Busting The App-Based Pulse Oximeter Myth
Why smartphone oximeters do not help with preventive COVID-19 care.
By Sharon Lewis
COVID-19 has accelerated the world’s appetite for innovation in the healthtech and healthcare sectors. As the world races to find effective containment and early detection measures, pulse oximeters have come under the spotlight.
Pulse oximetry is used to test oxygen levels in the blood (SpO2). COVID-19 mainly attacks the human respiratory system, and low levels of oxygen saturation (indicating that lung capacity has been affected) could hint at the onset of COVID-19 complications. Detecting this early on could help patients get early care and avoid critical hospitalization and mechanical ventilation.
Pulse oximeters became a humble sensation after a few media mentions brought them before the public eye. A New York Times opinion article highlighted them as potential preventive care devices, and American television show host Andy Cohen recommended that people buy oximeters when speaking about his recovery from COVID-19.
Mobile app versions of the oximeters are being looked at as a potential breakthrough, owing to ease of access and cost effectiveness. However, there are several reasons why this is a faulty line of thinking.
- App-based oximeters are not medical grade.
The biggest red flag is that pulse oximeter applications are not approved by regulatory authorities. This makes the readings clinically unreliable, and rates of accuracy are extremely poor. In fact, most apps simply measure the heart rate and give no SpO2 indications, even though they are called oximeters on Google Play Store or Apple App Store.
- Low SpO2 levels may not be a symptom.
Oximeters are best suited for users who already have other respiratory issues, because the readings are going to be more consistent.
A characteristic of COVID-19 infections is that seemingly healthy individuals develop extreme symptoms almost overnight. Healthier bodies could already be infected with the novel coronavirus and dangerous pneumonia, and still report a good or passable level of oxygen saturation.
- It can lead to increased anxiety.
While having a oximeter kept Andy Cohen from worrying too much, it may not play out the same way for everyone else. Having a pulse oximeter easily accessible on the phone could possibly make people more anxious.
For example, living in high altitude areas, or even simple app glitches, may result in readings that cry wolf when there is no real reason for alarm.
- There are other effective methods.
Monitoring breathing patterns and doing breathing exercises are simple, low-tech indications of the levels of oxygen saturation in the blood.
Counting one’s breaths per minute, the depth of each breath, and whether one is breathing more often or deeper than usual could be telling metrics of SpO2 levels – more so than app-based oximeters.
- The technology is still evolving.
Smartphone oximeter apps, while available in app stores, are relying on technology that is very much still in development. Studies so far suggest that this technology is simply not effective, and researchers are still looking for compelling evidence to suggest otherwise as the algorithms develop.
In fact, the oxygen saturation measurement tool was withdrawn from Samsung’s portfolio of inbuilt health apps in 2018 for this very reason.
In its current stage, the technology utilized in smartphone oximeter apps is simply too young, and raises numerous questions on reliability. This is not to say that the technology will not catch up, but depending on it at this stage could be the wrong idea.
The New York Times article was not without basis – the author himself is an emergency doctor and spent 10 days volunteering at a Washington hospital. The entire world’s healthcare system has been pitted against a single virus, and all suggestions for beating it deserve exploration.
But the fact is that even actual pulse oximeters can be inaccurate, much like glucometers. Their smartphone versions are even more so, and the risks associated with relying on such apps outweigh the potential benefits. When concerned about SpO2 levels, the most recommended course of action would be to visit a physician for basic tests.
Header image by Evgeni Tcherkasski on Unsplash