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TESTING

Return to Article: Putting Implants to the Test

In addition to biocompatibility testing, breast implants require other testing, which should occur during R&D. Breast implants consist of an inner barrier layer between two outer layers. In R&D testing, measurements of breast implants are normally taken with a micrometer. Manufacturers “measure the total thickness of the implant and then make some assumptions,” notes Steve Heveron-Smith, vice president of sales and marketing for Lumetrics Inc. (West Henrietta, NY). The firm makes gauging systems for industrial applications.

According to Heveron-Smith, the assumptions made involve the thickness of each layer—and even whether all the layers are present in the implant. These assumptions can be erroneous, he says, resulting in the production of implants with missing layers or layers that are too thin to prevent leakage.

To prevent such problems, Lumetrics offers a system that takes measurements using infrared light directed at a surface. Used during R&D testing of breast implants, the product’s probe shines infrared light through an implant. The light reflects off the interfaces of the different materials in the implant and travels back to the device, which uses algorithms to determine the thickness of each layer of the implant. The probe can be mounted on the end of a robot arm that moves the testing device to different places around the outside of the implant, allowing it to take a number of thickness measurements.

For a reading to occur, the probe must be oriented 90° to the implant surface. In addition, the implant material must be translucent, so light from the device can penetrate it.

This way, says Heveron-Smith, “you know that the total thickness is correct and that each layer is the correct thickness. You also know that all three layers are there. So the implant will pass the quality tests that have to be done.”

But such benefits don’t come cheap. The machine costs between $60,000 and $85,000, depending on whether special fixturing is needed, according to Heveron-Smith.