How can infrared thermography help you?
Can you imagine being able to take a photo of the energy released by your body?
Well, that is what infrared thermography allows. This tool has evolved in optical and optometric sciences, more specifically remote sensing, going from having a use mainly in the engineering sector to a biomedical application.
Thermal cameras are able to measure the radiation from the surface of objects, transforming it in Celsius degrees, and representing them into a colorful image known as a thermogram. In the building sector, for instance, thermal imaging is used to detect abnormal temperatures that might indicate damage materials or inefficient facilities or constructions.
However, in biomedical sciences it is used to observe skin temperature. In the same way we use a thermometer to measure temperature at a specific point on our body when we feel sick, thermal imaging can obtain, thanks to the radiometric data contained in each thermogram, as many measurement points as pixels (an 320×240 images has 76,800 pixels).
Evolution of infrared thermography
The first application of thermal imaging on medicine field was mainly focused on diagnosis. During the 60’s and 70’s its rapidity, harmlessness and objectiveness to detect thermal asymmetries boosted the research and clinical interest to diagnose certain pathologies. Among them, the diagnosis of breast cancer was (and indeed, it still is) one of the main uses. Even if some authors recommended its application as preliminary screening test (Isard et al., 1972) a lot of professionals used it as standalone diagnosis, causing hundreds of false positives because of its lack of sensitivity and specificity (Williams et al., 1990). As a consequence, the reputation of infrared thermography in the health sector was dramatically damaged (Feig, et al. 1997).
Currently, with the technical improvements and its complementary use with other technologies, the sensitivity of thermography to detect breast cancer has increased to 83%, and 95% when complemented with a mammogram (Kennedy, et. Al. 2009).
That is why a correct scientific basis and an extensive knowledge of thermography is absolutely necessary for a proper professional use. We will need objective analysis tools that are reliable to optimize the results avoiding mistakes of associating false diagnoses with skin temperature.
This point is a key factor: the temperature of the skin is related to the energy produced and released by the body; muscles, ligaments, joints and specially the cardiovascular system, which is responsible for distributing more or less blood, creating consequently hyperthermic and hypothermic responses (Hooshmand, et al. 2001; Neves, et. al. 2015).
To sum up, blood flow is the main responsible of showing the consequences of a change in body temperature, either by the influence of the nervous system or by a local event.
Skin temperature is related to muscle activity.
This aspect has special relevance, since the temperature of the skin measured by thermography will be related to (but not necessarily) muscle activity (Escamilla, et al 2017; Chudecka, et al. 2015; Sancibrian, et al. 2016; Cham, et al 2016).
So: the excess of energy released by deep muscles, or those surrounded by fat, has a greater convection path to reach the skin, so its intensity will hardly show up on a thermogram. While, in superficial muscles, closer to the skin, or in subjects with lower percentages of fat, we are going to find a direct relationship between the skin temperature and their activity. For example, in the muscles of the limbs, specially in athletes, thermography is a great tool to observe changes as a result of training, treatments, surgeries, etc. with the aim of evaluate its efficacy and evolution.
The body will generate thermal responses depending on the stimulus. For example, acute problems of a traumatic nature will lead to local inflammation and consequently to hyperthermia. While organic problems related to the nervous system are going to cause hypothermia. For this reason and with the aim of solving or preventing possible pathologies, thermography helps to detect the changes produced in the temperature of the body regions (Sillero-Quintana, et al. 2015)
The body tends to maintain a balance, a concept that in the scientific field is called homeostasis (Uematsu, et al. 1985; Cagnacci, et al. 1997; Vardasca, et al. 2012). Therefore, when we find an asymmetry in any of the body parameters, either in the production of force of one leg with respect to the other, in the speed of contraction of the muscles or in the temperature of the skin, this fact is highlighting an abnormal pattern to follow up.
This is one of the methodological issues on which ThermoHuman is based, a validated software unique in the world for its implementation of artificial vision and machine learning algorithms. This software allows to objectively analyze automatically human thermograms, saving a great amount of time (up to 86% compared to other techniques) and improving the reliability of the analysis (Requena-Bueno, et al 2020), to quantify and represent metrics such as thermal asymmetry in a fast, intuitive and customizable way.
What is the main added value from ThermoHuman?
How much do you value your time? We do, a lot. That is why we have developed ThermoHuman to automatically analyze thermograms, without any manual task. But that’s not all, our reliability is above manual intersubject analysis.
The procedure is simple: you take a thermographic image, access the online platform with your user account, select the subject on which you have made the analysis, upload the photo to the corresponding avatar of the body region and it is already analyzed.
At the end of the automatic recognition, the software shows you the body regions, detecting thermal asymmetries and representing them in an intuitive way into a customized report, with avatars, thermal images, charts and data tables.
The implementation of an intervention protocol based on these asymmetry alarms has been shown to be an effective tool for reducing injuries. In professional soccer teams, a reduction of muscle injuries between 63% (Côrte, et al. 2019) and 70% (Gómez-Carmona, et al. 2020) has been obtained using thermography as an assessment tool.
Furthermore, the scientific results published to date have shown that thermography can be a reliable tool in supporting medical diagnosis (Sillero-Quintana, 2015).
If you are already wondering how I can use it, we will tell you that it is quite simple. You will only need a thermal camera and correctly enable a space to be able to take thermograms. Remember that by capturing the body temperature the evaluation is totally harmless, you can take as many images as you want since it is not invasive and completely safe.
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Requena-Bueno, L., Priego-Quesada, J. I., Jimenez-Perez, I., Gil-Calvo, M., & Pérez-Soriano, P. (2020). Validation of ThermoHuman automatic thermographic software for assessing foot temperature before and after running. Journal of Thermal Biology, 92, 102639.
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