| Name ▼ | Specialty | Purpose | Description | Racial Differences |
|---|---|---|---|---|
| Electroencephalogram (EEG) scalp electrode | Neurology | Measures electrical activity of the brain at the scalp non-invasively | An EEG is a non-invasive test that records the brain's electrical activity through electrodes attached to the scalp. The electrodes must touch the scalp directly to facilitate optimal signal conduction. | For thick curly hair and hairstyles commonly worn by Black people, it can be challenging to place electrodes so they are in direct contact with the scalp. This can result in low-quality data, leading to the exclusion of data from Black people in research. In clinical diagnoses, it may cause both patient discomfort and misdiagnosis. |
| Photoplethysmographic sensor | Cardiology | Measures heart rate and rhythm in the peripheral circulation non-invasively | Photoplethysmography is an inexpensive optical technique to detect volumetric blood changes in peripheral circulation blood. It is used in wearable digital health devices for heart rate and rhythm monitoring, for example, to detect atrial fibrillation. | Photoplethysmographic sensors in wearable devices used to detect atrial fibrillation have been linked to poor performance on darker skin tones, which is similar to the issue that affects pulse oximeters. |
| Pulse oximeter | Pulmonology | Measures the level of oxygen saturation in the blood non-invasively | Pulse oximeters measure light absorption through a translucent part of the body, such as a fingertip or an earlobe. They use the difference in light absorption of oxyhemoglobin and deoxyhemoglobin in capillary blood to estimate oxygen saturation indirectly. | Skin pigmentation can affect light absorption, and research indicates that pulse oximeters overestimate blood oxygen levels in people with darker skin. Pulse oximeters are three times less likely to detect abnormally low concentrations of oxygen in Black patients, which can lead to missed hypoxemia. |
| Temporal artery (forehead) thermometer | Medicine | Measures the temperature of the skin surface over the temporal artery non-invasively | Temporal artery thermometers use infrared technology to measure temperature. They work by detecting the amount of infrared energy, or heat, emitted by the temporal artery. The thermometers absorb this energy and convert it to a temperature reading. | Temporal temperature measurement was associated with a lower likelihood of detecting fever in Black patients than oral temperature measurement, but not in white patients. This discrepancy, combined with commonly used fever cutoffs, may cause fever to go undetected in Black patients. Research suggests skin emissivity may affect temperature measurement variability, but its relationship to pigmentation is unclear. |
| Transcutaneous bilirubinometer (Contributed by Jose Gomez-Marquez.) | Pediatrics | Measures serum bilirubin transcutaneously at the sternum or forehead | Transcutaneous bilirubinometry is a noninvasive optical technique to determine serum bilirubin levels typically in newborns. It works by shining a beam of light on the skin of the forehead or sternum and measuring the intensity of light that is reflected back. | Transcutaneous bilirubinometers are used for detecting neonatal hyperbilirubinemia, and research shows that transcutaneous bilirubinometry measurements are correlated better with blood-based total serum bilirubin measurements in lighter skin color babies than darker skin color babies. |