ASOURCE Navi

As an initiative to prevent the spread of new coronavirus infections at medical institutions, temperature screening using non-contact thermometers and non-contact thermometers (thermal cameras) has begun to be conducted at the entrances and receptions of buildings. Even non-contact thermometers certified as medical devices have conditions such as room temperature when they are used, and in terms of accuracy of body temperature, we will rely on contact-type thermometers that measure by side or mouth. However, the hygienic and speedy features of non-contact thermometers and thermal cameras in Korona-ka are suitable for commercial screening. (figure).

Figure. Comparison of contact thermometer, non-contact thermometer, thermal camera

People and substances emit infrared rays, and it is said that the higher the amount of radiation in proportion to the fourth power of temperature, the greater the amount. The non-contact thermometer uses this infrared property to determine the temperature. It measures the amount of infrared rays emitted from the surface of the human forehead without touching the skin, converts it to sublingual temperature, etc. and displays it digitally. It is a handy type and can be carried around, and the temperature measurement staff can easily measure the temperature for many people such as medical institutions. To use it, keep the distance between the forehead and the measurement sensor about 0.5 to 3 cm, press the ON button to make an electronic sound, and the measurement result will be displayed on the display in about 1 second.

On the other hand, a thermal camera is a device that detects infrared energy emitted from the human body, converts it into body temperature, and visualizes the temperature distribution by color coding, and the mechanism is the same as that of a non-contact thermometer. The body surface temperature is measured and analyzed by focusing on the forehead of the face and converted into a body temperature display. The measurement distance varies depending on the device, but most of them are 1 to 3 m and can be operated unattended, and they are also installed at the entrances of many medical institutions as a measure against corona. When the temperature is low, it is displayed in blue on the monitor screen, and as it is high, it is displayed in yellow and red. When it detects a temperature above the set temperature (37.5 ° C or higher in many medical institutions), it notifies you of abnormal body temperature with an alert sound or the like. For people who are suspected of having a fever, it is common to use a thermometer to measure again in a separate room.

Both the non-contact thermometer and the thermal camera are easily affected by the outside air temperature and sunlight, so it is necessary to measure in a place that is not affected by the external environment. In addition, it is recommended that people who have just come from outside take some time before taking measurements to avoid the effects of sweating and hot flashes on the face.

The latest thermal cameras are equipped with artificial intelligence (AI) to identify a person's face with or without a mask and measure body temperature within 1 second. In addition, even if there is no problem with body temperature, people who are not wearing a mask can make a voice announcement saying "Please wear a mask".

In addition, a non-contact, complete walk-through system has been developed that can measure body temperature for a large number of people at the same time (see the main illustration). Face recognition is used to identify people entering the building through the front of a camera installed in front of the entrance of a hospital, and at the same time, the body temperature of about 20 people is measured, and if the body temperature is higher than the set temperature, a flash and an alarm sound. Works. The outpatient does not have to stop or turn to the camera. Then, it is a mechanism to notify the face and temperature of the fever with an image and an alert sound on the management screen of the personal computer or tablet. For small children and wheelchairs, models that can simultaneously measure the temperature with the upper and lower cameras have also appeared. Since it can detect fever efficiently, it is suitable for preventing the spread of infection and outbreaks.

Since the "thermometer" is a medical device, approval from the Ministry of Health, Labor and Welfare is required to manufacture and sell it. Sometimes, "thermometers" are sold as "thermometers", while others are sold as "thermometers" even though their appearance and use are clearly thermometers. I think that these are not recognized as medical devices because they could not meet the standards for ensuring quality and safety, so you should refrain from purchasing them. The medical device always has an authorization number on it, so it's a good idea to look carefully.