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Articles from 1998 In May

Software Manages Design and Development of Cardiovascular Device

Software Manages Design and Development of Cardiovascular Device

Quickly getting a new product to market is critical in today's economy. However, the complexities involved in creating a new product, especially under a paper-based documentation system, can be a major roadblock to rapid market introduction. CardioGenesis Corp. (Sunnyvale, CA), a manufacturer of medical devices for severe coronary artery disease, is seeking FDA approval for a series of new cardiovascular devices designed to relieve uncontrollable angina. How soon these devices become available to surgeons and cardiologists depends on how quickly CardioGenesis can meet regulatory requirements.

The company is currently developing three transmyocardial revascularization (TMR) devices to treat severe angina. These laser-based devices will enable doctors to create tiny channels in oxygen-deprived regions of the heart muscle that cannot be treated with either coronary artery bypass surgery or percutaneous balloon angioplasty. Critical to creating the TMR devices is maintaining a product development cycle that delivers these devices safely, precisely, and rapidly—and also is able to provide the necessary documentation for FDA and European CE-mark approval.

"Our cardiac surgeons and cardiologist customers expect a product that meets their needs and safely performs as it should every time it's used," says CardioGenesis CEO Allen Hill. Therefore, he says that an effective control system is essential to building products that have very high degrees of reliability when they are used in these incredibly demanding surgical environments.

Eliminating the Paper Trail

After reviewing several products, CardioGenesis selected the RapidPDM system from ConsenSys Software Corp. (San Jose) to manage its design and development processes. By implementing RapidPDM software, CardioGenesis automated its product development tracking and communications processes, reducing the time and cost associated with a paper-driven system. More important, the RapidPDM system facilitated quality control and regulatory approval by providing comprehensive documentation and an audit path for the TMR devices' development and design processes.

CardioGenesis required a software system that could be easily deployed and maintained, minimizing the demand on the company's information systems (IS) department. The program has empowered the company's engineering control board to plan, track, and manage the documentation release of its medical devices.

Within the 80-person company, CardioGenesis has approximately 25 installed computers. ConsenSys software resides on a Windows NT server and runs on Windows 95 desktops. The software was up and running within five days, and the company's users were trained on it in a half hour and were fully proficient in about two days.

"I find the ConsenSys system very intuitive and easy to use," says Marie Perez, CardioGenesis document services manager. "The key for a company such as ours is that we don't have the information systems department resources for administration and program management. With ConsenSys, I don't have to wait around for an IS technician; I manage the software myself."

Extensive Audit Trail Provided

FDA and European CE-mark review boards have the ultimate say on when and if a medical product will reach the market. The RapidPDM system has played an important part in facilitating the regulatory approval process by providing an extensive audit trail, documenting each stage of product development. According to the company, the software system has enabled it to move the TMR devices to market months fast-er than was possible before.

"The ConsenSys automated system effectively addresses a critical variable in the regulatory approval process—documentation. It greatly reduces risk in this game of infinite details," says Hill. "The software has helped us complete the review of documents related to the European approval process, providing us with market opportunities that are worth hundreds of thousands of dollars to our company."

Since RapidPDM was implemented in September 1996, it has helped CardioGenesis deliver the necessary documentation for CE-mark approval, contributing to the approval of the intraoperative TMR device launch in Europe. The software has also helped the company receive FDA clearance for beginning multicenter clinical trials of its percutaneous TMR device.

Product Development Process Streamlined

Prior to using RapidPDM, CardioGenesis relied on a manual, paper-driven development tracking and documentation process. The paper-based system was time-consuming, particularly when the company tried to get sign-off on engineering change notice (ECN) approvals. The review process was also time-consuming and burdensome. Approval required sign-off by six to eight people, resulting in a manual tracking of both reviewers and documents that could take days.

Using the software, Hill can now review a substantial ECN document in 15 to 20 minutes. He also can monitor the approval process on-line, making it possible to quickly identify and resolve any bottlenecks. According to Hill, benefits include the efficiency of the documentation process and the accuracy in product development. "I like how I can see the revisions on the system alongside the final document. In the old paper-based document system, I had to view each document physically side by side, and that took forever. Moreover, everyone had to manually write his or her annotations and then decipher each others' handwriting."

The software has also diminished the need for ECN board meetings. CardioGenesis used to meet two or three times a week for two hours in what Hill says often resulted in tumultuous debate. "Now, when the ECN board does need to meet, everyone sits in the conference room. The RapidPDM application and pertinent documents are projected on a screen for review and discussion, and changes are made in real time, eliminating additional review loops." The company estimates that the reduction of ECN meetings has saved $37,000 a year.

CardioGenesis has seen similar cost benefits by empowering its us-ers and keeping the document services group to one person, while still handling the increased documentation and workload that have resulted with the company's expansion. In medical device companies with manual, paper-driven systems, an average of two to six people are dedicated to the documentation process. By eliminating the need to hire additional document services staff, the company estimates that it has saved up to $300,000 a year.

"We've seen great benefits in our ability to solve our time-to-market and regulatory challenges while managing our resources effectively," says Hill. "This software will continue to play an important role in helping us bring our coronary medical devices to market worldwide."

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Machining services


Machining services

Ultraprecise machining of medical and dental components, devices, implants, and instruments is offered by a company that has capabilities in prototype and short runs to full production. The company specializes in titanium, platinum, stainless steel, and other exotic metals using CNC Swiss screw machines. Other services include turning, microhole drilling, fine threading, CNC milling, slotting, fine deburring and polishing, bead blasting, and other finishing. Specialized Medical Devices Inc., P.O. Box 1704, Lancaster, PA 17608.

Plastic components

A company supplies precision-machined plastic components to the medical device industry. It can machine reusable surgical instrument handles, bone-drill motor housings, fittings, and various other plastic components. Prototype through production-quantity runs are efficiently processed in its manufacturing center. Whether the requirements are preproduction-machined prototypes or a production run of an existing design, the firm can incorporate the customer as an integral member of its manufacturing team. Materials include Radel-R, Ultem, polysulfone, Delrin, UHMWPE, nylon, ABS, and PEEK. American Industrial Plastics Inc., 724 Fentress Blvd., Daytona Beach, FL 32114.

Precision machining

A full-service contract manufacturer has 37 years of experience with the design, production, and assembly of metal, plastic, and rubber products for medical applications. Capabilities include CNC machining (four axis), CNC jig grinding, CNC wire EDM, EDM drilling, mold building, plastic injection molding, and metal stamping (long and short run).The company also designs and builds compound and progressive dies for metal stampings from miniature components to those requiring up to 75-tn presses. Die design and building of rubber and plastic molds, as well as manufacturing of plastic injection molded parts, are also available. Straton Industries Inc., 180 Surf Ave., Stratford, CT 06497.

Close-tolerance parts

An OEM supplier provides extremely close-tolerance components. Surgical parts are machined for the dental, orthopedic, pacemaker, neurological, laparoscopic, and instrumentation industries. Materials routinely used include titanium, medical grades of stainless steel, gold alloys, and many other difficult-to-machine metals and plastics. The FDA-registered company also offers 100% burr-free inspection, CNC capabilities, and prototype-to-production services. Microcision Inc., 5805 Keystone St., Philadelphia, PA 19135.

Close-tolerance parts

An FDA-registered manufacturer is dedicated to machining close-tolerance metal and plastic components for use in medical devices, implants, and diagnostic instrumentation. Capabilities include CNC milling, turning, and Swiss turning. Prototype through production quantities are accepted. Manufacturing is in compliance with ISO 9002 and GMP standards. Criterion Instrument, 5349 W. 161 St., Brook Park, OH 44142.

Tubular products

Two problems that some medical device manufacturers face are finding desired alloys including 6-4 titanium in tubular form, and accurately drilling them in lengths beyond 3 or 4 in. Using a proprietary process, a company can solve both these problems. It can drill these alloys and maintain at least a 0.25- to 0.38-mm TIR wall variation throughout a length of 400 to 500 mm. A key advantage to this process is that the company can provide this accuracy in a device with a finished OD size. No finish grinding is necessary to correct concentricity. The process enables metallurgists to provide the optimum choice of alloys to design engineers for the development of tubular devices and implants. Dearborn Precision, 80 Portland St., Fryeburg, ME 04037.

Machining and contract manufacturing

A full-service contract manufacturer has capabilities in precision laser cutting and welding, five-axis CNC, five-axis machining and grinding, and five-axis EDM. It has stamping and coining presses up to 220 tn. Forming, bending, deburring, and finishing services are provided. The company has 20 years of experience in developing surgical, dental, and medical products. DS Mfg. Inc., 2188 Knoll Dr., Ventura, CA 93003.

Machining of specialty metals

A company specializes in the machining of precious metals. Services include CNC Swiss-type screw machining, electrical discharge machining, milling and lathing, machine part coating, and laser-weld subassembly. A range of medical-grade specialty metals are available. The firm's analytical measurement capabilities ensure that products are produced on time and to specification. Johnson Matthey, Precious Metals Div., 1401 King Rd., West Chester, PA 19380.

Rapid micromachining

A company offers complete prototype micromachining and contract manufacturing services. A compact system using laser micromachining technology allows quick prototyping of medical devices. The MicroMaster microdrills, strips, and etches polymers, glass, thin metals, ceramics, and inorganic materials with tolerances from microns to millimeters. It is designed for engineers who require a flexible machine to bring products to market from design concept to final tooling. Once the process is developed, the system can often be used as the final production equipment. Resonetics Inc., 4 Bud Way, #21, Nashua, NH 03063.

Custom high-precision machining

Custom-designed components are available as prototypes or for long production runs from a company that offers precision machining with CNC and Swiss automatic screw machines. Complex components can be manufactured with diam tolerances to ±0.0002 in. in sizes ranging from 1/32 to 3/4 in. Projects have included a catheter for atherectomy and a specimen carrier for high-pressure tissue freezing. Statistical process control is performed to ensure that high-quality parts are delivered on time. Swiss Precision Inc., 908 Industrial Ave., Palo Alto, CA 94303.

Laser micromachining

A company offers a variety of precision laser micromachining services. Capabilities range from the machining of thick- and thin-film ceramic substrates to resistor trimming and dynamic integrated circuit link blowing. Additionally, permanent laser marking of packages, lids, substrates, and components is provided. Other laser services include welding, package delidding, microfine wire stripping, precision heat treating, and surface ablation. Titanium, BeO, AIN, diamond, quartz, silicon, and tungsten are some of the materials processed. Questech Services Corp., 2201 Executive Dr., Garland, TX 75041.


An ISO-certified company has a micromachining division that provides manufacturing services, specializing in the machining of miniature and micromachined ultraprecision medical device components. Critical and complex parts are machined in one operation for enhanced accuracy, repeatability, and production rates using eight-axis Swiss CNC and five-axis micromills. Micromachining work includes prototyping for preproduction and production in a variety of volumes, applications, materials, and scheduling requirements. Remmele Engineering Inc., Micro Machining Div., 17701 U.S. Hwy. 10, Big Lake, MN 55309.

Wire-based components

A supplier of precision wire-based medical components offers continuous conical-needle grinding capabilities. The process produces mirror-finish parts with ultraprecision tips. Applications include solid conical points with straight linear tapers, and convex/concave or bullet-shaped profiles. Chamfered tubing and tapered pins can also be produced. Capabilities include diameters from 0.010 to 0.130 in. and lengths up to 5 in. in a variety of materials such as stainless steel, tungsten, and nitinol. New England Precision Grinding / Precision Wire Co., Milford, MA 01757.

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Design Center Helps Bring Complex Injection-Molded Part to Market

Design Center Helps Bring Complex Injection-Molded Part to Market

Parts evaluation at the design stage facilitated company's production process

A manufacturer of medical devices used worldwide in cardiac catheterization labs was designing a new product that would require multiple gates and a complicated configuration for an injection-molded part.

Merit Medical (Salt Lake City) wanted to evaluate the product design while it was still in the computer-generated prototype stage, to identify processing and manufacturing issues critical to the final success of the project. However, the company did not have the in-house capabilities required to do a proper analysis.

A development specialist at M.A. Hanna runs an evaluation of a part, while still in computer-generated prototype stage, to identify critical processing and manufacturing issues.

Merit turned to M.A. Hanna Resin Distribution (Cleveland) to review the project and make recommendations using advanced computer engineering tools.

With technical support provided by Hanna's design center, Merit Medical was able to review options and make critical decisions by weighing multiple factors for tooling before manufacturing. Mary Sinnott, project leader for Merit Medical, says it was a very worthwhile experience. "The product we were working on is very complex, with multiple components and intricate channels and valves. Evaluating where the knit lines would be and how we could adjust their positioning was very important."

Chris Harton, senior development specialist for M.A. Hanna, ran the evaluation of the part. Before his team did mold-flow analysis, they looked at the computer-generated model and made some initial suggestions that would help in processing and production. Harton says, "We did the analysis to determine the optimum gate locations to minimize weld lines. Other work involved looking at injection times and melt temperatures. Each step gave us different parameters and choices to evaluate."

The final phase of the analysis involved using new CAD/CAM software to examine the thickness of the part wall. "This is brand new," says Harton. "It allows us to look at the entire thickness of a wall rather than just at the midplane."

"The gating information was very important," says Sinnott. "At the design stage we were able to identify and minimize backfilling in critical areas. This process is valuable for designing challenging parts."

M.A. Hanna's design center offers advanced technical support in all areas of plastic application design, development, and manufacturing. Capabilities and services include CAE for product design using a 3-D solid modeling CAD/CAE system, finite element analysis for optimized part performance, and mold-fill analysis to provide guidance for tooling and final part performance. Other services include a range of analytical capabilities such as thermal analysis, Fourier transform infrared spectroscopy, atomic absorption spectroscopy, gas chromatography, polymer identification and selection, surface analysis, moisture determination, custom-compound formulation, prototyping, and physical testing.

Merit Medical is currently configuring its new product, which is expected to go to market midyear. The design and configuration of the tool was facilitated by the extensive capabilities and technical support services provided by M.A. Hanna Resin Distribution.

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Products Featured on the May 1998 issue of MPMN

Products Featured on the May 1998 issue of MPMN

Fluorescing UV adhesives permit in-line inspection

A line of fluorescing adhesives for medical device assembly offer fast cure times and low processing costs. The MD 1000 adhesives cure upon exposure to both visible and UV light. The adhesives glow when exposed to low-intensity black light, permitting in-line visual or automated inspection before or after the curing process. Applications include production and assembly of needles, face masks, reservoirs, catheters, and tube sets. Dymax Corp., 51 Greenwoods Rd., Torrington, CT 06790.

Precision metal stampings and preforms available

Metal stampings and preforms can be made from almost any alloy in sizes ranging from a 0.0035-in. square to custom shapes as large as 6 in. Capabilities include melting, extrusion and continuous casting, rolling, tool and die making, and stamping and deburring, as well as inspection and packaging. The products are commonly used as a brazing material in feedthroughs, which are incorporated into pacemakers and other devices. Coining Corp. of America, 280 Midland Ave., Saddle Brook, NJ 07663.

Miniature ultra-low-pressure sensors offered for airflow measurement

A series of miniature ultra-low-pressure sensors are intended for use in airflow measurements in handheld instrumentation or medical breathing equipment. The DUXL-series sensors provide a stable ratiometric millivolt output in low-profile PCB-mount packages. They are available in full-scale pressure ranges of 1, 5, 10, 20, and 30 in. H2O for gauge or differential measurement. Data Instruments Corp., 1000 Discovery Way, Acton, MA 01720.

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Editor's Page

Editor's Page

It's All in the Packaging

Even if your primary job function is the design of a medical device, it's likely that the product's packaging comes into play very early in the development process. After all, the package must be compatible with the function of the product, and it must be able to withstand the desired method of sterilization.

Packaging can also play an important role in a product's commercial success. While a well-designed package can increase acceptance of a product in the field, a poorly designed one can have a negative impact on sales.

Whether or not you're a packaging engineer, it's important to have a solid understanding of how to design a package and how to make sure it will maintain the product's sterility. And in this industry's ever-changing regulatory environment, it helps to stay informed.

A great way to do this is by attending industry conferences, which serve as forums for sharing ideas. One such event is coming soon: the Medical Packaging Symposium. Being held at New York City's Javits Center June 1—2, the fourth annual symposium will offer a comprehensive conference track designed just for engineers that deal with packaging.

The symposium is sponsored by Pharmaceutical & Medical Packaging News, a sister publication of MPMN, and will cover a variety of topics from regulations to working in the global environment. One session will be led by Andrew Lowery of FDA's Division of Small Manufacturers Assistance.

Several how-to sessions will focus on different methods of testing medical packaging. Topics include implementing a packaging performance testing program under ISO 11607, accelerated-aging studies, restrained-plate fixtures used in seal-strength testing, and nondestructive leak testing of porous packaging.

To prepare attendees for designing packaging for the global marketplace, sessions on global harmonization of standards and testing and on the global implications of bar coding will be offered. Leveraging and enforcing group purchasing contracts and monitoring distribution will also be discussed.

And technical sessions on such topics as optimizing thermoforming parameters when using Eastar PETG copolyester and polymer catalysts and their effect on materials performance will present in-depth information that can simplify medical package design.

The symposium will be held in conjunction with Medical Design & Manufacturing (MD&M) East—which features a comprehensive four-day conference track of its own—and the Atlantic Design Engineering show. Both shows will take place June 2­4 (conferences start June 1) at the Javits Center. For information on attending the Medical Packaging Symposium, contact Vaughn King at 714/992-1919. To register for MD&M East or the Atlantic Design Engineering show, contact Canon Communications, Trade Show Division, at 310/392-5509.

Ursula Jones

X-y-z dispensing systems

X-y-z dispensing systems

A line of x-y-z systems are designed for automatic placement of adhesives in medical device manufacturing applications. Many different types of adhesives can be used, including UV adhesives, epoxies, solvents, super glues, and RTVs. The manufacturer offers both stepper-controlled, belt-driven systems for point-to-point dispensing with repeatabilities of 0.0002 in. or servomotor-driven systems with precision-ground leadscrews that are capable of making arcs, circles, and complex movements with a repeatability of ±0.0008 in. The system software is capable of up to 2000 commands with a recall of as many as 512 programmed coordinates. Glenmarc Manufacturing Inc., 25661 Hillview Ct., Mundelein, IL 60060.

Adhesive dispensing system

A pneumatically operated dispensing system provides precise control for dispensing low-, medium-, and high-viscosity anaerobic, cyanoacrylate, and light-curing adhesives typically used in the assembly of metal, rubber, and plastic device subcomponents. The Bond-A-Matic 3000 eliminates the need for small-container premiums, reducing adhesive costs by as much as 50%. The unit's handheld Vari-Drop applicator valve enables the operator to control the amount of adhesive dispensed. Loctite Corp., 1001 Trout Brook Crossing, Rocky Hill, CT 06067.

Solvent dispensers

Solvent dispensers for use in medical device manufacturing are designed for bonding PVC, ABS, and other polymer components. The dispensers are available in three different configurations with one, two, or four dispensing bushes. Once the tubing or component is inserted into the bush, it is instantly ready for bonding. The dispensing bushes are custom made so that solvents can be dispensed on external or internal tubing surfaces, soft and rigid drip chambers, needles, conical surfaces, and various types of connectors and components. The solvent dispensers are manufactured with materials that are resistant to the most common solvents employed to assemble medical products, such as cyclohexanone, methylethylketone, dichloroethane, and tetrahydrofuran. All solvents or mixtures must be pure and particle-free. Technomed Inc., 68 Stiles Rd., Salem, NH 03079.

Pump for dispensing

A line of precision pumps integrates valveless piston technology with precision stepper motor control. The Model STQ pump features one moving part—a ceramic piston that rotates and reciprocates within a precision ceramic liner—and an inert fluid path of ceramic and fluorocarbon. The pump dispenses at a rate of 0.002­1.28 ml/stroke with greater than 1% accuracy. Fluid Metering Inc., 5 Aerial Way, Ste. 500, Syosset, NY 11791.

Dispensing systems

A variety of dispensing systems are offered for use in medical equipment manufacturing processes. Dispensed materials can include adhesives, soldering masks, RTVs, silicones, soldering paste, and more. The Model KDS834A-D can be adapted to accept materials directly or via prefilled syringes. Syringe sizes include 3, 5, 10, and 30 cm3. Kahnetics Dispensing Systems, 2260 S. Vista Ave., Bloomington, CA 92316.

Reel-to-reel dispenser

A reel-to-reel dispensing system has the ability to handle delicate membranes and filter materials. The Matrix 6100 easily supports most liquid-related processes required for lateral-flow test strip development and manufacturing. Its high-efficiency dryer allows for accelerated web speeds when running in either the discrete striping mode or the wide-angle spraying mode, or in the dipping configuration. Quick-change modules enable production changeover from one process to the next in a simple, repeatable manner. Kinematic Automation, P.O. Box 69, Twain Harte, CA 95383.

Solvent dispensing system

A dispensing system provides neat and controlled application of solvents, cyanoacrylates, and other thin, watery assembly fluids. A 0–15-psi pressure regulator and microprocessor-based timer allow thin fluids to be applied in consistent amounts. By combining accurate timed-pulse dispensing with precision components specifically designed for use with low-viscosity fluids, the benchtop 1500XL-15 dispenser ensures reliable bonds and reduces cosmetic rejects. Fluid is loaded into a handheld barrel reservoir, into which an LV barrier is inserted to improve fluid control and contain fumes. Dispense tips feature clog-resistant Teflon liners and a precision crimp that help restrict the flow of very thin fluids. EFD Inc., 977 Waterman Ave., East Providence, RI 02914.

Single-component dispenser

A lightweight single-component dispenser provides cost-effective dispensing of thick liquids, greases, or pastes. Designed for trouble-free point-of-use dispensing, the SC dispenser can accept a number of 30–35-ml barrels or syringes. The lightweight design is manufactured from a durable plastic with a good mechanical advantage. The unit is well suited for adhesives and glues. TAH Industries Inc., 107 N. Gold Dr., Robbinsville, NJ 08691.

Robotic dispenser

A stand-alone robotic dispenser features a programmable z-axis with three independently controlled dispensing heads, making it suitable for dispensing multiple liquids or pastes in one production process. Each head of the Challenger 3H is mounted on a microadjustable slide for quick setup and easy adjustment. Materials of various consistencies from water to thick paste can be used. The robot includes brushless programmable motors, preloaded leadscrews, and ball slides for tight machine tool performance. The unit can be constructed from stainless steel, hardcoat aluminum, or polycarbonate. A pressure pot slides up on precision guides, enabling easy access to containers when loading and unloading. Online Inc., 3980 Albany St., McHenry, IL 60050.

Dispensing pen

A lightweight dispensing pen designed for manual operations facilitates dispensing of low- to medium-viscosity materials. Materials such as solder mask, liquid flux, oil, or paint are fed to the JC1015 pen from a reservoir or cartridge. Material flow is easily controlled by the pressure regulator found on most reservoirs. Featuring an instant finger-controlled shutoff function that accommodates dot, bead, gasketing, and potting applications, the pen can accept a variety of tips. I & J Fisnar Inc., 2-07 Banta Pl., Fair Lawn, NJ 07410.

Positive-displacement valves

Metering rod positive-displacement valves offer precise, programmable dot-to-dot or bead dispensing consistency. The Model 1053 valves, designed for servo or step motor drives, accurately dispense beads or dots ranging from 0.002 to 3.6 cm3. Virtually any single-component material can be used, including sealants, lubricants, acrylics, urethanes, epoxies, UV curables, and silicones, in a variety of consistencies. The valves are adaptable to single- or multiple-needle dispense blocks as well as workstations and automated equipment. LCC/Dispensit, 6896 Hillsdale Ct., Indianapolis, IN 46250.

In-line automatic dispenser

A multipurpose in-line fluid dispensing system can handle virtually any conveyorized production application with ease. Featuring a noncontact dispensing head, the Champion 7600 system dispenses at a speed of 30,000 dots per hour and is capable of dispensing precise dots of material down to a volume of 0.0022 ml when equipped with the manufacturer's True Volume pump. The automatic dispenser works on a precision height- compliant conveyor system with antistatic belt. It also features path optimization, CAD download, and automatic vision alignment. Windows-style software facilitates setup and changes. Creative Automation Co., 11641 Pendleton St., Sun Valley, CA 91352.

Cartridge-filling machine

Achieving consistent and level void-free fills, particularly when filling dual-type cartridges that are typically used to package two-component epoxies, silicones, and urethanes, can be troublesome for some manufacturers. A new benchtop cartridge/syringe dispense system can automatically fill dual-type cartridges to accurate, repeatable preset levels and eliminate the need for secondary operations. The Filla dispensing machine delivers consistent, voidfree fills by combining bottom-up filling with a low-clearance nozzle and adjustable cartridge/material counterbalance system. Initially designed to handle medium- to heavy-viscosity materials, the dispenser also accepts materials of low viscosity. Tridak, 1120 Federal Rd., Brookfield, CT 06804.

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Laser System Incorporates Direct Beam Delivery


Laser System Incorporates Direct Beam Delivery

Spot-beam focusing capability permits fine cutting and drilling

A LASER MACHINING SYSTEM originally engineered for integration with fiber-delivered lasers for welding has been enhanced with direct beam delivery capabilities. Direct beam delivery, which enables beam focusing to smaller spot sizes than is possible with fiber delivery, expands the applications of lasers to include fine cutting and drilling.

Developed by Lumonics (Kanata, Ontario, Canada), the Laserdyne Model 140 uses precision mirrors and optics to direct the laser beam to the workpiece and focus it on a precise spot with a diameter of 0.001 in. or smaller. Product manager Terry VanderWert says that "this is essential for intricate cutting and drilling applications."

The system features a three-axis Class 1 laser workstation and a powerful Laserdyne 94/PC laser process control. An optional rotary table enables the processing of 3-D parts. Digital signal processors and a high-speed serial bus provide 200-microsecond servo update time for quick and accurate multiaxis motion.

The x- and y-axis travel is 12 in., while z-axis travel is 6 in. An optional rotary axis provides continuous rotation for applications involving circular parts and tubing. X- and y-axis accuracy is ±0.001 to ±0.0002-in. full travel, achieved by using linear encoders and laser interferometer calibration. Z-axis accuracy is ±0.005 in. Repeatability is within 0.0005 to 0.0002 in. for the x-and y-axes, within 0.005 in. for the z-axis, and within 20 arc-sec for the rotary axis. Load capacity is 100 lb for the x- and y-axes, and 50 lb for the rotary axis.

All laser, motion, and process parameters can be controlled from the keyboard or from within the part program. Programming features include variables, subroutines, beam radius compensation, character generation, and axis and plane rotation.

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Filter Ensures Delivery of Sterile Gas

Maximizes use of its membrane surface while maintaining a hydrophobic barrier

A FILTRATION DEVICE has been specifically engineered for sterile gas delivery in healthcare applications.

Pall Gelman Sciences (Ann Arbor, MI), a manufacturer of filtration and separation products used in healthcare, diagnostic, and laboratory research applications, recently developed the Intervene filter to handle gases filtered at extremely low pressures, providing complete use of the filter membrane's surface while maintaining a hydrophobic barrier. This allows maximum air/gas-flow rates with minimal pressure drop while protecting equipment from exposure to fluids. The result is consistent end product performance.

The rectangular, low-profile housing design incorporates an effective filtration area of 18.5 cm2 of PTFE membrane or a proprietary hydrophobic glass media. Connection options include 1/4-in. hose barb or 3/8—1/2-in. stepped hose barb connectors. Typical uses for the Intervene filter are in insufflation, blood oxygenation, vacuum protection, and oxygen concentration applications. Custom printing is also available.

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Uv Curing

Bonding Technique Yields Rugged UV Lamp

Can be used to cure adhesives or sterilize devices

USING A PATENTED TECHNIQUE for bonding sapphire to metal seals, a company developed a linear sapphire lamp that can tolerate very high operating temperatures (2050°C), enabling shorter processing and curing times. It also permits high lamp-operating temperatures and high power levels of lamp loading.

By bonding sapphire to metal seals, Xenon Corp. (Woburn, MA) eliminated a potential weak point—the seal between metal and nonmetal—and developed a lamp of high-quality construction and performance.

A manufacturer of standard and custom-designed pulsed- and continuous-wave UV curing and processing systems, Xenon uses this innovative sapphire-to-metal bonding technology to produce lamps that provide numerous benefits. According to the company, the fine optical properties of sapphire provide better wavelength transmission than do traditional quartz envelopes, and its strength offers safety advantages during lamp handling and mounting to equipment. Sapphire lamps are suitable for such applications as lasers, UV curing systems, and pulsed-light sterilization.

Sapphire lamps transmit from 140 nm of deep UV through 7800 nm in the far infrared. Heat transfer is up to 27 times faster than quartz, and operation at higher power levels for longer periods of time is possible. As a result, sapphire lamps can help reduce production costs and labor time.

Designed as an integral part of fast-acting curing systems, the lamps can also be used as replacement bulbs.

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European Wound-Management Market Expected to Grow 8.9% in the Next Five Years


European Wound-Management Market Expected to Grow 8.9% in the Next Five Years

Switch to moist dressings drives growth

According to a report from MarketLine International, the switch from traditional wound dressings to modern moist dressings has helped the European wound-management industry grow at a compound annual rate of 8% over the period 1993-1997. What's more, the market in Europe is predicted to maintain strong growth at a compound annual growth rate of 8.9% from 1997 to 2002. MarketLine predicts that the value of the market will increase from its current level of $269.7 million to $412.1 million in 2002.

Moist wound dressings are more cost-effective because not only is the frequency of dressing changes reduced, but wounds heal more quickly in a moist environment. With users recognizing the cost benefits of these dressings, MarketLine expects the rapid growth of the market to continue into the next millennium, despite strong downward pressure on prices as a result of hospital budget constraints. This is not good news for manufacturers of low-priced traditional dressings, whose products are looking increasingly obsolete.


Despite good prospects for moist dressings, the potential for new entrants to succeed in the market is unclear. MarketLine analyst Thomas Chan comments, "With such attractive growth in the modern dressings market, it should, in theory, be possible for new entrants to be accommodated. However, the reality is more complex, with different systems, such as reimbursement lists, operating in different countries. It remains to be seen how much of the approval process will be harmonized with the implementation of CE marking this year." The present high profits for moist dressings are set to come under increasing pressure in the future as competition increases and buyers command more power through the formation of buying groups and tendering.

Although certain market segments such as films are quite mature, there remains great potential for growth in newer sectors, such as the hydrocolloids market and the less developed segments of alginates, foams, and gels. The European hydrocolloids market has largely been driving the growth of moist dressings, as they have the greatest user awareness among the range of such dressings available. The market has increased almost 40% since 1993, from $126.2 million to $176.2 million. Despite the falling prices for dressings caused by increasing competition and buyer power, volume growth has been strong and will continue to drive the market in the future.

The foam dressings market is relatively young and represents just a small percentage of the overall market. Uptake of foam products is increasing, although it has been hindered in the past by a lack of product awareness. According to MarketLine's forecasts, there is great growth potential for this sector, especially as some users are presently unable to distinguish between hydrocolloids and the lesser-known products.

The fastest growing segment of the wound management market over the last five years has been in alginate dressings. It has been driven by an increasing awareness of their use as an alternative to hydrocolloids for treating specific indications. The European market is forecast to grow with a compound annual growth rate of 18.2%, reaching $49 million in 2002.

For more information on this report, contact MarketLine International at +44 171 6242200, e-mail

Foam Manufacturing Facility to Open

Zotefoams to invest $25 million in new facility

Zotefoams plc, a UK-based manufacturer of cross-linked foams, has announced that it is bringing its foam manufacturing technology to the United States. The company plans to invest $25 million in a new facility that is expected to be operational in 2000.

Randall Redd, president of Zotefoams Inc. (Hackettstown, NJ), the company's U.S. subsidiary, says, "When complete, the facility will produce our complete range of products, including Plastazote cross-linked polyethylene foams, Evazote cross-linked VA copolymer foams, Supazote cross-linked super-soft copolymer foams, and our new Propozote polypropylene foams."

The company's unique manufacturing process expands the foam by using pure nitrogen, resulting in high product quality and consistency. The process also allows production of foams with a very wide range of properties, from very soft and smooth Supazote materials to tough but moldable high-density Plastazote products.

For more information, contact Zotefoams Inc. at 800/362-8358.

Thomson Industries Acquires Airpax Mechatronics Group

Acquisition allows company to offer new line of subfractional-horsepower motors

Thomson Industries Inc. has acquired Airpax Mechatronics Group, a division of Philips Electronics North America Corp. As part of the Thomson Industries Group, the acquisition has been renamed Thomson Airpax Mechatronics LLC.

The Airpax Mechatronics Group designs and manufactures subfractional-horsepower motors, digital linear actuators, gearmotors, and motor electronics, and has operations in North America, the Far East, and the United Kingdom. John Thomson, Jr., chairman of Thomson Industries, says, "Thomson Airpax Mechatronics represents a strategic diversification in technology that complements our position in linear motion and our emerging strength in control technology. This will take us into new fields of motion control and motor technology."

For more information, contact Thomson Industries at 516/883-8000.

Design Award Finalists to Be Spotlighted at MD&M East

Award winners to be honored at gala dinner on June 3

The finalists of the 1998 Medical Design Excellence Awards will be on display at the Medical Design & Manufacturing East Conference and Exposition, June 2-4, 1998, at the Jacob K. Javits Convention Center in New York City. Show attendees will have the opportunity to view the finalist products and receive information about how to submit an entry for the 1999 competition. The award winners will be announced during a gala dinner ceremony at the Plaza Hotel on the evening of June 3, and will be subsequently published in the July/August issue of Medical Product Manufacturing News.

The awards program, which recognizes excellence in medical design and engineering, drew more than 230 medical device, component, and material entries. The awards program is sponsored by MPMN's publisher, Canon Communications llc, and endorsed and administered by the Industrial Designers Society of America.

For more information, contact Canon Communications at 310/392-5509, e-mail

Return to the MPMN home page

ISO 14001: Should Your Company Seek Registration?

Medical Device & Diagnostic Industry Magazine
MDDI Article Index

An MD&DI May 1998 Column


While ISO 14001 compliance isn't mandatory, it could make medical device companies more competitive and help save the environment.

Saving the environment is an enormously sensitive and growing concern around the world, triggering worries about the processes of manufacturing, packaging, and product use and disposal. In September 1996, the International Organization for Standardization (ISO) published ISO 14001, a voluntary environmental management system standard that has since been embraced by companies such as Kodak, Sony, and Toyota. U.S. medical device manufacturers and suppliers also may benefit from implementing the provisions of this standard, especially because several nations in Asia are considering making ISO 14001 compliance mandatory for conducting business in their countries. Further, most companies find that the costs of implementing an ISO 14001—based environmental management system are recouped within two years through gains in efficiency and cost reductions.

To be as universally applicable as possible, ISO 14001 does not establish environmental performance requirements. Rather, the standard was written to apply to organizations of all types and sizes in diverse geographical, cultural, social, and economic situations. It seeks to balance socioeconomic and business needs with the protection of the environment and prevention of pollution. Compliance with ISO 14001 is within the reach of powerful multinational companies that can afford the best available technology as well as of smaller businesses in less-developed countries.


ISO 14001 provides a disciplined system to enable an organization to achieve its stated environmental objectives and to satisfy regulatory requirements, while simultaneously attaining its financial and corporate goals. In spite of its similarities to ISO 9000, ISO 14001 is far more user-friendly than its quality system cousin. Its auditable requirements are succinctly stated in six sections on three pages.

ISO 14001 encompasses the elements that are common to all effective management systems and states that an environmental management system should be "part of an overall management system that includes organizational structure, planning activities, responsibilities, practices, procedures, processes, and resources for developing, implementing, achieving, reviewing, and maintaining environmental policy."

To comply with ISO 14001, an organization must first identify and then manage all significant environmental aspects of its activities, products, or services. Once a company has identified the processes that affect the environment, it can develop the objectives, targets, and programs necessary to manage those effects and meet its own goals as well as all other applicable rules and regulations.

Figure 1. The environmental management system model for ISO 14001 progresses through six phases.

In meeting ISO 14001 requirements, a manufacturer would employ an environmental management system that progresses continuously through six phases: development of policy, planning, implementation and operation, checks and corrective action, management review, and continual improvement (Figure 1). ISO constructed this management system based on five principles:

  • Commitment/Policy. A company should define its environmental policy and commit to an environmental management system based on it. The organization also must commit itself to complying with applicable legislation and regulations.
  • Planning. A company should formulate a plan to fulfill its environmental policy. During this stage, the company should determine its environmental objectives and targets and establish specific programs that will meet each goal.
  • Implementation. For effective implementation, a company should develop the capabilities and support mechanisms necessary to achieve its set environmental policy, objectives, and targets.
  • Measurement and Evaluation. A company should measure, monitor, and evaluate its environmental performance.
  • Review and Improve. A company should review and continually refine its environmental management system, with the objective of improving its overall environmental performance.

These five principles allow a great deal of flexibility in setting up an environmental management system. As the standard notes, "two organizations carrying out similar activities but having different environmental performances may both comply with [the standard's] requirements."

Further, the standard recognizes that the environmental management system it specifies may not be the complete answer to protecting Earth's natural resources:

The adoption and implementation of a range of environmental management techniques in a systematic manner can contribute to optimal outcomes for all interested parties. However, adoption of this international standard will not in itself guarantee optimal environmental outcomes.

In practical terms, this means, for example, that the Environmental Protection Agency (EPA) may accept an ISO 14001 environmental management system only as demonstration that an organization has partially met requirements. Proof that performance requirements have been met may also be necessary.

Because the standard is voluntary, companies may use its requirements merely as an internal benchmark, or they may self-declare conformance or hire an independent, third-party auditor, or registrar. If an organization uses a third-party registrar or self-declares its conformance, it must be able to objectively demonstrate that it has met the requirements specified by ISO 14001. Among other things, the organization must document its conformance to the standard, maintain procedures for critical elements of its environmental management system, and periodically audit the system.

The primary difference between self-declaration and third-party registration is that registration provides a professional, objective verification that an organization's environmental management system meets ISO 14001 requirements.


Like ISO 9000, ISO 14001 is a voluntary standard. And there is no evidence yet that this will change in the United States or European Union in the foreseeable future.

The situation in Asia may be different. China, Vietnam, Thailand, and Singapore reportedly are considering making ISO 14001 national policy. ISO 14001—with its associated apparatus of accredited registrars and course providers to assess, register, and monitor environmental management systems—would provide the regulatory infrastructure for environmental protection that these countries otherwise lack. Brazil is also encouraging companies to seek registration.

Even though the European Union hasn't required registration yet, the EU has closely embraced ISO 14001; the European Committee for Standardization (CEN) has implemented it as EN ISO 14001. The standard also has been integrated into the EU's primary system for voluntary environmental management, known as Eco- Management and Audit Scheme. EMAS, which was established under EU Council regulation 1835/93 on June 29, 1993, and came into full force on April 10, 1995, has been implemented by all EU member states—most widely in Germany. Under Article 12 of the EMAS regulation, compliance with EN ISO 14001 also demonstrates compliance with a number of EMAS requirements.

While ISO 14001 registration is not yet a requirement around the globe, thousands of organizations in Europe and Asia have secured or are seeking registration. Within the United States, the greatest push toward registration is from U.S. subsidiaries of European and Japanese companies, but U.S. companies could be wise to heed their examples. Peer pressure from other companies and customer demands are fueling the drive toward registration, as are some of the advantages inherent in adopting an environmental management system.

Smart Business. For many companies, environmental management is simply a sequence of unrelated reactions. One person works on EPA regulations; another is responsible for satisfying FDA; another works with OSHA. This is an inefficient and wasteful strategy.

ISO 14001 offers an alternative integrated approach that is within the reach of most U.S. medical device companies, which already have initiatives, procedures, and systems in place to manage hazardous wastes, prevent worker exposure to toxic chemicals, control rodents, ensure biological quality, manufacture uncontaminated products, minimize air pollution, and so on. These are all aspects of operations that have environmental impacts, and they should be incorporated into a single environmental management system.

In addition, overseas markets continue to change product requirements. For example, three new European medical device directives require manufacturers to control a product not only in manufacture but through sale, use, and disposal. Moreover, a packaging and packaging waste directive (European Council Directive 94/62/EC) sets targets for the recovery (50 to 65% by weight) and recycling (25 to 50% by weight) of packaging waste. The targets must be met within five years of the implementation date. The packager, e.g., the importer, is responsible for recovery and recycling.

Any company that wishes to do business in Europe will need to respond to these changes. Without a system to organize and coordinate its environmental activities, a company will simply react to these challenges instead of managing them.

Marketing/Public Relations. A registered environmental management system can give organizations a competitive advantage with customers that are strongly committed to protecting the environment. Community and Environmental Activist Groups may also be more satisfied with a registered system than with a self-declared one. Indeed, some groups may request environmental management system registration of a local facility.

Regulatory Bodies. EPA and/or state regulatory agencies may accept a registered environmental management system as satisfying some regulatory requirements, resulting in reduced reporting and monitoring and fewer inspections. EPA has already taken steps in this direction. For example, it waives penalties for companies whose internal auditing identifies, corrects, and reports noncompliances. Most states have similar programs. EPA's voluntary Environmental Leadership Program provides regulatory flexibility to companies that have acceptable environmental management systems in place, allowing companies to spend fewer dollars while also reducing their environmental impact.

Insurance. Insurance or banking and financing companies may provide preferences, e.g., lower rates or better access to capital, if a company has a registered environmental management system.

Judicial System. Recent actions by the U.S. Sentencing Commission indicate that companies with an active environmental management system (such as that defined by ISO 14001) may see real benefits if they are called to appear before federal courts for environmental violations. If the system is registered, a company is better protected.

Registration aside, an environmental management system provides considerable internal benefits—assurance to management that environmental impacts are structured and controlled, improved processes for continual improvement (e.g., setting objectives and targets, implementing programs to meet these marks, and creating systems to monitor and measure progress), better cost control, conservation of input materials and energy, and a source of evidence for reasonable care and regulatory compliance.

With these benefits in mind, it may make sense for a medical device company to begin to implement an ISO 14001—based environmental management system now. If registration later seems like the right strategy, a sophisticated, integrated system should already be in place and functioning.


For medical device companies, the foundation for building an environmental management system is already in place because of the new quality system regulation, which is harmonized with ISO 9001. Training, documentation (less is required for ISO 14001), document control, internal auditing, and management review are common to ISO 9001 and ISO 14001.

When creating an environmental management system, an organization should follow these steps:

Analyze Current Status. A company must first conduct a "gap analysis" to compare its existing system to the system required in ISO 14001 and identify any gaps. The organization then must develop a process to identify environmental aspects—i.e., the causes or possible causes (e.g., exhaust emissions, potential for spillage)—and their possible effects on the environment (e.g., air pollution or water contamination).

After this analysis is complete, the organization should develop or revise its environmental policy for managing these aspects and impacts.

Plan. With the environmental policy as a foundation, the organization next sets objectives and targets based on its significant impacts, regulatory requirements, stakeholder views, and business goals. It also develops the programs and plans to meet those objectives and targets.

Implement. The implementation stage includes analyzing and improving existing programs and systems, developing new ones where needed, and documenting and institutionalizing best practices. ISO 14001 elements such as training, communication, and document control can be integrated into other management systems, e.g., ISO 9000. Also during this time the organization begins the ongoing process of executing planned programs to meet objectives and targets.

Measure. During the initial analysis, the organization should measure environmental performance to provide a baseline and then maintain an ongoing measurement system.

Improve. Based on these measurements, management needs to take continual corrective and preventive actions. Management should regularly review and revise aspects, policy, objectives, programs, and systems.


Organizations that decide to seek registration typically will follow seven steps.

1. Define the scope for each organization that will be registered to ISO 14001. Conduct internal audits to assess facility conformance in preparation for formal registration assessment.

2. Select a registrar, and submit an application that defines the rights of both parties.

3. Make available to the registrar all documents applicable to the environmental management system.

4. Schedule a preassessment by the registrar or another party to determine the environmental management system's current status (an optional, but highly recommended, step).

5. Undergo a formal assessment by the registrar to validate conformance with ISO 14001 requirements.

6. Accept registration to ISO 14001. If a conditional approval or disapproval is issued, make all necessary corrections.

7. Plan for semiannual surveillance audits to ensure that the system is being maintained and improved over time, as well as plan for a complete reassessment every three years.


In this time of change, instead of waiting passively for local or international requirements to overtake them, many medical device companies are taking preemptive actions to meet the challenges posed by ISO 14001 and are beginning to harmonize their environmental management systems to the new standard.

There is little downside to this course of action. At the very least, compliance with ISO 14001 will improve companies' business processes, reduce costs, and enhance their competitive posture. In the years to come, compliance may position companies to meet future U.S. and EU requirements, which many now see as inevitable.

Suzan L. Jackson is business development manager for Excel Partnership, an international training and consulting firm whose U.S. operations are based in Sandy Hook, CT. She is also the author of The ISO 14001 Implementation Guide: Creating an Integrated Management System, New York, John Wiley, 1997. Ron Belmont is director of food/drug and health-care support activities for Excel Partnership.

Copyright ©1998 Medical Device & Diagnostic Industry

Recovering Viable Environmental Particulates

Medical Device & Diagnostic Industry Magazine
MDDI Article Index

An MD&DI May 1998 Column


A case study examining the levels of airborne and surface contaminants through the use of three different incubation processes illustrates that manufacturers should ensure the effectiveness of their existing systems, especially if the safety of their devices could be compromised by increased levels of particulates. Environmental monitoring is a key element in the maintenance and control of defined manufacturing conditions. Section 820.70 of the quality system regulation (QSR) requires that device manufacturers establish, conduct, maintain, document, and periodically inspect environmental control systems to "verify that the system, including necessary equipment, is adequate and functioning properly." An effective environmental control system provides information on many elements of the manufacturing operation, including the following:

  • Process deviations.
  • The ability to maintain validated conditions within the facility, equipment, and procedures.
  • The effectiveness of controls on the manufacturing environment as well as on product contamination levels.
  • The sterility assurance program for aseptically produced and terminally sterilized products.
  • The effectiveness of facility and equipment cleaning procedures.

Environmental monitoring programs usually measure both viable and total particulate contamination. Programs measuring viable contamination levels should effectively capture and count the indigenous flora in the manufacturing environment. It is not necessarily important to identify isolated organisms by means of environmental sampling. Whether it is important to do so depends on many factors, including the nature of the product, potential consequences to product safety or performance, and whether the product is terminally sterilized.1 Alert and action limits need to be established based on the total number of organisms observed. There are a number of methods to choose from to calculate such limits.2 If the optimal medium and incubation conditions are calculated and then used, the quantitation method should recover a majority of the environmental organisms. A comprehensive facility validation program should include documentation of the testing used to determine the appropriate quantitation procedure.


A device manufacturer evaluated the effectiveness of its current quantitative procedure for viable contaminants by comparing the data generated from its standard method with data derived from the use of different media and incubation conditions. Such an evaluation could lead to a procedural change, depending on the study results. The manufacturing procedure requires the handling and distribution of large amounts of fibrous and corrugated materials. Based on experience, a number of fungi were expected in the indigenous flora of the manufacturing environment. The manufacturer had already documented that the presence of fungal species in the final product has no adverse affects. However, because of their potentially high numbers, the manufacturer wanted to account for fungal species in the reports of results of total and viable organism monitoring.

Under the standard procedure, viable contaminants were recovered for air sampling tests using Biotest RCS sampler with soybean casein digest agar (TSA) and for surface tests using equipment surface swabs wetted with Stewards transfer medium. After sampling, the swabs were extracted with soybean casein digest broth (TSB) and extractant aliquots plated with TSA. The swabs were incubated for 48 hours at 35° ± 2°C.


In addition to the company's standard culturing process described above, additional samples were cultured in different media and incubated under different schemes to collect data to study the effectiveness of the various methods. The other cultures and incubation periods are described as follows:

  • TSA agar incubated for 48 hours at 25° ± 2°C, followed by incubation for 72 hours at 35° ± 2°C (cold/hot incubation).
  • TSA agar incubated for 48 hours at 35° ± 2 °C, followed by incubation for 72 hours at 25° ± 2 °C (hot/cold incubation).
  • Rose Bengal agar, a selective agar formulated for the recovery of yeast and mold species, incubated for 120 hours at 25° ± 2°C. Chloramphenicol, a component of this agar medium, inhibits bacterial growth.

Twenty sites were sampled for airborne contamination using the manufacturer's standard procedure, which involved sampling of 40 L of air with the Biotest RCS sampler during a 1-minute period. The sites represented a cross-sectional sampling of the entire manufacturing area. A total of three samples were taken at each sample location, two using TSA agar strips and one using Rose Bengal agar strips. Incubation was as described above. All airborne counts were reported as colony forming units (CFUs) per cubic foot of air sampled.

A total of 25 equipment surface sites were sampled by a Culturette II system with Stewards transfer medium. A 4-sq-in. area was sampled at each designated site. Within 4 hours of sampling, each swab was placed in TSB and extracted for viable organisms with 4 ml of TSB and 1 ml aliquots plated in either TSA or Rose Bengal agar. Incubation was as indicated above. The data from the surface samples were reported as CFUs per square inch.

Each plate was examined daily and all CFUs were measured after approximately 48 hours, when the incubation conditions were changed, and again after approximately 120 hours when the incubation period was concluded.


Airborne Samples. The optimal recovery of viable microorganisms from air and equipment surfaces occurred when using a TSA recovery medium and the cold/hot incubation scheme of 48 hours at 25° ± 2°C followed by 72 hours at 35° ± 2°C.

A total of 285 CFUs were observed from the TSA cold/hot recovery method of the 20 air sampling sites, as opposed to 187 CFUs recovered by the TSA hot/cold recovery method from the same sites. The hot/cold method therefore recovered only 66% as many CFUs as the cold/hot incubation scheme had. With Rose Bengal agar incubated for 5 days at 25° ± 2°C 141 CFUs were recovered, or 49% of the highest total from those sites.

Using the manufacturer's normal recovery method of incubating TSA for 48 hours at 35° ± 2°C, a total of 121 CFUs were observed from the 20 air sampling sites. This count is approximately 2.4 times lower than that observed with the TSA cold/hot incubation scheme and in fact this procedure yielded the worst results of all the investigated processes.

When the air counts from the manufacturer's current recovery method were added to the total observed with the Rose Bengal agar (for an estimate of total bacterial and fungal count), the total of 262 CFUs was approximately 92% of the air count results observed using the TSA cold/hot recovery method.

Treating the number of CFUs recovered from the TSA cold/hot procedure (285) as the total number of recovered microorganisms and comparing it to the total recovered by the Rose Bengal agar (141), it seems that approximately 50% of the recovered airborne microorganisms were fungi (Table I provides full results).

TSA/25°C/35°CTSA/35°C/25°CRose Bengal Agar
at 25°C
Sample NumberAfter First
48 Hours
After First
48 Hours*
After First
48 Hours
1 5 6 4 5 2 3
2 3 5 0 1 0 2
3 8 10 5 6 1 3
4 7 9 1 3 1 1
5 5 7 2 5 0 0
6 15 19 8 16 1 5
7 57 85 21 43 41 68
8 24 28 15 21 10 17
9 21 27 12 14 0 4
10 6 11 10 10 1 3
11 5 10 9 15 3 5
12 8 13 5 6 2 5
13 3 5 5 6 0 2
14 7 10 7 7 1 4
15 6 7 2 7 1 1
16 4 9 4 7 0 6
17 2 4 0 0 1 4
18 3 5 3 4 0 1
19 8 11 4 5 2 3
20 3 4 4 6 0 4
Total 200 285 121 187 67 141

Table I. Results on airborne samples, indicating measurements of the number of CFUs per cubic foot taken after a 48-hour incubation period, followed by a 72-hour period at a second temperature setting. The Rose Bengal agar testing was performed at one setting. The column designated by an asterisk represents the findings obtained from what had been the manufacturer's standard procedure.

Surface Samples. A total of 23 CFUs were observed using the TSA cold/hot recovery method from the 25 equipment surface sites compared to 16 organisms from the TSA hot/cold method from these same sites. This number is approximately 70% of the CFUs recovered using the TSA cold/hot incubation scheme. Two CFUs were recovered with the Rose Bengal agar from the same 25 sites.

The manufacturer's recovery method used TSA with a 48-hour incubation period at 35° ± 2°C. Using this recovery procedure, one CFU was observed from the 25 equipment surface samples. This count is approximately 22 times lower than that observed using the TSA cold/hot incubation scheme.

When the equipment surface counts using the manufacturer's TSA method (48 hours at 35° ± 2°C) were added to the Rose Bengal counts, the total of three CFUs was approximately 13% of the result observed with the TSA cold/hot recovery method (Table II).

TSA/25°C/35°CTSA/35°C/25°CRose Bengal Agar
at 25°C
Sample NumberAfter First
48 Hours
After First
48 Hours*
After First
48 Hours
1 1 1 0 0 0 0
2 0 0 0 0 0 0
3 0 0 0 1 1 1
4 0 0 0 0 0 0
5 0 0 0 0 0 0
6 0 0 0 0 0 0
7 0 0 0 0 0 0
8 0 0 1 1 0 0
9 0 5 0 1 1 1
10 0 1 0 0 0 0
11 0 0 0 0 0 0
12 0 0 0 0 0 0
13 0 0 0 0 0 0
14 0 0 0 0 0 0
15 0 0 0 0 0 0
16 0 0 0 0 0 0
17 0 14 0 13 0 0
18 0 0 0 0 0 0
19 0 1 0 0 0 0
20 0 0 0 0 0 0
21 0 0 0 0 0 0
22 0 0 0 0 0 0
23 0 0 0 0 0 0
24 0 0 0 0 0 0
25 0 1 0 0 0 0
Totals 1 23 1 16 2 2

Table II. Results of the three environmental particulate tests performed on samples from equipment surfaces, indicating measurements of the number of CFUs per square inch taken after a 48-hour incubation period at the first temperature shown, followed by a 72-hour period at the second temperature setting. The Rose Bengal agar testing was all performed at one setting. The results in the column designated by an asterisk represent the findings obtained from what had been the manufacturer's standard procedure.


The data showed that the recovery method traditionally used by the manufacturer to recover viable environmental contaminants was not optimal, because it did not maximize the recovery of fungal species. Based on a preliminary review of the manufacturing process, it had been hypothesized that there would be a significant number of fungal species. The data supported this initial hypothesis; in fact, approximately half of the recovered airborne CFUs were estimated to be fungi.

The data from this study convinced the manufacturer to revise its current recovery practice to use a TSA medium and the two-tier cold/hot incubation scheme of 48 hours at 25° ± 2°C followed by 72 hours at 35° ± 2°C. This method optimizes the recovery of viable organisms, including fungi, from the manufacturer's environment. Fungal species were observed on the TSA strips after the 120-hour incubation period. The manufacturer concluded that including a specific differential medium for recovering fungi into its routine monitoring practice would not increase the total number of recoverable CFUs. Since fungi did not adversely affect product safety or performance, there was no reason to routinely differentiate fungal and bacterial species. The manufacturer believes that total counts are sufficient to monitor and assess the capabilities and performance of its environmental control practices.

This study was not intended to serve as a validation of the proposed method. Additional studies are necessary to confirm the initial findings and demonstrate the reproducibility of the method. The data suggested that the manufacturer's historical environmental microbial database was not indicative of actual contamination levels, which were probably several orders of magnitude greater than those reported. Thus, the manufacturer decided not to use this historical database to establish alert and action limits for environmental surveys. Rather, data generated by the cold/hot incubation method will be gathered monthly for 1 year, at which time revised alert and action limits will be calculated. Preliminary alert and action limits will be established based on the data from this study.

This study clearly demonstrates that a cold/hot incubation scheme with TSA is more effective in recovering organisms from a manufacturing environment than a hot/cold incubation scheme with TSA or a Rose Bengal agar with a cold incubation procedure. These results are intuitively reasonable because it can be assumed that the indigenous environmental organisms have adapted to ambient conditions. The colder temperature used in the tests is more representative of those conditions than the warmer test temperature. The lower initial incubation temperature may have allowed the slower-growing fungi to proliferate and develop into visible colonies before being overgrown by the faster-growing bacteria at the higher incubation temperature.

Manufacturers should not universally extrapolate the conclusions of this study to other environmental-monitoring situations. Many factors influence the presence of microbial flora, including the product being manufactured, the facility, its geographic location, and time of year. Additionally, the significance of what a particular microorganism means to a product's safety or performance may require customization of the recovery program to identify these specific organisms. Therefore, the optimum recovery program for one facility will not necessarily satisfy the requirements for another company. Individual recovery programs should be designed for each facility, based on documented data.


1. Reich RR, "Microbial Taxonomy: When Is It Appropriate in Environmental Monitoring?," Med Dev Diag Indust, 17(1):220—221, 1995.

2. Wilson JD, "Setting Alert/Action Limits for Environmental Monitoring Programs," J Pharm Sci Tech, 51(4):161—162, 1997.

Robert R. Reich is president, Pharmaceutical Systems, Inc. (Mundelein, IL).

Copyright ©1998 Medical Device & Diagnostic Industry