By: 1 October 2008

We are all used to seeing the checkout operator scan the barcodes on our tins of food and drink at the supermarket. The scan provides the product price and links back to stock and other databases. Until recently, the European Article Numbering Association (EAN) provided these product codes to manufacturers for tracking products through manufacturing to the consumer's plate.

Worldwide, product traceability is becoming the norm in many industries including aerospace and biotechnology, due to health and safety legislation and improved quality standards. In the United States, Item Unique Identification (IUID) codes are currently a requirement on almost all equipment purchased by the US Department of Defense.

The medical manufacturing market in the UK is undergoing a similar transformation. In 2005, a new standard came into being, known as GS1 that impacts on the medical and orthopaedic supply chains. It was formed from EAN International and its local member organizations, including the UCC from the USA. GS1 is an independent global standards body which provides its members with an international system of unique identification numbering, already used widely in the pharmaceutical, retail and supply chains sectors. These numbers are generally applied via conventional bar codes, two-dimensional Data Matrix codes and radio frequency identification (RFID) tags. GS1 UK is providing its unique numbering systems and support to all NHS organisations.

Roger Lamb, healthcare manager for GS1 UK, explained the work of the new authority in more detail. “GS1 is a not-for-profit initiative that is part of the wider Department of Health initiative “Coding for Success - simple technology for safer patient care”, a commitment to quality that was launched a year ago. A lot of work has been done looking at raising standards across the board. There are 109 GS1 member organisations and we now have 1.25 million members in the world.”

GS1 is the issuing authority for numbers that form part of the unique codes applied via different symbologies. Hospitals apply to GS1 UK for a membership number and use this in different ways. Particular number series are used for different items. For example, assets and traded items will have different types of numbers. GS1 members are given advice and training on how to use standards, so that they are able to comply with quality guidelines on producing the code - ie colour, size, pattern, etc.

Lamb says: “A number of hospitals have signed up in the last six or nine months. The codes are used to keep track of loan-sets as well as instruments held in stock.”

Charlie Plain-Jones (left), traceability solutions manager of Pryor Marking Technology, said: “We now have a new standard, which is exciting. What a great idea - we can now share NHS standards for data presentation. We shall be able to move forward with confidence that individual items will be traceable in the medical sector.”

Use of the new GS1 code is not yet mandatory in the surgical field, but it is best practice, according to Plain-Jones. However, for specialist areas such as tonsillectomy and neurosurgery, the use of the code is mandatory on surgical instruments.

Best practice will inevitably become law, it is just a matter of time, and those leading the field of manufacturing specialist items for orthopaedic surgeons know this and are already implementing high standards in traceability. Comis Orthopaedics Ltd, Rotherham, UK is a privately owned business set up in December 2005 to design, develop, manufacture and market implants and instrumentation for Minimally Invasive Surgery (MIS). Its innovative product range includes the patented Minimally Invasive Hip Resurfacing or Comis MIHR®, that is deliverable as an open surgery implant; the Comis Leg Length System which provides an initial datum measurement of the joint position prior to dislocating a hip joint; and the MIS Retractor System, designed for near assistant-free use in hip resurfacing and total hip arthroplasty. The company makes a range of other devices and surgical instrumentation, manufactured on site at its factory in Rotherham, with implant production sub-contracted to specialists LPE Medical. UK market distribution is handled by JRI Ltd.

From the start, Managing Director, Shaun Palmer and his colleague Ryan Taylor, General Manager, knew that they would need to ensure full traceability on every part they made. The company decided to implement high-tech laser marking as the industry standard, state-of-the art marking method. A laser marks directly into the product's surface, a process that ensures long-term traceability throughout the product life cycle that includes frequent handling, cleaning and storage.

Above: The Pryor Marking Technology System used in medical product traceability

Every product can be made from different materials and will undergo several processes before it reaches final product stage. For example, a batch of 17 parts could be manufactured from a number of materials. Each batch will be given a lot number. If a recall was required based on the return of one product, the other 16 customers could be contacted through the use of the traceable identifier and the whole process monitored. As Ryan Taylor said, “You have to be aware of where the products are for recall - you need to know who can be at risk.”

Comis Orthopaedics approached Pryor Marking Technology, a leading provider of marking and traceability solutions based in Sheffield, UK. The chosen system was Pryor's HP20 Nd:Yag laser marker with a V2 enclosure, which was installed in September 2006 when the manufacturing site opened. This floor-standing machine has four-axis control, 160mm focal length lens and includes an electrical Z axis. It also has a useful circumferential fixture, an adjustable marking platform of 200x200mm and fume control for use on polymer marked plastics. The system is controlled using the Pryor Laser professional marking software on a PC connected directly to the laser system.

Charlie Plain-Jones of Pryor explains how a laser beam works. “The word 'LASER' actually stands for Light Amplification by Stimulated Emission of Radiation. A laser is a beam of light that has special properties. It is an un-natural kind of light and you will never find it in nature. Because of its man-made qualities, we are able to use it for all kinds of applications that one could not use natural light energies for. A laser beam has two features that are central to its functionality:- it is monochromatic (i.e. it has a single wavelength), and it is coherent (i.e. all of the waves are in phase or in step with each other). This means that we can focus a lot of light energy down to an incredibly small point - to just a few microns in diameter. The amount of energy concentrated on such a small space enables laser engraving, which is done by heating up and vaporising metal away from the local area. We can also oxidise or 'anneal' the material which changes the colour of the surface at the local area. Laser marking using both parameters can be done in sequence at the same point on the material. Lasers now come in several different frequencies, for use on metals, plastics and ceramics.”

A particular feature of the Pryor equipment is its functionality as a diode pumped marker - it maintains the integrity of the mark, even after acid passivation. Some other kinds of mark would disappear or show signs of corrosion during this process but the capability to program the marker's Q-switch to an unusually high frequency enables marks to be achieved which survive the passivation process and also overcome the problems of mark corrosion.

Taylor explained the rationale for investing in the Pryor system, “We know from previous experience that we used to use a sub-contracted marking firm which would charge for each different part. There was a £25 set-up charge and then £1.50 charge per mark. We can now do the same marking in-house (and more) for about 50p per mark. There is a definite cost saving to Comis Orthopaedics, but there is also the convenience that we can mark everything on site that we need to.”

Taylor continues, “As well as marking the parts for traceability purposes during the manufacturing process, before they are sold, we have taken the step of marking all of our jigs and fixtures. We mark it all. If parts are hard to handle during manufacturing, we would make a special jig to hold it and we mark those too so that they are easily identifiable and not accidentally discarded.”

In laser marking the products, the identifier includes the product code, ie stock, field and part number as well as the Comis Orthopaedics logo. On certain parts, eg power-driven tools, the company is required to add its CE mark to comply with European safety legislation and this confirms that the part has been tested to European quality standards and has passed final inspection.

Above: Some of the instruments traced by the Pryor System

Kabir Singh Chana, the company's commercial manager explains: “Each device, whether it is an implant or instrument, has to be graded according to risks. It is the risk level that determines the level of traceability required as this determines the level of product surveillance required. Some specific medical devices have their own applicable standards which may highlight the need for further identification marks over and above the general requirements.”

For purely regulatory aspects, the overriding standard is ISO13485:2003. This is the higher-level quality system the company operates in order to be a medical device provider. This also includes ISO9001:2000. Within ISO13485:2003, to comply, we also have to work to the medical device directives 93/42/EEC. Provision of traceability is a requirement for ISO13485;2003 and also as part of customer complaint/product surveillance for the medical device directives.

Comis Orthopaedics provides this typical list of standards for part marking but says that there may be other standards applicable to more specific medical devices:-

BS EN 980:2003
Graphical Symbols for use in the labelling of medical devices.

BS EN 1041:1998
Information supplied by the manufacturer with medical devices

BS EN 12011:1998
Instrumentation to be used in association with non-active surgical implants - General Requirements.

EN ISO 14630:2005
Non-Active surgical implants - General requirements.

Laser marking is one of the final operations undertaken during the manufacturing process. During machining, some materials will be removed; so marking is left towards the end. The Pryor HP20 will mark alphanumeric data onto either of two sorts of surface: polished (mirror-finish) or glass beading that is a grey, satin finish. Marking can be done on a straight surface or in circular patterns around the edge of a product using the circumferential marking axis.

The HP20 is also used to mark the required millimetre scale on surgical measuring devices using straight lines or curves. Comis Orthopaedics has a calibrated reference ruler against which the operator visually checks the marked scale.

Taylor explains: “We mark our own measuring guides and instruments for traceability. We book them in and can follow them through the manufacturing process and usage. We laser mark the products and then acid passivate them to remove all of the ferric material and create pure stainless steel; that finished part is then booked into stock using the lot number. The part can be easily identified from that point on.”

LPE Medical, a sub-contracted manufacturer in the Orthopaedic field, also laser-marks all of the products that it manufactures with a unique code dictated by its customers. The code will include various parts - the product code allocated by the given standards agency such as the BSI to the master manufacturer; the European CE quality mark, the manufacturer's logo, the kind of material the product is made of (C = Cobalt, T= Titanium and so on); and a traceability or lot number originating from the sub-contractor (in this case LPE Medical). Managing Director of LPE Medical, Marcus Daniels, says: “We laser mark a particular number onto the product to give full traceability to the item that has been made. Then if, for any reason, that part is found in someone's body, the lot code can be traced back to us and we can derive all kinds of important information from our database. We can tell when the item was made, who made it, the parameters used to manufacture that product, how it was processed, where the materials came from and what constituent materials went into the product, who inspected it - everything that the investigation may need to identify.”

With regard to product traceability in orthopaedics, Roger Lamb of GS1 UK comments: “As an industry it will be interesting to see how quickly they will take it up. The messaging from the NHS is clear - everything that's supplied now needs to have a number on it. Whether or not a product has a GS1 number will affect the renegotiation of the contract to supply - companies will be asked to do this. Those products that don't have a GS1 mark or the companies that don't go that route will fall behind the market. It is as near to mandatory as you can get.”