Under Medical Imaging I presented in Lakehead University winter semister 2019

1. THERMAL IMAGING AND ITS
APPLICATION
MD HAFIZUR RAHMAN
MSC IN CHEMICAL ENGINEERING,
LAKEHEAD UNIVERSITY, ONTARIO,
CANDADA
md.hafizur.rahman@gamail.com

2. Overview of Presentation
 Introduction
 Development history
 Physics of Thermal Imaging
 Medical application
 Comparison
 Other application
 Pros and cons
 Future development
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3. Introduction
 Thermal Imaging is the technique of using the heat given off by an object to
produce an image
 It is an infra-red imaging science
 First developed for military use purpose in the late 1950s and 1960 by Texas
Instruments, Hughes Aircraft and Honeywell
 In recent times it is being used in firefighting, low enforcement, medical, security
and many other industrial applications.
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4. Development history of Thermal Imaging
 1800: Infrared Discovered astronomer Frederick William Herschel
 1878 :American astronomer Samuel Pierpont Langley invented the bolometer
 1913: First Civil Application of Thermal Detecting
 1929: First IR Electronic Camera Invented
 1945: Near-Infrared Used by WWII Snipers
 1947: First Infrared Line Scanner
 1978: Microbolometer developed
 1982: Thermogarphy Approved to Detect Breast Cancer
 1987: Thermal Goes Mainstream (…movie Predator was released)
 1990s: Fire Departments Adopt Thermal Cameras
 2010s: IR-Embedded Testing Equipment
 2016: First Thermal Smartphone
https://www.newequipment.com/technology-innovations/brief-history-thermal-cameras/gallery?slide=12
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5. Physics of Thermal Imaging
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http://www.physicscentral.com/explore/action/infraredlight.cfm

6. Physics of Thermal Imaging
https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook
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7. Black Body radiation:
Every object at any given absolute temperature above 0 K emits radiation. The
maximum radiant power that can be emitted by any object depends only on the
temperature of the object.
1. A blackbody absorbs all incident radiation, regardless of wavelength and
direction.
2. For a given temperature and wavelength, no surface can emit more energy than a
blackbody.
3. Radiation emitted by a blackbody depends on wavelength.
Sources: Incropera, F.P. and DeWitt, D.P. (1996) Fundamentals of Heat and Mass Transfer,4th edn, JohnWiley & Sons, Inc.,New York.
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Physics of Thermal Imaging

8.  Kirchhoff's law of thermal radiation : The amount of radiation absorbed by any
object is equal to the amount of radiation that is emitted by this object. This is
usually written in the form ε = α
 Stefan–Boltzmann law : Energy radiated per unit surface area (also known as the
black-body radiant emittance) is directly proportional to the fourth power of the
black body's thermodynamic temperature
Source: Incropera, F.P. and DeWitt, D.P. (1996) Fundamentals of Heat and Mass Transfer, 4th edn, JohnWiley & Sons, Inc., New York.
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Four Basic Laws of Thermal Radiation

9. Planck’s law:
The radiation emitted by a blackbody as a function of temperature and wavelength.
The famous equation named after him (Planck’s equation) given.
http://spie.org/publications/tt48_151_blackbody_plancks?SSO=1
Kenneth Krane. Modern Physics, 3rd ed. Hoboken, NJ, USA: John Wiley & Sons, 2012.
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Four Basic Laws of Thermal Radiation

10. Four Basic Laws of Thermal Radiation
Wien’s displacement law :
The wavelength for which the
emissive power density of a black
body is maximum is inversely
proportional to its (black body)
absolute temperature.
Wien's Law is expressed simply as:
λmax × T =2.8978×10-3 mK
http://spie.org/publications/tt48_151_blackbody_plancks?SSO=1
Kenneth Krane. Modern Physics, 3rd ed. Hoboken, NJ, USA: John Wiley & Sons, 2012.
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11. Thermal radiation detectors
 Bolometers : It is a sensor that absorbs
thermal radiation, and changes resistance
and this change can be electrically
measured
 Thermopiles : A thermopile is an
electronic device that converts thermal
energy into electrical energy. It is
composed of several thermocouples
 Pyroelectric : Temperature fluctuations
produce a charge change on the surface
of pyroelectric crystals, which produces
a corresponding electrical signal.
https://www.micro-hybrid.de/en/products/ir-components-and-systems/pyroelectric-detectors.html
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12. Data processing
 Pick up Infrared signal
 Amplify
 Convert to useable information
through calculations
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Source: Sensors 2014, 14, 12305-12348; doi:10.3390/s140712305
https://www.mdpi.com/1424-8220/14/7/12305
Stefan-Boltzmann’s law

13. Image as surface temperature
 All objects emit infrared energy as a heat
signature.
 An infrared camera detects and measures the
infrared energy of objects.
 The camera converts that infrared data into
an electronic image that shows the apparent
surface temperature of the object being
measured.
https://www.fluke.com/en-ca/learn/best-practices/measurement-basics/thermography/how-infrared-cameras-work
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14. Medical Application- Thermal imaging
 Areas of the body that are more metabolically active and have more blood flow,
will produce more heat as well as infrared rays and will be visible on the
thermography.
https://knoxvillereflexology.com/the-study-of-heat/
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15. 15
Fig (a, b) illustrated the thermogram
of the palm region.
(a) In a control subject metabolic
function of the body and good
perfusion of the blood, the skin
temperature of the palm indicates
35.2 ° C.
(b) A diabetic object, the palm temperature was lower due to poor
blood perfusion and decreased metabolism. The skin temperature was
33.0° C in the diabetic subject.
https://www.researchgate.net/publication/312222298_Thermal_Imaging_in_Medical_Science
Medical Application

16. Medical Application
RSD is an older term used to describe one form of
Complex Regional Pain Syndrome (CRPS).
https://www.sciencedaily.com/releases
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17. Source: http://www.tiofsw.com/thermal-imaging/thermography-gallery/
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Medical Application

18. Early cancer detection
 In a cancer cell metabolism is more than normal cell and for that blood flow
is very fast in that area.
 Increased blood flow makes skin temperature increase. This rise in skin
temperature is helping the cancer cell area detection in thermography
Other post medical applications
 Monitoring healing progress
 Monitoring changes in overall heath
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https://www.breastcancer.org/symptoms/testing/types/thermography
Medical Application

19. Comparison with Mammography
Mammography Thermography
High rate of false positive Provide information on the root case of cancer also high rate of false
positive
Result in unnecessary biopsies and treatment Detect the growth of cancer cells prior to tumor formation
Subject patients to pain and consideration
cumulative radiation exposure
No radiation
Early detection method. When breast tissue
abnormality become evident
Early detection method, when abnormal vascular patterns and
temperature changes are deteted, generally much earlier than tissue
abnormality is visible
Imaging has ability to locate an area of
suspicious tissue
Focuses on physiologic changes, changes in temperatures and vascular
activity that could indicate abnormal activity of that area
Heath Canada approved Health Canada not approved yet.
http://www.breastthermography.com http://tbrhsc.net/breast-cancer-screening-an-informed-decision/
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20.  Fever screening (HINI, SARS)
 Fever inspection of patients or
travelers
https://reductionrevolution.com.au/blogs/news-reviews/69333381-over-60-unexpected-uses-of-infrared-thermal-imaging-camera-images
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Medical Screening

21. https://www.mdpi.com/1424-8220/14/7/12305
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Medical Imaging

22. Other Applications
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 Heat loss from home
 Leak detection in process industries (OGI)
 Aerospace/astronomy
 Defense and security
 Firefighting
 Inspection/maintenance
 Night vision
 Remote sensing
 Search and rescue

23. Pros and cons
Pros Cons
1. Non-invasive and non destructive
2. Can detect earliest of affected tissue
3. Less time and cost less than other
imaging.
4. Other than medical imaging it has a lot
of industry applications
1. Quality camera expensive and cheaper
are only 40X40 up to 120X120 pixel
2. Image can be difficult to interpret
accurately
3. Most camera have +/-2% accuracy or
worse in measurement
4. Only able to detect surface temperate,
source of affected tissue can not be
identified
http://www.rfwireless-world.com/Terminology/Advantages-and-disadvantages-of-Thermal-Imaging.html
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24. Future development
 Detector performance and reduced noise
 Better resolution [existing resolution of 40X40 till 120X120 pixel ]
 Lightweight systems and transformation of solid state detector
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https://www.researchgate.net/publication/312222298_Thermal_Imaging_in_Medical_Science

25. Thank You!
Thermal Imaging
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