More relevant to this blog, we've been busy working with our students to strengthen their basic engineering and fix-it skills. On Monday I gave a lecture on the fundamentals of motors - just about everything we'll be tackling in a hospital will have a motor of some sort in it. And yesterday (Tuesday) the lecture was about ventilators and oxygen concentrators. We talked about way of testing whether a ventilator is pushing out the correct volume an pressure. To measure volume, you can use the ventilator to inflate a balloon, and then put the balloon in a bucket of water to see how many inches the water level goes up. From there you can calculate the volume of displaced water, which is more or less the volume of air. To measure air pressure you can connect the ventilator to a clear tube with a u-bend that's filled with water. The more pressure, the more the column of water will be displaced.
|The transformer and light bulb.|
|Battery pack, switch (red), and LED (clear, at left)|
We also spent some time learning about fuses. Every lab group took a 1A fuse and shorted it across a pair of AA batteries. That created more than enough current to get the fuse to blow - we looked at the fuses before and after and you can see the little fuse wire inside gets physically burned away. Blown fuses are a constant source of headache when repairing medical equipment!