Modalities Unit 2 - Electromagnetic Radiation

- Infrared

- Ultraviolet

- Laser

- Diathermy

What are the physical agents that deliver energy in the form of electromagnetic radiation?

Electromagentic Radiation

______ ______ is composed of electric and magnetic fields that are oriented perpendicular to each other and do not require a medium.

According to frequency and wavelength.

How is electromagnetic radiation categorized?

True

T/F

Frequency and wavelength are INVERSELY proportional.

Low Frequency Waves

- SW

- MW

- IR

- UV

- Visible light

_____ _____ _____ are non-ionizing and cannot break molecular bonds or produces ions, so therefore can be used for therapeutic purposes.

Imaging

What is the use of high frequency EM radiation (x-rays, gamma rays)?

- Low frequency

- Low energy

EM waves with long wavelengths have ______ ______, and therefore have _______ ______.

- High frequency

- High energy

EM waves with short wavelengths have ______ ______, and therefore have ______ ______.

Wavelength

What is the distance between the peak of one wave and the peak of the next wave?

Frequency

What is the number of wave oscillations or vibrations per second (Hz, CPS, PPS)?

Wavelength x Frequency = Velocity

How do you calculate velocity?

When sufficient electrical or chemical forces are applied to any material.

When are electromagnetic radiations physical characteristics produced?

ALWAYs in a straight line.

What is the direction of travel of electromagnetic radiations?

True

T/F

Electromagnetic radiations travel readily through space at an equal velocity (300,000,000 meters/sec).

Electromagnetic Spectrum

What is the representation of various wave energies arranged in order of their wavelength, frequency, or both?

- Longer

- Shorter

The ______ the wavelength, the lower the frequency; the ______ the wavelength, the higher the frequency.

Wavelengths that are the shorter wavelength end of cosmic rays extending to the lower wavelengths of the electrical currents utilized in clinical use.

What does the electromagnetic spectrum include?

Right angle

Ideally any radiated material should be at a _______ ______ to the wave for maximal absorption.

- Short wave diathermy (SWD)

- Microwave diathermy (MWD)

- Ultraviolet (UV)

- Laser treatments

What are the different waves?

- Reflected

- Transmitted

- Refracted

- Absorbed

What are the different transmissions when entering biological tissue?

- Angle entering the tissue

- Type of tissue

What is the transmission of a wave dependent on?

False - HIGHEST speed

T/F

Electromagnetic waves travel through a vacuum at one of the lowest speeds.

Velocity DECREASES.

What occurs to the velocity as the diversity of the medium increases?

Grotthus-Draper Law

_____ _____ _____ states that waves of different wavelengths produce different effects, and the extent of the effect will be determined by the amount of energy absorbed by the tissue.

True

T/F

Only the waves that are absorbed can cause secondary effects.

It must be transmitted to the deeper tissues.

Keeping Grotthus-Draper Law in mind, if the energy is not absorbed what must occur?

There is less transmitted; therefore, less penetration.

Keeping Grotthus-Draper Law in mind, what happens when there is a great amount absorbed?

Yes

Does the quality of skin affect the absorption of radiant energy?

Reflects

Does dry, pale, scaly skin reflect or absorb more energy?

Absorbs

Does oily, darker, smooth skin reflect or absorb more energy?

- Inverse Square Law

- Cosine Law

- Bunsen Roscoe Law of Reciprocity

What are the 3 laws that govern the dosage of radiant energy the tissue receives?

Inverse Square Law

The ______ ______ _____ states that the intensity of the wave varies inversely with the square of the distance between the source of the energy and the absorbing tissue because of the divergence of tissues. In other words, if the distance is doubled, then the light will be 1/4 the intensity.

E = Es/D2

- E = energy received by the tissue

- Es = energy produced by the source

- D2 = square of the distance between the target and the source

What is the inverse square law formula?

Four

Inverse Square Law:

Doubling the distance between the tissue and the target decreases the intensity by a factor of ________.

Cosine Law

The _____ _____ states the maximum absorption of radiant energy occurs when the source is at right angles to the absorbing surface.

When they strike the surface on the perpendicular.

How do you get the most absorption of rays?

Decreased

As the angle between the beam and the perpendicular is increased, efficiency is ________ in proportion to the cosine of the angle.

Effective energy = Energy x Cosine of the angle of incidence

What is the formula for cosine law?

Decrease

Electromagnetic energy is most efficiently transmitted to the tissue when it strikes the body at a RIGHT angle, and if this angle of incidence deviates then the intensity of the radiation affecting the tissue will ________.

Bunsen Roscoe Law of Reciprocity

What law states the intensity and duration of the dose of radiant energy are inversely proportional?

Decrease the duration

What must you do to reach the same amount of energy when you increase the intensity?

Lengthen the duration

What must you do to reach the same amount of energy when you decrease the intensity?

- Frequency

- Wavelength

- Intensity

What are the effects of EM treatments dependent upon?

- Infrared

- Visible Light

- UV

- Shortwave

- Microwave

What are the clinical uses of EM?

Infrared

What is superficial heating without direct contact to the body?

UV

What produces erythema, tanning, and epidermal hyperplasia and is essential for vitamin D synthesis, and is used primarily to treat psoriasis?

Cold Lasers

What are used to improve cellular effects, alter nerve conduction, and regeneration?

Shortwave & Microwave Energy

What produces heat in deep tissues and may decrease pain, edema, and facilitate healing by non-thermal mechanisms?