The doppler fetal heart rate monitor uses high frequency sound waves that lets you hear the sound of your baby s heart beat through an audible device sometimes an earphone or a speaker that is usually built-in on the heart rate monitor. In order for this wave to travel, the doppler fetal heart rate monitor is aided by particular liquid often a lotion, oil or water. While she aimed to achieve this, the market had yet to have the suitable product that would answer this. Since, there was no time to read product level on eat food she buys, there was a great need to what she thought a device that would lessen the worry and reduce the time wasted on check what food to buy and what s not. This makes Nike heart rate monitor comes into the picture. Nike heart rate monitor is a revolutionary device that would enable you to check the status of your heart every time you demand it. In training, knowing your heart rate draws the line between efficiency and waste of time. Without the Nike heart rate monitor, you might fall short of your target fitness level. The Polar heart rate monitor answers the needs of every heart rate monitor user. Polar has specific heart rate monitors for specific activity such as fitness, running, cycling, outdoor, team management, healthy living, and weight management. Polar also has different types of heart rate monitors that are suited for each type of user with different demands. As a result, the heart rate monitoring would be more accurate. People using the heart rate monitor watch can also have an easy access on the status of their heart at any given time they wish to check it. This is far too different from manual reading since it would not require the reader to stop and check for his wrist or his neck to get a reading. To determine the best heart rate monitor for you, here are the criteria you can consider: The basic. Since we are talking about heart rate monitor, the basic and most significant thing it should do is to monitor the heart rate. The style and a wrist watch image is also basic in every heart rate monitor.