To be sure, the patient's next of kin cannot be kept out by this device - but the Man from Mars seems to have no next of kin.  The crew of the ill-fated Envoy had few ties on Earth; if the Man in the Iron Mask - pardon me I mean the "Man from Mars" - has any relative who is guarding his interests, a few thousand inquisitive reporters (such as your present scrivener) have been unable to verify it.