Smart watches are detected by heart rate bands and optical heart rates.
When myocardial cells are at rest, there is a potential difference formed by the concentration difference of positive and negative ions on both sides of myocardial cell membrane. With the beating of the heart, the potential difference of myocardial cells quickly becomes zero. This process is called depolarization, during which a slight voltage change occurs.
The principle of optical heart rate is called "Photoplethysmography (PPG)", which is a technique to measure pulse optically.
brief introduction
To put it simply-the electrode pads located on both sides of the chest band (heart rate band) will be responsible for capturing the tiny electrical changes on the skin surface caused by the beating of the heart, and these tiny changes will be sent to the heart rate meter to be converted into the heart rate we see at present.
The blood flow in the artery will also change periodically with the contraction and relaxation of the heart. When contracting, heme has a high density and will absorb more green light; During diastole, the density of heme is low, and it reflects more green light.
Baidu encyclopedia-heart rate table
Apple watch should be equipped with "ECG"! Touching hands can measure blood pressure and blood sugar.
Author JimmyMa
Laiyuan Ji Guo editorial department
Many friends may have brushed such a news these days. Is the ECG function of AppleWatch coming? ! # Highlights of digital technology #
According to the documents issued by the State Administration of Medical Products, Apple has obtained the approval of the "Mobile ECG AF Prompting Software".
Although it is not clearly stated in the document, basically everyone guessed that this is the electrocardiogram (ECG) function of AppleWatch.
In fact, three Apple Watch 4Es (except SE) starting from the 4th generation of Apple Watch all support this function, only in some countries and regions. What can this function do? Is it reliable? Future smart watches can even measure blood pressure and blood sugar? ! Ji will introduce this knowledge to your friends.
In fact, measuring the heartbeat with a watch or bracelet is not a new function. Take AppleWatch as an example, measuring heart rate depends on "light".
Use the "light volume description method" (PPG)-in short, this method measures blood flow by light, so as to judge the heartbeat.
Blood is red and absorbs green light. The green LED light on the watch glows green. The sensor judges blood flow by measuring the amount of green light returned. When the heart beats, the blood flow will increase accordingly, so the heart rate is measured.
However, watches don't always emit green light to measure heart rate. More commonly, they measure their heart rate with infrared rays every ten minutes or so. When infrared light is difficult to obtain more accurate results, green LED will be used.
So the watch only measures the heart rate through "light". You have to use it to measure something else, and there may be a "reading". Of course there is no reference value, such as this "tachycardia" banana.
By measuring heart rate, we can prompt the speed of heart rate and detect arrhythmia.
AppleWatch4(SE has added ECG since AppleWatch4 (except SE), that is, ECG function.
To understand its working principle, we must first know the principle of ECG. Simply put, every time the heart beats, the depolarization of myocardial cells will cause tiny electrical changes on the skin surface. If two electrodes are placed on both sides of the heart, during this process, the slight voltage change between the two electrodes can be recorded and displayed on ECG paper or monitor.
Friends who have been to the hospital for ECG know that a complete ECG needs to place multiple electrodes on the wrist, ankle, chest and other places to measure ECG. Why do you need so many "sensors"?
Generally speaking, the standard electrocardiogram consists of "lead 12". The so-called lead 12 means that the electrodes attached to the body can form 12 sets of circuits and can observe 12 sets of electrocardiogram, so it is necessary to place 10 electrodes on the body to "observe" the heart from multiple directions.
Schematic diagram of the position of lead 12 and electrode 10.
In addition, there are usually "3-lead" and "5-lead" electrocardiographs, which are used according to different requirements.
However, the ECG function of AppleWatch can only measure "single lead" ECG, that is, lead I composed of left arm and right arm. When using a watch to measure ECG, it is necessary to put the fingers of the hand without the watch on the crown to form a ring.
Ji used AppleWatch to measure the electrocardiogram.
If you put AppleWatch on other parts of the body to measure ECG, you can theoretically get the results of lead II and lead III detecting the heart from more angles, but this usage has not been officially confirmed by Apple, so Apple will not be responsible for the results of the other two usages, but experiments prove that the results obtained by this method are reliable.
At present, although the ECG function has been audited, it has not been opened for use. Friends who want to experience still need to wait. Although some e-commerce platforms provide services to help open this function, there are certain account security risks, so it is better not to try it easily.
The occurrence of atrial fibrillation can be found to some extent by measuring ECG with a watch. However, it must be noted that it is not omnipotent.
The lead I just mentioned is mainly to observe the high side wall of the heart. Therefore, when there is a problem in other parts of the heart, it may be difficult to find the problem only from this angle.
Therefore, AppleWatch is not suitable for people who already have heart disease for daily monitoring. Hundreds of portable ECG detectors on the market are all three leads (equivalent to observing the heart from multiple directions). After all, there is a specialization in the industry, and AppleWatch is not specially used to measure ECG.
A portable ECG monitor
But is the ECG function of AppleWatch completely useless? No, it can pass the certification of many countries and regions, which shows that it still has certain reference value. AppleWatch can effectively detect heart problems such as atrial fibrillation by detecting ECG. It is also reported that some people use the ECG function of Apple Watch to find heart problems and treat them in time, saving lives.
Foreign media reported that a woman's husband found atrial fibrillation through AppleWatch and treated it in time.
According to a study published by JAMA)2020, the accuracy of smart watches in correctly recording heart attacks is 90%. So, what is the correct usage of this kind of products?
If you are a person with heart disease, what you need to do is simple-see a doctor, not rely on a watch. It is your only choice to follow the doctor's advice and buy more professional medical equipment.
And if you are just a person with high health awareness and always pay attention to your health, then smart watches on the market are more suitable. Such products are like "insurance", which can find your possible heart health problems with a certain probability and give you an early warning.
Many heart problems are difficult to attract people's attention at ordinary times, and once they happen, the consequences are also very serious. At this year's European Cup, Eriksson, the core player of the Danish team, suddenly fell to the ground during the game because of a sudden heart problem. Fortunately, the rescue was timely, and now it is no big deal.
Eriksson posted a selfie on social platforms.
Of course, remember to see a doctor in time if you have any questions. Don't rely on a small smart watch. It can only remind you that you have to see a doctor! What else can AppleWatch do in the future? Blood pressure or even blood sugar?
What other health functions can AppleWatch have? One of Apple's patents is eye-catching.
Usually we need a process of inflation and deflation when measuring blood pressure. If copied to a smart watch, it will have a great impact on the size, battery life and even appearance of the watch.
However, an Apple patent titled "Monitoring Blood Pressure with Multifunctional Wrist-worn Device" shows that only three groups of electrodes on the wrist-worn device can sense the pulse electrical signal of left ventricular contraction and determine the value of blood pressure based on time.
The greater breakthrough of this technology is that it can continuously monitor blood pressure simply and conveniently. If you have the ability of continuous monitoring, all household sphygmomanometers on the market may be "unemployed".
If measuring blood pressure is not so powerful, then the function of measuring blood sugar is even more "divine". Generally speaking, measuring blood sugar is very troublesome and painful, especially for diabetic patients who need to monitor blood sugar for a long time. This is really a nightmare.
Apple's patent on blood sugar monitoring shows that "terahertz electromagnetic radiation" is used to "irradiate" blood vessels, and the blood sugar value is detected by measuring absorption.
Patent schematic diagram of measuring blood sugar by terahertz electromagnetic radiation
In addition, near-infrared light can also be used to monitor the blood sugar value, and the blood sugar concentration will affect the light absorption and light path. At present, related research is also in progress, and many smart watches besides AppleWatch also intend to add related functions.
But unfortunately, blood pressure or blood sugar function may not come so quickly. The readings of these two measured values must be accurate, and if the deviation is too large, it may affect the patient's control of drug dosage. For example, excessive intake of insulin leads to hypoglycemia.
At present, what changes are expected in the new generation of AppleWatch released this fall? In terms of appearance, the prediction may adopt the square corner design of iPhone 12 series. Which do friends think is better?
In terms of battery life, performance optimization will further reduce energy consumption. It is estimated that the battery life will be extended from the current 18 hours to about 20 hours. It's still a little difficult to charge every two days.
In terms of health functions, it can be said that AppleWatch is doing better at present, and smart watches from other manufacturers are also catching up. What function do friends expect most?
Compared with other versions, Huawei watchGT2proECG has an extra bump on the right side of the case, which is used for ECG detection.
To use it, the user reaches out the finger of the hand opposite to wearing the watch and touches the protrusion. After 30 seconds, an electrocardiogram will be generated, and the related data map will be viewed in the "Healthy Exercise" app of the mobile phone.
How does Huawei watchgt2e measure heart rate?
Compared with mobile phones, smart watches and smart bracelets are characterized by exercise mode and health monitoring function, and heart rate monitoring is a standard function of wearable devices. How does Huawei watchgt2e measure heart rate?
How does Huawei watchgt2e measure heart rate?
1. Click to enter the watch details page in Huawei Health APP, and click Health Monitoring.
2. Click to continuously measure the heart rate.
3. Turn on the switch and continuously measure the right heart rate.
This paper takes Huawei WATCHGT2e Huawei p40 as an example, which is applicable to the HarmonyOS2.0 system Huawei Health V 1 1.0.5 version.
How to measure heart rate with smart watch
Lead: There are many brands of smart watches, but it is always no big problem to follow the instructions. Here I take the millet I used as an example.
_ _ How does a smart watch measure the heart rate?
Charge the bracelet first, this operation is enough. Some bracelets may be bought without electricity.
Download a sports app of this brand on your mobile phone, and there will usually be a QR code on the manual. For example, Xiaomi's bracelet is Xiaomi's movement, which is probably such an aunt.
Register an account with your mobile phone number.
After registering, log in, then click "My", and then press and hold the button on the bracelet to connect the mobile phone and the bracelet according to the prompts.
Find the heart rate to be measured in the "Settings" in the upper right corner or touch the button on the loop to enter the heart rate measurement.
In this way, you can view the previous records and monitor the changes of heart rate through the mobile app.
How to Measure Resting Heart Rate with Huawei Watch
Turn on heart rate measurement
1. After wearing the watch normally, the heart rate App of the watch will automatically start measuring, and the green light on the back of the watch will light up. In order to ensure the accuracy of heart rate measurement, it is recommended that you avoid the protruding parts of the bones when wearing the watch, avoid tying the strap too loosely, and ensure that the back of the watch is close to the wrist;
2. You can see your real-time heart rate in the watch heart rate App.
Note: When you use it for the first time, the automatic heart rate measurement is turned on by default, and the watch will measure your real-time heart rate all day. If you don't want to use this function, while the watch is connected to the mobile phone, go to the "Health App Manage More Sports Health Settings" on the mobile phone and close it. Resting heart rate measurement
Resting heart rate refers to the heart rate measured in a quiet, awake and inactive state, which represents the health of heart rate to a certain extent. The watch will automatically get the resting heart rate value after monitoring that you are in a quiet state. If you are not in a quiet state or wearing a watch, you will not get a resting heart rate. Early warning of high heart rate
When the heart rate continues to be too high, the watch will pop up a notice warning, which mainly has the following two warning states:
1. Daily heart rate warning means that when the watch detects that your heart rate exceeds the set upper limit of heart rate 10 minute in a quiet state (algorithm monitoring), it will pop up a notification reminder;
2. The exercise heart rate warning is a reminder that will pop up when your real-time heart rate exceeds your maximum heart rate value (default is 220- your age) after you start various exercises of the watch.
Note: The upper limit of heart rate can be set in "Health App Manage More Sports Health Settings" on the mobile phone. Check the heart rate
1, the current heart rate data can be viewed in the watch heart rate App, and you can know the current real-time heart rate, average heart rate, resting heart rate and maximum/minimum heart rate;
2. After the watch is connected to the mobile phone, the heart rate measurement record will be automatically synchronized to the mobile phone health App. Click the heart rate card on the health page to view more historical data, which are counted by day, week, month and year respectively.