KLS Martin Quality Instruments
As an international supplier of medical devices, Gebrüder Martin GmbH & Co. KG has always given top priority to quality issues with regard to its surgical instruments. In fact, quality was a priority in our company long before legal regulations were put in place. Furthermore, since we have always gone a good deal beyond legal requirements, it is not surprising that competent KLS Martin employees have contributed greatly to the preparation and continuous improvement of both German and international standards governing the function, shape and quality of the various different instruments.
Development
It goes without saying that before an instrument can be manufactured, it must be designed first. The KLS Marin product divisions are, so to speak, the mediators and interpreters between the market and the design engineers. For any new instrument, they identify and define the features and properties desired by the user. In many cases, this involves bringing the development department in contact with leading surgeons, physicians or researchers. This collaboration is frequently reflected in the name given to the new product.
Once the requirements have been established, the design engineers can start developing the new instrument. Where new product series are concerned, we usually make use of our good relationships with leading research and testing institutes. All development efforts, including the tests performed and insights gained, are duly documented in the course of the design and development process. Upon completion of the development phase, the new product is validated against both the requirements defined by the product division and those defined by the law. A declaration of conformity is issued only for products that successfully passed these tests. The design is then released for production.
Materials
The materials used for the manufacture of surgical instruments are nationally and internationally standardized. As most instruments require a high mechanical strength for proper functioning, we are using hardenable chromium steels with a low to medium carbon content. In fact, a chromium content of at least 12.5% is required in order to guarantee sufficient corrosion resistance. As nickel-chromium steels, which have a distinctly higher corrosion resistance, are not heat-treatable, they can only be used for containers, trays and specific large-surface instruments (see Annex “Current reference standards for KLS Martin products“).
Raw Materials
The first step in manufacturing surgical instruments is forging a blank. There are only few certified specialized smithies that are capable of manufacturing such blanks in line with KLS Martin’s specifications regarding the material, shape and dimensions.
Only stainless steel of European origin is used as a source material for manufacturing the blanks. Each steel batch is delivered with a recognized test certificate, and the blanks produced from this source material are likewise duly documented. The quality systems of these contractors have been well aligned with KLS Martin’s own quality system. This guarantees that any product can be easily traced to the extent required by the law.
Manufacture
Based on the technical documentation established, the product then enters the manufacturing stage. All manufacturing specifications are subject to quality management. Any changes made on the product can therefore be easily tracked and pinned down at any time.
The manufacturing process is a batch process because the enormous variety of instruments required by our customers does not allow for serial production. This means that almost all instruments are, to a large degree, handmade. Intermediate tests and inspections are clearly defined steps in the process and as such included in the manufacturing documentation.
Heat Treatment
From a functional and reprocessing perspective, the most important step in the manufacturing process is the heat treatment. The heat treatment gives those instruments that are made of hardenable chromium steels the required strength, tenacity and corrosion resistance. In contrast, instruments made of nickelchromium steels are not hardenable, which means that the use of such steels is limited to special instruments.
In a first step, called “hardening” or “quenching”, the instruments are heated to a temperature of more than 1,000°C (1,832°F). At this very high thermal level, the chromium-carbon compounds previously encapsulated in the material dissolve completely, distributing uniformly in the steel. To preserve this ideal structure, the steel is “frozen“ by cooling it down fast, which results in a needle-type structure that gives the instrument the strength required for fulfilling its function. At the same time, the uniform distribution of the chromium content enhances the corrosion resistance to such a degree that the instruments are fully corrosion-resistant as long as the user respects the conditions specified for instrument processing.
In a second step, called “tempering”, the instruments are kept at a temperature of about 250°C (482°F) for several hours. This treatment reduces the tensions present in the instrument. As a result, the tempered instruments are significantly more elastic and less prone to fractures.
Proper heat treatment is directly reflected in the measured hardness values (see Annex “Current reference standards for KLS Martin products“). Lower (substandard) hardness values indicate insufficient heat treatment and, therefore, a lack of functionality and corrosion resistance.
Function and Finish
Following the heat-treatment stage, specially trained instrument makers give the instruments their final shape, function and finish. Notably, Tuttlingen is the only place in the world with a system of technical colleges and training institutions specially adapted to the needs associated with the manufacture of surgical instruments and medical devices. Highly qualified employees adapt each individual instrument to its intended function. Therefore, most instruments are really “handmade”. To complete the manufacturing process, all instruments are subjected to a passivation process. This provides all instrument surfaces with a chromium-oxide layer to make them extremely resistant to many chemical attacks.
The instruments’ finish has undergone changes lately as a result of more powerful operating lights and video camera systems being used in the OR. In spite of their superior corrosion resistance, mirror-finish instruments are available today only by special order because their light-reflecting surfaces tend to produce an irritating effect during operations. This is why state-of-the-art instruments feature a matte surface today. Whether such nonglare finish is achieved with glass beads or plastic brushes depends on the particular function of the instrument.
Final Inspection and Marking
On its way through the manufacturing cycle, each instrument undergoes a number of specified checks and tests, each of which is duly documented. Nonetheless, KLS Martin also insists on carrying out a classic final inspection. For each instrument, written inspection instructions and an inspection drawing have been put in place, against which every manufacturing batch is carefully checked. This final inspection is also documented in detail. Only those instruments that have passed this final examination are allowed to enter the next stage, where they are marked, cleaned and released for packaging and storage.
By affixing the CE-mark to the product, the manufacturer provides quality assurance. All products carrying this label fully comply with the “essential requirements” specified by the EC Directive concerning medical devices (MDD) as well as with KLS Martin’s documented and validated internal product profiles. As KLS Martin is convinced of the top quality of its surgical instruments, all instruments are covered by a lifetime warranty.
