We are living in one of the most unprecedented times when the entire planet is infected with COVID-19. The virus has wreaked havoc on every industry, including the healthcare system. You might be familiar with the importance of blood oxygen level, the uncontrolled level of which can cause many serious health implications. As a result, keeping track of your blood oxygen, and heart rate is critical. Wearable pulse oximeters and smartwatches are two typical ways to assess your blood oxygen level. This article will compare these two devices and help you decide which one to buy.
Due to COVID-19, the topic of blood oxygen is unprecedentedly popular.
According to the BBC report, a wearable pulse oximeter is a possible life-saving solution under the threat of Covid-19 “silent hypoxia.” Patients can monitor their own oxygen levels at home with the help of a wearable pulse oximeter. This not only avoids excessive contact with the crowd but also effectively monitors their own oxygen levels regularly. Dr. Inada-Kim believes that to solve the problem of silent hypoxia, and everyone should buy a wearable pulse oximeter. The wearable pulse oximeter can help improve survival rate, shorten hospital stay, and reduce the pressure of emergency services for medical staff. [1] With Covid-19 still raging worldwide, the wearable pulse oximeter is undoubtedly an effective and economical solution.
Reflectance oximetry vs. Transmittance oximetry
Blood oxygen monitoring equipment can use transmittance or reflectance mode according to the measurement position. In the transmittance mode, the light source and the photodiode are opposed to each other, and the measurement point is located between them. In the reflectance mode, the light source and the photodiode are on the same side, and the light is reflected to the photodiode through the measuring point. Studies have shown that the reflection mode monitoring of SpO2 in the wrist poses a challenge to clinical use, and the reflected red and infrared pulses can only be used in specific areas. [2] One of the main differences determining the smartwatch and wearable pulse oximeter is the reflected blood oxygen saturation and the transmitted blood oxygen saturation. Smartwatches use reflection oximeters, while oximeters use transmission oximeters.
Wearable oximeter vs. Smartwatch: Which has more accurate data?
If you don’t have an oximeter, should you accept the data on your wristwatch or wait till the oximeter comes? The accuracy of smartwatches and oximeters is influenced by various variables, including scientific research. The primary difference between the two devices is the difference in technology, i.e., Smartwatches use reflectance oximetry, while on the other hand, oximeters use transmittance oximetry to measure SPO2 level. Let’s analyze the accuracy of each device one after another so that it is easy to pick one that is more accurate.
- How accurate is the wearable pulse oximeter?
- A wearable pulse oximeter employs the technique of transmittance oximetry, and it also calculates the light that passes through the part of the body. Research indicates that SpO2 readings are accurate to 2%.[3] The accuracy of a wearable pulse oximeter is highest when the blood saturation level is above 90%.
How accurate is the smartwatch?
A typical smartwatch uses a plethysmography sensor to measure the blood oxygen level. Each company’s smartwatches have different standards and accuracy. For instance, the accuracy of the Apple Watch 6 is close to the consistency and accuracy of an oximeter.
The accuracy of smartwatches is less than the wearable pulse oximeter because both the light-emitting sensor and receiving sensor are on one side, which neglected the transmitting light, thus affecting the accuracy of the readings. Apart from the primary difference in the technology, there are additional factors that affect the accuracy of the device, such as the quality of sensors, the quality of the device, the method of reading and processing data, and many more. The SpO2 sensor uses red light and infrared light sensors to detect oxygen levels and perceives changes in these levels by observing the color of blood. The green, red, and infrared LEDs built into Apple’s smartwatches shine a light on the blood vessels in the wrist, and photodiodes measure the amount of light reflected. In addition, the accuracy of a smartwatch depends upon its calibration.
For SBP and SpO2, the wearable plus oximeter was much more accurate. The primary reason for the lack of precision in smartwatches is the source of inaccuracy. As a result, the ones you’re wearing are designed only for the consumer level, not for use in clinical settings. The reading of a smartwatch gives you a rough indication of the level of your blood oxygen. But you should validate it with an oximeter.