Infrared thermography helps to measure, chart and combat pain
To be able to chart pain, to describe it precisely and in accordance with clear criteria this is what doctors dream of and patients yearn for.
The Erasmus Medical Centre (ErasmusMC) in the
Netherlands, the university hospital of Erasmus University, Rotterdam,
is working on measuring pain and carrying out research on the combating
In the ErasmusMC’s pain treatment centre,
anaesthesiologists, neurologists, rehabilitation specialists, clinical
psychologists and physiotherapists are working together. Under the
leadership of anaesthesiologist Dr F.J.P.M. Huygen, they are engaged in
diagnosing and treating chronic, acute and oncological pain.
In this multidisciplinary environment, research is
also being performed into the causes, intensity and distribution of pain
as a symptom – does it involve an attack on nerves, pain nerve cells
that react to disorders of blood supply? What is the relationship
between pain, bodily temperature and the extent to which tissue is
supplied with blood?
An FLIR Systems infrared camera is used as a measuring tool to help answer these questions. ”Thanks to the skin’s high level emissivity, the human body is an object that rewards investigation using an infrared camera.”, says Sjoerd Niehof, clinical physicist and user of the FLIR Systems infrared camera. ”It can produce an image of the blood supply to the limbs, up to and including the influence of capillaries.” The camera in the pain treatment centre, a FLIR Systems SC 2000, detects variations in temperature of less than 0.08°C.”
Complex Regional Pain Syndrome
One project in which the FLIR Systems camera is
being used as an objective measuring tool, is research into the Complex
Regional Pain Syndrome (CRPS). A syndrome that resembles an inflammatory
reaction and develops following a (minor) traumatic event, such as an
injury, fracture, trauma or operation. This syndrome is accompanied by,
among other things, demonstrable changes in the blood supply to the
skin, resulting in an altered skin temperature and characteristics such
as oedema, reduced mobility and ongoing pain.
A qualitative measurement of the pain can be effected by means of a combination of questionnaires, thermography and other methods of measurement. But can thermography also help to establish the quantitative intensity of the pain? In other words, is there a connection between quantitative changes in skin temperature and the intensity of the pain syndrome in these patients?
Can thermography measure pain?
The research team, led by project manager Dr Freek J. Zijlstra, set up an experiment. They compared the temperature of the hands of CRPS patients and healthy volunteers at different environmental temperatures.
”You obtain an outstanding indication by the colour variations in the infrared image”, says Sjoerd Niehof, “but to obtain a more detailed analysis of the images, you need investigative software, that can process and analyse the underlying temperature levels.”
Anaesthesia, a new field of application for IR in the world of medicine?
The multidisciplinary approach adopted by the pain
treatment centre in Rotterdam opens up possibilities for experimenting
with new fields of application for thermography. And this approach also
ensures sensational results.
An infrared camera proves to be capable of
visualising the effectiveness of local anaesthesia of a limb and of
monitoring it over time2. Of course, a great deal of research is still
needed in order to develop the necessary parameters and systems. But it
is conceivable that infrared cameras could develop into a vitally
important anaesthetic instrument that could be used to make the
effectiveness of local anaesthesia more predictable than is the case
with the current pinprick and ice pack method. Localisation and
monitoring of a local regional blockade would then help to ensure more
precise dosing of the anaesthetic, which would lead to a significant
reduction in the time involved and possibly to a reduction in the risk
for the patient to be operated on.
”The camera is particularly sensitive, objective, reproducible and reliable”, says Dr Zijlstra, research coordinator in the Anaesthesiology Department. Dr Zijlstra still remembers infrared images from earlier research at the end of the 1980s, when an infrared camera still took up a large part of the research area.3” ”And”, he adds, “cameras of this kind, with advanced hand-held systems now coming on stream, entice us into exploring new areas of research.”
Read More Application Stories