Sandeep Koul, a Delhi-based marketing professional, recently discovered that his Fitbit Versa could track blood oxygen saturation (SpO2) levels. Though a bit peeved that the feature doesn’t show prominently, he has been using it ever since to keep track of oxygen levels.
Though blood oxygen levels fluctuate, a big variation is a sign of concern, often helpful in screening covid-19 patients. Low oxygen levels could be a symptom of other health issues, too.
Unlike standalone oximeters that are clipped on the finger, devices such as Fitbit Versa are worn all the time, and can continuously track SpO2, along with heart rate and other indicators.
After the covid-19 outbreak, many users like Koul are turning to smartwatches and fitness bands that can track SpO2 and body temperature. Realme sold 15,000 units of its new smartwatch, which has an in-built oximeter, within two minutes of going on sale in June.
“We have seen a lot of interest in these devices in the past few months," said Ali Rizvi, director of Garmin India Pvt. Ltd, which has been offering oximeters on many of their smartwatches.
Wearable devices startup Goqii’s budget fitness band Vital 3, which has an in-built thermal sensor and can take body temperature readings, is currently the No. 1 selling product on Amazon’s heart rate category.
Among rivals, Honor and Fitbit also added pulse oximeters across product lineups this year.
Most of these wearables use in-built sensors, which is why many companies can roll them out afterwards through a firmware update.
For instance, Garmin smartwatches use a combination of red and infrared lights to light up the skin and then use optical sensors to determine the percentage of oxygenated blood.
Given the increasing consumer demand, SpO2 and temperature readers are expected to become a regular feature in all wearable devices in the coming days.
However, experts caution that users need to be aware that these wearable devices are not medically approved and that their findings may not always give the correct picture.
Though there are no clinical studies to determine how accurate they are compared to medically approved devices, the manufacturers say their readings are not fully accurate. According to Garmin, certain limitations can lead to inaccurate measurements. The user’s physical characteristics, motion, fit of the device and presence of ambient light can impact the readings.
Honor India said these products and features are not meant to be treated as medical devices and are not intended to diagnose, treat, cure or prevent any disease. All data and measurements should be used for personal reference only.
"The feature helps keep a check of the SpO2 levels and inform users of their oxygen levels in the blood. The users may choose to seek medical consultation in case there is a significant change in their blood oxygen level, as an early indication," said Charles Peng, President, Honor India.
Bharat Agarwal, consultant, internal medicine, at Navi Mumbai’s Apollo Hospitals doesn’t mind recommending these wearables as they can help in screening the symptoms.
However, he warns that one abnormal reading which may not actually be abnormal can cause a lot of panic.
"Asymptomatic patients can use such wearables as a precautionary measure for early detection, as it can notify them if there is an issue. But we won’t recommend it for someone who has not been well and is at higher risk. They should be using more reliable devices," said Dharam Pani Pandey, head of the department, physiotherapy and rehabilitation sciences, at New Delhi’s Manipal Hospital.