Medical Device Link.

Originally Published EMDM January/February 2002

PRODUCT UPDATE

Michael Hirson

In addition to catching defects, testing equipment offers OEMs new ways to leverage information.

In the past, medical OEMs may have viewed testing equipment as an attractive option. Today, however, they may find that it is simply a necessity. Production processes are becoming faster and more complex, challenging traditional inspecting and measuring devices to keep pace. At the same time, manufacturers need to keep more-detailed records on these same processes. The good news is that next-generation inspection, measurement, and testing equipment is sophisticated enough to handle these emerging problems, while potentially saving OEMs time and money in new ways.

Ensuring Traceability and Repeatability

Between the demands of customers and those of regulatory bodies, the paper trail that device makers must supply to support their products is only getting longer. "Manufacturers need to show continuous traceability, that their devices have met specifications from beginning to end," says Ernest Henzi, senior vice president of marketing at Zumbach Electronics Corp. (Orpund, Switzerland). "It's a great comfort to be able to do this without relying on subjective, human means." Zumbach manufactures equipment that is used to detect defects and measure dimensions during the extrusion of medical tubing.

The Vinspec system from Vitronic GmbH performs high-speed inspections of injection needles, checking for bluntness, deformity, and positioning.

In many production environments, replacing eyeballs and fingers with sensors is no longer debatable. On a high-throughput line, parts must be inspected or measured, and that information recorded, in a matter of milliseconds. "A human simply can't keep up with a camera that records and archives everything it sees," says Kaz Naganuma, healthcare manufacturing manager for Cognex UK (Milton Keynes, Bucks, UK), which supplies integrated machine vision systems to the medical and pharmaceutical industries. That's especially true when regulatory requirements dictate that the inspection process be predictably repeatable. "If there's one thing humans are not good at, it's being predictably repeatable," he quips.

The need to validate processes has further tightened the bond between manufacturers and suppliers of quality control systems. "We work directly with the customer to make sure they meet new regulations," Naganuma says. There's good reason for that: once an inspection system has been validated as part of the customer's production process, "it's almost impossible for another company to get in," says Zumbach's Henzi. Established suppliers, who have had their products validated in different production environments, enjoy a clear advantage over newcomers.

Machine Vision Spots Errors Early

A major obstacle to implementing sophisticated testing equipment has always been its relatively high price. But thanks to rapidly declining prices for computer hardware and electronics equipment, manufacturers are able to afford testing systems that previously were out of their reach, and implement them in new ways. Machine vision, for example, was traditionally so expensive that it could often be used only as an end control, to catch defective products before they were shipped. Now, says Cognex's Naganuma, more companies are using such systems throughout the production line. "That's where you see the real savings," he says. "Rather than having to destroy an expensive part, such as a fully assembled syringe, at the end of the process, you can find and fix a problem before a part has been added to the device."

Martin Schumacher, sales engineer at Vitronic GmbH (Wiesbaden, Germany), says that affordability is key if machine vision is going to win more converts. "Customers know that the technology works," he says, "but in many cases, the product to be inspected has a very low cost, such as injection needles." To be cost-effective in these circumstances, the vision system must be set up quickly and implemented on a large scale. Schumacher says that Vitronic's long experience in the field allows it to do this. "We have a toolbox of products that can be quickly configured depending on the customer's needs," he notes.

From Quality Control to Process Control

The need for more-sophisticated testing equipment can also be seen in the off-line inspection room. There, device makers must measure and inspect parts that are smaller and more intricate than ever before. While touch probes still enjoy much popularity, technology advances have brought three-dimensional laser and vision systems to a wider audience. "Three-dimensional laser scanning is just now becoming affordable for many companies," says Tom Brem, communications manager at Taylor Hobson (Leicester, UK). The company's Talyscan 150 allows for detailed three-dimensional surface scans of complex parts. "If a scan is composed of 1000 individual profiles, we're dealing with a half billion individual data points. Six years ago, only a Cray supercomputer could handle that," observes Brem.

Such analytical tools are expanding the role of measuring equipment from pure quality control to process control. That being the case, Zumbach's Henzi notes that OEMs should look at testing, measuring, and process control equipment as an investment. Tubing manufacturers, he observes, are often hesitant to try to stringent exact customer specifications, because they're fearful that their processes are not precise enough. "Because they're not measurement people, they chicken out and pad the wall thickness," he says. "With the cost of materials today, it doesn't take long before you've run up costs significantly." On the other hand, manufacturers that have confidence in their measurements can keep the margin of error thin and profits fat. "Careful definition of process capability is an important milestone on the road to total quality control," says Henzi.

Advances in Testing Technology

No matter how sophisticated their products, suppliers of inspection and measuring equipment say that a major demand of customers is that equipment be easy to operate and automate. "We're at the point where an operator should be able to press the play button, walk away, and know that the inspection process will go according to expectations," says C.E. Johansson's Hobart. By reducing the need for personnel training, usability is a key factor in the equation to make sophisticated systems cost-effective. "It used to be that you needed C++ programming and courses in machine vision to implement a system," says Naganuma. "We design our products so that people who have never touched a vision system take it out of the box, spend a little time with it, and quickly get it going."

Despite advances in the field, Baty's David Martin says suppliers of inspection and measurement equipment can ill afford to rest on their laurels. "Nanotechnology will put pressure on the whole industry, and will probably require whole new solutions." Of course, even before the day when devices are measured in nanometers, there's plenty for suppliers to work on: medical manufacturers will continue to demand equipment that's powerful, easy to use, and pays for itself faster than ever.

More Products:
Taylor Hobson
PTI USA
C.E. Johansson
Vitronic GmbH
Baty International
Cognex UK
Zumbach Electronics Corp.
PPT Vision Inc.
Hounsfield Test Equipment Ltd.

Copyright ©2002 European Medical Device Manufacturer