App Using Phone Camera for Measuring Oxygen Levels Not Reliable
A study found that there is no evidence that any smartphone technology is accurate for the measuring oxygen level.
A viral WhatsApp message claims that an app called ‘Pedometer 2018’ can detect oxygen levels and heart rate just by placing the finger on the rear camera of the mobile phone.
However, Dr Vikas Maurya, director and head, department of Pulmonology & Sleep Disorders, Fortis Hospital, Shalimar Bagh told The Quint that while the technology used in oximeter can be put in any device, if the phone does not have the required technology, an app alone cannot measure the oxygen levels. Further, the app in question has now been taken down from Google Play Store.
The message goes on to describe the process of measuring the oxygen levels via the said app. This includes placing the finger on the rear camera, then “touch, measure, hold the finger until measurement is complete, reading will display on the screen.”
The message also mentions the link of the app. Several users have shared the message on Facebook and Twitter.
The Quint received a query on the claim made in the message on its WhatsApp helpline.
WHAT WE FOUND OUT
To begin with, the app in question has been taken down from Google Play Store. We also got in touch with health experts and cyber experts to know if it was possible to measure the oxygen level using an app.
APP ALONE CANNOT HELP IN MEASURING OXYGEN LEVEL: PULMONOLOGIST
Dr Vikas Maurya, director and head, department of Pulmonology & Sleep Disorders, Fortis Hospital, Shalimar Bagh told The Quint,
“The oximeter has two wavelengths, that is, infrared and red. The chips used in oximeters are really small and if the developers/manufacturers are able to put the exact technology in the phone, then it is possible. But if you don’t have the technology, an application cannot do this alone. It’s not sufficient to just have the app.”Dr Vikas Maurya, director and head, department of Pulmonology & Sleep Disorders, Fortis Hospital, Shalimar Bagh
Further, Dr Sumit Ray, a critical care specialist in Delhi NCR said that the the likelihood of detecting oxygen level through app is very less because it wouldn’t be able to pass infrared light to measure your oxygenated and deoxygenated haemoglobin.
“The pulse oximeter uses infrared light to differentiate between oxygenated haemoglobin and deoxygenated haemoglobin and that’s how it calculates the oxygen saturation. That’s probably not possible through the app,” he added.
WHAT IS A PULSE OXIMETER AND HOW DOES IT WORK?
Now, let’s understand what is the purpose of a pulse oximeter and how it functions. A tutorial on the website of World Health Organisation (WHO) mentioned that a pulse oximeter is composed of a sensor (probe) and monitor with the display.
While speaking to The Quint, Dr Vikas Maurya said that there is blood flow in the nail band of the fingers and the haemoglobin present there which basically carries the oxygen, sends out a wavelength which is seen on the monitor.
“All pulse oximeter probes (finger or ear) have light emitting diodes (LEDs) which shine two types of red light through the tissue. The sensor on the other side of the tissue picks up the light that is transferred through the tissues,” the WHO website mentions.
How will a technology like that work in a mobile application?
NO EVIDENCE TO SUPPORT SMARTPHONES RELIABLE FOR MEASUREMENT: STUDY
Meanwhile, a study conducted by Centre for Evidence-Based Medicine on whether smartphone apps should be used as oximeters for clinical purposes, found that there is no evidence that the said technology can yield accurate results.
“There is no evidence that any smartphone technology is accurate for the measurement of blood oxygen saturation for clinical use. Furthermore, the scientific basis of such technologies is questionable. Oxygen saturation levels obtained from such technologies should not be trusted in the clinical assessment of patients,” the study noted.
Trisha Greenhalgh, Professor of Primary Care, University of Oxford and one of the authors of the study also tweeted the same.
The study noted that a pulse oximeter requires the measurement of light transmission from the finger at two different – red and infrared.
Regarding a specific set of Samsung galaxy series, the study mentioned that the phones had a red light emitting diode (LED) in the phone in addition to the flash light and camera, “but it appears from publicity material on YouTube that it worked via a single-wavelength measurement (albeit with a monochromatic light source, the LED) and therefore that oxygen saturation could not be accurately derived from it.”
TELANGANA POLICE CAUTIONS PUBLIC AGAINST SUCH APPS
Telangana Police, too, issued a statement of its official social media handles cautioning the public that this could be another COVID related cyber crime and can steal your personal data.
“Note that, your index finger (fingerprint) is used for various personal data authentication. Especially, for eWallet transactions and as an alternative to password for screen lock and apps. It is risky, as these apps ask us to keep our finger on camera to compute the oxygen levels, where it can be misused by the hackers to steal our fingerprints,” it added.
However, the explanation, regarding stealing data by placing a finger on the camera, provided by the police doesn’t really add up.
Sai Krishna Kothapalli, an alumni of IIT Guwahati who founded Hackrew, a cyber security startup based out of Hyderabad, told The Quint, “If you are clicking a picture of your finger, then it will have enough clarity that you can get your fingerprint stolen like somebody can get the fingerprint data. But if you are directly placing it on the camera, then camera wouldn’t be able to see anything at all.”
Evidently, a viral message falsely claimed that an app can yield reliable results in measuring oxygen levels amid COVID-19 pandemic.
(With inputs from SM Hoax Slayer)
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