People fitted with heart pacemakers are supposed to take care not to go near strong magnetic fields. Some phones may cause their internal device to malfunction.
Today’s invention is a small phone which is attached to one’s pacemaker. This would be well shielded by eg a ferrous sheet placed between the two devices before insertion inside one’s body.
Pacemakers currently issue their users with an alert, in the event of some arrhythmia, by eg buzzing, but this system would also send data to a cardiologist and perhaps call an ambulance to one’s current location.