Which nail polish color would have the greatest effect on the accuracy of dual-wavelength pulse oximeters?

Which nail polish color would have the greatest effect on the accuracy of dual-wavelength pulse oximeters?

• A. Red
• B. Yellow
• C. Blue
• D. Green

Answer: (C)

Light-based oximetry relies on two specific wavelengths (red and near-infrared) passing through the nail and reaching the sensor. The device calculates oxygen saturation from how much pulsatile blood absorbs each wavelength. If nail polish sits on the nail and absorbs or scatters those wavelengths, the signals become distorted and the calculated ratio deviates from true values. Blue nail polish is most disruptive because pigments that look blue tend to absorb more across both measurement wavelengths, not just one. This means both red and near-infrared light are attenuated as they pass through the nail, compromising the signals the oximeter uses for its ratio calculation. Red polish mainly affects the red channel, while infrared would remain relatively less impacted, so the overall effect on the dual-wavelength measurement is smaller. Green also affects the red channel but typically not as broadly across both wavelengths as blue does. Thus blue produces the greatest potential error in dual-wavelength pulse oximetry readings.

Light-based oximetry relies on two specific wavelengths (red and near-infrared) passing through the nail and reaching the sensor. The device calculates oxygen saturation from how much pulsatile blood absorbs each wavelength. If nail polish sits on the nail and absorbs or scatters those wavelengths, the signals become distorted and the calculated ratio deviates from true values.

Blue nail polish is most disruptive because pigments that look blue tend to absorb more across both measurement wavelengths, not just one. This means both red and near-infrared light are attenuated as they pass through the nail, compromising the signals the oximeter uses for its ratio calculation. Red polish mainly affects the red channel, while infrared would remain relatively less impacted, so the overall effect on the dual-wavelength measurement is smaller. Green also affects the red channel but typically not as broadly across both wavelengths as blue does. Thus blue produces the greatest potential error in dual-wavelength pulse oximetry readings.