1. ELECTROTHERAPY / THERAPEUTIC MODALITIES – 1 Dr/ Amal Mohamed Abd El Baky L. chandrasekar muthusWamy

2. first lecture
First Lecture
4/27/2017

3. Lecture Outline This lecture deals about the following:-
1. Basics of electrotherapy
2. High frequency & EM spectrum
3. Laws governing its radiations
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4. Lecture Objective
At the end of this lecture / unit the students will be able to;
Define Electrotherapy / Therapeutic Modality, Production & physical properties of HFC.
List some of Instruments used in Electrotherapy / Therapeutic Modality.
Describe EMS & Laws governing its radiations.
First Lecture
4/27/2017

5. Introduction - Electrotherapy / Therapeutic Modality
Electro – Electric Current / Electrical Energy.
Modality – Machines/ Equipment's.
Therapy – Treatment.
It means various forms of THERAPEUTIC applications using ELECTRICAL ENERGY as primary source.
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6. Electrotherapy - Definition:
Electrotherapy can be defined as the treatment of patients by electrical means.
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7. FACTS OF ELECTROTHERAPY
All electrotherapy modalities involve the introduction of some physical energy into a biologic system. (Human tissue / Body)
This energy brings about the one or more Physiological changes, which are used for Therapeutic benefit.
In the Clinical environment, firstly to select the most appropriate dose & secondly to apply the treatment.
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8. General uses of Electrotherapy
1. Pain management 2. Treatment of neuromuscular dysfunction 3. Improves range of joint mobility 4. Tissue repair 5. Acute and chronic edema 6. Peripheral blood flow 7. Iontophoresis 8. Urine and fecal incontinence
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9. Classification of therapeutic currents according to frequency
Current in which the direction of electron flow changes periodically with a frequency of Hz.
Low Frequency
Those current of 10,000 Hz or more.
High frequency
Current in which alternate the direction of flow of electrons with a frequency between Hz .
Medium Frequency
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10. Instruments used in Electrotherapy
I-Low & Medium Frequency Modalities
TENS (transcutaneous Electrical Nerve Stimulation)
High-Voltage pulsed stimulation
Neuromuscular Electrical Stimulation
Galvanic Stimulation
Russian current
Faradic current
Iontophoresis
Interferential Therapy (I.F.T)
III-High Frequency Modalities
Shortwave Diathermy (S.W.D)
Microwave Diathermy (M.W.D)
Ultra Sound Therapy (U.S)
Shockwave therapy
IV-Actinotherapy
Infra - red Radiations (I.R.R)
Ultraviolet Radiations (U.V.R)
Laser Therapy
Other Modalities
Continuous Passive Mobilizer (C.P.M)
Traction unit (Cervical & Lumbar Traction)
Paraffin Wax Bath (P.W.D)
Hydrocollator Unit
Hydrotherapy – Whirlpool therapy
Fluido - Therapy
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11. TENS
Ultrasound
LASER
IRR
SWD
UVR
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12. Definition of H.F.C
A high frequency current is a current which alternates so rapidly that it does not stimulate motor or sensory nerves.
High frequency (HF) / radio frequencies are between 3 and 30 MHz.
Oscillating Systems
Oscillation is the repetitive variation
Each day we encounter many kinds of oscillatory motion, such as swinging pendulum of a clock, a person bouncing on a trampoline, a vibrating guitar string, and a mass on a spring.
First Lecture

13. Oscillating system
In an oscillating system such as the oscillation of a simple pendulum, the oscillation does not continue with the same amplitudes indefinitely.
This loss in amplitude is called “damping” and the motion is called “damped harmonic motion”.
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14. compare the motion of un-damped and damped oscillators.x t x t
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15. Physical properties of H.F.Current
An Oscillating current-H.F.Current
Production:- It is produced by discharging a condenser through a low ohmic resistance containing an inductance.
Physical properties of H.F.Current
1. Damping of oscillations
2. Heat Production
3. Electromagnetic waves
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16. Radiant energy
Radiant energy is the energy in the form of waves or rays in the ether.
Waves are set-up in the ether by movement of electrons & are known as Electromagnetic waves.
Sunlight Is A Form Of Radiant Energy
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17. Electromagnetic radiation
They are waves and particles in motion. The energy of the electromagnetic radiation is in the form of oscillating electric and magnetic field perpendicular to one another and to the direction of travel.
If currents in an AC circuit change rapidly, some energy is lost in the form of EM waves
EM waves are radiated by any circuit carrying alternating current
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18. Electromagnetic Waves and Their Propagation Through the Atmosphere
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19. Characteristics / Properties of electromagnetic radiation
Transport energy through space & it carries energy.
Travel through a vacuum or a material substance at a constant speed of 300 million meters\sec
Energy carried by EM waves is shared equally by the electric and magnetic fields
It is categorized according to its wavelength and frequency which are inversely proportion to each other.
Long wavelength-lowest frequency
Short wavelength highest frequency
The higher the frequency the higher the energy.
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20. Wavelength: it is the horizontal distance from one wave beak to the next.
Frequency: it is the number of cycle that occurs in second.(cycle / second) and expressed in hertz.
Amplitude: The magnitude of the maximum displacement from equilibrium is called the amplitude of the motion.
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21. WAVELENGTH & FREQUENCY
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22. General Physiological effects of electromagnetic radiation
Electromagnetic radiation can affect biological system via thermal and or the non-thermal mechanisms.
Infrared radiation and both continuous diathermy(shortwave and microwave) can increase tissue temperature, as they primarily affect tissue by thermal mechanism.
Ultraviolet radiation, therapeutic laser, and pulsed diathermy don't increase tissue temperature and though to affect tissues by non-thermal mechanisms.
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23. ELECTROMAGNETIC SPECTRUM
Electromagnetic Spectrum—name for the range of electromagnetic waves when placed in order of increasing frequency
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25. The electromagnetic spectrum is the entire range of electromagnetic waves arranged according to their frequencies or wavelengths.
Electromagnetic waves all have different properties. But they all travel the same speed – what we call “The speed of light”
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26. Regions of electromagnetic spectrum
Ionizing range :
It includes X-ray and gamma rays.
It can break molecular bonds to form ions.
It can easily penetrate the tissue and deposit its energy within the cell. If the energy is sufficient high the cell division is inhibited and the cell will be killed.
This energy can be used in diagnosis and therapeutically in radiation treatment for some forms of cancer.

27. Non ionizing rang: It includes lower frequency range as light spectrum, diathermy, electric currents it can't break molecular bonds or produce ions. It can be used for therapeutic medical applications.

28. The light spectrum: Diathermy: Electrical currents:
This portion of the spectrum includes ultraviolet, visible light, laser and infrared.
Diathermy:
It is electromagnetic radiation of longer wavelength. It has an intensity sufficient to increase tissue temperature. As shortwave and microwave . These electromagnetic energies create a magnetic field that changed into heat.
Electrical currents:
It lies in range above shortwave. It is used for therapeutic purposes to stimulate muscles and nerves.

29. Physical laws governing the application of electromagnetic radiation
Reflection
Refraction
Absorption
Inverse square law:
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30. The angle of reflection θr equals the angle of incidence θi:
LAW OF REFLECTION
When a ray strikes a new medium which will not transmit it causes the ray to turned back.
The incident ray, the reflected ray, and the normal to the surface all lie in the same plane.
The angle of reflection θr equals the angle of incidence θi:
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32. LAW OF REFRACTION
When a beam of light passes from one medium to other the rays are BENT.
This causes the rays to be deflected from its original course by an amount depending on the medium involved & the angle of incidence.
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33. REFRACTION
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34. LAW OF ABSORPTION
When rays strike the surface of a new medium some may be ABSORBED by the new medium.
The proportion of the rays absorbed depends on the nature of the medium, wavelength of the rays & the angle of incidence.
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35. LAW OF ABSORPTION
When the angle of incidence is 90˚ then NO RAYS will be absorbed as they will be travelling parallel to the surface.
If the angle of incidence is 0˚ then the rays are striking the surface so as to make a right angle with it & the maximum rays will be absorbed.
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36. The angle of incidence is ZERO DEGREES for most effective treatment.
LAW OF ABSORPTION
When applying I.R.R & U.V.R. to the patient greater efforts should be made to ensure that the maximum number of rays strike the surface perpendicularly.
The angle of incidence is ZERO DEGREES for most effective treatment.
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4/27/2017

37. Inverse square law
The relationship between the distance from the source & intensity of radiation is expressed in the inverse square law. All radiations is subject to the inverse square law.
It states that “ The intensity of the radiation from a point source is inversely proportional to the square of the distance from the source
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38. Source d
Full strength 2d
One quarter strength 3d
One ninth strength
Target
The inverse square law. At twice the distance (2d) the intensity is only one quarter of that at the source (d) and at three times the distance (3d), the intensity is one ninth of that at (d)
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39. According to this formula; I = Intensity of radiation
I = 1/ D²
According to this formula;
I = Intensity of radiation
D = Distance travelled by the radiation.
This has greater practical importance.
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40. Cosine law:
When the angle of incidence is 90˚ then NO RAYS will be absorbed as they will be travelling parallel to the surface.
If the angle of incidence is 0˚ then the rays are striking the surface so as to make a right angle with it & the maximum rays will be absorbed.
First Lecture
4/27/2017

41. First Lecture 4/27/2017 The cosine law
Maximum penetration angle of incidence=0 Cos0=1
70% of maximum penetration angle of incidence= 45 , Cos 45= 0.707
Zero penetration angle of incidence= 90, Cos 90=0
surface
The cosine law
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42. The Arndt-Schulz law: -According to this law, a certain minimum intensity of electromagnetic radiation is needed to initiate a biological process. -Beyond a certain level stronger intensity will have a progressively less positive effect and become inhibitory. They would explain the non-thermal effect of electromagnetic radiation.
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