Thus depending on your age the pulse rate will change significantly. As the fluctuation of the pulse rate is due to the flow of blood through the arteries a medical device that is made for monitoring this is a pulse oximeter. A pulse oximeter is a medical and health device that is really the right hand tool of all health care physicians and clinicians who want an accurate reading of the individual's pulse rate and are needing a device that is also extremely portable that can be taken with them as they please. The pulse oximeter has its roots in the clinical setting but it is now used in the home setting as well as by athletes to monitor the pulse rate. More advanced models actually have a feature known as the perfusion index which in essence measures the strength of the heart beat of the individual