I'm always amazed.

I'm so not a science person. The things that they can do with seemingly simple medical equipment really does amaze me. My friend has a condition where she needs to know her blood oxygen levels. She has this little thing called a pulse oximeter that she just sticks her finger in. It gives her a digital reading of her levels. It's crazy that such a little piece of equipment can do that with any accuracy at all, but it does. I have no idea how it works, but because I love my friend I'm sure glad that it does.