How can an Apple watch placed above the skin measure the blood oxygen level from below the skin without access thereto? Thanks in advance for the explanation of a point absent from the sensor’s description.
How does the blood oxygen sensor work?
The blood oxygen sensor is built into the back of the Apple Watch. It uses four clusters of red, green and infrared LED lights and four photodiodes, devices that convert light into an electrical current. The lights shine onto the blood vessels in your wrist and the photodiodes measure how much light bounces back.
I won't get into the medical specifics, but essentially oxygenated and deoxygenated blood absorb red and infrared light differently, so the light that bounces back allows the Apple Watch to determine the color of your blood.
How does the blood oxygen sensor work?
The blood oxygen sensor is built into the back of the Apple Watch. It uses four clusters of red, green and infrared LED lights and four photodiodes, devices that convert light into an electrical current. The lights shine onto the blood vessels in your wrist and the photodiodes measure how much light bounces back.
I won't get into the medical specifics, but essentially oxygenated and deoxygenated blood absorb red and infrared light differently, so the light that bounces back allows the Apple Watch to determine the color of your blood.
Thank you Ferd Ii. Your response appears very logical and far above my technical background.
Sogosumi1 wrote:
Thank you Ferd Ii.
Your response appears very logical and far above my technical background.
You are welcome.
...and also mine. Just quoting a source.😀
How can a watch placed above the skin measure the blood oxygen level from below the skin without access thereto?
