Smartwatches
are commonly used among young people. With so many functions mixed in a little
device, people are getting more reliable on a smartwatch by wearing it in many
different situations. Counting how many steps you are walking, making payment
transactions, or even checking your physical health could all be achieved by a
smartwatch. These amazing features are proceeded by the sensor, which is
available in most smartwatch models such as watch gt4. In
this article, we would like to go deeply into the powerful sensors of a
smartwatch.
Sensors: The Spirit of a Smartwatch
With
the advancement in technology, there are now more smartwatch sensor
technologies available every year. In this section, we will introduce a few
common and several newly emerged sensor technologies.
Acceleration Sensors for Exercise Pedometer
Simply
put, gravity acceleration sensors detect acceleration and transform it into an
electrical signal, which is then used to calculate the number of steps taken,
the distance traveled, and the number of calories burned. Typically, it makes
use of Hall, GMR, TMR, and particular algorithms.
Optical Heart Rate Sensor and Bioelectrical Impedance
Sensor for Heart Rate Detection
The
most popular optical heart rate sensor, which was also one of the first sensors
used in smart bracelets, works by illuminating the skin and nearby blood
vessels with green LED light, which is then measured to determine how much
light is being absorbed by changes in heart rate. This technology is used for
auxiliary sports detection as well as for the early detection of cardiac
anomalies. In addition, through the biological muscle's own impedance, the
bioelectrical impedance sensor can monitor blood flow and translate it into a
specific heart rate, respiration rate, and dermato-electric response index. As
it combines different types of data, detection accuracy is improved and
information is meaningful.
Sleep Monitoring: Via Three Different Methods
Firstly,
simple sleep monitoring also uses an acceleration sensor to determine whether
you are asleep. This method's basic principle is that people sleep less and
move less frequently, making it difficult to detect when they are sleeping.
While this method does have a certain degree of accuracy, it is also simple to
make mistakes. For instance, if you maintain the same position in the quilt
while using the phone, using this method of detection may also result in false
positives. Secondly, the heart rate sensor is used to determine the sleep
state. The HRV heart rate variability detection is completed using the PPG
photoelectric volumetric pulse wave tracing method, which has higher accuracy
than a pure acceleration sensor. Thirdly, the CPC analysis would detect the
sleep situation. The basic idea behind this type of analysis is to use the
coupling relationship between the heart and the lungs to determine a person's
overall wakefulness, light sleep, and deep sleep states. For the time being,
this solution is more accurate and can also lower the rate of incorrect
judgments made when a user is ill, or when they are slightly below the stated
state of continuous stillness but have not yet fallen asleep. However,
high-level smart wearable products frequently have this type of program, so
cheap, basic smartwatches won't have it.
Conclusion
In conclusion, the sensor is the core of smartwatches by bringing them
incredible functions. Dividing by different technologies, sensors allow
smartwatches to complete multiple complex tasks. For instance, the acceleration
sensors for exercise pedometers benefit the users by showing their physical
situation. Moreover, the optical heart rate sensor and bioelectrical impedance
sensor will detect the heart rates, respiration rate, and dermato-electric
response index that are useful. Finally, by monitoring the sleep situation by 3
methods, users could understand the sleeping quality and reduce the chance to
get sick.