The Doctor is...At Home?
You have a chip in your hand
It is small, about the size of a grain of rice. It has a passive, radio frequency Identification (RFID chip inside it, protected from your body's interference by a thin shell. This chip, contains a single, long, unique number code shared by no one else on the planet.
The chip is in your palm, or maybe the back of your hand, nestled near the wrist. It is in the hand so anything you reach out to touch or grasp gets close enough to activate the tag. Currently this range is just twelve inches - one foot - but it may get longer as technology advances.
You use that hand to reach out. Maybe you press it into a human-hand shaped depression on a control pad, or simply grasp the railing on the side of your shower. The reader accesses the RFID, reads the identification number, and maybe checks the house database to see which family member it is. Not finding the number there, it goes online, jumps on the house's broadband connection to access the national health database, and finds your number on there. Using it as a primary key - for that is what it is - the number unlocks your basic medical information.
More advanced medical history requiring password information, which the unit does not have, it pulls out your usual blood work records, your dietary requirement, allergies, brief details of any medical conditions you are known to have. Quickly downloading what it needs to compare its about-to-begin analysis with, it has identified you, it knows you are a guest in this house, and it is prepared to be your physician never the less.
A battery of tests is possible in the small space that is the home. Indeed, they could conceivably fit into a space not much more than twice the size of a standard shower. In fact, the shower may be the perfect place for such, as it is a sterile environment.
Biochip arrays will work happily on a pinprick of blood, no more than is necessary for a diabetes test. Modern-day biochips can test for hundreds of different conditions from a simple sample, limited only in scope by the complexity of circuit designs. Near future chips will test for thousands, if not tens of thousands of chips, perhaps in a stackable array for easy removal and replacement, for sterility.
The machine doesn't have to stop there. Blood pressure can be taken easily, the lungs can be listened to via an automated system, to check for sounds that should not be present, and analyse them, stool and urine can be checked in much the same way as blood.
It should be possible for simple scanning equipment to be integrated in much the same way - a simple ultrasound or X-ray device, maybe even a mini-MRI to check for broken bones, or analyse organs for iron deposits or other minerals. (MRI slices can be analysed for iron content as well as a few other materials thanks to recent imaging technology enhancements)
You can then relax, or do other things about the home whilst you wait an hour or two for the machine to finish its scans, and produce a result. Conceivably others can use the machine whilst it processes. When it has finished scanning, it can tell you of any problems it has found, and if it thinks you should see a GP or hospital to check them out. It can then upload any changes it has found, to the national health database, routine home check-up completed.