AACH!(en)

        On Wednesday we went to Aachen as a class and visited the cardiovascular department of Applied Medical Engineering (CVAME) at Aachen university. The first thing that stuck out to me was that there were practically NO biomedical engineers working there, but they were working on artificial hearts, heart valves, cardiac assist devices, and extracorporeal oxygenation machines. They were mostly civil engineers, with some electrical engineers thrown in there, and a smattering of other sciencey people. That was the coolest thing about the place, and potentially one of the reasons for their success. People who know the body well and know everything that can go wrong will sometimes discount ideas outright because of one possible complication. As engineers with not a whole lot of specialized biological knowledge and a generalized understanding of the body as a machine, they are able to come up with some ideas that may at first sound far-fetched but turn out to work quite well. Also, they are very adept at designing testing rigs for their designs, and even make money on the side by testing devices for other companies.
         One of the most surprising things to me is that we have yet to find a good heart valve replacement with both an indefinite lifespan and few to no side effects. This was made clear by their little artificial valve "museum" which contained all the major models for heart valve replacement However, even though it is true that we don't have the ideal replacement, I learned that one of the best valves on the market was introduced in the 90's (by a Texas-based company!) and is still in use today.
         The CVAME's design for a total artificial heart (the ReinHeart) was also very surprising. I don't really know much about the pumping mechanisms of total artificial hearts in general, but the speaker-driver model for the ReinHeart's pump was an example of what I imagine is the result of using civil engineers in biological design. It is basically a piston that uses an inductor to drive the compression cycles. Biologists don't generally think of such solutions to these kinds of problems.

         After this, we went out to lunch and regrouped to tour the Aachen cathedral and the cathedral treasury. The first surprising thing was that the floorplan is not shaped like a cross--a feature shared by almost every large church in Europe. The sanctuary was in the shape of an octagon, covered with marble, and had a decidedly Moorish influence when it came to the decorative patterns on the floors and walls. The Throne of Charlemagne was amazing, both in the concept of it as a throne for God and because the marble from which it is constructed supposedly came from the Temple in Jerusalem. We also learned a little bit about the reliquaries which contained Charlemagne's bones. They were apparently used as propaganda in the middle ages, arguing that the principate had more authority in spiritual matters than the priesthood.

After this, we returned to Bonn, and my device design group worked for several hours on our presentation for the next day. We of course encountered several problems in this very important polishing phase of the project, and many *facepalm*s were committed. Thankfully it all ended up with a successful presentation on Thursday, and we are all one assignment closer to rounding out a successful semester.