I work in the intensive care unit of a very busy hospital and I am learning a lot these days.  We have so many different types of equipment that they can often be difficult to use.  There is one thing that I have found is the best piece of equipment and that is a fingertip pulse oximeter.  It works the best in measuring the amount of oxygen our patients are receive, and best of all it is not invasive to them.  I think our patients appreciate these little things because we want them to be as comfortable as they can be.