Meditherm cameras are designed and built exclusively for medical / clinical applications including mass fever screening. Meditherm has over 17 years experience in this specialized industry.
Meditherm’s advantage is our experience in physiological testing. The depth of research that has gone into the development of our cameras and the design criteria specific to human testing cannot be matched by any other manufacturer. Our system is easier to use with minimal training. We also provide superior customer support and the operating manual is simple and easy to understand.
- Optimized 11° field of view giving accuracy from 18 m down to 2 m. Allows for rapid movement of multiple people though a large area. Additional FOV available. 17°. 25°. 32°. 50°.
- Optimized frame rate of 7.5 fps giving temperature sensitivity of 0.01°c and increased acuracy Additional Frame rates available: 30 frames per second. 60 frames per second (special quote).
- Easy to use software with Auto ambient correction and Auto averaging of individual persons gives better accuracy with less false positives and false negatives while proprietary threshold fever alarm (audio and visual) reduces the operator training time to one hour.
The system is sold in a mobile configuration. To become totally stand alone mobile and independent an optional battery pack gives 13 hours continuous operation. (no requirement for main power).
The system can also be sold as work station or with a wall or ceiling mounting.
Meditherm is an FDA registered medical device manufacturer and the Meditherm 520 Fever screen system is listed as a class I medical device. (FDA Certificate to Foreign Government is available on request). The systems also carry the CE mark as a class I medical device and comply with the European MDD conformity.
Choosing the Right System
Industrial cameras have a wide range of temperature measurement and as a consequence the sensitivity and accuracy is also spread over a wide range. A medical camera like the Meditherm system has a very narrow range of detection (within the range of human physiology) and so our sensitivity and accuracy is concentrated in this narrow range of IR emissivity and temperature….. which provides higher sensitivity and easier protocols which are not as affected by the outside environmental factors as an industrial camera will be (because of the wide range detected in all industrial applications, emissivity from electrical equipment, lighting, reflective surfaces, sunlight, and other IR sources in the immediate area will affect the results and require the operator to be very skilled as a thermography technician).
Our system is designed and built specifically for clinical use and the detection of physiological IR.
Industrial cameras have many features and functions that are irrelevant to medical applications and actually work against the sensitivity and objectivity of results. Many of these features like edge enhancement, auto averaging and emissivity correction have to be disabled before the camera can be used for applications like fever screening. Many industrial cameras without internal temperature reference calibration require an additional external black body calibration unit (at extra cost).
All industrial cameras have a ‘lens correction’ built in. This is because they use actual lenses (just like normal cameras) to focus and zoom. (in industrial applications they have to look at objects at all distances from very close to very far away) the industrial camera lens will absorb about 17% of the emitted radiation (IR) so this needs to be corrected for by the software. The Meditherm camera does not use standard camera lens, so there is no loss of signal from the object emitting the radiation. We use a small germanium window which does not absorb measurable amounts of the emitted radiation, so we are detecting close to 100% of the IR being emitted from the human body. (no lens correction = better accuracy)
Industrial cameras all have a % of thermal drift. Which they use software ‘averaging’ to compensate for. This does not make much difference to most industrial applications but it is very important when using thermography for clinical applications.
The only way to counter the problems of thermal drift is to have a reference temperature. Industrial cameras do not have a stable reference temperature point. All industrial cameras being used in airports for fever screening should have an outside temperature reference source (black body emitter or calibration emitter) that is seen within each view. (basically an accurate temperature that can be seen by the camera and used to calibrate each frame)
Meditherm has proprietary technology which gives us an internal reference temperature accurate to 1/100th deg c. This handles any thermal drift and calibrates the results on a frame by frame basis End result: more stable results, repeatability, better accuracy and less need to continually alter the range and scale of detection like the industrial cameras which give higher percentages of false positive and false negative results and demand a higher level of training to be operated efficiently.
Our med520 software has developed from over 20 years of medical research and is specific to the appli-cation of mass screening for physiological abnormality. Industrial camera software has been adapted (at best) for fever screening from the industrial application software which is in most instances not suitable or easy to use by untrained operators. Meditherm operating guidelines are available at : http://www.compix.com/TemperatureMonitoring
Help Meditherm technical support is available world wide.
Q. What is Interpolation and how does this relate to definition?
A. Interpolation is when you process the number of available pixels with the software. You can increase the number or decrease the number with software. It can be very confusing to the layman in terms of real definition, resolution and thermography images. The pixel count in normal photographic cameras (mega pixel) tells you how smooth the picture is …. more pixels are generally better (higher definition). This is not the case with thermography.
When talking about thermal definition we need to know not only how many individual temperature measurements have been taken in an image but are they all individually accurate and sensitive to the claimed specifications.
You can have a single temperature measurement (one pixel) which is split into 4 by the software, this effectively increases the definition x4 but you still only have the same amount of temperature data, it just looks smoother visibly.
If a camera is claiming 76,800 pixels (320×240) …… are all of those pixels individual temperature measurements that are accurate and sensitive to the claimed specifications ? Meditherms are. Industrial camera definition is also prone to averaging bad pixels (which have no temperature), and thermal drift, which again averages temperature range pixel to pixel but most significantly there is a trade off between the speed of temperature measurement and the accuracy of measurement of each pixel.
Interpolation can be done in both directions….. making more pixels by splitting them into multiples to show the appearance of higher definition or combining multiple pixels into a single temperature measurement (pixel) with better accuracy.
Q. Why is imaging frame rate important?
A. The longer you leave the detector looking at each pixel the better the accuracy. The faster you run the detector (to take more pixels) the lower the accuracy.
Industrial cameras scan at 30 + frames per second so the accuracy of each pixel is low……(in medical terms) which is why they have the software perform averaging and edge enhancement.
We have slowed our frame rate down to 7.5 frames per second for the specific reason that this is the speed that we can measure each individual pixel (temperature measurement) to the required accuracy ….. so every one of our pixels is a real temperature (and can be counted). There is a ‘trade-off’ between ‘speed’ and ‘sensitivity’.
Faster is not always better !