Advanced Thermal Imaging May Help Get More People Back to Work

Heather R. Johnson
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Can technologies such as AI-enhanced telethermographic systems help prevent the spread of viruses?

Not all companies are rushing to bring back employees as the country reopens for physically distanced business. Coca-Cola, headquartered in Atlanta, will keep workers home, despite loosened restrictions in Georgia. Most of Morgan Stanley’s employees, spread across the United States, will continue working remotely.

What will it take for people to return to work on a grander scale? Generally, state governments want to see flattened and decreasing infection rates, an increase in COVID-19 testing and contact tracing, and adequate hospital beds and PPE. As states move closer to their testing, tracing, and PPE targets, employers are developing new policies and procedures to keep their people safe.

Hardware and software developers are racing to develop products to help them reopen. Telethermographic systems, thermal imaging cameras that measure skin temperature in high-traffic areas such as businesses, airports, and warehouses, are one tool that may help ensure healthier workplaces.

In guidance issued in April 2020, FDA stated that it “will not object” to the use of telethermographic systems when intended for adjunctive screening, provided the manufacturer meets certain performance and labeling requirements. These devices are not required to obtain 510(k) clearance during the current public health crisis.

The Need for Touchless Temperature Checks

The U.S. Equal Employment Opportunity Commission (EEOC) also gave a green light. In late March, the EEOC said employers may conduct temperature checks before employees enter the building. It’s not a foolproof plan, as fever doesn’t mean a person has COVID-19, and COVID-19 doesn’t always come with a fever. But it is a way to identify individuals who are either ill or on the verge of illness.

Using a touchless thermometer comes with a host of logistical challenges, however. To check every employee individually would create bottlenecks at the door. Will people stand six feet apart? Will they get paid for that time? Who does the checks? What PPE should they wear?

To help companies avoid these complicated queues, several companies are either revising existing thermal imaging cameras or developing new devices that can measure body temperature en masse.

Kogniz, an AI-based security products company that develops enterprise-level facial recognition solutions, designed a product to address COVID-19. Kogniz Health, an AI health response platform, can integrate with existing security cameras or operate as a standalone solution.

Kogniz Health uses medical-grade thermal sensors optimized specifically to look at skin temperature. Applying AI, the thermal and optical cameras work together to give a reading of each individual as they enter a building.

Facial recognition technology identifies these individuals. If someone presents with an elevated temperature, the person in charge receives an alert. If, after a more-thorough evaluation, the employee tests positive for COVID-19 or another virus, the device will identify employees who have come in contact with that individual.

“It's contact tracing inside a building,” said Kogniz president and CEO Daniel Putterman. “If an employee presents with COVID-19, the flu, or another contagious illness, AI tells us who else was in contact with that person over the past 10 days.”

While Kogniz Health suits businesses of all sizes (budget permitting), Dubak Electrical Group developed a fully integrated body temperature measurement system best suited for industrial and commercial applications. Called DuThermX, the product measures body temperature of up to 40 people at once.

Like Kogniz Health, DuThermX can integrate with existing security systems. It can also include facial recognition. It’s the type of system one could easily see at airports, large entertainment venues and manufacturing plants.

“The technology and integrated alarming system allows us to adapt to a variety of entry points, from manufacturing and factories to schools to medical clinics and courthouses,” said Nick Dubak, chief operating officer of Dubak Electrical Group, which developed DuThermX.

How it works: The DuThermX camera scans visitors’ faces when they pass through an entry point. When the device detects an elevated temperature, it puts the face in a red box, displays the temperature, and alerts the person in charge—via sound, visual, email, text, and/or video capture—so they can take further steps. The device stores images to server and network video recorders as well as to an on-screen monitor.

Dubak Electrical Group has provided industrial electrical construction services, many of which use thermography, for more than 30 years. In late 2019, Dubak had a hunch the virus spreading in Wuhan, China, would become a serious global health issue. The company started working on a safety solution in January 2020 and announced the product in late April.

“We poured over 3,000 R&D hours into a fully integrated system that would protect points of entry,” said Dubak. “There were a lot of 18-hour days, but we had such rigorous testing and modeling that we could put our name behind it with confidence and certainty.”

DuThermX is up and running in 50 U.S. locations, with 150 more under installation.

Work in Progress

iThermo, another AI-powered temperature screening device, is being piloted at two Singapore hospitals. Device manufacturer KroniKare is testing iThermo in various settings, including outpatient clinics and commercial buildings. According to the company’s website, they have so far discovered the device only works in one-way foot traffic and cannot screen people with bangs, thick makeup or heavy perspiration.

The Importance of True Accuracy

Established companies that manufacture thermal cameras for the industrial and military sectors are pivoting to market their products as fever detectors. But to comply with FDA guidance, they must contain a calibration source for 2.3 degrees Celsius.

As Putterman explains, not all thermal imaging systems have the calibration technology to adjust for external environments. Product specs may say a device is accurate within 0.5 degrees Fahrenheit, but he says temperature readings from some devices could actually vary between five and seven degrees throughout the day because of the influence of the external environment on skin.

“It takes between five to ten minutes after you enter a building for your body temperature to acclimate to the ambient temperature,” Putterman said. To adjust for this fluctuation, he said an employer would have to get the average temperature of three healthy people every 30 minutes to arrive at a “new normal” temperature. The temperature-taker would then have to use that new normal to determine who may have a fever. In the alternative, the company could hire a thermographer to adjust for false positives. Realistic? Hardly.

“We correct for this,” Putterman said. “We keep a running histogram, establish baselines and adjust the baselines in real time. We refactor that into the skin temperature and compare it to the ambient temperature in the room, which we also track and give a completely normalized reading.”

The DuThermX camera contains an onboard temperature detection algorithm and a calibration source. “It’s a heat source that has an emissive area that is tuned to 104 degrees Fahrenheit,” said Dubak. “It’s installed within the camera’s field of view. The camera constantly looks at the calibration source to make certain we have accurate readings. It’s a reference point for the camera to always be reading and not manipulated by outside reflectance sources or surfaces that would induce false positives. This helps us stay calibrated within 0.54 degrees Fahrenheit plus or minus.”

Companies with less-precise thermal imaging systems may have assistance from companion software. According to an IEEE article, Alejandro Kurtz de Grino, a design and research engineer at Madrid-based software company BCB Informática y Control SL, is developing software that will help thermal cameras measure temperature more accurately.

The Next Normal

As most of the world nears the end (we hope) of stay-at-home orders to help control the spread of the coronavirus, we’re getting glimpses of freedom: elective surgeries resuming, small businesses opening for curbside pickup, even a few restaurants opening. As we gradually return to some type of normalcy, various technologies, including AI-enhanced telethermographic systems, will play a role in containing the virus and, ideally, prevent the spread of future viruses.

“This helps restore order at the door,” said Dubak. “It restores confidence that a workplace is healthy and safe. This is the new normal, but we want it to feel like the old normal.”

DuThermX can measure the body temperature of several people at once.
 

DuThermX can measure the body temperature of several people at once.

 

Kogniz Health's thermal sensors are optimized to look at skin temperature.