Current, common tolerance testing involves a statistical technique. For example, typically for every 100 devices that are produced, a subset is sampled and measured to determine if the lot is within specifications. The measure is usually performed manually, with the person performing the measurement doing the work, then completing a form to document the measurements and the process. This manual method, while meeting minimum requirements, presents a whole host of problems in the event of an FDA challenge, including human errors, inconsistencies and auditing costs.
A technique that is being adopted more readily is the use of surface scanning lasers to assess the exact measurements of the produced part. The surface scanning laser can measure the surface of a part to a high degree of accuracy and produce a wireframe digital representation of the part in three dimensions. Then, using sophisticated software that can align this mesh of the actual part to a CAD representation of the part, it is possible to assess the result of the manufacturing against the desired specifications. This technique, called co-registration, is an image analytics technique that takes two images—two representations—of the same object and determines how those two images relate to each other spatially so that you’re actually looking at the same element in the same coordinate system.
Sophisticated scanning is a better approach that is beginning to be used in the manufacturing process. Using this laser technology, manufacturers will be able to quickly and accurately assess the surface quality of a part, and then co-register the original manufacturing specification against the actual part and automatically identify out of tolerance issues. For example, as you can see in Exhibit 1, it is possible to color-code areas of the part that are above or below the ideal model of the part.
Exhibit 1: Height Mapping
Height mapping for tolerance of a manufactured part provides assessment of an ideal part model.
Of course, advanced CT scanning techniques and laser surface scanning provide outstanding insight into the manufacturing process. However, in many cases, a simpler approach for imaging can leverage the full power of software analysis. Simple visible light camera images, combined with power analysis software, can be a very effective approach. Take for example the images of a circuit board seen in Exhibit 2. The image on the left is a simple photograph taken with a handheld camera, without the need for a sophisticated or expensive camera rig. Through the creation of analysis software, it is possible to confirm that the wiring has been done appropriately. This provides a powerful and cost-effective means for definitively checking the wiring process.
Exhibit 2: Wiring Assessment through Software Analysis
This circuit board image on the left was taken with a handheld camera without the need for a sophisticated or expensive camera rig. Through the creation of analysis software, it is possible to confirm that the wiring has been done appropriately.
Imaging techniques and analytical software are among the many new and groundbreaking techniques deployed by the medical device industry as key business strategies. Use of imaging allows innovative leaders to improve data accuracy for impending increased FDA scrutiny, reduce their QA costs to compensate for the impact of the medical device tax and improve manufacturing profitability. Imaging hardware and custom analytical and operational software can deliver strong manufacturing ROI, as well as a competitive price and quality advantage.
Tim Kulbago is Chief Executive Officer of ImageIQ, an imaging CRO and software development company located in Cleveland, Ohio.
Continue to learn from ImageIQ: Attend a presentation by Amit Vasanji, Ph.D., Chief Technology Officer, ImageIQ, Inc., at OMTEC 2013 in Chicago.
Using Imaging Analytics to Improve Manufacturing Quality Assurance
10 a.m.-11 a.m. Wednesday, June 12
Utilizing a number of new image acquisition techniques, coupled with advanced processing and analysis software, it is becoming possible to address some of the most challenging quality assurance issues in a cost effective manner. Attendees will be exposed to the latest imaging techniques that can be applied to the manufacturing process. The session will also describe the economic benefits of implementing customized analysis software in the manufacturing pipeline.