At various times throughout the manufacturing process, medical device and orthopaedic implant manufacturers need to carry out a wide range of inspections and measurements of the parts that they produce. Operators in the orthopaedic industry, for example, may check hip stems against a template many times during the grinding and polishing process. Like many manufacturers across a wide range of industries, they have traditionally used optical comparators to check parts directly on the shop floor.
Traditional Optical Comparators
Optical comparators are robust, versatile measurement and inspection devices, and up until now, they have been the easiest way to quickly compare a part to its drawing to allow the user to make a pass/fail determination.
Optical comparators, however, require overlays, also known as templates or Mylars ™, to allow operators to verify that parts are in tolerance. Overlays present a number of problems: they must be physically stored and managed, they cannot be used simultaneously by multiple operators, and they need to be re-calibrated periodically. Beside every comparator, there needs to be a storage cabinet with the Mylars for all of the different parts that can be produced in a given environment, including a polishing cell. The 30" optical comparators have a large footprint as well, and they take up floor space. Optical comparators also cannot provide any type of record of the inspection and measurement operations.
To allow manufacturers to overcome the limitations of traditional optical comparators, VISIONx (Pointe-Claire, Quebec, Canada) developed the Vision- Gauge® Digital Optical Comparator (patents pending). This system has been adopted by a number of leading medical device and orthopaedic implant manufacturers as an improved way to quickly and accurately check parts directly on the shop floor throughout the manufacturing process and collect complete device history. Many medical device manufacturers are using the VisionGauge Digital Optical Comparator to make sure that various implants meet specifications. Common examples include hip and knee implants, medical instruments, craniomaxillofacial implants, bone screws, and other spinal implants.