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Articles from 2001 In June


Connectors Offer New Twists on the Mating Ritual

Originally Published MPMN June 2001

Connectors Offer New Twists on the Mating Ritual

Suppliers focus on size and cost reductions to keep device OEMs satisfied.

Whether intending to attach cables to electronic devices or to create a link between two different sizes of tubing, medical device manufacturers must consider several factors when choosing their connectors. A chief concern is cost: designers want to trim down expenses as much as possible but without compromising the quality of their finished products. Size is also important, as some devices require multiple components and run the risk of becoming too bulky and heavy if their parts aren't as compact as possible. Other important factors include assembly time and cost, chemical resistance, and EMI and heat reduction. In an effort to meet these challenges, suppliers have developed a range of connectors to suit varied requirements. Read on for examples of new developments in connector technology.

Feedthrough minimizes overheating and electromagnetic coupling

Manufacturers requiring metal connectors for electronic devices seek components that help to prevent overheating and resulting power loss. Ceramaseal has designed an RF feedthrough that brings cooling water close to the seal at the conductor-insulator interface to control heat without complex cooling jackets. The ceramic-to-metal feedthrough is suitable for a variety of RF applications including sputtering, plasma generation, and induction heating. "Metal components of RF feedthroughs usually will heat up and negatively affect the efficiency of the system as well as damage their own hermetic seals," says design engineer Rich Combs. "Ceramaseal's RF feedthroughs keep all metal components at a proper distance, place the hermetic seal at the joint to improve reliability, and utilize a dual conductor design with one piece of ceramic so that no metal flange resides between conductors." The feedthroughs have a 100-kHz to 13.56-MHz frequency range and a -55°–350°C temperature range. They handle currents up to 800 A and voltages up to 10 kV. Standard feedthroughs are available as weldable and flange-mounted units. Custom configurations include additional coolant lines, custom coolant flow paths, solid conductors on the vacuum side, large flanges, coils, and other accessories. The <1-in.-diam single-conductor version can fit into a specially designed O-ring seal and is available with compression fittings.

Stamped and formed contacts cut costs

The Minisnap PC from Odu-USA Inc. is a light connector that is easily integrated into assemblies.

Metal connectors used on medical devices can add significant weight to the end product. In addition, the labor required to make a cable termination can cost as much as the connector itself. To address these concerns, Odu-USA Inc. has developed the Minisnap PC, which can be used in handheld instruments and portable equipment. The connector weighs only 15 g, providing a significant weight reduction. This plastic cylindrical push-pull connector requires minimal panel space, can be blind mated, and clearly indicates whether it is mated or unmated. The connector is made of temperature and chemically resistant polyethylenimine that allows it to be used in mechanically demanding applications. Its exterior is made of all plastic parts, which enables users to touch it even in high-voltage applications. A nonmagnetic connector makes the Minisnap PC suitable for MRI machines and other applications that cannot tolerate EMI. According to the company's CEO Ralf Eberlein, the most innovative feature of the Minisnap PC is "the stamped and formed contact that can be produced for only a few cents, offering a tremendous cost advantage over machined contacts that can cost as much as 60 cents." In addition, the contacts can be terminated on automated crimping machines, reducing the cost of connector assemblies. The connector is autoclavable when used with PEEK inserts and can be produced in a shielded version with metallized internal surfaces.

Heat-seal connectors attach by hot bar bonding

Manufacturers integrating displays into their portable devices may have difficulties attaching them safely without creating excess bulk. This problem is eliminated when heat-seal connectors are used to connect glass or plastic flat-panel displays to PC boards without solder or clamps. Elform Inc. offers ultrafine-pitch monostropic heat-seal connectors that have an integral conductive adhesive system that attaches by hot bar bonding. The company uses graphite-based adhesive inks that offer 35-W/sq in. resistance in lieu of amorphous carbon, which provides 100-W/sq in. of resistance. Synthetic rubber used in the graphite ink formula makes connector traces flexible at any pitch: the connectors may be repeatedly hard creased without compromising performance. The monostropic construction involves screen printing the ink on 23-µm PET-based film at a pitch as fine as 0.18 mm. A second layer of ink is loaded with gold-plated nickel particles to ensure low contact resistance, and is screened over the first layer. The part is then covered with a thermoset adhesive that is loaded with titanium dioxide and yellow pigments to simplify part inspection. Monostropic construction allows fine pitches, high yields, and low bonding rework rates without the risk of particle cross talk or shorting.

Circular connectors offer snap-in screwless assembly

To enhance connection options and reduce assembly time, a line of miniature circular connectors features snap-in application, screwless assembly, and a nonthreaded, self-activating, push-pull locking system. The newest additions to the series, the Neutricon and Nanocon from Neutrik USA, offer a chuck-style relief that accepts 3- to 7-mm cable diameters and flat ribbon cables. The Neutricon is a modular system of one- to eight-pin cable connectors and panel receptacles that can be used for medical instrumentation in nonsterile applications. "The miniaturization of this connector does not jeopardize its quality or reliability," says product applications manager Fred Besnoff. "In fact, this connector is extremely versatile and can withstand high-traffic areas." The system includes mechanically protected gold crimp, solder, or vertical PCB contacts. Nickel or black chrome-plated receptacle or cable end housings absorb vibration and protect loaded inserts. Splashproof cable shells are standard.

Like the Neutricon, the Nanocon has gold-plated contacts that are suitable for hardwired soldering. It is a three-pole subminiature connector that measures only 0.19 x 1.22 in. The Nanocon offers a selective load of one to three contacts in mating cable ends, PCB vertical or horizontal male and female receptacles, or male and female solder termination receptacles. Panel receptacles with blank inserts, mating cable ends with interchangeable inserts, and fully loaded PCB receptacles are available. "The spacing between the contacts allows the Nanocon to be selectively loaded with the precise amount of contacts required," says Besnoff.

PEEK luers are cost-effective and chemically resistant

Value Plastics Inc.'s PEEK luers feature a versatile single-barb design.

Medical-grade polyetheretherketone (PEEK) barbed male and female luers have been developed to provide OEMs with connectors that can withstand various types of sterilization. Supplied by Value Plastics Inc., these components accommodate tube sizes from 1/16 to ¼ in. The luers integrate the company's 500-series single-barb design that uses blended radii for enhanced versatility with various tubing sizes and types. Compared with compression fitting techniques, the luers require fewer components to make a tubing connection and are more cost-effective. PEEK luers offer high-temperature performance, chemical resistance, and hydrolysis resistance in steam or high-pressure water environments. PEEK can retain its properties even after repeated autoclave cycles and can be EtO, gamma, or E-beam sterilized. "PEEK luers were developed in response to the industry's need for a material that would not lose its properties after repeated sterilizations, yet it still costs less than brass or stainless steel," says sales manager Dave Splett. "While polysulfone is a good material for the medical industry, it is not as chemically resistant as PEEK."

Katherine Sweeny

Connecting Robots, Surgeons, and Patients

Originally Published MPMN June 2001

Profile

Connecting Robots, Surgeons, and Patients

Connectors designed for robotic surgery applications feature enhanced shielding.

Zero-insertion-force connectors can withstand more than 10,000 mating cycles with no signal degradation.

Robotic surgical systems can require the use of dozens of connectors to maintain a reliable information flow. A crucial concern for engineers who specify connectors for these systems is the potential for electromagnetic interference (EMI) and radio-frequency interference (RFI). Zero-insertion-force (ZIF) connectors developed by ITT Industries Cannon (Santa Ana, CA) have a built-in shielding mechanism, which was developed for use in the da Vinci robotic surgical system designed by Intuitive Surgical (Mountain View, CA) to perform minimally invasive surgery.

"The da Vinci creates three small punctures between the patient's ribs and sends in probes," explains Cannon design engineer Jim Moore. "One probe is fitted with a camera, and two others have fingerlike devices, or endofactors. All of these parts—the input video, video monitors, robotic arms, and endofactors—are modular and need to be connected," Moore says.

ITT Industries Cannon engineer Jim Moore developed a version of the company's connectors for use in the da Vinci robotic surgical system.

Moore collaborated with Intuitive Surgical and other manufacturers of robotic surgical systems to develop a version of Cannon's DL ZIF connector that would meet the OEMs' rigorous requirements. In particular, he enhanced the connector's shielding to protect the devices from EMI and RFI.

Conventional connectors with a plastic housing require an outer shell of some kind, or mounting hardware, to act as a shield, notes Moore. "Our connector has a metal backshell that is attached to the body of the cast aluminum, nickel-plated connector," he explains. "This provides a direct shielding path."

Reliability and durability were also key factors in the connector design, he notes, and Cannon's track record in ultrasound equipment, where its connectors have an 85% market share, was a significant asset. "It's a proven component guaranteed for a minimum of 10,000 cycles with no signal loss or degradation," Moore says. The high cycle rate is a function of the zero-insertion-force feature.

"When the ZIF connector is fully mated, the contacts do not touch each other," says Moore. Conventional pin-and-socket connectors are limited in their number of cycles because the plating deteriorates each time they are mated, he adds.

Intuitive Surgical's da Vinci system integrates computer-enhanced robotic technology to translate the surgeon's natural hand and wrist movements on the console into corresponding micromovements of instruments positioned inside the patient. The device received FDA clearance for use in thorascopic surgery in March 2001; it was previously approved for use in laparoscopic procedures. "This brings Intuitive one step closer to receiving clearance of the da Vinci system for cardiac surgery," says Intuitive Surgical medical director and cofounder Fred Moll.


Neoprene Isolators Reduce Oxygen Concentrator Noise, Vibration, and Assembly Time

The elastomer isolators are more durable than rubber mounts.

It would be rather ironic for an oxygen concentrator to clear the air while emitting noise pollution. Yet the motor that typically runs a concentrator produces so much vibration that the device could shimmy across a table if it were not properly isolated. When Mallinckrodt (St. Louis), a manufacturer of medical respiratory equipment, sourced new isolators for its concentrators, attenuation of noise and vibration was a key criteria. As it turned out, durability and a reduction in assembly time were part of the bargain.

The Mallinckrodt Model 590 oxygen concentrator is designed for home use. The concentrator takes in room air and passes it through a compressor. The compressed air then passes through timed valves into a regenerative system. Air is pumped into one canister, or sieve column, which captures the nitrogen and releases oxygen from the bottom. The system then switches and pumps air through a second column to release further oxygen.

During operation of the valves, the compressor runs continuously on an electrical motor with two pistons, causing considerable vibration. According to Sandy Walker, manufacturing engineer for Mallinckrodt, "These devices are used in a person's home, so they need to be nondisruptive. You don't want to have to put the concentrator in the other room while you're watching television."

Vibration isolators ensure that Mallinckrodt's oxygen concentrator operates quietly within a patient's home.

Mallinckrodt had been using vibration isolators on its oxygen concentrator, but the components were expensive and they complicated the assembly process. Mallinckrodt engineers surveyed the marketplace for alternatives and found Barry Controls (Brighton, MA), a company specializing in products and systems that control vibration, mechanical shock, and structure-borne noise.

The rubber mounts that Mallinckrodt had been using would degrade after three or four years of use. The company briefly tried a spring-mount system, but the engineering team realized that this created its own set of problems. According to Walker, "The assembly of the spring-mount system was comprised of a lot of parts. Because these parts were custom made, they were costly and had long lead times." They also added to an assembly process that was already very time-consuming.

Barry's engineering department performed several weeks of rigorous vibration tests on the concentrator and, based on their observations, developed a multiplane isolator constructed from a neoprene elastomer.

The isolators are made of a neoprene elastomer and attach to the feet of the compressor.

Mallinckrodt tested the isolator design for several months, evaluating its performance at extreme temperatures and conducting shock and vibration testing. The company's engineers determined that the neoprene was able to withstand the tests better than a silicone isolator that they had also been considering. "We picked the neoprene elastomer because it had better tear resistance, and the material properties indicated that it would last through our five-year warranty period," says Walker.

The Barry engineering team also was able to streamline the number of parts needed for the isolators. The original spring-mount system required six different parts—Barry reduced that number to three. To Mallinckrodt, this meant an improvement to its bottom line, because it resulted in less assembly time.

Furthermore, Barry's isolators worked on both the domestic and international models of the concentrator, whereas other mounts Mallinckrodt tested did not.

Mallinckrodt has been producing the Model 590 concentrators with the new isolators, and, considering the cost and assembly time savings, is pleased with the results. The patients who use it are breathing a little easier, too.

Copyright ©2001 Medical Product Manufacturing News

Ultrasonic Welders Multiply Control Functions

Originally Published MPMN June 2001

EQUIPMENT NEWS: Welders and Sealers

Ultrasonic Welders Multiply Control Functions

Users can manipulate fine details of the welding process

The secure joining of plastic or metal parts is an important part of the fabrication process for many medical devices. In this section, new welding and sealing equipment is described that can help you to perform these operations. Ultrasonic welders that offer in-depth process control, an industrial arc welding robot, and a laser assembly system with a large work area are among the featured products.

Many weld parameters can be controlled via a user interface on an ultrasonic welder by Branson Ultrasonics Corp.

Offering multiple operating modes for applications that require a high level of process control, an ultrasonic welder from Branson Ultrasonics Corp. ensures quality by allowing users to digitally program many parameters, including weld force and actuator-descent speed. The versatile 2000f ultrasonic assembly system can also adjust weld distance, time, energy, energy compensation, and peak power. Step force can be manipulated during both welding and holding cycles. All adjustments are made via a user interface with a four-line display that eases setup, operation, and troubleshooting. The password-protected unit stores all operating parameters to preset values to eliminate the need for manual adjustment. Most values can be set in either metric or standard units.

But versatility is not the system's only feature. The 2000f welder is also equipped with an advanced power supply that automatically tracks and compensates for changes in the horn frequency. Special electronic circuitry offers five levels of power protection to prevent equipment failure and increase weld quality. This quality is further improved as the actuator return speed is fixed independently of other settings. Rapid traversing increases production rates. Other features include processing limits that identify suspect parts. According to worldwide media segment manager Michael Kan, these factors "reduce cavitation, minimize rejects, and tremendously increase operating windows."

The 2000f is designed for use in manual, semiautomated, and fully automated environments. The system can function as a stand-alone unit or it can be mounted to a machine frame. Three models are available, with power configurations of 20, 30, and 40 kHz. The advanced power supply provides increased output for all frequencies. The 20-kHz model is rated at 1100, 2200, or 3300 W; the 30-kHz unit at 1500 W; and the 40-kHz welder at 400 or 800 W. All three models are compatible with many material-handling devices and external controls.

An ultrasonic welder from Stapla Ultrasonics Corp. features an indexed tool exchange system.

The K1 ultrasonic welding system from Stapla Ultrasonics Corp. also allows increased process control. Weld time, energy, and both absolute and relative depth are programmable via a user-friendly controller with a key switch. Once programmed, the generator allows one-button operation. The welder has an indexed exchange system for changing welding tools. Business manager Juergen Gaebler says that the system "eliminates unnecessary alignment and setup by allowing users to exchange tools by loosening just two bolts." With the capability for self-calibrating force measurement and automatic data adjustment, the unit's control system examines process inconsistencies and adjusts tolerances accordingly to decrease the occurrence of defects. Other features include a self-diagnostic program and an optional PC control unit. The welder operates at a frequency of 20 kHz and has a power rating of 3000 W.

RF welders seal tubing

The generator for an RF welder by Markperi International Enterprises Inc. is mounted directly beneath the press to improve voltage distribution.

Suited for tube sealing and progressive die operations, an RF welder from Markperi International Enterprises Inc. combines a space-saving generator with high-efficiency electronic circuitry. The generator for the Console welder is mounted directly underneath the press, allowing the use of a special power feed that ensures equal voltage distribution and uniform sealing. This unique construction "lets the transmission line be shorter and wider, increasing stability and balance," explains Markperi president Mark Gruenspecht. With an accuracy of ±0.6%, the frequency-stabilized generator outputs energy at a frequency of 27.12 MHz. The rugged unit features a welded steel cabinet and heavy-duty C-frame press. Three digital timers measure preseal, seal, and press dwell durations. Controls for power level and arc suppressor sensitivity ease use. Safety features include a high-voltage circuit breaker and two-handed operation. An optional switching network with dual power and seal time selectors allows the generator to perform two separate sealing cycles simultaneously. Because the special construction also gives the unit a small footprint, the welder can be used where space is limited.

An RF welder from Sebra seals a variety of dielectric tubing materials.

The Model 3113/3120 industrial RF welding system by Sebra seals dielectric tubing made of a variety of materials, including PVC, polyurethane, ethylene vinyl acetate, and some nylons. The pneumatically actuated unit's generator is CE marked and features solid-state electronics. It can produce outputs of 150 W. An autoswitching feature guarantees correct operation for single-phase input voltages of 100–230 V. Operator controls on the front panel set power levels and welding and clamp times. Dwell time can be controlled externally using a PLC. Suited for bonding applications required for external-use medical devices, the unit's electrodes can be customized to fit customer requirements.

Robot performs arc welding

Performing intricate welding tasks, an industrial robot from Fanuc Robotics North America Inc. features six axes of motion.

Featuring six axes of motion, an industrial robot has the flexibility needed to perform intricate arc welding tasks. The Arc Mate 50iL from Fanuc Robotics North America Inc. has good dexterity and fast wrist speeds to improve throughput. With a modular construction and electric servomotors, the robot also has a small footprint, which increases the number of units that can be installed in a given workspace. The machine can be mounted in either upright or inverted positions with no modifications. A double-jointed design allows for overhead welding. With sealed bearings and drives, the machine can be used in harsh factory environments. An optional collision guard is available to detect collisions before damage occurs.

Computer system stores weld data

A welding control system by Weldlogic Inc. stores data on thousands of welds.

The AWS-2000 control system from Weldlogic Inc. allows a high level of process manipulation in tungsten inert gas and plasma welding applications. Built around an industrial computer capable of storing data on thousands of welds, the system includes a 14-in. color monitor and graphics-based software. The machine can be used to set a weld current of 150–300 A, determine weld speed, provide arc distance control, and perform data acquisition. A modular design eases the integration and upgrading of weld elements. A selection of welding lathes, weld heads, motion devices, and high-purity chambers are offered as options.

Ultrasonic sewing horn minimizes drag

Amplitude modulation allows an ultrasonic welder from Dukane Corp. to be used on a variety of materials.

An ultrasonic sewing machine for joining fabrics and films has a horn capable of rotating 360° to reduce drag. Suited for use with most synthetics, the DLSM 360°–20 sewing machine by Dukane Corp. also features a 20-kHz generator that offers 35–100% of amplitude control. "By being able to control the amplitude," explains marketing manager Joe Re, "it is possible to use this machine on a wide range of materials." The sewing machine is constructed with a heavy-duty frame and is available with a variety of lace and seal patterns. A large LED display is used to monitor system procedures. Independent speed controls for the horn and lace roller allow for fine control of the sewing process. The machine can be controlled by an operator or integrated into an existing production line. Edge-guiding, rewinding, and feed rolls can also be added to the machine.

Laser system features large workspace

A laser system by Zmation Inc. has a usable workspace of 48 x 48 in.

Offering a repeatability of ±0.0004 in. and a maximum travel speed of 19.6 in./sec, a laser welding system from Zmation Inc. has a usable workspace of 48 x 48 in. The Z-LMP welding system comes equipped with a precise CO2 or Nd:YAG laser that has a wavelength of 10.6 or 1.06 µm and a power rating at 10–500 W. Vice president John Lee says that this accurate laser "provides a fast, uniform weld, even on dissimilar materials." The system requires a power feed of 115 or 220 V, 60 Hz. The welding process is controlled by a rack-mounted computer with menu-driven software that is suited for high-volume jobs or low-volume, high-mix applications. Safety features include an interlocked enclosure and a fume extractor. Video-alignment or automated vision systems are available to ensure quality. The versatile system can also be configured to perform laser marking and machining.

Benchtop heat sealer provides versatility

Benchtop equipment from Packworld USA offers repeatable control of sealing times up to 9.9 seconds.

The BPS sealer by Packworld USA is suited for both laboratory and production-line heat sealing of plastics and other materials. Consisting of a control module and a platen press, the benchtop machine allows precise, repeatable control of sealing times up to 9.9 seconds and temperatures as hot as 300°C. An auxiliary device output allows for even greater process control. The machine is available with a 6 x 8-in. platen that delivers up to 490 lb of force. For safety purposes, the platen is initially closed against the work piece at a low pressure. The press can be tooled to seal pouches and clamshell packages, form contoured seals, and attach fittings. Standard and custom sealing heads and platens allow the machine to fit specific needs. A model rated for Class 10 cleanrooms is available.

Zachary Turke

Copyright ©2001 Medical Product Manufacturing News

Nondestructive Method Improves Porous-Package Testing

Originally Published MPMN June 2001

HOTLINE

Nondestructive Method Improves Porous-Package Testing

Gas sensor is used to detect leaks

Technology for the nondestructive testing of Tyvek packaging will be integrated into machines like Mocon's Pac Guard 400, which is designed for production-line quality control and package development applications.

A manufacturer of testing equipment recently acquired intellectual property that provides a unique method for detecting defects in porous packages. Mocon Inc. (Minneapolis, MN) purchased technology from True Technology Inc. (Boston, MA) for the nondestructive testing of packages made of DuPont Tyvek. The technology promises to provide an attractive alternative to current methods, which rely on destructive dye or pressure tests.

"Tyvek-containing packages breathe—how do you know if they are leaking?" asks Dane Anderson, chief financial officer at Mocon. The company's new test relies on tape placed over a porous Tyvek package. A tracer gas is introduced, and a sensor detects any leakage of the gas from within the package.

According to Anderson, the advantages of the new testing method for medical OEMs are twofold: "First, it's sensitive; the test gives a specific signal with defective packages," he says. This is in contrast with the visual inspection methods currently employed by device manufacturers. "Secondly, the test is nondestructive, so you are not losing package and product," he adds, explaining that this is particularly important for high-value products.

Mocon is a provider of testing systems and consulting services for the assessment of materials and processes. The company plans to incorporate its new technology into a new whole-package integrity testing device that will join its standard product line early next year. "This patented technology will enable us to introduce other instrumentation and services for testing the integrity of a variety of sterile medical packages," says the company's president and CEO, Robert Demorest. Mocon began by manufacturing permeation-testing equipment, but now also offers technology for leak-testing nonbreathable packages for drugs and medical devices.

Benjamin Lichtman

For more information, contact Mocon Inc., 7500 Boone Ave., N. Minneapolis, MN 55428; ph: 763/493-6370; fax: 763/493-6358; URL: www.mocon.com; email: mocon@mocon.com or True Technology Inc., 143 California St., Newton, MA 02458; ph: 617/630-9911; fax: 617/630-0365; URL: www.truetechnology.com; email: info@truetechnology.com


Laser-Sintered Metal Prototyping Process Yields Durable Metal Parts Quickly

The process makes fully dense metal parts using stainless-steel alloy material

LSM prototypes are fully dense metal parts made directly from CAD data.

Laser-sintering of metal is one of the fastest ways to rapid prototype fully dense metal parts, prototypes, and tooling inserts for plastic injection molding. Rapid Prototype Company, Inc. (Auburn Hills, MI) uses LaserForm ST-100, a powdered metal material made with a stainless-steel alloy to produce complex, durable metal parts directly from CAD data. The metal material allows a better surface finish and a stronger model. Parts can be polished, textured, plated, and machined, and typical turnaround time is only four to seven days.

Laser-sintered metals offer two advantages. First, cavity and core tooling inserts can be created quickly and use production materials. "Most other short-run or bridge-tooling options can't run production materials, and the few that can don't get high part volume because the tooling quickly wears," says Rob McCarthy, Rapid Prototype Co. marketing manager. Laser-form molds have shot greater than 100,000 injection-molded plastic parts.

The other advantage of this process is that it can be used to create metal parts directly. "Previously, parts could be made in nylon materials, or in photo polymers, and used to evaluate form," says McCarthy. "But if the part is metal in production, a plastic one just doesn't have the same feel. Imagine a plastic fork versus a stainless-steel one." Designers want the feel of the real thing, he adds. "Previously this meant machining parts, investment casting, and sand casting, processes that take more time and that have constraints. With the sintering process, we can provide multiple iterations in less time," says McCarthy.

Karim Marouf

For more information, contact Rapid Prototype Company, Inc., 4141 N. Atlantic Blvd., Auburn Hills, MI 48326; ph: 248/391-6600; fax: 248/391-7462; URL: www.rapidprototypeco.com; email: rapid@rpparts.com


Software Manages Manufacturing Changes

Streamlining the change process helps shorten time to market

Using Manufacturing Change Manager, anyone involved in a manufacturing process can track changes via the Internet.

Manufacturers can shorten product introductions and achieve faster time to market and volume production using Web-based Manufacturing Change Manager (MCM) from Ingenuus Inc. (Sunnyvale, CA). MCM is an automated solution that allows manufacturers to manage product and process change requests and orders in real time throughout the global supply chain. Using MCM, every kind of change request and change order is efficiently routed, reviewed, and approved.

"The rapid rate of technological change, combined with a demand for more powerful and customizable products, means that product lifecycles are often measured in months rather than years," says Dave Allenbaugh, vice president of sales. "These developments are forcing manufacturers to rethink and streamline their change process in order to remain competitive."

Since it integrates easily with any enterprise data system, MCM is suited to companies managing multisite engineering, manufacturing, sales, and distribution operations connected via the Internet.

MCM's Smart Expediter controls the flow of change by providing a virtual tracking agent that understands business relationships, monitors progress, and eliminates bottlenecks. The Smart Expediter pushes and tracks entire packages of information through the supply chain, including manufacturing and engineering orders, indentured bills of materials, drawings, specifications, procedures, and other essential documents. It tracks change of all types, including customer, supplier, purchasing, manufacturing, engineering, ISO, and variation change requests.

Karim Marouf

For more information, contact Ingenuus Inc., 830 E. Arques Ave., Sunnyvale, CA 94086; ph: 408/774-2199; fax: 408/522-9450; URL: www.ingenuus.com; email: dklint@ingenuus.com


Medical Product Manufacturing News is always on the lookout for innovative products and services. If you are aware of any that have recently been or are about to be introduced, please call the Hotline editor, Karim Marouf, at 310/445-4267

Copyright ©2001 Medical Product Manufacturing News

Conference Summary: Radiation Processing Professionals Go Back to the Future at Avignon Meeting

Originally Published MPMN June 2001

INDUSTRY NEWS

Conference Summary: Radiation Processing Professionals Go Back to the Future at Avignon Meeting

Ionization equipment manufacturers and subcontractors joined researchers from around the world at the majestic Palais des Papes in Avignon, France, in March for the 12th International Meeting on Radiation Processing. The biannual meeting provides industry professionals and members of academe with an opportunity to share news on scientific advances, new applications, and evolving standards. The unusual conference venue prompted chairman Théo Sadat from Thomson CSF Linac, the French manufacturer of accelerators, to welcome delegates to industry's "first high-tech meeting in the new millennium . . . in a historic 700-year-old building." Following a dramatic opening ceremony with a medieval accent, delegates rolled up their sleeves and got down to the business of the twenty-first century. In the Conclave room, where cardinals once sat to elect a pope, and elsewhere within the palace, discussions turned to topics such as polymeric grafting, e-calibration of dosimeters, and substantiating a 25-kGy sterilization dose.

Better polymers through grafting

A palace guard leads the opening ceremony of the International Meeting on Radiation Processing, held this year at the Palais des Papes in Avignon, France.

Grafting polymers by means of a radiation or UV source holds enormous potential for a range of industries including the biomedical sector, according to Adolphe Chapiro, former president of the French Association of Polymer Research and Applications (Strasbourg, France) and noted scientific author. Calling it a powerful means to alter a polymer's properties and to create new materials, Chapiro noted that the technology permits bulk or targeted modifications. "In grafting polyethylene to acrylic acids, for example, you retain all of the properties of polyethylene while fostering strong adhesion to metals," he said. "For implant applications, a biocompatible polymer can be grafted onto the surface of another polymer that is not suited for invasive use [but which may be desirable for other properties]," he added. Although there have been few industrial applications of this technology thus far, Chapiro noted that animal trials have shown great promise.

By combining grafting with the charge-transfer (CT) complex engendered by ionized curing, a much stronger bond between materials can be created, noted Jack Garnett from the department of materials and chemistry at the University of Western Sydney (Australia). Chairing a session devoted to curing processes, Garnett told attendees that the use of photoinitiators (PIs) to promote UV-initiated and E-beam curing, as is common today, limits the effectiveness of the process. "These additives increase the cost of UV-curing materials and may lead to contamination of the cured film with PI fragments," he said. Recently discovered UV- or gamma-initiated CT complexes--defined as an aggregate of two or more molecules in which the charge is transferred from a donor to an acceptor--eliminate the need to add PIs. However, he added, this may adversely affect a material's adhesion to a substrate. To remedy this, Garnett recommended concurrent grafting and curing, which can be accomplished by using either a UV or radiation source.

The combination of grafting, which produces a chemical bond, and curing, which creates a physical bond, results in strong adhesion, he said. Radiation processing has an advantage over UV in this regard, he added. "With ionizing radiation systems, you produce radicals as well as positive and negative ions," Garnett explained. "This provides additional mechanistic pathways to achieve grafting."

Compact radiation units introduced

A compact irradiator designed for low-volume applications was presented by MDS Nordion (Kanata, ON, Canada; www.mdsnordion.com) at the Avignon meeting. By rethinking the structure and operation of conventional gamma sterilizers, MDS was able to substantially reduce the cost of the unit (which is briefly described in the Equipment News section of the April 2001 issue of MPMN). The Brevion is affordable for a category of customers that, until now, may not have considered investing in an on-site gamma unit, according to Daniel Levesque, director of sales, Europe, industrial irradiation, at MDS Nordion.

Unlike traditional gamma systems, the Brevion transports totes to the irradiator source via tracks. To reduce downtime during batch changes, MDS developed a cartridge concept that enables a single unit to process two source passes. As one batch of irradiated products slides out from the sterilizer, the track system automatically positions the second batch for processing. Changeovers are performed in less than 5 minutes, and typical processing time is 3 to 5 hours. Because there is no maze or storage conveyor and the unit is shipped largely preassembled, installation costs have been slashed by 75% compared with conventional units. Setup time is less than 4 weeks. The primary markets for the Brevion, according to Levesque, are medical device manufacturers processing small product volumes and contract service providers in developing countries with a small but growing device industry.

A compact E-beam system developed by Mitsubishi Heavy Industries Ltd. (Nagoya, Japan; www.mhi.co.jp) was also presented at the meeting. The C-band 5712-MHz accelerator is reportedly the first of its kind to achieve 10 MeV acceleration energy. It measures 60 cm in length and weighs 20 kg. The machine is suited for sterilization and nondestructive inspection applications.

On-line dosimetry calibration coming soon

"Industry wants high-quality calibration services, rapid turnaround, and, everyone wants it as cheaply as possible," said Marc Desrosiers, research chemist at the Institute of Standards and Technology (NIST; Gaithersburg, MD) at a session devoted to dosimetry.

The organization is currently testing a system that would allow companies to calibrate dosimeters via the Internet. "The company would have to be equipped with an Electron Paramagnetic Resonance (EPR) spectrometer connected to a PC and a batch of presupplied alanine dosimeters," he explained. The Internet calibration program on the NIST server will control the evaluation and guide the technician through the various steps. A provisional certificate will be issued within a matter of minutes; after appropriate quality checks have been conducted at NIST, an official certificate will be delivered.

An obvious advantage, noted Desrosiers, is the elimination of the current 3- to 5-day turnaround time. "Calibration services will be offered on demand 24 hours a day, seven days a week, and the results will be available in minutes." Because the process requires no oversight from NIST staff, fees will be drastically reduced, he added.

On-line calibration against the U.S. national standard gamma-radiation source is currently undergoing testing. NIST expects to make the subscription-based service available to customers worldwide starting in 2002. For more information, go to the NIST Web site at www.nist.gov.

Substantiating the 25-kGy sterilization dose

Both ISO 11137 and EN 552, standards related to the validation and routine control of radiation sterilization, permit the use of 25 kGy as a sterilization dose provided that it can be substantiated that it achieves a sterility assurance level of 10-6. Unfortunately, neither document provides guidance on how to show substantiation. Craig Herring, senior fellow, sterilization science, at Ethicon Endo-Surgery Inc. (Somerville, NJ), a Johnson & Johnson company, presented a paper in which he described a process, called Method VDmax, for the substantiation of 25 kGy.

"The process is markedly similar to Method 1 in ISO 11137, which was done deliberately to avoid confusion," said Herring. "If you test 0/10 or 1/10 positive, then the dose is substantiated. If you show 2/10 positives, a confirmatory test is required; a 3/10 positive rate means that the dose is not substantiated," he explained. The method was tested in a parallel study against Method 1 at three different J&J facilities, said Herring, using three different categories of products: disposables, implants, and sutures. A total of 421 dose audits were conducted over a three-year period without any failures, reported Herring. "Only a handful of products required confirmatory tests, all of which ultimately proved to be positive," he added. The procedure will be described in AAMI/FDSB-1 TIR 27, which will be available this summer from the Association for the Advancement of Medical Instrumentation (www.aami.org).

Norbert Sparrow

Robotic Fish May Hold Key to Better Artificial Limbs

Robotic Fish May Hold Key to Better Artificial Limbs

Scientists at Massachusetts Institute of Technology (Cambridge, MA; web.mit.edu) have developed a robotic fish incorporating whole frog-muscle explants that may be the first step toward building better prosthetic devices for humans. Based on Luigi Galvani's 1786 discovery that an electrical current makes a dissected frog's legs twitch, this new research explores the issue of tissue to replace the inefficient synthetic means of momentum currently used in artificial limbs. The first successful example of this technology is a 120-mm biomechatronic "fish" that combines an electronics package with a 50-mm section of frog muscle. Buoyed by a Styrofoam block in a glucose solution that serves as a source of energy, the unit uses a microprocessor to send variable electrical signals to the muscle tissue. The resulting contractions enable the fish to start, stop, and turn with a maximum speed of 60 mm/sec.

Using real muscle in prosthetic devices will yield many benefits, according to researchers. Muscle has the ability to adapt to its environment, healing and changing structure as required. It is also very efficient, generating as much as 4000 kJ from 1 kg of glucose under aerobic conditions. This energy is generated silently, eliminating many of the noise concerns associated with traditional devices. Because it delivers great isometric force, hybrid technology would also allow prosthetics to have extremities that are light but still very strong.

MIT scientists are presently working on developing muscle cultures that can survive outside their source body for several months. The tissues currently used remain effective for only a few hours. Other goals include creating the technology necessary to engineer muscle tissues directly from small tissue samples taken from the device user. Native sampling would allow the prosthesis to be fully compatible with its beneficiary. Among the many parties that have shown interest in this hybrid technology are the Pentagon's Defense Advanced Research Projects Agency, which may focus on developing hybrid suits to increase the physical capabilities of U.S. soldiers.

Zachary Turke

Midwest Molders Form Collective

Midwest Molders Form Collective
The Midwest Tooling Association used its combined resources to produce this Class 101 mold in just four weeks.

In an effort to combat a slowing economy, 20 Midwestern plastic injection molding companies have formed a collective corporation that offers fast turnaround and consistent quality regardless of the tooling package size. The Midwest Tooling Association (Stillwater, MN; www.midwesttoolingassociation.com) uses its combined resources in plastic-injection, die-cast, and thermoset molding to match each project with the individual tooling shop that has the required expertise and availability. A customer simply submits a print or CAD file to begin the process. Additional markups are avoided because each shop works directly with its clients. All molds are tested and have samples submitted and approved before shipping. According to president Scott Wahl, the association allows OEMs to "get molds rapidly built and tested without having to deal with molders who aren't interested in just building the mold."

Zachary Turke

Design Software Simplifies Creation and Validation of Automation Systems

Design Software Simplifies Creation and Validation of Automation Systems

The Onestep Generator program from Schneider Electric reduces automation system design costs for regulated industries.

An object-oriented software program simplifies the design process for automation systems in regulated industries by configuring applications using a smart control-device code library. Aiding with compliance to FDA 21 CFR Part 11 regulations, the Onestep Generator program from Schneider Electric (Philadelphia; www.schneiderelectric.com) translates functional specifications into a process control system format. The program also automatically creates content for validation protocol documents, provides version control, and tracks changes. New applications are created using a process analysis view that draws on a cache of stored data for pumps, drives, valves, and other process objects. Incremental compile and generation features allow engineers to add, delete, and upgrade the system throughout the software's implementation and maintenance phases. Because it provides a uniform platform for design and specification, the software also facilitates a common design methodology among users and minimizes mistakes, implementation times, and engineering and validation costs.

Zachary Turke

New Smart Plastic Has Good Memory

New Smart Plastic Has Good Memory

This shape-memory plastic from mnemoScience reverts to its parent shape in 45 seconds at a temperature of 65°C.

What if it were possible to create plastic objects in one shape, deform them to fit other requirements, and then have them return to their original `shape when needed? For years, nitinol and other alloys with these memory properties have been used in everything from catheter wires to eyeglass frames and orthodontia. But these metals have limitations, including restricted pliability and resource-intensive fabrication. That is why Robert Langer and Andreas Lendlein, two scientists working at Massachusetts Institute of Technology (Cambridge, MA; www.mit.edu), set out to create a shape-memory plastic that would be easier to mold and control. And as announced in the January 30, 2001, issue of Proceedings of the National Academy of Sciences, the pair has succeeded in creating a mixture of polymers that reliably remembers its shape when properly combined and treated.

This novel material, composed of oligo-dimethacrylate and n-butyl acrylate, works similarly to existing shape-memory alloys. The plastic is formed in its parent shape and heated to a high temperature, locking in that particular arrangement as the unit's natural structure. Upon cooling, the piece can be molded into any desired temporary shape that is within the material's mechanical limitations. This structure is retained until the material is subjected to its transition temperature, when it rebounds to its original shape. This process can be repeated an unlimited number of times.

Though these new plastics may work in a similar fashion to their metallic predecessors, they hold several distinct advantages. Programming metal to remember its shape is a time-consuming process that requires temperatures of several hundred degrees Celsius. Shape-memory plastics, on the other hand, can be conditioned in seconds at temperatures around 70°C. Plastics can also be bent to a greater degree and still return to their original shape. The maximum deformation with metal is about 8%; with plastics, it is 300–400%. By varying the ratio of the two polymers, plastic also offers the benefit of an easily adjustable transition temperature. "Sometimes it doesn't make sense to have the material transition at 32°C," Dr. Lendlein explains. "You might want 42°C instead. With this polymer, you can easily adjust the transition temperature. With a shape-memory metal, that's difficult." It is also thought that it may be possible to make shape-memory plastics respond to transition stimuli other than heat. Light, ultrasound vibration, and moisture have been cited as possible alternatives.

Because the material is also biocompatible, shape-memory plastics have numerous potential medical uses. They could increase the flexibility in stents, stitches, and catheters. They could also be used to produce the opposite effect in devices that contract as a result of an environmental stimulus. Lendlein and Langer have set up a new company called mnemoScience (Aachen, Germany; www.mnemoscience.de) to explore these and other medical and commercial applications. Among some of the nonmedical uses being considered: car bumpers that snap back to their original shape after an accident.

Zachary Turke

New Technologies Cut Production Times at Emerson & Cuming

New Technologies Cut Production Times at Emerson & Cuming

Manufacturing a complete line of electronic materials including lossy microwave absorbers and low-loss dielectrics, Emerson & Cuming Microwave Products Inc. (Randolph, MA) has added a pair of new production technologies that reduce fabrication times and costs. A water-jet CAD/CAM unit eliminates the lengthy process of working with suppliers to identify die tooling requirements and to produce prototype parts. This machine allows the company's design engineers to provide in a matter of days drawings and cut parts, including those made from their Eccosorb, Eccostock, and Eccoshield lines of elastomers. Parts with complex dimensions are not suitable for this process.

Recently installed autodispensing equipment has also reduced costs and increased the application speed of liquid-cast microwave-absorbing materials. Fully automating the precision loading of absorbers into housings, this mold-in-place technology makes it unnecessary to die-cut and manually apply adhesive-backed materials. Handling a wide range of temperatures, the epoxy-based material has a long adhesion life. Material thickness and absorption loading can be varied to suit specifications. According to Michael Plante, director of sales and marketing, "typical turnaround time to apply the mold-in-place absorber is two weeks from the receipt of customer order and hardware."

Zachary Turke