Adrian Weckler on thermal scanners
AS of this month, visitors to University Hospital Limerick are greeted by a new contraption inside the entrance.
Hooked up to a laptop, a special thermal camera reads their skin temperature from a few feet away.
A finding of over 37.5C means you’re unlikely to get in, as hospital authorities fear you might be contagious.
If you’re a worker, an existing patient or someone with an appointment, you’ll get a second manual test, to make sure the equipment is telling the truth.
But if you’re a regular visitor, you probably won’t.
“This is an additional measure we have taken to try to help prevent the spread of Covid-19 at UHL,” says Dr Sarah O’Connell, infectious diseases consultant and clinical lead for Covid-19 at UL Hospitals Group.
The hospital is not alone. Thermal cameras are the latest technology that swathes of Ireland are pinning their hopes on as a safety valve in a national back-to-work scenario.
Supreme Court judges want them. Airlines want them. Warehouse bosses and captains of industry are starting to set them up in their facilities.
“Perhaps in the future, we should all only have entry [to courts] subject to temperature checks,” wrote Supreme Court judge Peter Charleton in a March letter uncovered and published by Right To Know’s Ken Foxe.
“This can be done on screens, as in Korea or Singapore, or by individual non-contact temperature-taking at points of entry.”
In Ireland, there’s something of a gold rush under way around the technology with a growing number of local resellers importing (mostly) Chinese hardware and flogging them to desperate companies, politicians and media pundits as an answer to lockdown restrictions.
But do they actually work? Only as an indicator of a symptom, say experts. “They definitely have potential,” says Trinity College Dublin researcher Dr Seamus O’Shaughnessy, who has used similar thermal cameras to those suggested for airports and hospitals in his ‘Fluids and Heat Transfer’ laboratory in TCD for a decade.
“But they’re fraught with several problems.”
Getting an accurate reading isn’t as easy as just picking it up and pointing it at someone, any more than taking a clear photo can be achieved by just pointing a camera. Impediments to accuracy can include everyday things such as glasses or hair covering, he says. Atmospheric factors can also skew readings.
There’s even some thought that the body’s circadian rhythm can interfere. It’s especially weak in crowds, he says. “It’s usually not a tool for mass measurement.”
This hasn’t stopped the marketing blitz, with daily reports on how thermal cameras can free us from our stay-at-home stasis and waiting lists of up to 10 weeks from some Irish vendors. Big companies are most prominent in racing to install the cameras.
This week, Apple put temperature checks in place for both staff and customers in its reopened Apple Stores across Germany.
Amazon has deployed the technology in warehouses and in its US Whole Foods retail stores. It claims that its temperature checks have detected staff who went on to test positive for Covid-19. In Ireland, some small businesses are cautiously trialling the technology. “It’s valuable as a screening device if set up correctly,” says a spokesman for Maxem Engineering, a Kildare-based firm, which has put up a thermal camera. “We’re testing one.”
Is this all above board from a data protection perspective?
Apple’s retail installation of the devices has drawn scrutiny – but no censure yet – from at least one regional German privacy regulator, covering outlets in the Frankfurt area.
Ireland’s Data Protection Commissioner has not directly commented on setting up thermal cameras at workplace entrances, but has indicated that with the right notification processes and precautions, they may be fine.
But data protection shouldn’t be the decisive element, some sectors argue.
Airline bosses, desperately looking at the collapse of their businesses, are pleading for some variant of the technology to be used as a way to readmit travellers in high volumes.
CityJet CEO Pat Byrne told the ‘Sunday Independent’ last week that “profiling of passengers and random testing” might be a desirable way of moving forward, arguing that the “danger will be in security queues and the airport terminal” as opposed to on board the aircraft itself.
In the UK, London Heathrow Airport is to begin a test rollout of the thermal cameras in Terminal 2 this month.
“The first of these trials will be a temperature screening technology which uses camera detection systems capable of monitoring the temperatures of people moving through the airport,” said a spokeswoman for the airport.
Last month, the Emirates airline started to trial the technology, while similar systems have been in use in South Korea and other parts of Asia for at least six months.
So how do thermal cameras actually work?
The basic idea is that they can read skin temperature, from a distance, using infrared and other sensors. Most can get it to within half a degree (Celsius).
Experts and manufacturers are at pains to point out that this does not mean it can detect Covid-19. It is merely designed to offer a substantial clue.
The technology has been used previously in some airports during the Ebola and Sars outbreaks
According to the HSE, a fever is generally considered to start at just around 38C.
So if you’re assessed by the thermal camera as being at that level (or hotter), you can be alerted to it.
But problems arise as to accuracy and context.
TCD’s Dr O’Shaugnessy says that the technology can be limited in the hands of someone who doesn’t fully understand the importance of the operating environment and atmospheric conditions.
“If you have on a pair of sunglasses or reading glasses, it may not register an accurate temperature,” says Dr O’Shaughnessy.
“That might also apply to a hair covering.”
Even when these are removed, the background behind the person being scanned can make an important difference.
Putting a ‘black body’, meaning a non-reflective, matt surface as a context helps accuracy.
Atmospheric and climatic problems are also an issue, he says.
“Because the atmosphere also contains heat, it can interfere with measurement,” says Dr O’Shaughnessy.
Therefore, you might get a slightly different reading in a hot, humid climate than a dry, cold one.
This can disproportionately affect cheaper thermal cameras, he says, adding that climate-controlled zones are a smarter implementation approach.
“Camera resolution is also very important, especially if measuring something like the tear-duct temperature since this region is physically very small.”
In this context, he says, organisations thinking of this as a way to tick a box so that they can get people back in the door should be very mindful of moving too quickly.
“I think this is probably only useful to identify high fevers like 38.5 [Celsius] or higher because of issues and sensitivity of equipment available,” he says.
“The danger is that people might get the cheap handheld stuff.
“But it still has potential, especially in a controlled environment with a reference temperature and a calibrated source. In a work environment, that might be implemented, but a climate controlled system would help.”
Other experts believe that the accuracy problem that thermal cameras have may lead to potential GDPR hurdles.
“We immediately have issues from a data protection perspective in terms of accuracy of the data and, more importantly, the adequacy of the data given the potential for false positives and false negatives,” says Daragh O’Brien, founder and CEO of Castlebridge, a prominent privacy and data protection consultancy.
“The awkward realities of temperature in humans are that there is a wide range of ‘normal’, right up to 38 degrees Celsius.
“Then we need to consider the potential triggers of false positive high temperatures.
“This can include exercise, menopause, other non-infectious illnesses, or other inflammatory conditions. Other
‘If you have on a pair of sunglasses or reading glasses, it may not register an accurate temperature’
‘There is no way to thermally detect an infected individual’
conditions can lead to an artificially lowered temperature, such as hormonal issues, fibromyalgia or diabetes. These can then mask a viral temperature spike, giving a false negative.”
This, he adds, is before issues such as asymptomatic transmission and pre-symptomatic Covid infections are taken into account.
Mr O’Brien concedes that Dutch, Spanish, and French regulators have issued guidance “which basically says that having the thermometer is OK… but when you start doing something with the reading, you are into GDPR territory.”
Some advocates say that GDPR is less of a concern than it might obviously be, because many of the devices don’t record any data but simply give a ‘yes’ or ‘no’ reading on the spot.
Ireland’s Data Protection Commissioner cautiously allows for new technology such as thermal cameras to be set up, even where it involves “sensitive, special category personal data such as data relating to health”.
It only looks for “suitable safeguards”, such as adequate staff training, limitation on access to any data and time limits for erasure. It also points out that the measure must be “necessary and proportionate”, should involve “only the minimum necessary amount of data” and generally be subject to confidentiality.
Regardless, some companies in Ireland have wasted no time in marketing and selling thermal imaging devices to businesses wondering about how they can get people back to work.
Hikvision UK-Ireland, a major thermal camera manufacturer, is currently pitching its products at Irish companies so that they “can monitor the temperature of returning employees and visitors”.
Dundalk-based Satir recommends a couple of handheld thermal scanners that “some small and medium-sized businesses may want to introduce to protect their staff and business from the coronavirus” under the heading “Helping Businesses Get Back to Work”. These are its entry-level D160F and its slightly pricier Hotfind-S for “mid-level fever screening”. Both devices claim to be accurate to within 0.5C.
Meanwhile, Midlands-based Thermal Imaging Ireland has devoted a section of its website to the topic (“Screening For Coronavirus Covid-19”), with videos, advice and product recommendations. It also warns that there is a 10-week waiting list for some of its equipment due to availability being at “an all-time low”.
And it’s not just standalone cameras that are being considered.
Some are hoping that self-administered checks through phone apps can become more widely accessible.
Feevr, a system set up by US company X.labs, has an app that it says can allow employees to conduct their own facial scan from a smartphone using a digital thermometer.
The scan sends the temperature result to the employer, which can then advise on whether or not it’s safe to come into work that day.
Yet the top manufacturers make it clear that all of this equipment is limited and shouldn’t be thought of as a one-stop detection device.
“Our products are not used to diagnose the coronavirus,” warns one of the biggest makers of thermal cameras, FLIR, in a highlighted disclaimer.
“FLIR is not advertising our cameras for use in the medical industry or for medical purposes.
“Our products can identify individuals in a population that show higher than average temperature in relation to a sample population.
“Our cameras do not find individuals experiencing coronavirus symptoms.
“There is no way to thermally detect an infected individual who doesn’t have an elevated body temperature and only a licensed medical professional can determine if a ‘hot’ individual is experiencing an abnormal medical condition.”
And privacy experts warn that there are further rights issues around the mass-implementation of such devices, especially in workplaces.
“The impact on some rights is a big question,” says Castlebridge’s Daragh O’Brien.
“There is a right to work, so employers would need to be very careful about how they deal with not letting staff into the workplace.”
Thermal cameras may prove to be a valuable aide to some companies and organisations in getting people safely back to work, or protecting others from obvious infection.
Together with the country’s upcoming contact-tracing app, the technology may provide support for a country that is desperately looking for practical tools to help normalise our lives as a Covid-19 vaccine is waited for. But the evidence so far shows that they cannot be relied on alone.
“Organisations deploying these technologies will need to consider whether there are better ways of implementing control measures other than ‘thermometer theatre’,” says Mr O’Brien.