Medical Thermal Imaging Camera Applications
Thermal technology used in the medical industry can spot problems with humans without the need to carry out invasive testing. The devices enable doctors and medical professionals to put patients at ease and find problems such as arthritis, abnormal skin complaints and other problems by detecting hot/cold spots which may indicate problems in the person being tested.
One of the best ways of performing medical evaluations always involves non-invasive testing. It's both easier for the medical professional and is much more comfortable for the patient as it doesn't require in-depth evaluation inside of the body. The thermal imaging camera's usage inside medical applications is rapidly growing because of this reason; thermal cameras allow the medical professional to spot problems with a patient without the need to carry out complex invasive procedures, helping to make diagnosis long before things become a significant problem.
To understand how these cameras work in the medical industry it is first important to understand exactly how a thermal imaging system works.
Thermal Camera Technology: How Does it Work?
One of the most important things you need to know about thermal cameras is that they don't work like you might expect a normal camera to. When we press a button to capture an image on a normal camera, that system sees the world before the lens as visible light and captures exactly what it sees, storing the image on the camera for further usage. A thermal camera does this too, but the way it differs from a normal camera is that it does not see the world as visible light, but instead uses IR (infrared) light to construct a detailed thermal image.
But what is IR light? You might be amazed to know IR is actually around us constantly every single hour of every single day. It is produced by everything from common appliances to our own bodies and exists constantly as part of our ecosystem. Chances are you've never seen it before - IR is completely invisible to the human eyes as our ocular systems simply aren't designed to detect it - but take it from us when we say that it is very much around you constantly. IR is basically the emissivity of an object. Emissivity refers at its most basic level to a degree of heat output by an object and it is this heat distribution that a thermal imaging camera is able to pick up on and display as a thermal image.
In medical applications, the heat of the individual may change dramatically depending on the nature of the ailment affecting the body. Bruising, abrasions, inflammations, viruses and much more can cause rises or drops in body temperature in certain areas and by interpreting this distribution a medical professional can diagnose a problem in a specific area and take action to cure the patient.
Medical Research and Thermography
Thermography is rapidly being adopted as an extremely useful tool in carrying out research into the effects of drugs, charting the effects of pain on the body and can even be used to determine how diseases affect the patient's core body temperature and heat emissivity levels.
The examples below further outline how thermal technology is being incorporated into the work of medical professionals.
Medical Thermal Cameras as a Virus Detection Aid
Humans naturally pick up viruses. Many of them are relatively harmless (apart from making us feel ill for a few days) but some, if left unchecked, have the potential to kill hundreds, thousands or even millions of people. With the constantly growing abilities of humans to travel all over the world in consistently easier ways, clamping down on viruses entering countries before they have a chance to flourish is becoming increasinly more commonplace as the threat of viral epidemics looms.
This is particularly important in various countries as the immune systems of the people living there may not as adapted as those who come from other countries where medical care is much more prevalent. If a person carrying a potentially deadly virus is let into a country unchecked where the humans living there don't have the immune system to cope, an epidemic could easily occur.
In this example, a thermal camera is used to detect victims of the S.A.R.S virus
As you can see by the image above, thermal technology is often used as means to detect spikes in internal body heat. Due to the skin on our bodies constantly adjusting to let heat out into the environment, viral strains in the system can cause spikes in temperature suddenly and this can be picked up on by a thermal imaging system. Although its likely the man above is simply a tad warm from being in a building, the excessive heat around his cheek area (shown as a slightly darker colour) shows that his body temperature may be elevated as a result of contracting a viral strain.
In this case, the camera was deployed to examine potentially victims of SARS, a deadly strain of avian flu that became prevalent in Japan several years ago. To prevent the spread of this disease many airports and other areas deployed the use of thermal imaging systems as a quick way to test people passing through for temperature spikes without the need to carry out extensive invasive testing.
The green spots you can see on the man's face above are there because the FLIR camera used in this application detected that they were the hottest part of his face and used its alarm technology to show the user that excessive heat has been detected. Again, this is no guarantee of the virus' presence but could be a precursor to the virus being inside the human in question.
Thermal Camera Usage in Anaesthetics
Some medical centres around the world are now starting to use thermal imaging systems as a means of checking the use of local anaesthetics. Commonly these types of anaesthetics are applied to a specific part of the body that must be numbed; the patient in question is then pinpricked to see if the anaesthetic has worked and feeling in the operating area has been numbed completely.
This method can have significant flaws though as a patient's numbed area might not extend exactly to where is needed, leading to pain during the procedure. It can also be a significant problem if the patient is not able to communicate due to the effects of the anaesthetic as medical professionals don't always have a fully accurate way of checking the administration of the anaesthetics.
In a case study with FLIR, DR. Ir. Sjoerd Niehof from the Anesthesiology Department of the Erasmus University Medical Center said: "“As a response to the local anaesthetics the blood vassals dilate, a phenomenon called vasodilatation. This leads to an increased blood flow and subsequently to an increased skin temperature in the area affected. In our research we found that in case of a successful regional block the skin temperature rises with 4.5 °C in about 20 minutes. In case of a non-effective block the maximum temperature difference was just 0.8 °C. This difference in temperature increase can be detected and documented using a FLIR thermal imaging camera.”
The thermal camera used in this application can be used to non-invasively look at the heat distribution under the patients' skin. This enables the imager and the medical professional to determine the effects of the anaesthetic regional block, thus making sure that the anesthetic has taken correctly and blocked the area properly. In the image shown above, you can see how the thermal camera used is able to spot the temperature distribution throughout the hand of a patient when anaesthetics were applied.
For more information on the use of medical thermal cameras in anaesthetics, please see the case study attached further below.
Recommended Medical Thermal Cameras
Many thermal cameras are suitable for use in medical applications. Although higher specification models are more suited to evaluations due to higher sensitivity and advanced features, lower-grade models such as the FLIR i3 and i5 are also perfectly suitable for use in the work of medical professionals.
The following is a list of recommended units.
FLIR i7 Thermal Camera
Handheld, portable and capable of producing thermal images at 140 x 140 resolution with high thermal sensitivity, this thermal camera is ideal for use in medical applications and makes it easy to spot temperature distribution throughout the body.
It can spot problems that are completely invisible to the naked eye and includes the ability to download captured images into an included software package for further analysis on a PC. The high sensitivity of this unit makes it simple to spot even minor differences in temperature levels.
An ideal entry-level camera for any medical professional.
Testo 876 Thermal Imager
With flexible, fold-out screen that can be rotated, the Testo 876 makes it easy for the user to adjust the screen as necessary when working at difficult angles.
This thermal imaging camera produces high quality thermal images at resolution of 160 x 120, packing 19,200 thermal measurements points into each image captured. For referencing purposes this camera also includes a digital camera and it comes with advanced features such as high sensitivity, SuperResolution technology that enhances images further and automatic hot/cold spot recognition.
This mid-range camera is more suited to detailed medical research and evaluation.
FLIR B660 Thermal Camera
Available with a selection of lenses for viewing different angles in applications, this superior-grade thermal imaging system is capable of producing extremely high quality, extremely detailed thermal images.
This camera is most suited to extremely detailed research due to its higher price point and abilities. It features a 640 x 480 pixel detector which produces images of practically unbeaten quality, features a wide measurement range, has a built-in 3.2 megapixel digital camera with LED lights, blends together thermal and digital images to enhance detail and can even be used to create panoramic images.
The FLIR B660 is available with either a 12, 24 or 45° lens.
Medical Thermal Camera Downloads
The following is a list of application stories and downloads associated with medical thermal imaging systems.
|Using IR to Detect Elevated Body Temperature||Detecting Small Nerve Fiber Dysfunction||Thermal Cameras and Local Anaesthetics
| Electronics Company, Thermal Cameras and Health
||Anti-Allergy Medicine Effectiveness
||Charting and Combatting Pain with Thermal Cameras