Medical Device Link.

Originally Published MDDI July 2001

Medical Plastics and Biomaterials

Contract suppliers who get in on the development process early will be the most valuable and reap the largest rewards.

Todd Owens

Today's healthcare industry is a rapidly evolving market in which the requirements demanded of suppliers—including shorter lead times—are projected to become increasingly complex. One of the most dynamic segments of the overall healthcare market is that of medical devices, where it is an ever-more-common practice for manufacturers to outsource part or all of their assembly operations. Many companies offset the risks associated with a new product by relying on experienced partners to design, develop, and manufacture their medical devices. This is especially true with start-up companies that choose not to become manufacturers. Rather than build a staff to handle manufacturing operations, these companies contract with operations experts, thereby freeing themselves to concentrate their time and resources on core product development technologies.

In a poll published in June 1999, 80% of medical device manufacturers who responded indicated that they outsource part of their business, 71% reported that their use of contract services had grown between 6 and 15% in the previous two years, and 35% expected their outsourcing to increase by more than 10% within their companies in the following two years.¹ The trend in the medical device market for polymer-based products specifically is clearly toward an increased number of alliances between medical companies, molders, and raw material suppliers.²

REGULATORY COMPLIANCE

For many years, FDA has required medical device manufacturers to validate processes when the quality of their output cannot be fully verified prior to product leaving the manufacturing site. The agency has generally enforced this process validation requirement on medical device manufacturers and not on component suppliers. With the changes to the rule on good manufacturing practices (GMPs) in 1996, FDA put more emphasis on medical device manufacturers (the owners of the device) placing controls on their component suppliers to ensure that those components are safe and effective for the use for which they were designed. As a result, many OEMs are requiring their suppliers to implement GMP-compliant quality systems, including process validation.

In the injection molding arena, for example, manufacturers are demanding that their suppliers provide process validation of plastics molding and component assembly processes. These device firms want evidence to present to FDA that the components in their devices have been verified or manufactured using validated processes.

Figure 1. The elements of product development.

TECHNOLOGY OVERVIEW

As outsourcing increases, the desire to ensure a smooth transition from concept to product means that product design and development is frequently becoming the supplier's responsibility. Design for manufacture and assembly is vital to compressing lead times and enhancing quality. Suppliers are using technologies such as stereolithography, selective laser sintering, and cast urethane models for a variety of applications—from verifying fit and function to creating prototypes for focus groups. Finite element analysis and mold-flow analysis are employed to verify structural and mechanical elements and optimize part design and processing conditions before tool steel is cut. With manufacturers insisting on high-quality, cost-effective components, those suppliers able to provide a range of materials and services—from design through manufacture, including validation, decorating, and turnkey assembly—will be in the greatest demand.

For medical molders, current manufacturing trends include multishot, metal, and magnesium injection molding. In the quest for enhanced ergonomics, aesthetics, and component integrity, multishot molding can be an attractive alternative for medical manufacturers looking for product differentiation, ease of assembly, and reduced component cost. Metal injection molding, used for producing small, complex components at a fraction of the cost of machined parts, is becoming a popular choice for many device manufacturers that require both intricate part detail and cost savings. Magnesium injection molding offers inherent EMI/RFI shielding, exceptional component strength, and part weights comparable to those of engineering-grade plastics.

In recent years, OEMs and suppliers have been forming alliances to coordinate resources and build relationships based on a lowest-total-cost approach. This provides the OEM with a leading-edge source for technology, faster time to market, and the highest possible quality. However, forming supplier alliances has been difficult for some organizations to accomplish, and many fail to recognize the benefits afforded by this approach.

Suppliers that embrace an early-involvement philosophy and have broad-based expertise in the design and manufacture of medical components are the most capable of ensuring a quality product. A supplier's strict adherence to FDA's quality system regulation—along with certification to ISO 9000 and European medical standard EN 46000—generally results in efficient transfer of documentation, traceability of parts and components, and the ability to meet specialized requirements of specific medical projects.

Figure 2. The traditional product development cycle includes transition spikes at the start of each phase.

ACCELERATED PRODUCT DEVELOPMENT

Time to market is a key parameter for successfully manufacturing medical products in today's worldwide economy. Accelerating the product development cycle plays an important role in time-to-market improvements.

The product development cycle can be compared to a wheel, as shown in Figure 1. The hub comprises the industrial design and mechanical engineering activities that create and build a database of information and product geometries, and the spokes represent the various activities and resources that provide support throughout the evolution of the database. All products go through this development cycle at some level.

In order to achieve an accelerated development cycle, activities must be completed concurrently. Most products today are created using some amount of concurrent engineering; however, the concurrent activities tend to transpire primarily within each phase of the program. Figure 2 shows the spikes in cost and time that can occur due to reengineering at key hand-off points during the traditional development cycle. At each phase transition, a new group of people assumes direction of the program, and there are typically changes that must take place to make the design fit the requirements of the next phase.

Manufacturers can reduce both overall costs and time to market through early-phase partnerships with suppliers that have the in-house technologies to support all phases of the product development cycle. As Figure 3 indicates, the traditional spikes in cost and timing can be eliminated by involving the entire team in the program from its inception. Because all issues are addressed at the early phases, there is no lost information or obligatory reengineering.

The case studies that follow exemplify some of the benefits that can accrue from early involvement of qualified suppliers in the product development process.

Figure 3. With early supplier involvement, cost increases gradually throughout the product development cycle, and the process advances more quickly.

CASE STUDIES: MOLDED COMPONENTS

DNA Separator. A biochemical reagent supply company developed a magnetic resin used to extract DNA from blood and cell media cultures. The resin bonds with DNA in suspension and is then separated from the liquid media using exceptionally strong magnets. The company needed a hand-held separation device to house the magnets and hold the vials during the separation process, and contacted a contract molder to assist in the design and manufacture of the product.

The separator had an array of functional requirements, yet initially there was no clear-cut idea of what the product would look like. The two companies began with concept sketches to determine the direction in which the program would proceed. After a concept was chosen, foam models were made to verify the look and feel of the device prior to the creation of stereolithography models, which were vital in testing the functionality of the separator's magnets. Design issues related to wall thickness surrounding the magnets—a too-thick wall threatened to impede the magnets' power—were resolved, and the process was verified via mold-flow analysis before tool steel was cut, thus saving time and avoiding costly tool revisions.

Meeting Aggressive Timelines. In line with current outsourcing trends, the injection molder was selected for its expansive list of capabilities, its willingness to manufacture highly engineered components in low volumes, and the speed with which it was able to move the program from design through injection molding.

The program was conducted within an aggressive time frame, with the period from concept to initial parts lasting only 12 weeks, including a 5-week tool build. The manufacturer had a targeted release date for the resin, and needed to produce the separator within a certain work cycle. The injection molder's in-house capabilities—from design and tooling to manufacturing—were critical in keeping the project on track and avoiding the kind of reengineering spikes depicted in Figure 2.

Design and Manufacturability. Of particular importance to the separator project was the molder's in-house industrial design group. According to the manufacturer, the molder's design expertise prevented wasted design-phase iterations by enabling the companies to rule out designs that seemed attractive but cost too much to manufacture or were not manufacturable at all. The project team also designed so as to eliminate complex features in the mold, producing tools that did not require slides, thus saving the company significant tooling costs.

Anesthesia Equipment. A leader in the anesthesia equipment market developed a proprietary patient breathing unit that could be assembled and disassembled for autoclaving without tools using a series of thumbscrews, interlocks, and snap features. These complex, injection-molded components posed unique challenges to the design capabilities of the contract molder selected for the project.

Reducing Tool Costs. The molder used stereolithography, selective laser sintering, and urethane castings to verify fit and function of the various components prior to the costly step of cutting tool steel. In addition, mold-flow software was employed prior to tool build to verify design features and ensure that the difficult-to-process, high-melt-point resins required to withstand autoclaving would perform under the necessary processing conditions. Tools were built in prehardened P20 steel, with hardened tool-steel inserts for shutoff and other critical areas that might need revisions. This method of tool building has long-term benefits because necessary tooling changes can be made with relative ease by revising or replacing an insert rather than rebuilding the entire mold.

CONCLUSION

One of the few constants in the rapidly evolving medical market is the ongoing need of manufacturers for compressed product development time frames and ever-more-sophisticated devices. Those contract suppliers capable of contributing to all stages of a project—from the earliest design and prototyping through manufacturing and assembly—will provide the greatest benefits and reap the largest rewards.

REFERENCES

1. N Sparrow, "Special Report: Outsourcing in the Device Industry," European Medical Device Manufacturer 10, no. 3 (1999): 78–82.

2. NJ Hermanson, "Growth of Plastics Use in Medical Devices is Spurred by Cost-Cutting," Modern Plastics, (November 1998): A-30.

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