I work in a medical research lab that specializes in using a experimental kind of Ultrasound.
Basically, its like the kind that you can use to image things, like babies, but our stuff is many times more powerful and only lasts for under 1/2 a second. I've been working there for two full years now, and I'm now leading my own project, and get to boss some newer undergrads around.
I'm using our ultrasound to 'push' on tissue. Painful tissue 'hurts' when it is touched, as everyone knows. However, there are sources of pain in places that a doctor cant push on, like the spine. Our idea is that because our ultrasound can produce a push sensation under the skin, at about a centimeter in, we could use it to 'push', or tap, on the persons back. Doctors really need this, because pain in your back can come basically from anywhere, and right now the only solution is to do discographies (sticking a 4 inch needle into your back and taking out some tissue).
Right now I'm testing our idea out on rat models. We've shown that our ultrasound can push at a level that causes inflamed tissue to react, but not normal tissue. Now we're working on a neruopathic pain model, but we might actually be just going ahead with human trials, if all goes well this week. Hopefully we'll have our device clinically availible in a few years, probably around the time I graduate.
So yeah, I'm a scientist that experiments on rats. I'm paid on a scholarship, so I dont get a per hour. But its a lot of fun, and its going to be cool getting a paper published with my name on it.