Pulse oximeter
device · 1974 · Digital age
Measures blood oxygen saturation with light (Aoyagi).
What it is made of
- LED — has part. Red and infrared LEDs.
- Photodiode — has part. A photodiode.
Principles and materials it uses
- Infrared radiation — uses. Infrared absorption by haemoglobin.
- Plastic — is made of. The case is plastic.
Where it is used
- Smartwatch — is part of. A heart-rate and SpO₂ sensor.
- Fitness tracker — is part of. An optical heart-rate sensor.