OSA: Measurement of Visible Light Devices for Medical Equipment

A pulse oximeter is a medical measuring instrument that measures oxygen saturation in blood without collecting blood. Oxygen saturation is measured using the difference in the absorption characteristics of HbO2 (oxyhemoglobin) and Hb (reduced hemoglobin) in blood. Two LEDs with wavelengths of 665 nm and 880 nm are used for this measurement. Since the absorption characteristics of HbO2 and Hb change greatly depending on the wavelength, a LED with a high wavelength accuracy of about ± 0.5 nm is required for accurate measurement of oxygen saturation. The measurement wavelength range and high wavelength accuracy of the applicable models are suitable for measuring LEDs for pulse oximeters.

Laser treatment devices use lasers with different wavelengths depending on the treatment target. The laser requires the singularity in wavelength so that it does not affect other parts than the target.