University Hospitals Birmingham tests ear device to fix skin tone bias
- Researchers at University Hospitals Birmingham are conducting a clinical study to test whether oxygen monitoring devices placed inside the ear can overcome the accuracy limitations of traditional fingertip...
- Traditional fingertip pulse oximeters estimate blood oxygen levels by shining light waves through a patient's skin.
- Dhruv Parekh, a consultant in critical care and respiratory medicine, noted that these medical probes have been known to exhibit inaccuracies in patients with darker pigments.
Researchers at University Hospitals Birmingham are conducting a clinical study to test whether oxygen monitoring devices placed inside the ear can overcome the accuracy limitations of traditional fingertip pulse oximeters in patients with darker skin tones.
The Hidden Bias in Standard Medical Devices
Traditional fingertip pulse oximeters estimate blood oxygen levels by shining light waves through a patient’s skin. However, research has demonstrated that this light can behave differently depending on skin pigmentation, causing monitors to potentially overestimate oxygen levels in people with darker skin tones, particularly when those levels are already low.
Critical Risks Exposed During the Pandemic
Dr. Dhruv Parekh, a consultant in critical care and respiratory medicine, noted that these medical probes have been known to exhibit inaccuracies in patients with darker pigments.
While these discrepancies did not render fingertip oximeters unsafe for normal clinical use—since medical staff traditionally evaluate readings alongside other observations and tests—the limitations became critical during the COVID-19 pandemic as patients increasingly monitored themselves at home without clinical supervision.
Parekh stated that recent studies show individuals with darker skin pigments can be falsely reassured that their oxygen levels are better than they actually are when they are unwell.
Shifting the Focus to the Ear Canal
To combat these discrepancies, researchers began investigating alternative sites on the body for measuring blood oxygen levels. The investigation involves 29 volunteers and evaluates a novel device developed by healthcare technology company EarSwitch, which measures blood oxygen levels through the external ear canal rather than the finger.
The new device, created by EarSwitch founder Dr. Nick Gompertz, shines light into the external ear canal instead of through a fingertip.
Uniform Pigmentation Near the Core Supply
According to Gompertz, the inside of the ear canal is typically non-pigmented across racial backgrounds, offering a consistent color for everyone while also sitting much closer to the core central blood supply.
Carlos Lee, an Asian participant in the 29-volunteer study in Birmingham, noted that he wanted to contribute to research featuring more diverse skin tones.
Gompertz emphasized that during the COVID-19 pandemic, it became evident that standard pulse oximeters did not work adequately for people with brown or black skin, a disparity linked to higher death rates in those groups.