the medical analysis thingy which clips on your finger is called a pulse oximeter-it reads the data thru infra-red light being bounced into the bloodstream in your finger and back.It measures the amounts of oxygen and CO2 in your blood. On another note:: I saw a show recently on teh discovdry channel about scientifically measuring the electro magnetic waves in places where ghosts and spirits are seen, felt and heard. the waves are measurable, and this gives a scientific credence to subjects formerly not proveable~! subjective/objective evidence~~ these modern "ghost busters" also were able to record ultra (low? high?) frequency sounds in zones where spirits have been known to frequent.