Deep sleep is called "golden sleep", so it is desired by many people. In order to pursue deep sleep, many people also try to use smart watches and other tools for sleep detection. However, Xie Liang warned that those watches on the market that claim to be able to judge whether the human body is in a light sleep or a deep sleep are inaccurate.
Light sleep and deep sleep are divided according to brain waves. If your brain wave frequency is relatively fast, it means that you may be in a light sleep state; If the frequency of brain waves is slow and deep, you may be in a deep sleep state. But the watch is worn on the wrist and does not touch the scalp, so it is impossible to detect brain waves. It can only judge the sleep state according to the range of the wearer's activities, and at best it is a means of assisting judgment. If you want to get an accurate judgment, you must go to a professional medical institution for brain wave monitoring.
What is the working principle of a smart bracelet?
With the whirlwind of smart wearable devices blowing all over the IT world, Google Glass and smart watches continue to be exposed, and the attention is extremely high. The smart bracelet seems to be on fire. Many people must have questions. Seeing these smart watches and smart bracelets sold in the market, they all say that they can detect sports status and sleep through Bluetooth. How do they work? How to realize the function? Let me give you a detailed introduction.
What is the working principle of a smart bracelet? 1
First, the principle of smart bracelet
The motion monitoring function of smart bracelet is realized by gravity acceleration sensor. Gravity sensor is a very mature technology, and mobile phones have been used for a long time. For example, the screen flipping function of smart phones is realized by sensors. Sensors get some basic data by judging people's movements, and then combine the basic information of personal signs input by users to get personalized monitoring data for individuals according to some specific algorithms, such as steps, distances, calories consumed, etc., so as to judge the frequency and intensity of exercise. Because everyone's exercise has different effects with different physical signs, users need to input their own gender, age, height, weight and other information in the APP before using the bracelet to monitor, and the information will be automatically synchronized to the bracelet, and the movement will be monitored through sensors, and finally the function of motion monitoring will be realized through a specific algorithm.
Sleep monitoring is also achieved by the same sensor technology. According to brain wave signals, people's sleep can be divided into five stages: falling asleep, shallow sleep, deep sleep and rapid eye movement (REM). People's brain waves can change rapidly at different stages. Interestingly, the gravity acceleration sensor does not directly detect brain waves, so it judges which stage of sleep is based on the amplitude and frequency of people's movements during sleep. The smart alarm clock function of the bracelet will wake the user during the rapid eye movement period. "Because during the rapid eye movement period, sleepers will have high-frequency and low-amplitude brain waves similar to those when they are awake, and they are more likely to be awakened. If they wake up at this time, they will feel.
Second, what is the working principle of the smart bracelet?
Heart rate: there are two electrode pads (ECG principle), which can be used to check the ready-made scheme online;
Respiratory rate: three-dimensional acceleration sensor (vibration principle) can be used, but there is no ready-made scheme, so we need to make our own model, and there should be a better filtering algorithm, which is very promising;
Blood pressure, so simple, I don't know what to do.
Difficulty: But the difficulty of this product lies in how to collect all kinds of data with a simple product without disturbing users. The data here involves blood pressure, blood sugar, blood oxygen, pulse and other data. Our normal process of measuring these data is to draw blood to measure blood sugar and oxygen content, to measure body temperature with a thermometer, and to measure blood pressure with compressed blood vessels.
This problem is actually a problem faced by many smart devices now. The sports bracelet still stays in the function of obtaining position information through the gyroscope and analyzing various complex States of the human body from exercise to sleep, and the accuracy of the data is limited.
Imagine this:
1, through the principle of reflection, the oxygen content of human red blood cells is detected.
2. By detecting the pulse conduction rate and calculating the time difference between ECG detection and pulse detection, blood pressure information can be obtained.
3. Through internal and external temperature induction, more accurate human body temperature value can be obtained.
4. After detecting metabolic heat, blood oxygen saturation and blood flow velocity, the blood glucose concentration was calculated by metabolic heat integral method.
The biggest breakthrough of this principle is to realize the non-invasive collection of sign data with little interference to people. The changes of blood pressure, blood sugar and body temperature are very helpful for people with hypertension, diabetes and pregnant women to test their physical data. Guo Hui said that this principle has passed the theoretical certification and the hardware design is being planned. Of course, he also hopes to have more investment to promote the development of the project. At present, the bottleneck of smart devices is mostly information acquisition. If Guo Hui's team can realize this idea, it won't be a problem to make bracelets and watches.
The core is a 3-axis gravity acceleration sensor, and its output value is converted into living momentum by algorithm. The basic principle is to calculate the amount of work done to overcome gravity and inertia, so it is necessary to bring in weight to participate in the calculation. Now all bracelets, trackers, etc., regardless of brand model, are the weights set by users from the outside when synchronizing. Formula or something can refer to some papers of physical education major. In addition, the bracelet has a special feature that it can only stay on one hand, so compared with the ordinary preset user who will wear a tracker at the center of gravity of the human body, the algorithm is not feasible and needs to be corrected by a special algorithm. The specific algorithm is a trade secret.
Basically, it is a three-axis accelerometer, and then an algorithm is used to judge the number of steps of people. Algorithm is the core, I can't tell you.
What is the working principle of the smart bracelet 2?
First of all, briefly introduce the smart bracelet.
A smart bracelet is a wearable smart device. Through this bracelet, users can record real-time data such as exercise, sleep and diet in daily life, and synchronize these data to iOS or Android devices to play a role in guiding healthy life through data. The smart bracelets that attract attention mainly include Nike+Fuelband, FitbitFlex, JawboneUp2 and several domestic brand products that follow up.
"Google Glass" is not on sale yet, and "Smart Bracelet" is coming. When traditional e-commerce is still "true" to the price of a home appliance, Yi Xun. Com, a subsidiary of Tencent e-commerce, has taken a different approach and shifted its focus to the joint development and introduction of high-tech products. Since yesterday, the smart bracelet "Jawboneup" has been sold exclusively in China, becoming the first e-commerce company in China to officially enter the Internet "wearable smart device" market.
It is reported that the "Jawboneup" smart bracelet launched by this network is a very popular wearable smart device on the market. It is widely welcomed by white-collar consumers.
Second, the structure of the smart bracelet
The main body of the smart bracelet is generally made of medical rubber and memory rubber.
Natural non-toxic, high-grade design, fashion generous, both the function of sports health secretary, but also the function of fashion accessories, streamlined garlands, and diverse colors.
Silver-plated metal caps at both ends are very suitable for wearing, which is different from traditional bracelets with locks or buttons.
The smart bracelet has a built-in lithium battery with a battery life of 10 days, a vibration motor and a motion-sensing accelerometer. The silver cap at the end of the bracelet is a button to change the settings, and the other section is a 3.5 mm plug connected to the mobile phone.
Third, the function of the smart bracelet
This design style of smart bracelet is quite attractive to users who are used to wearing jewelry. More importantly, the design style of the bracelet is versatile. Moreover, although the small hand ring is not big, its function is still relatively powerful. For example, it can be said to be an advanced pedometer, which has general functions such as counting steps, measuring distances, calories and fat, as well as special functions such as sleep monitoring, advanced waterproof, Bluetooth 4.0 data transmission and fatigue reminder.
Its built-in battery can be used for 10 days, the vibration motor is very practical, and the simple design style can also play a decorative role in jewelry.
Take sleeping as an example. Set Jawboneup to sleep mode before going to bed, and get up the next day and synchronize with iPhone device, so you can see your sleep time, waking time, deep sleep/light sleep, overall sleep quality and other information. For people who lose weight and exercise, the "JawboneUP" smart bracelet is a responsible personal trainer, which can tell you the daily exercise path, calorie consumption and calorie intake. You can also set exercise goals, such as how many steps to take, how many calories to burn, and so on. It will also show the completion rate of exercise in real time, and exercise weight loss can be quantified, which is a great boon for those who can't persist. The smart bracelet has advanced waterproof function, and can swim in shallow water or rivers within the range of 10 meter, which overcomes the defect that the traditional pedometer cannot track swimming and is more widely used.
The smart bracelet also has a social network sharing function. For example, users can share sleep quality, diet, exercise and emotional records by binding Facebook or Twitter. For the elderly, it is also a patron saint. Through the built-in GPS connector, you can inform the relevant hospital or family members of your physical condition and location at any time.
Fourth, the working principle of the smart bracelet
Covered with waterproof rubber material one meter deep, it is said to be skin-friendly and comfortable to wear. Provide a variety of colors to choose from, S, M, L three sizes also meet the needs of different people. 3.5mm headphone jack can not only charge, but also synchronize data with mobile phone. It can last 65,438+00 days after being fully charged. Two pieces of silver-plated metal caps and Jawbone logo, accompanied by the flashing of breathing light in different states, make the whole bracelet look very fashionable and exquisite.
Specially configured mobile phone application can easily check your daily exercise data (including exercise time, kilometers and steps walked, calories burned, etc.) by connecting to iPhone. ) and sleep data (total sleep time, wake-up time, wake-up times at night, etc. ). You can also input dietary data through the mobile phone, and the bracelet will give nutritional information according to the type of food for users' reference and adjust their eating habits.
Do you wear smart watches when you sleep? There is a sleep test.
Some people will say that sleeping is to rest the brain and body and revive blood-such an obvious answer can't stand scrutiny. Why can't we have a rest when we are awake, but we have to experience unconscious drowsiness?
Sleep is also common in animals, but they sleep in different ways. Bats sleep 20 hours a day, while horses seem to adopt the so-called "Da Vinci sleep method", and a few hours' nap a day is enough, which adds up to only three hours. Some birds and aquatic mammals sleep in a more peculiar way. The left and right brains take turns to sleep, and they can fly or swim while sleeping. Even reptiles, fish, fruit flies and nematodes have quiet rest periods, which reduces their response to external stimuli, although the scientific community is still hesitant to define it as "sleep".
Sleep is so polymorphic that researchers who want to find a unique universal ultimate explanation for sleep are distressed. However, sleep in many species has one thing in common-brain changes, for example, all or part of consciousness will be lost during sleep, and lack of sleep will damage cognitive function. To understand sleep, we must study the brain and nerves-in the field of neuroscience, we are still waiting for Newton, and everything is still chaotic.
By studying EEG, people still have a general understanding of the various stages of sleep. There are two stages in the normal sleep cycle: inactive sleep (NREM) and active sleep (REM). NREM and rem appear alternately, and one cycle lasts about 90 minutes. There are about 5-6 sleep cycles a night. NREM can also be divided into four stages. There are different EEG activities in different stages.