2. Electromagnetic Waves
• If you have ever tuned in to
listen to a radio ,a spoken
headphone , turned on a light
,hand on X ray taken, felt the
warmth of the sun on your
skin.
• You have experienced
ELECTROMAGNETIC WAVE.
3. Definition
• “Electromagnetic waves are waves
which can travel through the
vacuum of outer space .
• Electromagnetic waves are formed
when an electric field couples with
a magnetic field.
• The magnetic and electric fields of
an electromagnetic waves are
perpendicular to each other and to
the direction of waves.”
5. What is the speed of EM waves?
• All EM waves travel 300,000 km/sec in space.
(speed of light-nature’s limit!)
• EM waves usually travel slowest in solids and
fastest in gases.
Properties of electromagnetic wave
1. All are electromagnetic waves are transverse
2. They do not required any medium to travel though .
3. They travel at speed of 3 multiple by 10 -8 in vacuum.
4. They can all be reflected and refracted.
5. They can all be emitted and absorb by matter.
7. Electro Spectrum
“Frequencies is called the
electromagnetic spectrum.”
• Different parts interacts with matter in
different way
• As wavelength decreases, frequency
increases…
• The ones humans can see are called visible
light, a small part of the whole spectrum.
9. Electromagnetic spectrum
• Includes following types of waves :
• Radio waves
• Microwaves
• Infrared waves
• Visible light
• Ultraviolet
• X rays
• Gamma rays
10.
11. Radio waves
• Radio waves have the longest
wavelengths of all the
electromagnetic waves.
• Low frequency.
• Radio waves are often used to
transmit data and have been used
for all sorts of applications
including radio, satellites, radar,
and computer networks.
12. Radio waves are used in
medicine
• Is used to produce images of soft
tissues, fluid, fat and bone.
Example : MRI and RFA.
• DIAGNOSE MANY PROBLEMS.
Example : helps identify tumors.
• Radiofrequency Ablation (RFA)
uses heat to destroy cancer cells.
13. • Microwaves are radio waves with wavelengths less
than 30 cm and higher frequency & shorter
wavelength
• Cell phones and satellites use microwaves between 1
cm & 20 cm for communication
• Microwaves are useful in communication
because they can penetrate clouds, smoke,
and light rain.
• Microwave also in radar that helps to predict
the weather.
14. Microwave waves are used in
medicine
• Hyperthermia therapy is a type of
medical treatment.
• Microwave ablation: used in
treatment of liver tumor
• Microwave diathermy: used in pain
management
• Transurethral microwave :
thermotherapy used in treatment of
lower urinary tract syndrome
15. Infrared waves:
• Infrared waves are sometimes classified as "near"
infrared or "far" infrared
• Between microwaves and visible light are infrared
waves.
• Can be detected by heat and used in heat lamp.
• Higher energy then microwave and lower the visible light.
• Used daily in remote controls, to read CD-ROMs
• Strong infrared radiation in certain industry high-heat
settings may be hazard to the eyes, resulting in damage
or blindness to the user.
Since the radiation is invisible, special IR-proof goggles
must be worn in such places
Precautions
17. Infrared Imaging in Medicine
• Oncology
• Vascular disorders
• Respiratory disorders
• Skeletal
• neuromuscular diseases
• Surgery
• Tissue viability
18. Visible light
• This is the range of wavelengths from 390 to
700 nm which corresponds to the frequencies
430-790 THz.
• The portion of the electromagnetic
spectrum that human eyes can detect.
You see different wavelengths as
colors.
Blue has shortest Red
is the longest
Light looks white if all colors
are present
19. Visible light use in medicines
• Visible light is also used
in Scanning laser
ophthalmoscope.
• In Endoscopy/ Keyhole
Surgery
20. Ultraviolet Waves
• Ultraviolet waves have the next
shortest wavelength after visible
light.
• EM waves with wavelengths from
about 400 billionths to 10
billionths of a meter.
• Used in tanning beds and
sterilizing equipments.
21. Ultraviolet Waves use in medicines
• Have enough energy to enter skin cells
• Longer wavelengths – UVA
• Shorter wavelengths – UVB rays
• Both can cause skin cancer
• Ultraviolet light is used in treatment of
Psoriasis and Vitiligo
• Pregnancy
• Abnormalities in the heart and blood vessels
• Organs in the pelvis and abdomen
• Symptoms of pain, swelling and infection
22. Can UV radiation be useful
• Helps body make vitamin D for
healthy bones and teeth
• Used to sterilize medical supplies &
equip
• Detectives use fluorescent powder
(absorbs UV & glows) to find
fingerprints
23. X Rays • High wave energy
• Used in :
Medicines Industry
Transportation
• To much exposure can damage the
living tissue or even cause cancer
• X-rays play an important role in
dentistry and orthopedic
investigation.
• They can penetrate soft tissue like skin and
muscle.
• Are used to take X-ray pictures of bones in
medicine.
24. • Gamma rays the highest
energy electromagnetic
waves
• The actually come from
radioactive elements or
stars
• Inspection tools in industry
25. Positron Emission Tomography (PET) is a nuclear
medical imaging tool which used gamma rays.
• Example :
• Neurological diseases such as Alzheimer’s and
Multiple Sclerosis
• Effectiveness of treatments
• Heart conditions
• Gamma Knife uses beams of highly focused
gamma rays to treat tumors or other
abnormalities in the brain.
• Gamma rays can check how far a cancer has
spread and how well treatment is working.
