OK, I have resisted saying too much on this topic as it is not in my realm of experience. I can, however, provide some insight into the use of one of my better thermal cameras that was sold to a Doctor who specialises in thermography of the human body. He claims to be able to identify all manner of illnesses through the use of detailed thermography in association with bespoke image analysis software written especially for him by a company in Germany. The Doctor needed my NEC AVIO TH7302W static "Box" camera as the analysis software was written for it. That camera falls into the "professional" category with excellent imaging, measurement accuracy and flatness of field. The Doctor suggested these aspects were essential for medical imaging of the human body. The camera was also manual focus and this permits a nice sharp image of the test subject for optimum image quality.
Now some thoughts on thermography of the human body.....
To evaluate the skin temperature the test subject must not have any clothing covering the region of interest and should be in a room with an ambient temperature that does not trigger a response form the body that draws its thermal energy into its core organs and away from the skin. The skin is a very large organ and part of the bodies thermal regulation process. As such the surface temperature of skin can vary greatly depending upon many variables including ambient room temperature, draughts, stress, illness and blood alcohol level. When carrying out thermography of the human body you only see the surface in terms of detail. Veins stand out because they are just below the surface and warmer than the surrounding flesh and skin. A thermal camera does not provide detailed insight into the bodies blood circulatory system where it is located deeper in the flesh. It is possible to image the inadequate circulation to body extremities such as hands, fingers, feet and toes but detailed imaging the point of circulation constriction is unlikely to be possible. In general the human body will present itself as a surface that varies a few degrees in temperature depending upon how close to the surface blood is flowing. Classically a human loses heat through their head and thighs and these will show hotter than the abdomen. The hands/fingers and feet/toes will often show cooler as they are extremities of blood circulation. From what I understand Reynauds disease effects the circulation and so temperature of the hands and feet. This should be clearly visible on most thermal imaging cameras as the effect is pronounced in many cases.
Sadly images of other parts of the human body may provide far less obvious changes in temperature, if indeed Reynauds effects them as well. The blood flow is deeper under the surface and sometimes the fatty layers preclude detailed imaging. It is when examining these more challenging areas of the body that a thermal camera with good imaging and measurement performance is needed. In medical imaging it is not uncommon to use cooled MWIR thermal cameras as these offer great sensitivity and very low noise imaging. An uncooled microbolometer based thermal imaging camera can still provide some useful imaging but it is more limited in terms of sensitivity and image noise content that can interfere with the diagnostic process.
I would advise against spending large sums of money on a professional thermal camera setup as much of the diagnostic process relies upon image interpretation by those with significant experience in body thermography and illnesses that may be detected and profiled by such technology. For general interest in your bodies thermal profile and behaviour to various stimuli, any of the modern budget thermal cameras on the market can provide basic imagery. Infiray, Hikvision, Guide Sensmart and UNI_T all offer budget cameras with resolution just under QVGA (256 x 192 pixels). At close range the imaging will show warmer and cooler areas of the body, but little detail in the thorax region. I personally recommend a camera that provides manual focus to enable the sharpest possible imaging of your skin at various distances. Fixed focus cameras do work but are a compromise solution with less than optimum focus at most distances. Image analysis software on a PC is very useful for post image collection analysis and measurement. Carrying out image analysis on a camera or phone is far from ideal due to the small display size.
I do not know what you hope to achieve with the thermal imaging that you collect of your body but I wish you well with the exercise and hope it helps you. You may wish to talk to you doctor about the idea and please be careful if self-diagnosing without the training and experience of a specialist Doctor.
With all that said, thermography of the human body can be great fun. If you image a person before and after they have been in cold water, you see how the human body tries to cope with the 'threat' to its core temperature. Arms and legs become cold as blood is diverted to keep the core at operating temperature. In a runner you can see the work that certain muscles are doing and when out in cold weather the benefit of wearing a warm hat may be clearly seen
The human bodies thermo-regulation system is very clever indeed and responds to perceived threats to the core temperature quickly as otherwise Hyperthermia kicks in and the body fails.
One thing people keep asking me is whether a thermal camera can measure a human body core temperature. The simple answer is NO, not directly. Core temperature may be estimated or predicted using well studied regions of interest such as in the corner of the eye, nearest the nose, Temporal Artery and inside the ear canal. Those temperatures reflect core temperature because of good blood flow from the core. If core body temperature drops very much, you begin to die ! Core temperature should remain within quite tight limits if you are healthy.
All good fun
Fraser
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