Using an unapproved medical devices is allowed in a case where clinical trials are supposed to be submitted as claims for a pre-market approval (PMA) but with only a small group of people and with their approval. Apart from this if the physician knows that the device is capable of curing a life-threatening disease then it should be used with proper consent of the user and with proper safety tools. But as far as possible the use of FDA approved devices should be considered before reaching out to the unapproved medical devices.