Heart rate monitor
- This article refers to a device used by laypersons. For the article on the medical device performing a similar function, see Electrocardiography.
A heart rate monitor is a device that allows a user to measure their heart rate in real time. It usually consists of two elements: a chest strap transmitter and a wrist receiver (which usually doubles as a watch). Strapless heart rate monitors are available as well, but lack some of the functionality of the original design. Advanced models additionally measure heart rate variability to assess a user's fitness.
The chest strap has electrodes in contact with the skin to monitor the electrical voltages in the heart (see electrocardiography for more details). When a heart beat is detected a radio signal is transmitted, which the receiver uses to determine the current heart rate. This signal can be a simple radio pulse or a unique coded signal from the chest strap; the latter prevents one user's receiver from using signals from other nearby transmitters (known as cross-talk interference).
There are a wide number of receiver designs, with all sorts of advanced features. These include average heart rate over exercise period, time in a specific heart rate zone, calories burned, and detailed logging that can be downloaded to a computer.
The Polar Electro company's website states they invented the first accurate, wireless electrocardiogram heart rate monitor in 1977, to be used as a training tool for the Finnish National Cross Country Ski Team. [1]
The MIO Watch (http://www.miowatch.com) company website states they invented the first ECG accurate strapless heart rate monitor watch that is used as a weight management tool for consumers along with the patented calorie management system.
In December 2005, Textronics Inc. introduced the first garment with integrated heart sensors in the form of a sports bra. (www.numetrex.com)Special materials in the sports bra sense heart rate from the body and transmit it to a wrist receiver. The garment provides a comfortable alternative to the chest strap.
Today, the same concept of heart rate training is used by many people for training, weight management & in race performance analysis.
In 2006 Zephyr (http://www.zephyr-technology.com) supplied Textronics (recently bought by Adidas) its new version of a smart fabric heart rate monitor. This device used BioSense algorithms to analyze the persons electrocardiogram, ECG, real time and calculate heart rate. This level of sophistication was required because fabric sensors suffer from movement artifacts more than traditional plastic straps. Additionally fabric sensors suffer from a persons conductive sweat shorting out the bodies signals used to detect heart beats. Zephyr has taken this concept and combined heart rate with a patented breathing rate sensor, body temperature, activity and posture in a product called the BioHarness. This device has been used for remote patient monitoring, looking after soldiers and fire fighters in harm's way and professional athletes who required more than just heart rate to determine fitness and fatigue using multiple physiological and bio-mechancical sensors. What makes the BioHarness especially useful is that it uses Bluetooth technology and communicates over VHF radios or mobile phones to the Internet. This allows its diagnostic software to be viewed anywhere in the world.
The HXM product by Zephyr is a consumer Bluetooth heart rate monitor that also measures speed and distance in the same device, eliminating the need for a foot pod from the likes of Polar, Suunto or Dynastream. Using a phone for training has become more popular since people have started exercising with Apple's iPOD. Music phones from the likes of Blackberry, Sony and Motorola have allowed a person to measure their work out, listen to music, and stay connected via voice calls and texting. Companies such as Trimble Allsport and Bones in Motion have also introduced the concept of GPS in a phone for exercise with fitness and mapping applications.