The Center for Devices and Radiological Health (CDRH) has regulatory authority over several thousand different kinds of medical devices, with thousands of manufacturers and variations of devices. Because of its concern for the public health and safety, the CDRH part of FDA has been in the vanguard of examining medical device EMI (electromagnetic interference) and providing solutions. Extensive laboratory testing by CDRH, and others, has revealed that many devices can be susceptible to problems caused by EMI. Indeed, CDRH has been investigating incidents of device EMI, and working on solutions (e.g. the 1979 draft EMC standard for medical devices), since the late 1960s, when there was concern for EMI with cardiac pacemakers.