Problem statement for measuring the temperature of people - Page 1
Forum section: electronics / general

author: rgbdt
author_rank: Newbie
timestamp: September 09, 2021, 05:14:15 pm
content: As you know, a person's skin temperature and core temperature can vary greatly. Ambient temperature, sun, snow, rain, wind, individual characteristics of people and so on contribute to this.Because of these problems, identifying sick people is difficult.Sometimes this task is reformulated in a different way. Instead of trying to measure a person's core temperature directly, it is possible to find people with skin temperatures that are very different from those of people who have recently been measured. This reformulation greatly simplifies the task, but it is not clear how much the task with this formulation will help identify sick people.We now use neural networks to detect and track people, average a person's temperature over all frames of the video, and output one message with the temperature for each person. The temperature is calculated as the maximum temperature inside the head region.What difficulties might arise in finding temperature anomalies? What other approaches are used to measure people's temperatures.It would be great if you could recommend articles or other sources that describe approaches to solving such a problem.

author: svgurus
author_rank: Regular Contributor
timestamp: September 09, 2021, 11:21:39 pm
content: "face region" is bad degree of accuracy, you need forehead or chin, not obstructed by hair. Some pics from normal-resolution imager in attachment)

author: Ultrapurple
author_rank: Super Contributor
timestamp: September 10, 2021, 11:43:19 am
content: Intuitively, I'd have thought that the 'someone's hotter than everyone else' would work best when there is a relatively controlled environment.In somewhere like an airport arrivals situation people usually have to walk together for several minutes, all experiencing the same environment. This would greatly reduce the natural variations that have been mentioned (people coming in off the street affected by wind, rain, getting out of a hot car...) so that, at a guess, 'most' people would have pretty-much the same visible-skin temperature.That said, we've all seen individuals for whom walking in an airport is physically stressful and thus causes a temperature rise - think of a sweating, fat man - but if the screening system is just identifying persons ofinterestthen the natural next step is of course to run an individualised, more-accurate (and more intrusive) test such as an in-ear check.Just my thoughts.

author: Bill W
author_rank: Super Contributor
timestamp: September 10, 2021, 12:13:12 pm
content: Quote from: Ultrapurple on September 10, 2021, 11:43:19 amAs someone who had a thermal camera pointed at me / by me daily for many years, I found that while 'coming down with the flu' did result in temperature changes they were not so intuitive. Generally appearing colder (sweat) or higher contrast in the head and vanishing (cold) hands.Bill

author: jpanhalt
author_rank: Super Contributor
timestamp: September 10, 2021, 12:13:32 pm
content: As you realize and others have confirmed, forehead temp is not a reliable indicator of core temperature unless in a controlled environment. In my experience, for example, my daughter and her family visited in early Spring. It was cold and windy when we visited a tourist attraction downtown. They did forehead temperatures. The walk from parking was a few hundred yards. I suspect no one tested high. On the other hand, a relative lives in a desert community in California. Temps >115°F in Summer. A restaurant was doing such testing and almost everyone tested high, so they had a shady place to sit for a few minutes to cool off.It astonishes me that anyone does such testing, except as a prop for a false sense of security. Nevertheless, politicians were satisfied with that effort.What are your plans? What the the consequences of false positives? False negatives? Measuring tympanic membrane temp with disposable specula might be more productive, but a little slower and not suited for crowds.

author: Ultrapurple
author_rank: Super Contributor
timestamp: September 10, 2021, 12:41:25 pm
content: Quote from: jpanhalt on September 10, 2021, 12:13:32 pmHuge amounts of money are spent on providing a false sense of security, asYes Ministerpointed out several decades ago:.

author: bap2703
author_rank: Regular Contributor
timestamp: September 10, 2021, 08:41:31 pm
content: Quote from: jpanhalt on September 10, 2021, 12:13:32 pmPeople may not care about the actual protection that a detection system could provide... well what they care about is thelegalprotection they acquire by doing what's generally accepted (mostly by manufacturers) as an effective measure of protection for their clients/employees.

author: frogg
author_rank: Regular Contributor
timestamp: September 10, 2021, 09:12:01 pm
content: Way too easy to get obsessed with pessimism or the exceptions.This topic is wrapped up with politics. Many EEVBlog forum folks are notorious for going nuts about politics and are obviously unable to handle sensitive topics with decorum.To everyone else, no need to throw out the baby with the bath water.Detecting high fevers is much easier than low fevers, obviously. Forehead temps are used by medical professionals.Could do oral, rectal, or tympanic probes. Obviously those are impractical en masse.Maybe prescribing the need for a core temp is presupposing a solution. This creates bias in a "solution".Maybe elevated core body temp in and of itself is not the signal you are looking for.Maybe "identifying sick people" and "measuring core temperature" do not overlap much.If finding sick people was as simple as accurately measuring core body temperature, then medical practice would be significantly easier.