The portable Pulse Ox, which has been in use for 50 years, is undergoing upgrades to address its limitations. The National Heart, Lung, and Blood Institute (NHLBI) is supporting this initiative through the Small Business Innovation Research (SBIR) program. It is important to be aware of these limitations to ensure cautious interpretation of data.

The current technology has four limitations:

  1. Accuracy decreases as oxygen saturation levels drop.
  2. The pulse oximeter does not perform well if perfusion to the upper extremities is compromised.
  3. Physical motion can impact the measurement.
  4. The pulse oximeter tends to overestimate oxygen saturation in individuals with darker skin tones due to the interference of melanin, which blocks ultraviolet light and skews measurements upward.

These limitations have significant implications, especially considering the disproportionate impact of COVID-19 on communities of color and socioeconomically disadvantaged populations. Overestimating oxygen saturation levels in these populations can lead to delays in appropriate interventions, exacerbating health disparities.

Researchers are working on life cycle design changes for the technology, as well as calibrating the devices using a skin pigment color scale. The ultimate goal is to develop a wireless pulse oximeter that can accurately measure oxygen levels during exercise, regardless of skin color, and interface with mobile devices. These advancements will help improve healthcare outcomes and reduce disparities in access to appropriate care.

Thanks for allowing me to share what I think is very interesting information! Hope you find it valuable.

Cindy Sylvia

NIH/National Heart, Lung and Blood Institute
Journal reference:
Yang, B & Moss, J., (2023) Evolution of the Pulse Ox. CHEST Journal.