By Bharat Upadhyay

New Delhi, Sep 16 (IANS): With Apple Watch Series 6 expanding the health capabilities of previous models with a new feature that conveniently measures the oxygen saturation of the user's blood, health experts in India on Wednesday welcomed the wearable with oximeter that is the need of the hour for Covid-19 patients who are in home quarantine to monitor their oxygen saturation frequently.

They, however, stressed that any device that is used for monitoring oximeters needs to be certified and validated by competent authorities before it can be relied upon.

"Still, the new feature on Apple Watch Series 6 will be helpful in monitoring the disease as the blood oxygen levels are an indicator of the severity of Covid-19 and can also signal to patients when it's time to go to the hospital," Dr Nikhil Modi, senior consultant, respiratory, critical care and sleep disorder at Indraprastha Apollo Hospitals, told IANS.

Oxygen saturation, or SpO2, represents the percentage of oxygen being carried by red blood cells from the lungs to the rest of the body, and indicates how well this oxygenated blood is being delivered throughout the body.

To further refine the tool, Apple is joining forces with researchers to conduct three health studies that include using Apple Watch to explore how blood oxygen levels can be used in future health applications.

This year, Apple will collaborate with the University of California, Irvine, and Anthem to examine how longitudinal measurements of blood oxygen and other physiological signals can help manage and control asthma.

According to Dr Harshal R Salve, Associate Professor at Centre for Community Medicine, IT solutions are important interventions in the management of Covid-19 pandemic.

"The newly-launched Apple Watch with oxygen saturation measurement is a good example of it. However, word of cautions should be well propagated regarding its accuracy and calibration and its non negotiability with examination by trained doctors," Salve told IANS.

To compensate for natural variations in the skin and improve accuracy, the Blood Oxygen sensor employs four clusters of green, red, and infrared LEDs, along with the four photodiodes on the back crystal of Apple Watch, to measure light reflected back from blood.

Apple Watch then uses an advanced custom algorithm built into the Blood Oxygen app, which is designed to measure blood oxygen between 70 per cent and 100 per cent.

On-demand measurements can be taken while the user is still, and periodic background measurements occur when they are inactive, including during sleep.

According to the tech giant, all data will be visible in the Health app, and the user will be able to track trends over time to see how their blood oxygen level changes.

According to Dr Manoj Goel, Director, Pulmonology, Fortis Memorial Research Institute, Gurugram, some patients who have recovered from Covid-19 but the lungs have not fully recovered and suffer from low oxygen in those cases, home monitoring of oxygen saturation by pulse monitoring can guide them to oxygen therapy to maintain oxygen saturation in optimum range within the blood.

"Through such advancements in technology, we can identify the severity of diseases and need for hospitalisation, which helps people get timely medical services," Goel said.

Apple will work closely with investigators at the Ted Rogers Centre for Heart Research and the Peter Munk Cardiac Centre at the University Health Network, one of the largest health research organisations in North America, to better understand how blood oxygen measurements and other Apple Watch metrics can help with management of heart failure.

"Finally, investigators with the Seattle Flu Study at the Brotman Baty Institute for Precision Medicine and faculty from the University of Washington School of Medicine will seek to learn how signals from apps on Apple Watch, such as Heart Rate and Blood Oxygen, could serve as early signs of respiratory conditions like influenza and Covid-19," Apple said in a statement on Tuesday.

Dr Modi said that low oxygen levels are usually not the sole indicator of having Covid-19.

"Patients should be vigilant of other symptoms such as cough, shortness of breath, chest discomfort, high fever and high pulse rate even if the oxygen level is normal," he added.