Disclaimer: SpO2 on BodyScan 2 is a wellness (non-medical) feature and is not intended to diagnose or treat any medical condition.
Your BodyScan 2 estimates your SpO2 (blood oxygen level) directly from the handle on your left thumb. SpO2 is a wellness (non-medical) feature, exclusive to BodyScan 2. This article explains how the measurement works and how to take it successfully.
What is SpO2?
SpO2 (also known as Blood Oxygen) stands for peripheral capillary oxygen saturation, an estimate of the amount of oxygen in the blood. More specifically, it is the percentage of oxygenated hemoglobin (hemoglobin containing oxygen) compared to the total amount of hemoglobin in the blood (oxygenated and non-oxygenated hemoglobin). It is often considered to be the fifth vital sign, along with pulse, respiratory rate, blood pressure, and body temperature. Hemoglobin is a protein that carries oxygen in the blood to your organs. It is found inside red blood cells and gives them their red color. Once oxygen is in our organs, it acts as the fuel that allows our cells to work.
How is it measured?
SpO2 can be measured by pulse oximetry, an indirect, non-invasive method—meaning it does not involve the introduction of instruments into the body. It works by emitting and then absorbing a light wave reflecting the blood vessels, or capillaries, in the thumb.
- Oxygen-rich blood absorbs infrared light better than oxygen-poor blood.
- Oxygen-poor blood absorbs red light better than oxygen-rich blood. This is why venous blood is darker than arterial blood.
BodyScan 2 uses a multi-wavelength sensor called PPG (photoplethysmography) sensor that emits and measures red and infrared reflections on the blood vessels in the left thumb. The algorithm then compares the reflection at each wavelength to compute the SpO2 value.
When is SpO2 measured on BodyScan 2?
SpO2 is captured while you hold the handle during a scan:
- Longevity Scan: automatically included as part of the full health assessment.
- Daily Scan: included only if the measurement is activated in the app.