How is the Blood Oxygen Level (Spo2) Measured by Smartwatches?
In simple terms, Blood Oxygen Level is the amount of oxygen available in the blood. It shows how much percentage of our blood is saturated with oxygen. The measurement process is medically called Pulse Oximetry. This is one of the top 5 vital measurements used in hospitals and clinics. Oxygen scarcity can surely be fatal, which is why this test is of vital importance.
What is Spo2? What does Spo2 stand for?
In the case of wearables such as smartwatches and smartbands, the term Spo2 comes into the picture. Spo2 is “Saturated Peripheral Oxygen”, and is also considered as an important measurement to detect continuous oxygen supply in the blood. Spo2 measurement is non-invasive, meaning there is no need to pierce the body to calculate this value. This is unlike Sao2, “Saturated Arterial Oxygen”, where a blood sample is drawn for testing.
Is deoxygenated blood even possible?
Yes! The foundation of blood oxygen level measurement is the amounts of oxygenated and deoxygenated blood in the body. Oxygenated blood is bright red in color and deoxygenated blood is dark red.
Why is this?
This is because oxygenated blood reflects red light whereas deoxygenated blood absorbs red light.
How is Spo2 measured?
There are broadly 2 types of Spo2 pulse oximetry: transmissive and reflectance. Machines such as the pulse oximeter use the transmissive method where light is made to pass through a body part, usually a finger, and the light that emerges from the other side is captured. Based on how much light was absorbed, the blood oxygen value is measured.
How do smartwatches measure Spo2?
In the case of smartwatches and smartbands, reflectance pulse oximetry is used. In this method, the amount of light that is reflected is captured. This method can be used in body parts such as the chest, wrist, and others.
In simple terms, infrared and red lights are reflected off the surface of the body, usually a subcutaneous tissue or bone, and is captured by a sensor in the smartwatch. The difference between the light emitted and reflected is used to measure the Spo2 levels.
Do Spo2 Measurement by SmartWatches have Medical Certification?
No. They do not. These are just an approximation of the original blood oxygen levels. People can identify that the levels are low when using these. These readings must not be taken as it is, as they can have offsets.
Keep Checking my blog space for more such articles on the technology domain. While here, do check out my articles on business and people.
