For the "unconscious patient in the emergency room without a working phone" situations, put an RFID tag or a printed QR code in the hospital admission armband,

For the "unconscious patient in the emergency room without a working phone" situations, put an RFID tag or a printed QR code in the hospital admission armband, then the doctor / nurse can scan it to enter records from their own device. Those records go onto the hospital's / practice's server, then when the patient wakes up / next of kin arrives and they find / charge their phone, they enroll by an app that generates a private key on the device, then shows the public key in QR code form. Nurse scans the QR code on their device and signs off on a dialog box that says "Yes I verified the person with this phone has the right to this patient's records," then the server lets the app authenticate and get the records. The API should be open source so if you want your records, you can hack some JSON, sign an API request with your private key and download it (maybe with jigdo or rsync or something if it's huge X-rays and 3D CAT scans and stuff?). A third party app can put it on your phone for you, but hopefully there will be regulatory stuff that tries to make barriers to consolidation to encourage the system to remain federated. I.e. regulations should try to make sure your medical history stays within the offices of primary physician / specialist / hospital where you're a patient, and your phone's local storage. But we really don't want some "too big to fail" medical data startup putting ten million people's medical records in one AWS bucket.