Heart Rate Monitor
Patent 12459494 Filed on July 2, 2009
Issued on January 21, 2010
Inventors: John Mix and Roar Viala
US Classification: 600/508
This invention is an electronic athletic training device which measures heart rate for the purpose of aiding swimmers while training. The main components of the device include a light sensor that measures changes in light due to blood flow in the skin, a micro-processor that calculates heart rate based on changes in the light detected by the infrared sensor, and a component to convert the output to audio signals representative of heart rate. To use this device, a user would position the infrared sensor near the temple using a clip that is attached to the strap of the user’s goggles. Additionally, the user would wear an earpiece which receives the audio signals. This device also has the ability to be powered by an internal lithium-ion rechargeable battery, be operated with a power button, and store the history of the user’s heart rate during workouts.
I think this invention could be useful for Olympic swimmers as well as ordinary people who are interested in heart-rate-training and enjoy swimming. For those interested in using this device for heart-rate training under moderate-intensity exercise this could be a very useful device. I think this is interesting because if I were to design a swimming workout based on my target heart-rate I would want to use this device. For swimmers, monitoring and maintaining target heart-rate for aerobic activity can be challenging using a typical wrist watch heart rate monitor, because it requires them to look at their wrist while swimming. I can understand how frequently glancing at a wrist heart rate monitor to get your heart-rate can be an annoyance for a swimmer. Therefore, this invention is novel because it removes that task altogether by providing the user with an audio rather than visual representation of heart rate.
The technology of this device consists of infrared sensors that sit against the skin, and a microprocessor that is coupled to the sensors which calculates the number of beats/minute and generates output signals to an earpiece. The engineering behind this device is based on the principle of measuring the change in light through the user’s skin due to blood flow. Once that information is obtained, it is possible to calculate the heart rate by measuring the background noise with a separate infrared sensor and then subtracting it from the light measured via the infrared sensor at the skin’s surface. The micro-processor then generates a correction factor for calculating the heart rate based on background noise. Audio signals are generated through a transducer attached to the ear or temple wherein the transducer communicates the heart rate to the user’s ear where sounds are transferred. Aside from the actual device, the user also has the option of processing workout data from the heart monitor to generate a graphical representation of his/her heart rate on a computer.
Figure 1. device showing infrared sensor and earpiece components of heart rate monitor