and sales, are constructed from layers of glass. Each layer has channels, holes, or electrodes, or a combination of all three. Fabricated using lithographic techniques borrowed from the semiconductor industry, these microfluidic chips are made on 4- to 6-in. wafers and have features that typically range in size from 5 to 500 µm. Such minuscule features are made using chemical wet etching, micropowder blasting, or metal deposition techniques.

Measuring less the 1 cm2, Micronit’s chips are designed for one-time use, eliminating the need for cleaning and the risk of cross-contamination. They work on the principle of capillary electrophoresis, a technique for separating substances from a fluid substrate that does not entail the use of moving parts for pumping fluids.

Battery powered, the chips enable users to perform analyses in less than a minute using a single drop of fluid. First, they separate molecules according to their charge/size ratio. Then, the molecules pass by a detector that measures their conductivity or fluorescent signal, resulting in a quantitative value.

Sounding a familiar refrain, Lelivelt remarks that current-generation microfluidic devices are constrained by their need for external pumps. “External pumps such as high-performance liquid chromatography–type pumps work well in automated lab instruments but take up considerable space,” he remarks. “While they are a good choice for benchtop instruments, they are not an option for handheld microfluidic devices.”

For single-use devices, capillary forces are a potential option because they are compact and energy efficient. But like Gray from Dolomite, Lelivelt believes that EOF pumping could be a viable alternative to using capillary forces. Employed in fuel cells, EOF pumps do not have moving parts, scale well, and can be powered by batteries or even cell phones. Other solutions, according to Lelivelt, include micromembrane pumps and disk-shaped microfluidic devices that use centrifugal forces to pump liquids.

Micronit’s chips are used in a range of applications, such as drug-delivery systems. “For this market, we have developed etching technology that is used to fabricate flow restrictors,” Lelivelt comments. Employed in implantable medical devices to control drug release, flow restrictors consist of a pressurized reservoir containing a relatively high dose of a drug and a fluid-restricting component. “Patients suffering from chronic pain, for example, receive morphine dosed at a certain rate by the microfluidic device’s pumps,” Lelivelt says. “Too little morphine fails to relieve pain, while too much can be fatal.”

Drug delivery is just one of many possible microfluidic applications. “This technology allows people to monitor their health at home and allows professionals to make fast decisions in time-critical situations,” Lelivelt says. “Thus, the healthcare system and society will benefit significantly from its ability to provide early diagnosis and reduced sample logistics.”

Focus on Assembly Equipment

Modular Machine Performs Small-Part Assembly
A standardized, modular assembly machine designed specifically for the medical device industry is suited for use in the production of test kits, syringes, needle sets, and other medical products. Capable of operating at rates up to 120 parts per minute, the QuickLink linear indexing system performs ultrasonic welding, UV bonding, and small-part assembly tasks. Among the system's features is the ability to self-diagnose problems and then decide on an optimal course of action using the company's 'smart' programming techniques. Configured with a steel welded frame and aluminum work surface, the machine is equipped with a 2- or 4-m working zone. It is available in partially or fully automated versions and can be integrated with the company's QuickPouch packaging systems.
Adaptive Manufacturing Technologies
Ronkonkoma, NY
www.amtautomation.com

Assembly System is 25% Smaller than Similar Equipment
Featuring a footprint that measures approximately 6.5 by 6.5 ft, an automatic medical device assembly system is about 25% smaller than a typical pilot-scale machine, according to its manufacturer. Configurable as a semiautomatic or fully automatic system, the KS Pilot is compatible with the company's KSL and KSD platforms, which enables validated processes and stations to be transferred or duplicated on a high-speed automated assembly line. This capability, the company states, can reduce time and costs. The entire system can also be reused or retooled for new applications, when required. It can be employed as a stand-alone machine or can accommodate multiple units strung together to create a large automated assembly system. Applications include safety syringes, inhalers, and diagnostic devices.


Komax Medtech
Rockford, IL
www.komaxmedtech.com

Hybrid Welding Machine Joins 3-D Plastic Parts
Joining complex 3-D parts can be accomplished by a company's robot-supported hybrid welding system. Capable of yielding welded assemblies for medical applications, the TwinWeld3D machine performs laser plastic welding operations that offer high welding-seam quality and fast processing times, according to its manufacturer. Based on dual irradiance, the welding technology combines laser light with the infrared radiation emitted by conventional halogen heating lamps. As a result, the company says that its technology can increase processing speeds and fault tolerances.
LPKF Laser & Electronics North America
Orion, MI
www.laserequipment.com

Modular Conveyor System Is Suited for Cleanroom Use
Touted by its manufacturer as the first truly modular system to meet ISO Class 3 standards, a conveyor is optimized for cleanroom use. Many conveyors cannot meet Class 3 standards for cleanroom environments because they require particulate-emitting lubricants. The DynaCon conveyor, however, does not require lubrication and has been rated to meet the ISO standard by an independent laboratory. Lightweight and portable, the conveyor promotes lean manufacturing principles and flexibility for medical device assembly operations. It is based on a building-block concept of high-impact, interchangeable plastic modules, accessories, and components.
Dynamic Conveyor Corp.
Muskegon, MI
www.dynamicconveyor.com

Automated Conveyor Line Performs Multiple LSR Production Steps
Custom-designed, fully automated conveyor systems are available to medical device OEMs for the manufacture of liquid silicone rubber (LSR)-based products. A custom, fully automated line can perform dispensing, filling, and curing processes. If desired, production-line assembly can be carried out by filling the dispensed medical-grade LSR into a complex mold and allowing it to cure inside to ultimately yield the finished product. Monitoring and control mechanisms are implemented during each step. Automation minimizes the opportunity for human error while ensuring repeatability.
Scheugenpflug Inc.
Kennesaw, GA
www.scheugenpflug-usa.com

Outsourcing Outlook on Extrusion

In choosing an extrusion provider, the OEM should think beyond tubing and other products. Because the manufacturer often requires the services of an extruder early in the design process, the prospective supplier must be able to provide collaborative product development, as well as supportive and innovative design and engineering capabilities. 

An essential component of product development is die building. Manufacturers benefit from working with extruders that have in-house die-building and prototyping capabilities, which is essential for creating consistent, high-quality products. In addition, in-house die building facilitates product modification and evolution. Hence, to accelerate die development, manufacturers should look for an extrusion partner that is also well grounded in CAD and CAM technology, 3-D prototyping, and EDM processes.

Medical device manufacturers should partner with an extruder that has a proven track record in providing not only simple, single-bore tubing extrusions but also complex multilumen, paratubing, and co- and triextrusion processes. The extruder should also demonstrate capabilities with a range of resins. For example, many medical device OEMs require medical-grade DEHP-free or phthalate-free plastics that can undergo all traditional sterilization methods.

In-line quality control monitoring and assessment are also important considerations. Thus, the OEM should choose a vendor that can demonstrate thorough and comprehensive quality control, regulatory, and document control capabilities. These capabilities may include in-line laser measuring to ensure strict compliance with outer-diameter specifications, ultrasonic monitoring of wall thicknesses to ensure tubing concentricity, and statistical quality and process control for providing real-time data and anticipating problems before they occur.

- Richard Brooks, vice president of sales/medical, Pexco Medical Products, Athol, MA.


Custom profile extrusions
An extruder offers custom profile extrusions made from PTFE and a variety of melt thermoplastic materials such as polyurethane, nylon, and polyethylene. Providing design, engineering, and manufacturing services, the company produces extrusions for a variety of medical applications, including catheters and replacement biopsy channels for the repair or manufacture of endoscopes. While its melt thermoplastic materials can be used to fabricate single- and multilumen tubing with a maximum outer diameter of 9 mm, its PTFE tubing features inner diameters ranging from 0.0366 in. with a 0.002-in. wall thickness to 0.068 in. with a 0.010-in. wall thickness. PTFE rod sizes range from 0.008 to 0.038 in. The vendor can also spool materials or cut extrusions to specific lengths.
International Polymer Engineering
Tempe, AZ
www.ipeweb.com


Thermoplastic and composite extrusions
Using thermoplastic and composite materials, a supplier develops and produces extruded components, including handles, clamps, and hand grips for surgical equipment; parts for diagnostic and blood analysis equipment; and components for the orthopedic-trials market, trauma fixation, and surgical caddies. In addition, the company is developing and testing new materials that are designed for use in x-ray and MRI imaging applications. Based on premium-grade resins, the service provider's products are manufactured in an ISO 9001:2008-compliant and FDA-registered facility. Because some applications require materials testing, the company's in-house labs are equipped to analyze materials to ensure that they meet customer specifications.
Ensinger Inc.
Washington, PA
www.ensinger-online.com

Custom extruded thermoplastic tubing
Specializing in custom extruded products, an ISO 9001:2000-compliant contract manufacturer provides wire coating, balloon tubing, shrink tubing, and vacuum sizing. With capabilities ranging from development studies and engineering runs to prototyping and production-quantity runs, the company can fabricate final tube designs in single-lumen, multilumen, profile, bump, multilayer, and paratubing configurations. Extrusions are available in a range of thermoplastic materials, including PVC, LDPE, MDPE, HDPE, C-Flex, polypropylene, urethane, nylon, and Pebax.
Medical Extrusion Technologies Inc.
Murrieta, CA
www.medicalextrusion.com


Flexible tubing and tubular shapes
Coupling extrusion capabilities with an inventory of existing tooling, a contract manufacturer offers custom flexible medical tubing and tubular shapes in a range of sizes and geometries. The company's medical products are made from various materials, including PVC, TPE, polyurethane, and polyethylene compounds that meet medical certifications such as USP Class VI and EU regulations for phthalate and DEHP content. Extruded products include negative-pressure wound drains; insufflation systems; suction, extension, oxygen, and drain lines; catheters; IV systems; peristaltic pumps; cannulae; and protective coverings for surgical instruments. The company also offers radiopaque products and tubing that can be sterilized using EtO, gamma radiation, or autoclaving processes. As an ISO 9001:2008-registered company, the vendor maintains quality control standards, including tight dimensional tolerances that are controlled using laser micrometry.
Grayline Inc.
Waukesha, WI
www.graylineinc.com


Rigid and flexible tubing
Thermoplastic medical extrusions are produced in Class 100,000 cleanrooms at a contract manufacturer's FDA-registered and ISO 9001:2008- and ISO 14001:2004-certified facilities. The supplier's capabilities include single- and multilumen tubing, thermally bonded paratubing, coextrusions, triextrusions, custom profiles, SPC documentation, on-line measurement controls, and in-house wire EDM services. In addition, the company offers CAD/CAM, printing, bar coding, subassembly, and packaging operations. Specializing in medical-grade flexible or rigid tubing and custom profiles, the company fabricates extruded products made from USP Class VI materials such as PVC, polyethylene, polypropylene, polycarbonate, nylon, thermoplastic elastomers, radiopaque materials, and PVC alternatives.

Pexco Medical Products
Athol, MA
www.pexco.com

 

Spotlight on Wound-Care Technologies

Transdermal adhesives
A line of temporary transdermal adhesives is suitable for use in drug-delivery and combination devices. Offered as part of a company's drug-delivery silicone family, DDR-1370 is a traditional pressure-sensitive adhesive (PSA), while DDR-4355 is a strong-tack silicone gel. A one-part noncuring PSA dispersed in ethyl acetate, the former material has a typical viscosity of 1450 cP, can be die-cut once it has been coated onto a substrate, and exhibits high cohesive strength and release force. The latter material has a viscosity of 15,000 cP and cures at a low temperature to a soft, high-surface-tack temporary adhesive. Both materials can be applied by means of coating processes, and can be used in wound-care applications for dispensing pharmaceutical ingredients such as antibiotics, anti-inflammatory drugs, or antimicrobials.
NuSil Technology LLC
Carpinteria, CA
www.nusil.com

Porous transfer adhesive
A hydrophobic porous transfer adhesive features a stable pore structure of isolated channels in the z-axis, enabling ultrahigh moisture-vapor transmission rates (MVTRs) for management of exudate and moisture in wound-care dressings. Demonstrating good adhesion to skin, the ARcare 92174 adhesive offers MVTRs greater than 9000 g/m2/day. It is formulated to withstand gamma sterilization and is suited for bonding to dressing backings made from polyester foams, nonwovens, fabrics, and hydrocolloids. Available in rolled transfer film, the customizable adhesive has passed tests for cytotoxicity, primary skin irritation, and skin sensitization.
Adhesives Research Inc.
Glen Rock, PA
www.adhesivesresearch.com

 

Medical-grade adhesives and tapes
Tapes and films for wound-care applications that call for moisture management, patient comfort, and extended wear time are available from a company that also supplies related materials and converting solutions. For advanced wound-care products, the firm offers hydrocolloids and advanced hydrocolloids, odor-absorbing systems, progressive thin films, and custom island dressings. Other products include soft and pliable carriers designed for optimum conformability, systems that form a bacterial barrier, high-breathability films and conformable nonwoven materials, and gentle pressure-sensitive adhesives. Medical adhesives for wound-care device assemblies are provided in the form of single-coated film tapes, single-coated foam tapes, single-coated nonwoven tapes, single-coated hydrocolloid film tapes, and hydrocolloid transfer tapes.
Avery Dennison Medical
Mentor, OH
www.stus.averydennison.com

Custom wound dressings
A contract manufacturer specializing in the fabrication of wound dressings has developed proprietary products that use adhesive systems to enable the removal of devices from fragile patient skin with minimal trauma. Whether employing a silicone or hydrogel system, the low-trauma adhesive can be made to attach a dressing to compromised skin for as long as five days before its easy removal. The dressings are designed with various materials depending on the specific types of wounds. For example, heavily exudating chronic wounds require highly absorbent materials such as foams. Foams and other more-absorbent materials can be bordered with low-trauma adhesives to make an effective dressing for geriatric patients and others with sensitive skin, according to the company.
Brady Medical Solutions
Mesquite, TX
www.bradymedical.com

Biobased elastomers
Elastomeric materials produced sustainably from the guayule shrub are offered to manufacturers of medical and wound-care products seeking materials that are 100% Hevea latex-free and thus safe for patients with a Type I latex allergy. The supplier's wound-care material portfolio includes emulsions for open-cell foams, films, adhesives, and binders, along with dry elastomers for closed-cell foams. All of these alternatives are suitable for traditional and advanced wound-care systems such as cohesive wraps, bandages, dressings, and prosthetics. Producing all of its biobased elastomers from plants it grows, the manufacturer supports customers throughout their product development cycle, offering prototyping, materials development, design and testing services, technology transfer, and custom compounds.
Yulex Corp.
Maricopa, AZ
www.yulex.com

 

Spotlight on Cables and Connectors

I/O cable assemblies
Designed to provide a high-current-density alternative to cable-to-board power connectors, a line of low-profile I/O cable assemblies is based on stamped and formed power contact technology. Pwr Profile+ connectors are available with two power contacts for power and return applications, two signal pins for power control or for determining which ports have mated cables and which are empty, and an optional grounding shield on the board connector to support electromagnetic compatibility. Signal pins for power control can be used when the application requires current or voltage monitoring or battery-level feedback. The polarized connectors are rated to 37 A per power contact without exceeding a 30°C temperature increase in still air.
FCI
Etters, PA
www.fciconnect.com


ZIF connectors
Utilizing a landed contact system, a range of zero insertion force (ZIF) connectors for medical diagnostic and imaging equipment does not exhibit connector-engagement force. The only wear on the contacts occurs as they are pressed together and lightly wiped past each other during the camming and locking operation. The connectors feature a minimum rated life of 10,000 complete mating and unmating cycles with no performance loss. They can also be mated in less than two seconds and keep crosstalk to a minimum, making them suitable for ultrasound equipment, patient-monitoring and portable imaging machines, MRI machines, and hospital equipment. Available with 60 to 2496 contacts, the connectors feature gold-plated copper-alloy contact material.
ITT Interconnect Solutions
Santa Ana, CA
www.ittcannon.com


Plug connectors
A line of versatile medical connectors and cables consists of plug connectors with leads and electrode clips. The 1.5-mm plug connectors in the Medicalline series are suitable for transmitting voltage away from patients in ECG and heart-monitoring devices. Compliant with E-DIN 42802-2, the 2-mm connectors in the series can also be used for voltage and current supply to the patient through such devices as pacemakers and muscle stimulators. Meeting DIN 42801 requirements, the 6-mm plug connectors and connecting leads offer potential equalization between the bodies of electrical medical devices and the conductive elements of other objects. The connectors can be equipped with gold-plated contact elements for high reliability and corrosion resistance, and insulating materials that can withstand steam sterilization are offered.
Multi-Contact USA
Santa Rosa, CA
www.multi-contact.com


Protected connectors
Featuring a virtually unchanged exterior, a touchproof, watertight, and shielded electronic equipment connector has been redesigned to simplify internal components. The redesign reduces the likelihood of complications arising during the assembly process. Besides offering a simplified design, the Mini-Snap PC connector incorporates shielding to protect against electromagnetic interference and seals that offer IP67-rated protection against liquid ingress in the mated condition. Specializing in cable and connector integration, the manufacturer also offers cable assemblies that can withstand challenging medical environments. Its connectors and assemblies are also available in disposable and autoclavable models.
ODU-USA Inc.
Camarillo, CA
www.odu-usa.com


Custom connectors and cable assemblies
With capabilities ranging from small to large production volumes, a contract manufacturer specializes in the custom fabrication of durable connectors and cable assemblies for the medical device industry. Each product is designed with tight tolerances to fit cleanly into small devices, including parts that are assembled under a microscope. However, components in standard and above-standard sizes are also produced. The company can manufacture and assemble connectors and cables for patient diagnosis and monitoring, nerve integrity monitoring, hearing enhancement, and sleep and respiratory studies. Design, molding, and assembly are all carried out in a single facility that includes a mold-making shop and injection molding technology. Products are designed in conformance with ISO 9001:2008 standards.
Plastics One Inc.
Roanoke, VA
www.plastics1.com


Coaxial cable
A patented dual-monofilament coaxial cable design is suitable for use in demanding medical applications. Designed to withstand harsh environments, the cable's monofilaments protect the signal. In addition, its air-gap design allows air to circulate around the conductor, increasing signal speed. The monofilaments are twisted and wrapped around the signal, enabling an 85% velocity of propagation. Then, an FEP fluoropolymer dielectric is extruded in a tube over the twisted monofilaments, surrounded by shielding, and covered with a final jacket. The high-speed data cable is manufactured to customers' specifications and features mechanical tolerances that yield consistent electrical performance. Design options include impedances ranging from 50 to
75 Ohm.
Temp-Flex Cable Inc.
South Grafton, MA
www.tempflex.com


Limiting-port cables
Low-power, passively equalized copper cables that are compliant with the SFF-8431 Revision 4.1, Chapter 3 specification for limiting modules are offered as an alternative to active copper technology and optical transceiver modules in medical equipment applications. The limiting-port SFP+ assemblies, based on patented conductor technology and a low-loss ePTFE cable dielectric, satisfy the limiting-port specification up to 7 m without dependence on active technology. These cables do not have to provide electrical dispersion compensation on the receive side. In addition, the core and skin design of their conductors provides a distributed per-unit-length equalization without requiring resistor-inductor-capacitor circuitry on the connector paddle card. This equalization minimizes jitter, which could limit the maximum signal transmission.
Gore
Newark, DE
www.gore.com