Get best of the week

Why thermal imagers cannot measure a person’s body temperature



Demand for thermal imagers as a tool to help detect fever, as one of the symptoms of coronavirus, has increased dramatically as coronavirus has begun to spread rapidly around the world.

The world's largest manufacturer of FLIR thermal imagers, said its global demand has increased by 700%. Everyone instantly smelled a lot of money! However, not every thermal imager can change the temperature of the human body.


Table of contents




…
?
FDA?
FDA
?
FLIR ?
FLIR
… FLIR
FLIR
?
?
…
…
…
…
…




Most thermal imagers are designed for use in industry, they really can almost all measure the temperature of objects.

However, thermal imagers for measuring human body temperature are specialized medical devices. The problem is that manufacturers simply ignore this fact, and especially malicious ones are directly misleading. Let's analyze the offers of the most famous manufacturers.

5 billion for the sale of Chinese thermal imagers.
The Russian Government allocated 5 billion rubles to the Ministry of Industry and Trade for the production of domestic thermal imagers to support the work of federal executive bodies with thermal imagers. The money was received by the Shvabe holding, which is part of the Rostec state corporation.

The Shvabe holding company has several companies involved in the production of thermal imagers, and most of them produce thermal imagers that are indistinguishable from the Chinese . Let's take a closer look.

JSC UOMZ Production Association is one of the key organizations of the holding company Shvabe JSC. It produces three thermal imagers for remote measurement of body temperature:
HMX315 - externally one in one Chinese thermal imager ISMTB-ZS-315 . By the way, the Chinese became famous due to the fact that he was unworkable a little less than completely. Here he is a handsome man already installed at the railway station in Yekaterinburg.
W400 - and here, his Chinese twin brother TE-W400H
W1- and here, his Taiwanese brother-in- law Dynacom WQT530-S

Krasnogorsk plant named after S. A. Zverev produces an infrared temperature measuring system IR236 painfully reminiscent of GUIDE IR236 IR from the Chinese manufacturer Guide Sensmart. Russian Railways, by the way, is already testing it in full .
Separately, I was struck by the advertising video in the Chinese product card, this unique device measured the temperature of a person behind the glass.


Screen from Guide Sensmart Promotional Video

It is well known that glass does not transmit thermal radiation, on the left side of the screen it can be seen that the person behind the glass is invisible to the thermal imager. On the right side of the screen, we already see the image from a conventional CCTV camera and a person behind the glass. However, despite the fact that the person is invisible, the thermal imager captures his temperature, we see a yellow die with a temperature of 35.9. What is shown in the video is the purest sell.

In fairness, it is worth noting that on the website of Lytkarinsky Optical Glass Plant JSC (LZOS JSC) is also part of the Shvabe holding "and I managed to find a thermal imager a bit like a tank, whose visual analogue is not found on the Internet.

Rostelecom
Following "Rostelecom" offeredRussian enterprises have a high-precision body temperature monitoring system using thermal imagers. Such a decision, according to Rostelecom, allows for contactless, automatic measurement of body temperature up to 80 people per second at a time . It is modestly silent that it seems like cheap Chinese, the inscription on the screen of "Dahua", hints at this explicitly.
Podkin Rostelecom royal advertising slogan: Measure the temperature of the entire population of Russia with one Chinese thermal imager for 20 days. But it is not exactly.

Dahua was
not without our Chinese partners. Dahua, decided to go on the run. In the image below you can see how the temperature of people leaving the train on the railway platform is measured online.


Screen from Dahua advertising materials.

The problem is that it is technologically impossible to accurately measure the temperature of several people at the same time, outdoors, at a considerable distance, over a large area. That is, it is a banal 100% drawn fake.
Despite this, it was easily absorbed by both foreign and Russian media . distributors naturally did not stand aside, and thanks to them we probably have the most famous fake advertising dedicated to thermal imagers in the world.

Sunell
Another world-famous irreconcilable Chinese fighter with coronavirus. Developed unique cameras capable of encircling their heads with a green rectangle. And how can this help in measuring temperature, you ask me? There is an opinion that nothing, but it helps a lot to fill Sunell’s accounts with a cache, perhaps, in their opinion, this is enough.


A screen from Sunell

FDA promotional materials recommends measuring body temperature only to one person at a time. Temperature measurements for several people at the same time will be inaccurate. And in accordance with the recommendations of IEC and ISO, the mask and goggles on the face should be absent, as this reduces the accuracy of measurements.

Plant Alexander
Ryazan Plant did not begin to trifle andmastered the production of thermal imagers, immediately with the face recognition function. And all this in a month and a half. “The cost of the prototypes is commensurate with the Chinese counterparts, and when it goes into mass production, it will still decrease by 20-30%.” And they even got the typical website for Ryazan in the .moscow domain zone www.teplovisor.moscow . They probably hint that with such success the day is not far off when Ryazan will be renamed New Moscow, and Moscow to Old Ryazan.

HikVision
Of course, I could not help but mention the leader on cyber security and ban issues from the United States for human rights violations in Xinjiang.


Screen from HikVision promotional materials

They are modest in their promotional materials, they just write that they can measure the temperature of up to 30 people at a time. Well, judging by the video, medical masks and glasses are no problem for them. Although the FDA , IEC and ISO claim that the mask and goggles on the face should be absent, and a large number of people in the frame reduce the accuracy of the measurements.

An intermediate result The
Russian market of thermal imaging equipment in most cases is flooded with low-quality Chinese, as well as Russian equipment, for inexplicable reasons, outwardly not different from the Chinese.

Promotional materials and descriptions are contrary to FDA guidelines and international standards developed byIEC and ISO .
And that would be just ridiculous, especially in video surveillance, the situation is almost the same, but when we talk about thermal imagers, we are talking about human lives and it becomes no laughing matter.

How to measure a person’s body temperature thermal imagers are not designed for this


There is one very illustrative and absolutely hopeless case that is worth exploring. The company Laser Components delivers another unique Chinese thermal imager ISMTB-ZS-315 to the Russian market.

Many years of work, and finally deserved glory overtakes the heroes, in the person of the television program Vesti from channel Russia 1. However, neither the heroes nor the journalists from channel Russia 1 notice that the temperature of a person changes from 36.8 to 37.4 degrees Celcius.
Which may more clearly indicate that for accurate measurement of body temperature this device is approximately as necessary as a saddle for a cow.


Screen from the video from Rossiya1 channel, a person’s temperature changes during passage from 36.8 to 37.4 degrees Celsius

Original video“Laser components” were uploaded to their YouTube channel, but after the mess came up, they edited their video. That is, they cut out a piece where you can see how the person’s temperature jumps, and continue to try to sell this hat. And this is of course a special cynicism.

But, the Internet remembers everything! Here it is this piece, cut from the original video.


However, let's not do an absolute evil from the company "Laser Systems", this is just one of the distributors of Chinese manufacturers of thermal imagers which in the Russian market are like dirt. And this is not surprising, Chinese thermal imagers are so cheap that at first you do not believe your happiness.

Thermal imagers are not an exception to the Chinese strategy for promoting goods, which is roughly formulated as - Yes, we sell trash, but it’s cheaper.


Thermal imagers have long been used in video surveillance, so I even wrote a small review about a year and a half ago. And if you read this review, you will quickly realize that they have a number of serious advantages compared to CCTV cameras.

For example, to protect the perimeter, thermal imagers perfectly detect a person in complete darkness and at a considerable distance. And they can even measure the temperature. And here attention, yes they can, but not the temperature of the human body .

Because measuring human body temperature is an absolutely specific and very difficult task.

Normal body temperature is a relative concept. In one study, the scatter of normal values ​​ranged from 35.3 to 37.7 ° C, in another- more.

The human body temperature changes during the day, reaches a peak in the late afternoon, and the lowest temperature is recorded in the morning. This circadian rhythm can lead to fluctuations of 1-2 degrees.

In addition, normal temperatures tend to vary by group . In women, usually the temperature is slightly higher than in men. Older people tend to have lower temperatures than younger people. Human skin

temperature is not equal to body temperatureTherefore, the most accurate thermometers are rectal. It is body temperature that is a symptom of coronavirus, and most cheap thermal imagers measure skin temperature. Also, different parts of the body have different skin temperatures.

Also, the temperature differs depending on the time of the year, on the phase of the menstrual cycle, on whether a person ate before measuring (after eating, the temperature rises), ambient temperature and other factors.

To summarize all of the above, we can say that 99% of thermal imagers are designed for video surveillance, and thermal imagers designed to measure body temperature, these are medical devices that are very different from ordinary ones.

Slowly but surely, we approached the main question of the article.

Are there thermal imagers capable of accurately measuring a person’s temperature?


The key point is who answers this question ! It is clear that any Chinese will swear by all his Chinese gods that his equipment can. But only the British government trusts such statements, and as it turned out in vain.

In fairness, and my answer to this question will also be subjective. Therefore, I will enjoy the modest role of a translator and provide the opportunity to respond to the Food and Drug Administration (FDA) .

The FDA is the only authoritative independent source of information that answers the question of which thermal imagers can accurately measure a person’s body temperature. But before the FDA answers this question, a few words about why they can be trusted.

Why is it worth trusting the FDA?


The United States Food and Drug Administration (FDA) is considered a flagship among national health services and is credible and responsive . Few in other countries approach risk assessment so rigorously and scrupulously.

In Russia , there is talk of automatically recognizing FDA decisions.
Well, or if you go to the site of the most popular pharmaceutical directory in Russia , you can open any substance that comes to hand and you can see there a fascinating phrase: “FDA category of action on the fetus” and this is understandable when it comes to life and death rely on reliable sources.

Another serious argument is that the USA is the largest market in the world. And first of all, any manufacturer, no matter Chinese or European, generally any, seeks to enter the US market precisely. And FDA approval is a serious help in promoting products in the US market. And if the manufacturer does not have such approval, then most likely its thermal imagers are simply unsuitable for measuring human body temperature.

If you suddenly come up with the idea that the FDA is an American office and it gives green light only to American companies, then chase it. Firstly, with such an approach, the attitude to the FDA would be approximately the same as to our Ministry of Health. Secondly, it is full of American large companies that produce thermal imagers, but do not have FDA approval. For example, Fluke Corporation .

FDA Approved Thermal Imagers


Here is a list of companies producing thermal imaging cameras on the FDA website and devices approved by the FDA for detecting elevated human body temperature. I especially want to draw attention to the fact that the FDA approves the device . Those. The listed company can produce tens or hundreds of thermal imagers, but only some devices get FDA approval as devices that are suitable for detecting elevated human body temperature .

FDA Approved Manufacturers

- 11 Health and Technologies, Inc.
- Infrared Cameras, Inc.
- InTouch Technologies, Inc.
- Med-Hot Thermal Imaging, Inc.
- Meditherm, Inc.
- Optotherm, Inc.
- Spectron IR
- Titronics Research & Development
- FLIR Commercial Systems Inc.

On this list are not only manufacturers of classic thermal imagers, which are discussed in this article, but also companies specializing in telemedicine, their thermal imaging equipment is only one of the devices for remote diagnostics that allow doctors to consult with patients in real time.

Can I buy in Russia thermal imagers designed to measure human body temperature?


In Russia, many manufacturers offer their own thermal imagers.

Our catalog contains several brands that you can buy.



And you can buy all these thermal imagers in our company, but here I added them only for one purpose, I do not recommend using one of them for measuring the body temperature of a person. Rather, the FDA does not recommend, but I believe that there is not a single reason not to trust them.

In our catalog, only FLIR thermal imagers are approved by the FDA for measuring human body temperature. Moreover, not the entire range of thermal imagers is approved by the FDA, but only specially developed several series. Handheld thermal imagers FLIR - E53 , E95 , E85 , E75 , T530, T540, T620, T640 , T840 , T860 , T1020 , T1040.
Fixed Mount Thermal Imaging Cameras FLIR - A320 Tempscreen, A300, A310, A315, A325, A615, A655 and A400 / A700 .


Despite all the financial attractiveness of thermal imagers - Axis, HikVision, Idis, Evidence, there are no reliable data that would indicate that they can be used to accurately measure the temperature of a person’s body.
Of all the devices approved by the FDA, only FLIR thermal imagers are represented in Russia. Anyway, if we talk about the market for thermal imagers, FLIR is an American giant that controls 50% of the global market for thermal imagers.

How do FLIR thermal imagers work for determining body temperature?


Among the wide range of thermal imagers that our company offers, only FLIR thermal imagers are approved by the FDA for measuring body temperature.
Therefore, everything that I will tell relates mainly to FLIR, however, almost all of these principles apply to all high-precision thermal imagers designed to measure body temperature.

Strictly speaking, thermal imagers, in principle, cannot measure the temperature of a person’s body, thermal imagers can measure the temperature of a body on a surface, i.e. human skin temperature.

The temperature of human skin is also not uniform, somewhere more, somewhere less, depending on the site. In the inner corner of the eye, the temperature is closest to the temperature of the human body.


The temperature of the inner corner of the eye is closest to the actual body temperature, because there is an ophthalmic artery nearby, which increases blood flow. Therefore, the corner of the eye is less susceptible to environmental influences, such as heat, cold or humidity, which lead to changes in skin temperature.

The disadvantage is that the glasses hide the inner cavity of the eye from the thermal imager, so they will need to be removed to measure the temperature.

How all this roughly works is demonstrated in the latest FLIR demo video:



Temperature measurement accuracy with FLIR thermal imagers


Thermal imaging cameras FLIR designed to measure human body temperature can achieve accuracy ± 0.5 ° C. High accuracy is achieved when using the FLIR thermal imager designed to measure the temperature of a person in an environment without sudden changes in temperature and humidity. Also, many factors can influence the accuracy of temperature measurement, for example, focus and distance to the person whose temperature is measured.

Thermal Imagers FLIR Measure Relative Temperature


You already know that there are a bunch of factors affecting a person’s temperature, these factors change over time, for example, ambient temperature. In the morning, people came in from the street, where the temperature was +15 ° C; in the afternoon, the temperature in the street was +20 ° C. Naturally, this will affect the absolute value of human skin temperature.

In order to level various factors that affect the absolute temperature value, FLIR thermal imagers automatically form an indicator - the average value of the sample temperature. This indicator is formed on the basis of data from ten people who are the first to take temperature measurements directly at the installation site of the thermal imager. Naturally periodically, this value needs to be updated.

Then, based on the average temperature in a sample of 10 people, the operator sets the alarm temperature .

All subsequent measured values ​​of the human temperature are compared with the alarm temperature and when it is exceeded, an alarm is triggered. Or if the thermal imager is integrated with an access control system, the passage may be blocked.

FLIR thermal imagers do not require the use of a completely black body


This is another advantage of FLIR thermal imagers. Thermal imager manufacturers such as HikVision and Dahua offer a thermal imager complete with an emitter in the form of a completely black body model for calibrating the thermal imager at the installation site.

However, they do not indicate anywhere that the blackbody emitter has its own error and its own conditions for stable operation. Also, the emitter requires calibration with a pyrometer , highly qualified personnel and laboratory conditions. In general, if you want to punish the person who will be responsible for the operation of the thermal imager, this is your choice.

And here we come to the second main issue of the article.

Can I use a thermal imager for non-proliferation of coronavirus infection?


It is understood that FLIR thermal imagers can effectively detect elevated human body temperature. But the question of whether they can be effectively used for the non-proliferation of coronavirus infection is not as obvious as it seems at first glance.

Despite the fact that an increase in body temperature is a common symptom of coronavirus, only in 43.8% of patients, an elevated temperature was recorded upon admission to the hospital.

According to WHO, symptoms develop on average 5-6 days after infection, and the incubation period is from 1 to 14 days.

There are a couple of studies that evaluate the effectiveness of using thermal imagers for the detection of coronavirus patients.

  • , , 75% .
  • , , , .

However, these studies have one serious drawback, they take into account neither the technical characteristics of thermal imagers, nor the manufacturer, or which model of the thermal imager is used.

One way or another, it is important to understand that thermal imagers cannot be used to detect coronavirus infection in humans.
Specialized thermal imagers can accurately measure the temperature of human skin, which in some parts of the body is close to the temperature of the human body. Some people with fever may be infected with coronavirus.

People who have an elevated temperature using a thermal imager should be examined by medical professionals using additional tools for diagnosing coronavirus.

Why is control of human body temperature important?


According to epidemiologists Helen Jenkins of Boston University and Bill Hanage of Harvard: “Preventing even one transmission of the infection has huge consequences.



So, specialized thermal imagers can be used as one of the barriers to the spread of coronavirus infection. And in the Russian regulatory environment, this will also ensure compliance with the requirements of the law.
Here are a few examples of exactly how they can help.

Compliance with legal requirements


To prevent workers and clients from infecting each other with coronavirus and other dangerous diseases, Rospotrebnadzor recommended that employers throughout Russia check their temperature .

And in Moscow, the mayor no longer recommends, but obliges to do so. If the temperature is elevated, the employee should not be allowed into the workplace.

Eliminate the possibility of transmission of the virus when measuring temperature


At present, many enterprises use hand-held infrared thermometers to measure the temperature of people at the entrance to control temperature.

The person who takes the temperature with such a thermometer should be very close to the potentially infected person, which increases the risk of transmission of the virus, even if the person using the personal protective equipment.

Having become infected, the inspector himself can already in turn infect many people to whom he will measure the temperature.

As we know from the sad statistics of the deaths of medical workers using high-quality personal protective equipment. Even they cannot guarantee safety against infection.

Entry Jams


Individual temperature checks with a hand thermometer take a lot of time. The specifics of enterprises, as a rule, involves two points with a peak load on the entrance. This is coming to work and leaving work. And, as a rule, all employees come to the same time at 8 or 9-00.

Together with measuring the temperature at the entrance with a hand-held thermometer - all this can lead to the formation of a queue or congestion at the entrance. And, as we already know for sure, it is precisely the places with a massive concentration of people that become ideal sites for the spread of coronavirus .

The virus doesn’t care what it will be, mass infections occurred at religious events , during the funeral, and of course sports - the Champions League football match between Atalanta and Valencia on February 19 in Milan became a real “ biological bomb ”.

If you do not want your checkpoint to become a "biological bomb", you simply must not allow lines at the entrance. One way to do this is to use thermal imagers, since scanning with a thermal imager is much faster than using a manual thermometer by a person.

If someone enters a room with a high temperature, an alarm sounds, indicating that he is potentially transmitting the virus and should be checked by a medical professional.

Second wave of coronavirus


Nicholas Popper, a mathematician from the Vienna Technical University, whose team is developing models that can help governments more accurately predict the development of a pandemic, believes that as soon as the first prohibition measures are loosened, new clusters will emerge that will accelerate the spread of the virus.

The reason is also that as soon as prohibition measures begin to weaken, a trigger will trigger in the minds of most people that the danger is gone. And tough precautions are no longer necessary.

The thermal imager can, and with proper design, should be used as an automated means of control, i.e. working without a person, or with minimal participation. It depends both on the model of the thermal imager and, as a whole, on the access system.

For example, a thermal imager can be integrated into an automated access control system of an enterprise, and when detecting elevated body temperature, access will be denied.

It's cheaper


Of course, I understand that looking at the price tag of FLIR thermal imagers, the only ones suitable for detecting elevated human body temperature, it does not seem so. However, this is only when compared with the price of a hand-held infrared thermometer, and such a comparison is not entirely correct.

Why this happens is understandable, in the minds of most people, coronavirus is a temporary complication, but it is not.

The head of Rospotrebnadzor Anna Popova believes that the restrictions on coronavirus in the Russian Federation will be completely removed only after the advent of the vaccine. And the creation of a vaccine is from 1.5 to 5 years , and by the way, no one gives guarantees that it will be created. For example, a vaccine for human immunodeficiency virus does not exist.

Western experts also share forecasts on the long-term duration of restrictions. Computer modeling by Harvard University warns of the possible need to maintain restrictive measures by the end of 2022.

Now that we have complete data, let's compare the prices correctly, for this we need to add the salary of the person who will use it to the price of a manual thermometer. And most likely not just one, but two people, because, firstly, one person will not be able to measure temperature quickly, and most likely a congestion will form. And this is the worst that can be done in the face of a viral threat.
And secondly, there are such things as lunch or a smoke break, and if a person is alone, then while he is having lunch, a crowd will again form in front of the entrance. The minimum salary of two people in Moscow is approximately 100 thousand rubles. Well, and then as they say, the calculator will help you and, depending on the chosen thermal imager, you can easily calculate the payback time.

Recommendations on organizing the conditions for measuring temperature


In order to effectively organize the process of temperature measurement, it is necessary to follow the recommendations developed by international independent organizations IEC and ISO .

ISO / TR 13154: 2017 Medical electrical equipment. Installation, application and operation manual of screening thermographs for determining febrile human temperature.

IEC 80601-2-59: 2017 Medical electrical equipment . Part 2-59. Particular safety requirements, taking into account the basic functional characteristics of screening thermographs for screening elevated temperature in humans.

ISO 80601-2-56: 2017Medical electrical equipment. Part 2-56. Additional requirements for the basics of safety and the basic characteristics of medical thermometers for measuring body temperature.

These are quite voluminous documents that it makes no sense to retell on the pages of this article; we will leave this for private consultations.

Key recommendations:


  • , . , FDA, IEC ISO .
    IEC ISO .
  • , , —

  • .
    , . , , , , , . , .
  • FDA


As you already understood, we also sell equipment for security systems in general, and thermal imagers in particular . Of course, we also felt a surge in demand for thermal imaging surveillance cameras.

The specifics of the B2B market is that, as a rule, procurement specialists turn to purchase equipment, the task of which is to purchase, something in accordance with the decision made by the management. It is important here that the purchasers themselves do not make a decision on the appropriateness of the purchase, they only ensure the implementation of this decision.

With this article, I want to reach out to decision makers so that when deciding on the choice of means to combat the spread of infection, they have reliable information for choosing means with proven effectiveness, rather than spending huge money (and thermal imagers are expensive), which are unlikely to be even somehow help.

More articles:


All Articles