At the recent Hong Kong Clock and Watch fair organised by the Hong Kong Trade Development Council (HKTDC), the smartwatches and wearables zone attracted the most footfalls. But, even though the array of fitness trackers and smartwatches lining the pavilion was exciting, it was surprising to hear some dubious voices articulating concerns about the accuracy of these gadgets — especially those tracking health metrics like heart rate and blood pressure.

And when those concerns were voiced by none other than entrepreneurs displaying the devices, eyebrows shot up. Chandan Sethi, founder and CEO of innoWear, a Hong Kong-based wearable brand debuting its fitness trackers (priced at US$99 or ₹6,995) in the Indian market through Woodland stores, proudly showed his latest heart beat tracker device, Innoband HR. Sethi said he had delayed launching as the lawsuit on Fitbit had given him the jitters. “We are plus or minus 2 per cent of Omron’s heart rate measuring device, which is medical grade, but still we have decided to launch only once we are 100 per cent satisfied about accuracy,” he said. “It is very difficult to get heart rate right as the technology is based on sensors and you need lots of algorithms,” said Sethi.

Off the mark

Early this year the American pioneering brand in wearables Fitbit was hit with a class action lawsuit that claimed that heart rate monitoring features in its Charge HR and Surge were inaccurate by a significant margin. Fitbit was not the only one — earlier, both Nike and Apple had to partially refund customers (with gift cards) after a suit that claimed that iOS exclusive Nike+ Fuelband did not track steps accurately. In fact, Nike, which set the pace in wearable technology, took the extreme decision of killing the Fuelband and disbanded its team.

Can there be 100 per cent accuracy?

Not a medical device yet

Vishal Gondal, whose Goqii fitness tracker has been flying off the shelves in India, says that people need to understand that a smart wearable can never be a medical device. Goqii is positioned as a 'lifestyle change service,' not as a health check device, he clarifies. Interestingly Fitbit’s response to the US lawsuit was similar: that its trackers were not meant for scientific or medical purposes.

So if they are not accurate, what real use are they? What is the point of buying devices that give you only halfway meaningful metrics? Especially in view of all the noise made that these could be healthcare game changers.

In fact, a 2015 study by the Center of Behavioral Cardiovascular Health at Columbia Medical had set out to see if Fitbits could be used by physicians to monitor their patients’ physical activity objectively. The study found that early generation Fitbit devices worn on the hip were just one step off from 100 per cent accuracy. However, devices worn on the wrist were off by 11 steps a minute.

Other studies showed that chest straps track heart rate better than smartwatches though they are cumbersome to wear. That is because they cancel noise better.

Talk to users and a common complaint is that often wearable activity trackers record steps when they are sitting in cars. Gondal has an explanation. He says that most wearable companies rely on accelerometer technology which uses sensors. These catch jerks and record them too. “Using GPS technology would be more accurate, but GPS has challenges: it does not work indoors. It will drain your battery,” he explains.

Net result

Most wrist-worn wearable devices will win no prizes for accuracy though some are decidedly more on the mark than the rest.

Meanwhile, at a Connected health summit in San Diego last week, where smartwatches that could measure blood pressure, pain relief cuffs, posture pendants, wearable heart rate monitors et al were exhibited, another issue flagged was when we would see a wearable that gives all these functions in one band, rather than forcing customers to buy multiple devices. Could we have a Swiss Army knife equivalent of such a smartwatch — a converged wearable?

But doctors in the US at the moment are frowning at some of these functions on these devices since they do not have FDA approvals and medically, the use case is debatable. Back home, Dr Anoop Misra, Director Diabetes and Metabolic Diseases, Diabetes Foundation India is less conservative.

Misra who himself uses Fitbit everyday and walks an average of 7000 steps on weekdays and 10,000 on weekends, says, “Recording steps walked and calorie spent helps better compliance with exercise.” While he feels heart rate is measured reasonably accurately by a smartwatch, blood pressure readings may not be reliable.

“Go for the ones that measure steps, distance, calories and heart rate,” he advises.

In sum, the jury’s verdict seems to be — use them for fitness but not as a health metric. But going forward, tech will find a way to solve these glitches, for sure.