Last week, I interviewed Dr. Leslie Saxon, executive director of the University of Southern California's Center for Body Computing, who talked extensively about multidisciplinary collaboration. Well, check out what happens when you get medical professionals and engineers together.

As the Wall Street Journal reports this week, otolaryngologists, audiologists and sound engineers at the Chinese University of Hong Kong have teamed with a Hong Kong software firm Ximplar to develop a smartphone app that could replace the humble hearing aid.

The product, called ACEHearing, goes far beyond just amplifying sound, the way hearing aids used to annoy your grandparents. It adjusts sound output to fill in gaps in the sound spectrum based on each user's unique hearing profile. According to the Journal, Ximplar has clinical trials showing no significant difference between ACEHearing's smartphone-based hearing test and one given by an audiologist. I can't find the evidence myself, but I imagine someone is working on getting a study published in an academic journal.

Ximplar and the Chinese University of Hong Kong apparently are not marketing ACEHearing as a full replacement for the hearing aid—more of an alternative for when the user is on the phone to help eliminate the noisy interference telephones often cause in traditional hearing aids. But the Journal says the developers are looking at embedding the ACEHearing firmware in other consumer products such as headsets and MP3 players. Given how often some have their earbuds in, wouldn't this seem like a great alternative to an unsightly hearing aid, especially for younger hearing-impaired people?

While the Hong Kong developers have been focused on refining software, a multidisciplinary team at Vanderbilt University have gotten inside the guts of smartphones to make prosthetic limbs, well, smarter. Let me repeat: Vanderbilt engineers have put smartphone components into an artificial leg.

Why? Well, as Fast Company reports this week, the current generation of smartphones contain powerful processors, motion detectors and batteries that last far longer than those from just a few years ago.

"Passive" prosthetic limbs without computer assistance tend to drag because they don't move until the wearer actually shifts his or her body. But this so-called "Vanderbilt leg" can sense the user's body position and make educated guesses about the next movement, automatically adjusting the robotic joints accordingly. The batteries can last for as long as three days under everyday use, or for about 14 kilometers (8.7 miles) of continuous walking.

You won't be able to run a marathon with the Vanderbilt leg, but this could give the typical amputee a much more normal life again.

If you think this is cool, just think of one of other possibilities that Fast Company has raised. Smartphones contain tiny camera chips—perhaps the basis for a future bionic eye. This technology already powers a smartphone-based microscope.

"Gentlemen, we can rebuild him. We have the technology. We have the capability to build the world's first bionic man." And now, we can do it with a smartphone.