Feature Article

By: R.E. Hall, Medical Pack Solutions, Shannon, Co. Clare, Ireland

1990 was an important year: Medical Device Technology (MDT) was founded, the first of the medical device directives¹ was published and on 3 October the German Democratic Republic ceased to exist, as the Federal Republic of Germany was simultaneously expanded by five new states. The word “validation” had yet to become an important part of my vocabulary. Medical device customers were expected to read English-language labels; if they were lucky they might also have French and German text. In 1990, the editor of MDT used a monochrome PC.

 

In 1990, much packaging machinery used cam shafts, gears, chain, notched belts and pulleys to maintain synchronisation. Timers were mainly electromechanical with clutches, some temperature readouts were still analogue, temperature control was generally by power-on/power-off at set points and remote machine controls were basic and hardwired. The development of stepping motors, microprocessors, networking and the Internet has changed all this. There have been problems with electromagnetic compatibility—mobile phones interfered with machine electronics, especially some metal detectors. However, compliance with the European Electromagnetic Compatibility Directive ², which came into force in the 1990s, has helped to minimise this issue.

 

Now cams are replaced by stepping motors with their attendant adjustment and control flexibility. Time controllers are extremely accurate because they use quartz crystal controlled electronic clocks. Electronic temperature controllers have gained proportional control ability; some even automatically tune themselves to compensate for changing load conditions. Worldwide, the influence of electronic miniaturisation and falling prices of electronics has revolutionised machine design. Validation requirements form part of machine design criteria. Machines may now be fitted with computerised systems that make a record of the parameters used for each successive machine cycle. Recording systems and secondary control panels can be linked by Ethernet cable to any conveniently located PC for supervision. As appropriate, this can be anywhere in the world that has an Internet connection.

 

During the past 20 years many devices previously sold nonsterile for sterilisation by the user are now terminally sterilised by the manufacturer. Improved machine control systems have, in many cases, aided the validation process. For example, an orthopaedic surgeon will normally receive a sterile knee or hip femoral component in pristine condition in a manufacturer’s sterile barrier pack. In earlier times the implant may have reached the surgeon after several visits to the local central sterilisation unit for autoclaving. Now there can be confidence that the bearing surfaces have not suffered in the handling process and there are no worries about the actual sterilisation conditions in a mixed autoclave load.

 

People’s expectations have changed. I remember resistance to the introduction of the clean-peel opening for single-use disposables. There were complaints that the new chevron pouches did not exhibit fibre tear at their paper–film interface when peeled open—nurses were wary of undetected leaks if the seal was not strong enough to tear paper. Now some quality inspectors fear complaints if a little delamination occurs when removing an otherwise clean-peel Tyvek lid from a thermoformed tray. In the 1990s concern was still being mooted that nonporous materials would prevent the escape of contaminates caused by product degradation on irradiation. The current usage of nonporous peel pouches suggests that those concerns have been forgotten.

 

In 1990 much of industry still followed Eucomed labelling recommendation 83/10: “If product is subject to material degradation within five years, the expiry date (year and month) should be printed on the unit and shelf container. For all other practical purposes, products will remain sterile indefinitely if handled correctly. Maintenance of sterility is event-related rather than time related.” US FDA did not demand expiry dating.

 

Despite creation of the HIBC³ in 1984, bar codes were little used for inventory control. One senior orthopaedic sister with responsibility for inventory in three operating theatres remarked to me that she had personal control of more than £210 000 of implant stock and more than £140 000 of disposable items and yet used pencil-and-paper stock-control methods. Clearly computers and bar codes bring progress. Advances in computer and printing technology have enabled device manufacturers with appropriate software to meet the ever-increasing demand for more languages on product labels. I can now report that our Editor in Chief uses a colour monitor.

 

 

 

Medical Pack Solutions, Pinewood Lodge, 16,
Tullyvarraga Hill, Shannon, Co. Clare, Ireland
tel. +353 61 364837
e-mail: rolande@m-p-s.ie
www.m-p-s.ie