Why New Inspection Methods Can Cost Less
This article describes the challenges and successes in which a modern, non-contact technology replaced older manual methods. Four scenarios are discussed in which this newer technology can be integrated into a company’s process: new product development, process improvements, problem resolution, and existing products.
Razor blades, hand micrometers, metal pins of various sizes, and microscopes—these antiquated devices are still being used to measure medical equipment today. Why?
Are engineers unaware of the wide array of new tools and methods that exist to help more accurately measure their products? Do they feel so crushed by the weight of past regulation that they forget there are new and streamlined ways to gain approval for new products?
Methods are in existence today that not only work with mind-blowing accuracy, but also work at lightning speed. These methods include many light-based methods of measuring translucent materials—ranging from interferometry to florescence to lasers—while ultrasounds and x-rays are available for opaque materials.
Even the timing of measurement can be changed for the better. Many professionals in the medical device manufacturing industry have become comfortable measuring products offline. Yet, this can be a cumbersome and costly method of measuring. Today, thousands of products can be measured efficiently in-process.
Improved test methods—especially when automated and in-line—can reduce scrap costs, improve productivity, and produce a safer, more consistent product. Regulators need to encourage better test methods for medical devices and be open to modifications in qualification procedures. Manufacturers need to investigate newer, more effective test methods for medical devices that will lessen their risk and reduce costs.
A non-contact technology, OptiGauge, uses advanced infrared interferometry (with no moving parts) to ensure trouble-free operation. Additionally, the OptiGauge can be integrated into a production facility’s process control system for smooth and efficient plant operation. The system provides non-contact measurements at up to 200 samples per second and can measure objects as thin as 12 microns or as thick as 50 mm.
New Product Development
In many cases, incorporating a new measurement technology is easiest when developing a product through R&D and then moving into production as part of the process. During new product development, companies have the ability to implement new inspection and measurement technology. Creating new products can often be a catalyst for implementing state-of-the-art technology.
Some companies are able to quickly implement a new inspection process, especially if they are building a new medical product. An example is Direct Flow Medical, which designs advanced catheter and balloon products for its minimally invasive implant. In order to measure their balloons, engineers used to have to wait for the lot to be built and then take samples to destructively test. The process was time consuming, inefficient, and costly.
“The OptiGauge allows us to understand our balloon manufacturing processes very clearly,” said Gordon Bishop, chief technology officer. “By obtaining precise, direct measurements of balloons upon line startup, we are able to make adjustments immediately and produce products that meet the design specifications from the beginning.”
“The system has allowed us to achieve precise measurements with an added benefit of reduced inspection time,” said Andrew LaPlante, quality engineer. “Today, I can inspect a balloon in five minutes versus more than a day and obtain much more data. Additionally, all the operators find the system extremely easy to use.”
The system can be used for process improvements and one company that made bio-absorbable medical components did just that. Engineers within the company had seen the technology at a trade show and were in the process of building a new product, with a new production process, new extruder, totally new polymer, and extremely tight tolerances for the final product. The use of the OptiGauge provided data that was never obtainable before.
“Originally intended to be a QC instrument for monitoring production, the OptiGauge has allowed us to quickly and easily determine the geometry of our tubing during development,” said the operations manager. “This information has enabled us to immediately identify abnormalities in prototypes, isolate the cause, and take corrective actions. The speed with which we were able to make changes to the process reduced the time to produce qualified product from four to six months to just weeks.” Since their first installation, Lumetrics, the company behind the OptiGauge system, has provided more complex systems that measure the tubing even faster and with less intervention by an operator.
Some companies are systematic in their approach to implementing new technology, at times, to their disadvantage. Even when a new inspection capability is discovered, investigation and implementation times can double or triple the cost due to inherent resistance to change.
The lengthy process and resulting additional costs and reduced quality during that time should be a concern to business leaders. Many companies ignore the costs of an engineer’s time and leave them without the tools to effectively solve new product design and manufacturing problems. Engineers will spend endless hours manually inspecting products or trying to identify process problems without the correct tools; too often, that cost is not captured.
In one recent example, a customer’s implementation delays cost more than the new instrument itself. This customer is a medical device company that made dipped silicone balloons. The company’s engineers felt that non-contact infrared technology would provide them with a better method of measuring balloons, with which they were having trouble. The typical method of measuring silicone balloons is with a micrometer, after the product is made and removed from its mandrel.
After a few rounds of sample measurement and a trip to Lumetrics’ facilities, it appeared that the technology would provide the accuracy the customer needed. Balloons could easily be measured on the mandrel, and corrections made to the production process. But at that point, more testing was requested and the customer’s engineers discussed postponing a system until an online fixture could be designed.
Lumetrics argued against a final fixture design and instead recommended installing a system with simple fixturing at the line to investigate production process variables. The customer agreed and in September, approximately seven months after seeing the technology, a system was delivered to the production line. Within an hour of being installed the production line was halted because of out of spec product. The OptiGauge allowed the customer to quickly determine the problem and put a correction plan into place.
The decision to install the system at the production line with a simple fixture allowed engineers to save months and tens of thousands of dollars. By using the system immediately, engineers could measure balloons at the production line, determine if balloons were out of compliance, at what point within the process, and by how much.
There are many customers with existing product and inspection technology that should be updated. In these cases, even if a new technology is discovered, there is the difficulty of providing comparable results between the old and new inspection technology. In tubing inspection, many companies measure the wall thickness and concentricity of tubes with razor blades and optical comparators. This has the inherent problems involved with dull blades, forced cuts, and the differences in reading comparator screens among multiple operators.
Outside diameter is typically measured with a digital micrometer while inside diameter is provided by metal pin gauges. Both of these methods are highly subjective based on the operator. A micrometer reading that gets “rechecked” until they obtain the correct measurement, or a pin gauge that is forced into a tube to get the correct reading, are problems that are all-too-common.
An additional issue in many legacy inspection systems is the problem of data entry and validity. In many of today’s typical inspection methods, data is entered onto paper or computer forms manually—subject to transcription errors. With newer automated systems, data is automatically displayed, entered, and stored for full FDA compliance.
Although creating a process to move from the older manual inspection method to a newer, more automated system takes some time, the results have been dramatic for companies that have made the switch. The transition involves a series of Gauge R&R tests for both the older process and the OptiGauge. One of the common findings observed is the variability of Gauge R&R results in customers’ manual inspection methods. In one case with a customer working on a soft polymer product, Gauge R&R was 44% to 47% with its existing system and 2% to 4% with the OptiGauge. In addition to Gauge R&R, there is also a reduction in the time to conduct inspection with an old method versus the new technology. In this example, inspection time was reduced 96%—from 180 minutes to only six minutes.
It’s Worth the Effort
In evaluating inspection and measurement technology throughout the medical device marketplace it is easy to find newer, more precise methods that provide dramatic improvements. Many factors go into the decision to implement a new technology. Costs are a major factor but customers should consider the price of maintaining the status quo and not just the purchase price. Extensive engineering costs, time to market costs, labor costs, and scrap costs are among the most forgotten costs in deciding on new technology. Implementing new products can significantly reduce many of these costs, while providing greatly improved quality. All of these costs and advantages should be considered when evaluating whether current inspection methods are just “good enough” or “great.”