One of the problems with implantable electronic medical devices like pacemakers, is that you need to get a new one installed with fresh batteries every few years. This tiny power turbine could end that routine, by using your own blood flow to generate power for recharging the pacemaker.
The Swiss seem to be particularly good at building tiny mechanical devices, (think of all those watches), so it makes sense that the tiny blood turbine was developed by a team from the University of Bern in Switzerland led by Alois Pfenniger. He refers to the heart as "a pump in a prime location, brimming with energy for the taking," and in the case of his arterial turbine, it works out to about one milliwatt. That might not sound like a lot, but it's actually enough to run about 100 pacemakers.
Currently Pfenniger and his team are tweaking the design to ensure that it won't contribute to the risk of blood clots, because it wouldn't be much use having a steady ticker, if you simply fall down dead from a turbine induced stroke instead.