The ISO 10993 is a standard developed by the International Standards Organization (ISO) to evaluate the biocompatibility of medical devices in an effort to ensure patient safety. Established in 1995, this standard creates guidelines for biocompatibility testing globally. It is a 20-part standard that tests for everything from irritation to delayed hypersensitivity, interactions with the blood, and the chemical properties of the materials involved. It can broadly be understood as a set of tests and principles that evaluates medical devices to ensure that there are no adverse effects to the human body as a result of their use.
It is vital to thoroughly assess the biocompatibility of medical devices — different devices may have different types of interactions with the body's tissues and organs. For instance, a material may leach off the medical device into the surrounding tissues or enter the bloodstream inadvertently. Some of these elements may be unsafe. The ISO 10993 standard uses animal models, in vitro tests, and analytical chemistry to perform the assessment. Devices are evaluated according to their chemical and physical makeups, the types of tissue they come into contact with, and the duration of overall exposure.
Providing guidelines on the types of testing necessary, the ISO 10993 helps in understanding and evaluating the data obtained. It also helps in identifying areas where more information is needed and aids in spotting gaps using risk analysis methodologies. All medical device manufacturers, regulators, and laboratories have to comply with the ISO 10993 standard. Devices are categorized as either implant, surface, or external communicating, and they are further subdivided according to the duration of exposure. Limited exposure stands for less than 24 hours, prolonged is considered to be anything between a day to a month, and permanent stands for more than a month.
Some of the tests involved in ISO 10993 include checking for local effects after implanting a device within the body, whether any residues are present, and how materials like ceramics, metals, and polymers degrade with exposure to the body. Every test is important for numerous reasons. For instance, one test involves evaluating systemic toxicity. This is to investigate whether the device releases materials into the body and, if so, in what concentrations. If the concentration is too high, then it could be absorbed and circulated to different areas, resulting in extreme toxic effects.
Experts who use ISO 10993 to test for systemic toxicity have to use their own judgment in selecting the relevant procedures from the lists of standards to ensure they apply to the device being tested. There is room to exercise judgment in the application of these standards because over rigidity or excessively detailed specifications could prevent the expert from applying the most relevant testing methodologies. If they deviate from the prescribed methodologies laid out in the standard, they need to explain the rationale behind their testing methods and show enough scientific support for their decisions.
