When running, how does the smart watch monitor the heart rate?

Keeping healthy is our capital, and we are becoming more and more concerned about this kind of thing, and physical exercise has gradually become a part of people's lives. Running is the most common form of exercise for people, but many people only know about running, but they don't know anything about heart rate management while running. Heart rate is an important indicator that reflects a person's physical health. Real-time understanding of the heart rate status during exercise and choosing an appropriate heart rate interval exercise can better grasp the exercise intensity and improve the exercise effect. A variety of heart rate monitors or smart watches with heart rate monitoring on the market now have a heart rate measurement function, and heart rate chest straps and armbands are also common heart rate measurement tools. Some relatively high-end smart watches on the market, such as Apple watch, HUAWEI watch, Samsung Galaxy watch, Veekoon watch RIG, Fitbit, Garmin. Smart watches such as Xiaomi can accurately monitor changes in heart rate. These smart watches are not just simple heart rate monitoring, but these smart watches are more biased towards health monitoring and monitoring. In addition to heart rate monitoring, there are HRV, ECG, pulse rate, sleep apnea monitoring, blood oxygen monitoring, blood glucose monitoring and other functions. Smart watches have broken away from the simple monitoring of steps and calories in the past. Now smart watches have turned to the primary direction of monitoring human health.

Heart rate monitors and smart watches generally use photoelectric measurement. When a certain wavelength of light continues to shine on the skin, the blood flow through the wrist will vary with the heartbeat, which leads to the absorption of light by the blood. The intensity of the reflection changes as the heart beats. When the heart contracts, blood is pumped out, and more blood flows through the wrist. At this time, the blood absorbs more light, and the reflected light decreases accordingly. When the heart relaxes, the blood flow at the wrist decreases, and the absorption and reflection of light by the blood will change accordingly. The photosensitive sensor in the watch receives the change in the intensity of the light reflection, thereby generating different electrical signals, thereby determining the beating frequency of the heart.

The light emitted by the heart rate monitor and smart watch is green. Compared with the red blood of blood, green light can achieve a greater absorption rate, which increases the fluctuation range of the light reflection intensity, which is more important for detecting blood flow. Sensitivity makes it more accurate to judge the heart rate. But its shortcomings are also more obvious. This kind of photoelectric watch has strict requirements on the state of the skin. When there is sweat in the place where the watch and the skin are in contact or the contact is not close, it is easy to cause the error of the measurement result to increase. The photoelectric measurement method is suitable for the measurement of resting heart rate and sports with a relatively stable heart rate, such as running at a constant speed.

Heart rate monitors and smart watches can monitor heart rate very well when people are running. Such monitoring can better prevent the occurrence of sudden heart disease. We should pay more attention.