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Philips develops contactless way to check blood oxygen saturation

Steve Rogerson
June 28, 2016
Absolute oxygen saturation of arterial blood (SpO2), a vital sign that is commonly monitored in hospitalised and other patients, can be accurately measured across multiple patients using contactless technology, according to research by Philips.
The study, published in the June issue of the journal Anesthesia & Analgesia, used Philips proprietary camera-based monitoring technology to measure the light reflected off the foreheads of 41 healthy adults to calculate SpO2. Through the results of this study, the Dutch company has demonstrated that contactless SpO2 can be calibrated across patients, just like conventional contact probes, allowing accurate measurements without individual adjustments.
In many care settings, monitoring heart rate, arterial blood oxygenation, respiration rate and activity is a standard part of patient care to detect complications or deterioration. The current method for measuring these key vital signs requires the use of sensors on the skin or devices strapped to the body; however, these contact sensors may cause damage and distress in patients with fragile skin such as newborn babies.
“Vital signs monitoring is crucial across all types of care settings, but for patient populations with specific conditions, managing their care in a less intrusive way is critical in order to avoid unnecessary distress,” said Carla Kriwet, CEO of Philips patient care and monitoring division. “Contactless monitoring will offer clinicians with a way to accurately measure vital signs for patients in a non-obtrusive way, and provide them with the data needed to know when to intervene.”
For specific patient populations, including premature infants in the NICU, a contactless alternative would provide potential advantages such as avoiding skin damage in fragile patients and freedom to select a more physiologically central location with a possible faster response rate. With every heartbeat, the cardiovascular pressure wave causes tiny micro-blushes (small changes in skin colour) in the face. While these changes are not visible to the human eye, contactless monitoring algorithms can calculate an accurate pulse rate by quantifying these changes.
Over the past ten years, an increasing number of papers have been published on the topic of contactless monitoring in the measurement of pulse or respiration rate; however, only a handful have explored SpO2 and this is the first study that has been able to demonstrate convincingly that calibrated contactless monitoring of absolute blood oxygen levels is possible. In this recent study, calibration of contactless, camera-based pulse oximetry was performed on a population of 41 healthy adults and the results are promising for the successful use of contactless monitoring for absolute blood oxygen levels in care settings without individual adjustments.
In addition to the results of this study, Philips’ contactless monitoring shows promise for accurately measuring key vital signs such as heart rate and respiration rate.