TECH UPDATE ONLINE EXCLUSIVE
A medical device package must be subjected to a series of rigorous tests to ensure that it complies with standards and performs up to expectations. One common—but sometimes overlooked—test is transportation (or distribution) simulation, which mimics real-world shipping conditions in a controlled laboratory setting. And while there is a consensus among testing labs that these shock and vibration tests are essential, there are differing opinions as to which aspects are necessary for packaging of lightweight, medical disposables.
There are two main vibration tests performed as part of distribution simulation: random vibration and fixed vibration. Fixed vibration tests determine how a package holds up to movement at one frequency. Random vibration tests, on the other hand, simulate natural frequencies often encountered by trucks during shipping, such as bumps in the road. Most testing facilities conduct both tests on a given package as part of ASTM D4169 and as a manner of defensive engineering.
Barry Kazemi, president of Life Science Outsourcing, Medical Package Testing Div. (Brea, CA), however, questions whether random vibration testing is truly necessary for packaging of lightweight disposable devices. He notes that although they can be part of a defensive engineering approach, random vibration tests typically cost two to three times more than fixed vibration tests. “A lot of disposable packages are so lightweight, there’s no benefit in random vibration,” Kazemi says. “There is no study that I know of that shows someone could find a problem through random vibration that could not be discovered with fixed vibration.”
Scott Levy, packaging engineer for DDL Inc. (Eden Prairie, MN), in contrast, believes that random vibration represents a form of offensive engineering that provides OEMs with an effective evaluation of how the package will perform in a variety of scenarios and allows for the identification of weaknesses. “When you’re doing transportation simulation testing, you’re only taking a snapshot picture,” Levy says. “You’re never going to mitigate for every situation; but, if you’re only doing fixed displacement vibration, you’re not simulating what actually is occurring in the real world. The ultimate goal is to develop a safe and effective package using good engineering practices to ensure efficacy for the sterile barrier system.”
While there is no conclusive opinion on vibration testing methods of disposables, OEMs should speak with their testing labs to determine the optimal run of tests that should be conducted.
For more information on issues and advice relating to destructive medical package testing, read The Powers of Destruction, the Tech Update article published in our January/February 2010 issue.