There are many tools available or being developed today that are reminiscent of the tricorder medical apparatus on Star Trek.
You remember the characters Montgomery Scott and Leonard McCoy from Star Trek. Scott—or Scotty—was the engineer, and McCoy was the physician on the series. However, most of the tools McCoy used were products of Scotty's domain. That is, the medical tools were engineering achievements, such as the medical Tricorder, which, in that imaginary world, non-invasively checked vital signs and other medical parameters.
There are many tools available or being developed today that are reminiscent of the medical apparatus on Star Trek. These tools constitute what I call the bio-trek universe (not to be confused with Bio-Trek shoes).
One such tool is the Micro Medical Devices Mobile B-Scan. This is a hand-held ultrasound scanner that plugs into any PC via a USB port. It could even conceivably be plugged into a tablet computer.
Another tool is the hand-held nuclear magnetic resonance (NMR) detector, which detects molecules associated with different diseases or conditions in very tiny samples of fluid, via the aid of magnetic nanoparticles that bind to the molecules of interest.
There is a contest concerning more advanced development of such tools going on now that EE's might be interested in. It's the Tricorder X Prize competition. Run by the X Prize Foundation and Qualcomm, it is intended to stimulate invention of a device that will detect 15 common illnesses independent of a physician, in a hand-held unit reminiscent of Star Trek's medical Tricorder. If I understand correctly, the object of the device is to inform the user when professional help is needed, rather than take the place of a physician. Contest details are on Qualcomm's website. While I saw mentions of an entry fee, I did not see where the amount was shown. Nevertheless, the prize is $10 million.
In summary, the device that is entered must weigh no more than five pounds, but may pack as many components as can be fit. According to the contest website, the "tool will collect large volumes of data from ongoing measurement of health states through a combination of wireless sensors, imaging technologies, and portable, non-invasive laboratory replacements." There are no specifications concerning appearance or functionality. However, data collected and stored on the device must be uploadable to and sharable on the Internet.
There is one device that is already very much along the lines of the X Prize Tricorder, and it may not be what you would have envisioned to be a medical instrument. It is the iPhone. Just look at the myriad number of medically related apps there are for it. For example, the Pennsylvania Gazette has an article that describes some of the currently available medically related applications for the iPhone. There is an electronic stethoscope, called "Stethoscope Expert," which comes with a library of sounds intended to train the human listener in identifying the heart sounds recorded with the iPhone. Okay, the sounds are not interpreted by the iPhone, but perhaps by connecting the iPhone to a remote computer, the analysis could be performed in real time by the remote machine, with the results transmitted back to the iPhone. (I believe using remote artificial intelligence is permitted in the X Prize contest.)
Another app described by the Gazette article is NETRA, or Near Eye Tool for Refractive Assessment. The app determines the prescription needed for vision correction using a simple "make the lines overlap" system, as the user looks through a simple lens.
The article mentioned that there are over 6,000 medical or health-related apps in the Apple App store. Many of these apps are miscategorized. For instance, should "Marijuana Truth" and "Police Radio" be considered to be medical apps? There is a lot of room for improvement. With the right new apps, and a few wireless sensors thrown in, there could be a real improvement in awareness of and control over one's health, and it could be done by the Noble Profession.