are then selected and must meet the general 'biocompatibility' require- ments. Prototypes are built and tested to include biocompatibility evalua- tions based on ASTM standard procedures. The device is validated for sterility and freedom from pyrogens before it can be tested on animals or humans. Medical devices are classified as class I, II or III depending on their invasiveness. Class I devices can be marketed by submitting notification to the FDA...