Medical devices are regulated by the us food and drug administration (FDA), there is a specialized division names Center for Devices and Radiological Health (CDRH) which reviews device application and monitors the safety of the medical device sold. The devices are classified on the basis of the risks possess to patients and the users. There are three classes in medical devices in which the medical devices are classified they are: Class I, Class II and Class III with level of risk low -medium, medium- high and high respectively. FDA classifies medical devices based on the risks associated with the device.