Low-Coherence Interferometry Enables Precision in Medical Implant Applications
Over the past several years, the market for non-contact, light-based measurements for medical implants such as balloons and catheters has continued growing. Emerging from research and development in this area, these solutions are more precise, automated, and standardized, using interferometry technology to overcome the limitations of the conventional micrometer gauge used for these purposes.
The ability to accurately measure the thickness of silicone coatings is key to the implant manufacturing process. Whether dip or spray coating methods are used, the OptiGauge II and OptiGauge II EMS can measure the additive thickness in process without the need for destructive testing.
What are the limitations when using micrometer gauges?
While micrometer gauges are simple and inexpensive, they have several critical drawbacks, especially when used to measure medical devices that require a maximum degree of accuracy. Micrometers are often subject to operator variability and, by their nature, measure total thickness only — and not the actual individual wall thickness of medical implants.
Another key limitation of micrometer gauges is that they require contact, which may compress the part being measured. As a quality assessment tool, micrometers do not provide medical implant engineers with the precise and detailed information they need to develop and improve their products or production processes.
What are the benefits of low-coherence interferometry for medical implant testing?
Low-coherence interferometry technology provides an extremely viable option that eliminates the subjective nature of micrometers.
For example, Lumetrics’ Scanning Tubing Measurement System (STMS) is a non‑contact, motion‑controlled inspection platform that integrates low‑coherence interferometry at a 1310nm measurement wavelength to simultaneously measure tubing ID, OD, and wall thickness with ±0.1µm accuracy across a measurement range of approximately 16µm to 16mm. This demonstrates how easily this method can provide fast and accurate wall measurements using an all-fiber low-coherence time domain interferometer.
Learn about our user-friendly scanning tubing measurement system with Lab Dave.
In its simplest form, this technology enables light from a low-coherence light source to be directed at the sample. For each new layer (interface) where it encounters a change in refractive index (RI), a small amount of light is reflected back into the system, where sophisticated and proprietary software produces highly accurate measurement results.
Optigauge II is capable of measuring multiple layers with an optical thickness range of 12µm – 16mm. Actual physical thickness is based on the refractive index of the material. Lumetrics can determine the Group Refractive Index at 1310nm using our Refractive Index Calculating System (RICS).
Advancing Next-Generation Medical Implant Testing with Low-Coherence Interferometry Technology.
Ideal for non-contact, non-destructive testing of medical devices, interferometry applications are transforming the market with a superior testing method that delivers streamlined, safe, and highly precise results. This directly contrasts the largely manual process of using a micrometer gauge, now an archaic measuring tool, which yields inconsistent results due to operator variability.
Given the extremely high level of accuracy, speed, and integrity demanded of medical implant manufacturers, the advancement of available tools is an exciting new dimension that promises to provide product and production engineers with a non-contact inspection tool that has the potential to create a new paradigm of quality. This not only has the potential to benefit all organizations that are designing, producing, and marketing medical implants, but also it can provide the highest standard of quality to support peace of mind for patients who rely on it when having a medical implant put into their bodies.
Learn more about the use of non-contact, light-based interferometry for medical device testing.
