How does a smart watch detect a person’s heart rate?
Smart watches detect heart rate through heart rate straps and optical heart rate.
When myocardial cells are in a resting state, there is an electrical potential difference formed by the concentration difference between positive and negative ions on both sides of the myocardial cell membrane. As the heart beats, the electrical potential difference of myocardial cells rapidly changes to 0. This process is called depolarization, during which small voltage changes occur.
The principle of optical heart rate is called "Photoplethysmography (PPG)", which is a technology that measures pulse optically.
Introduction
To put it simply - the electrode pads located on both sides of the chest strap (heart rate monitor) are responsible for capturing the tiny electrical changes caused on the skin surface when the heart beats. These small changes will is sent to the heart rate monitor and converted into the current heart rate we see.
The blood flow in the arteries also changes periodically with the contraction and relaxation of the heart. During contraction, the density of hemoglobin is high and more green light is absorbed; during relaxation, the density of heme is low and more green light is reflected.
Reference for the above content: Baidu Encyclopedia - Heart Rate Monitor
The Apple Watch must be equipped with an "electrocardiogram"! You can measure your blood pressure and blood sugar with just a touch of your hands
Author JimmyMa
Source: Jiguo Editorial Department
These days, there may be many Many friends have come across such a piece of news. Is Apple Watch’s electrocardiogram feature coming? ! #digitaltechnews#
A document released by the National Medical Products Administration shows that Apple has received approval for a “mobile electrocardiogram atrial fibrillation reminder software”.
Although it is not clearly stated in the document, everyone has basically guessed that this is the electrocardiogram (ECG) function of Apple Watch.
In fact, all three Apple watches starting from the 4th generation of Apple Watch (except SE) support this function, but it is only available in some countries and regions. What can this function do? Is it reliable? Will future smart watches even measure blood pressure and blood sugar? ! Jiguojun will introduce this knowledge to all of you.
In fact, using watches and bracelets to measure heartbeat is not a new function. Taking Apple Watch as an example, measuring heart rate relies on "light".
Using the "Photovolume Description Method" (PPG) - simply put, this method uses light to measure the blood circulation to determine the heartbeat.
Blood is red and absorbs green light. The green LED light on the watch emits green light. The sensor determines the blood flow by measuring the amount of green light returned. When the heart beats, the blood flow will increase accordingly, so The heart rate was measured in this way.
However, watches usually do not always emit green light to measure heart rate. Instead, they use infrared light to measure heart rate every ten minutes or so. When infrared light is difficult to obtain more accurate results, green light is used. Light LED.
Therefore, the watch only detects heart rate through "light". If you have to use it to measure other things, there may also be "readings". Of course, it has no reference value, such as this "heartbeat" Fast” bananas.
By measuring the heart rate, it can indicate the speed of the heart rate and detect irregular heartbeats.
Since Apple Watch 4 (except SE), Apple watches have added ECG, which is an electrocardiogram function.
To understand its working principle, you must first know the principle of electrocardiogram. Simply put, every time the heart beats, the depolarization of myocardial cells will cause small electrical changes on the skin surface. If two electrodes are placed on either side of the heart, then during this process, tiny electrical changes between the two electrodes can be recorded. The voltage changes can be displayed on the electrocardiogram or monitor.
Everyone who has gone to the hospital to have an electrocardiogram done knows that a complete electrocardiogram requires placing multiple electrodes on the wrist, ankle, chest, etc. to measure the electrocardiogram. Why do you need to bring so many "sensors"?
Generally speaking, a standard electrocardiogram consists of "12 leads". The so-called 12 leads mean that the electrodes attached to the body can form 12 groups of circuits and observe 12 groups of electrocardiograms. This requires a By placing 10 electrodes, the heart can be "observed" from multiple directions.
Schematic diagram of the location of 12 leads and 10 electrodes
In addition, there are usually "3-lead" and "5-lead" electrocardiogram instruments. According to Used according to different usage requirements.
The ECG function of Apple Watch can only measure "single-lead" ECG - that is, Lead I (Lead I) composed of the left arm and the right arm. When using a watch to measure an electrocardiogram, you need to place the fingers of the hand not wearing the watch on the crown to form a circuit.
Jiguojun’s electrocardiogram measured with AppleWatch
If you place the AppleWatch elsewhere on the body to measure the electrocardiogram, you can theoretically get the test results of lead II and lead III. Detect the heart from more angles. However, this usage has not been officially confirmed by Apple, so Apple will not be responsible for the results of the other two usages. However, experiments have proven that the results obtained by this method have a certain degree of reliability.
At present, although the ECG function has been reviewed, it has not yet been activated for use. Friends who want to experience it still need to wait. Although some e-commerce platforms provide services to help activate this function, there are certain There are potential security risks to your account, so it’s better not to try it easily.
By using a watch to measure the electrocardiogram, the occurrence of atrial fibrillation can be detected to a certain extent. But be sure to note that it is not a panacea.
Lead I just mentioned mainly observes 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 by only looking at the electrocardiogram from this angle.
Therefore, Apple Watch is not suitable for daily monitoring by people who already have heart disease. There are hundreds of portable ECG monitors on the market that all have three leads (equivalent to observing the heart from multiple directions). After all, there are specialties in the industry, and the Apple Watch is not specifically used to measure ECGs.
A portable ECG monitoring device
But is the ECG function of Apple Watch completely useless? No, the fact that it has been certified by multiple countries and regions shows that it still has certain reference value. Apple Watch can effectively detect heart problems such as atrial fibrillation by detecting electrocardiogram. There have been reports that some people discovered heart problems using the electrocardiogram function of Apple Watch and received timely treatment, saving a life.
Foreign media reported that a woman’s husband discovered atrial fibrillation through Apple Watch and received timely treatment
The results of a study released by the Journal of the American Medical Association (JAMA) in 2020 showed that , the smartwatch correctly recorded heart attacks 90% of the time. So, what is the correct use of this type of product?
If you are a person suffering from heart disease, then what you need to do is simple-go to the doctor instead of relying on a watch. Listening to your doctor's advice and purchasing more professional medical equipment is your only option.
And if you are just a person who has a relatively high health awareness and always pays attention to your body, then the smart watches on the market are more suitable. This type of product is like "insurance" and can detect with a certain probability Warn you about possible heart health problems.
Many heart problems are usually difficult to attract people’s attention. Once they occur, the consequences will be serious. At this year's European Cup, Eriksen, the core player of the Danish team, suddenly fell to the ground during the game because of a sudden heart problem. Fortunately, he was rescued in time and is now fine.
Erickson’s selfie posted on social platforms
Of course, remember to see a doctor in time if you have any problems. Don’t rely on a small smart watch. It can only Reminder: It’s time to see a doctor! What else can the Apple Watch do in the future? Blood pressure or even blood sugar?
What other health functions does Apple Watch have? One of Apple’s patents is “eye-catching”.
Usually when we measure blood pressure, we need a process of inflation and deflation. If it is copied to a smart watch, it will have a big impact on the size, battery life and even appearance of the watch.
However, an Apple patent titled "Blood Pressure Monitoring Using a Multifunctional Wrist-Worn Device" shows that the left ventricular contraction pulse can be sensed through only three sets of electrodes on the wrist-worn device. Electrical signals determine blood pressure values ??based on time.
The biggest breakthrough of this technology is that it can continuously monitor blood pressure simply and conveniently. If it can have the ability to continuously monitor, then all the home blood pressure instruments on the market may become "unemployed."
If measuring blood pressure is not that powerful, then the function of measuring blood sugar is even more amazing. Generally speaking, measuring blood sugar requires drawing blood, which is very troublesome and painful. Especially for diabetic patients who need to monitor blood sugar for a long time, it is really a nightmare.
Apple’s patent on blood sugar monitoring shows that “terahertz electromagnetic radiation” is used to “irradiate” blood vessels and detect blood sugar levels by measuring the amount of absorption.
Patented schematic diagram of using terahertz electromagnetic radiation to measure blood sugar
In addition, it is possible to use near-infrared light to monitor blood sugar levels. Blood sugar concentration will affect the absorption of light and the optical path. Currently, Relevant research is also ongoing, and many smartwatches besides Apple Watch also plan to add related functions.
But unfortunately, blood pressure or blood sugar function may not improve so quickly. The readings of these two measurements must be accurate; if the deviation is too large, it may affect the patient's ability to control the amount of medication. For example, taking too much insulin can lead to hypoglycemia.
At present, what changes will there be in the new generation of Apple Watch expected to be released this fall? In terms of appearance, according to predictions, the square-corner design of the iPhone 12 series may be adopted. Which one do you think looks better?
In terms of battery life, performance optimization will further reduce energy consumption. It is expected that the battery life will be extended from the current 18 hours to about 20 hours. It is actually a bit difficult to charge it every two days.
In terms of health functions, it can be said that Apple Watch is currently doing better, and smart watches from other manufacturers are also catching up. Which function are you most looking forward to?
Compared with other versions, the Huawei watchGT2proECG model has an extra bump on the right side of the watch case, which is used for ECG detection.
The method of use is that the user reaches out and touches the bump with the finger of the hand opposite to the one wearing the watch. After 30 seconds, an electrocardiogram will be generated, and the relevant data graph will be viewed in the "Healthy Sports" app on the mobile phone. .
How to measure heart rate on Huawei watchgt2e
Compared with mobile phones, the most prominent features of smart watches and smart bracelets are exercise modes and health monitoring functions. Heart rate monitoring is a standard feature of wearable devices. . How to measure heart rate on Huawei watchgt2e?
How to measure heart rate on Huawei watchgt2e?
1. Click to enter the watch details page in the Huawei Sports Health APP and click Health Monitoring.
2. Click to continuously measure heart rate.
3. Turn on the switch on the right side of continuous heart rate measurement.
This article takes Huawei WATCHGT2e Huawei p40 as an example and is applicable to Huawei Sports Health V11.0.5 version of HarmonyOS2.0 system
How to measure heart rate with a smart watch
Introduction: Smart There are many brands of watches, but there is no big problem if you follow the instructions. Here I will take the Xiaomi I have used as an example.
__How to measure heart rate with a smart watch
First, charge the bracelet with enough power for this operation. Some bracelets may have no power after you buy them.
Download a sports app of the brand on your mobile phone. There will usually be a QR code on the manual. For example, Xiaomi's bracelet is Xiaomi Sports, which is probably like this...
Register an account with your mobile phone number.
Log in after registration, then click "My", and then follow the prompts to press and hold the button on the bracelet to connect the phone and the bracelet.
Find the heart rate measurement in "Settings" in the upper right corner or touch the button on the ring to enter heart rate measurement.
In this way, you can view previous records and monitor heart rate changes through the mobile app.
How to measure resting heart rate on Huawei Watch
Turn on heart rate measurement
1. After wearing the watch normally, open the watch heart rate app and the measurement will start automatically. The green light on the back of the watch will turn on.
In order to ensure the accuracy of heart rate measurement, it is recommended that you avoid bone protrusions when wearing the watch, avoid fastening the strap too loosely, and ensure that the back of the watch is close to your wrist;
2. You can view it on the watch heart rate app to your real-time heart rate.
Note: When used for the first time, automatic heart rate measurement is turned on by default, and the watch will measure your real-time heart rate throughout the day. If you don't want to use this function, while the watch is connected to your phone, go to the "Health App to manage more sports and health settings" on the phone to turn it off. Resting heart rate measurement
Resting heart rate refers to the heart rate value measured in a quiet, awake, inactive state, which represents the health of the heart rate to a certain extent. The watch will automatically obtain the resting heart rate value after detecting that you are in a quiet state. If you are not in a quiet state or are not wearing the watch, you will not be able to obtain the resting heart rate value. High heart rate warning
When the heart rate continues to be too high, the watch will pop up a notification warning, mainly in the following two warning states:
1. Daily heart rate warning is when the watch detects that you are quiet In the status (algorithm monitoring), when the heart rate value exceeds the set heart rate upper limit for 10 consecutive minutes (the default upper limit is 120 beats/min), a notification reminder will pop up;
2. The exercise heart rate warning is when the watch is turned on. After various exercises, a reminder will pop up when your real-time heart rate value exceeds your maximum heart rate value (default is 220-your age).
Note: The upper limit of heart rate can be set in the "Health App to manage more sports and 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. You can know the current real-time heart rate, average heart rate, resting heart rate and maximum/minimum heart rate;
2 When the watch and mobile phone are connected, the heart rate measurement records will be automatically synchronized to the mobile health app. Click the heart rate card on the health page to view more historical data, including statistical data by day, week, month, and year.