| A heart rate monitor is a personal monitoring device | | | | transmitter with embedded electrodes in contact |
| that allows a subject to measure their heart rate in | | | | with the chest. |
| real time or record their heart rate for later study. | | | | In old versions, when a heart beat is detected a |
| Early models consisted of a monitoring box with a | | | | radio signal is transmitted, which the receiver uses to |
| set of electrode leads that attached to the chest. | | | | determine the current heart rate. This signal can be a |
| While these still exist, modern versions usually consist | | | | simple radio pulse or a unique coded signal from the |
| of two elements: a chest strap transmitter and a | | | | chest strap (such as Bluetooth, ANT, or other |
| wrist receiver or mobile phone (which usually doubles | | | | low-power radio link); the latter prevents one user's |
| as a watch or phone). In early plastic straps water or | | | | receiver from using signals from other nearby |
| liquid was required to get good performance. Later | | | | transmitters (known as cross-talk interference). |
| units have used conductive smart fabric with built in | | | | Newer versions include a microprocessor that is |
| microprocessors that analyze the EKG signal to | | | | continuously monitoring the EKG and calculating the |
| determine heart rate. | | | | heart rate, and other parameters. These can include |
| Strapless heart rate monitors are available as well, | | | | accelerometers that can detect speed and distance |
| but lack some of the functionality of the original | | | | eliminating the need for foot worn devices. |
| design. Advanced models additionally measure heart | | | | There are a wide number of receiver designs, with |
| rate variability, activity, and breathing rate to assess | | | | various features. These include average heart rate |
| parameters relating to a subject's fitness. Some | | | | over exercise period, time in a specific heart rate |
| newer monitors have replaced the plastic straps with | | | | zone, calories burned, breathing rate, built in speed |
| fabric sensors for comfort or garment integration. | | | | and distance, and detailed logging that can be |
| The new smart fabric technology has some promise | | | | downloaded to a computer. |
| to eliminate the need for elastic straps that hold the | | | | |