Pulse Oximeter

I saw this interesting gadget in the net today. It is called pulse oximeter, a gadget use to monitor your pulse rate. I have actually heard of it before but it is only now that I learned that there are various kinds of pulse oximeter. I never knew that there is a pulse oximeter for children or the pediatric pulse oximeter. I don't want to sound so ignorant (big grin); pardon me if I am starting to sound one. But honestly it was only now that I got interested to these gadgets. Recently, when my Mother had her eye operation I became interested to these things. I want to learn more about these gadgets that would come in handy in the future. Having old people in the house that have health concerns, it would be best to know what are the gadgets that are convenient to use to monitor their health.