Passive Care Exam 2: CONDENSED

What type of energy is ultrasound?

Acoustical energy (high frequency sound waves)

What is an electrical current passed through a crystal which causes the crystal to vibrate creating sound waves?

Reverse piezoelectric effect

What are the frequencies of sound waves used for ultrasound? Which is used for deep penetration and which is used for superficial penetration?

1 MHz = Deep

3.3 MHz = Superficial

What is the ratio of on time to on + off time expressed as a percent?

Duty cycle

What are the two common duty cycles used for ultrasound?

50% & 100%

What type of ultrasound uses a 50% duty cycle and does NOT create heat?

Pulsed ultrasound

What type of ultrasound has a 100% duty cycle and does create heat in the patients tissues?

Continuous ultrasound

What treatment zone for ultrasound is where the main treatment effect occurs?

Near field zone (Fresnel Zone)

What treatment zone for ultrasound is beyond the near filed zone there is an increase in circulation?

Far field zone (Fraunhofer zone)

How is the intensity of ultrasound described?

ISP (spatial peak intensity)

Or Peak intensity & Spatial average Intensity (ISA)

Or Average intensity

What is the area of the sound head which produces sound energy, with this always smaller than the size of the ultrasound head (but only slightly), as it represents the size of the crystal?

Effective Radiating Area (ERA)

What is the ratio between the peak intensity of the beam and average intensity with ultrasound beams not uniform across the ultrasound head so this ratio shows how much variability there is?

Beam Nonuniformity Ratio (BNR)

What is the ideal BNR? What is the acceptable range?

Ideal = 1:1

Range is 2:1 - 8:1

(lower the better!)

What describes how large the area of peak intensity (hot spot) is on the sound head?

Peak Area of Maximum Beam Nonuniformity Ratio (PAMBNR)

Why do we need a coupling medium for ultrasound?

Air is poor conductor of ultrasound

-- US gel helps transmit the sound waves

What type of ultrasound is when the ultrasound head is in direct contact with the patient? How about when a gel disk or water is between the ultrasound head and patient?

Direct Ultrasound

Indirect Ultrasound

What are the parameters of ultrasound: Amplitude? Frequency? Duty Cycle?

Amplitude = watts/cm2;

(heating)

Frequency = 1 - 3.3 MHz

(depth of penetration)

Duty cycle = pulsed or continuous

T/F: With ultrasound, the more watts, the more penetraton

FALSE

More watts = more heating

NOT greater penetration

What is it called when the ultrasound waves change direction back toward the emitter?

Reflection

What is it called when the ultrasound waves change direction but continue moving away from the emitter?

Refraction

_____C increase causes an increase in metabolic activity.

_______C increase causes reduction of muscle spasm, increases blood flow, and reduces chronic inflammation

_______C increase alters the viscoelastic properties of collagen

1 = metabolic

2-3 = blood flow, reduced muscle spasm & chronic inflammation

4 = viscoelastic collagen

What are the Non-thermal effects of ultrasound?

Tissue healing & alter cellular activity

(stimulate fibroblast, increase blood flow, increase proteins for repair)

What does non-thermal effects of ultrasound happen due to? (2)

Acoustical streaming & Stable cavitation

What is the movement of fluids along cell membranes due to mechanical pressure exerted by sound waves, with the movement occurring int he same direction as the sound waves (microstreaming) and this facilitates fluid movement and increases cell membrane permeability?

Acoustical Streaming

What is the rhythmic expansion and contraction of bubbles during repeated pressure changes over many acoustic cycles that facilitates fluid movement and membrane transport?

Stable cavitation

In ultrasound, what is the size of area that should be treated?

2-3x the size of the ERA

(Effective Radiating Area)

Why must the ultrasound emitter be kept moving while treating a patient?

To minimize effects of hot spots (prevent patient from getting burned)

What is the use of sound energy to drive medications into the tissue?

Phonophoresis (Sonophoresis)

What is the combination of US and Premod where the ultrasound head becomes the treating electrode when using with a dispersal pad?

Combination therapy

What are the 4 indications of Combo therapy?

1) Trigger points

2) Epicondylitis

3) Superficial pain areas

4) Decrease adhesions

What is low intensity US used for fracture healing?

Low Intensity Pulsed Ultrasound (LIPUS)

What is ultrasound applicator that sprays droplets of water across a burn or wound and used for cleaning and debridement?

Noncontact Low-Frequency Ultrasound (NCLFUS)

What is electromagnetic energy that causes heat in body tissues?

Diathermy

What are the two types of diathermy?

1) Short wave diathermy (MC)

2) Microwave diathermy

What two things does diathermy use to cause heating?

Dipole rotation & Ionic oscillation

What is the idea that dipole molecules (like water) rotate to align with the electric field causing friction and heat?

Dipole Rotation

What is the idea that ions in solution oscillate back and forth leading to friction and heat?

Ionic oscillation

Which of the two types of electrodes used in short-wave diathermy produces an electrical field?

Capacitor electrodes (capacitive technique)

Which of the two types of electrodes used in short-wave diathermy produces a magnetic field?

Induction electrodes (inductive technique)

What creates an electrical field which is absorbed by subQ fat so only good for small body parts and thin patients?

Capacitance Technique

What creates a magnetic field which penetrates deeper so its good for larger body parts and heavier patients?

Inductive technique

What law of electromagnetic energy is the "common sense" law where electromagnetic energy must be absorbed to have an effect, and if its absorbed superficially it will have a superficial effect, but if it's absorbed deeply it will have a deep effect?

Grotthuss-Draper Law

What law of electromagnetic energy is dose vs response with low doses stimulating and high doses inhibiting tissue?

Arndt-Schultz law

What law of electromagnetic energy is the greatest amount of energy delivered if the electromagnetic energy is perpendicular to the body part, and if the angle is changed from perpendicular the amount of energy is equal to the cosine of the angle?

Lambert's Cosine Law

What law of electromagnetic energy is the amount of energy received by tissue varies with distance, and if the distance is 1/2 as far, the tissue will receive 4x the dose, but if the distance is 2x as far, then the tissue will receive 1/4 the dose?

Inverse Square Law

What are the 5 interactions of electromagnetic energy with tissue?

1) Transmission

2) Refraction (change of direction)

3) Absorption

4) Reflection

5) Scatter

What are the 3 physiological effects of diathermy?

1) Pain relief (via counterirritation)

2) Wound management (via increased blood flow and increased metabolism)

3) Joint contractures (via increased tissue elasticity and decreased joint viscosity)

What is the 4 step process for the application of short wave diathermy?

1) Test cold/warm sensation

2) Remove jewelry

3) Add 2-3cm layer of towels for spacing

4) Advise patient to remain still

What does the acronym LASER stand for?

light amplification by stimulated emission of radiation

What is an atom with energy that's been added to electrons causing them to achieve a higher energy orbit?

Excited atom

What is when an electron in a higher energy orbit gives up energy as a photon of light, returning the atom to ground state?

Spontaneous emission

What is it called when the number of excited atoms is higher than the number at ground state?

Population inversion

With the application of an external source of power to the lasing medium (pumping of the lasing medium), what does this cause?

Population inversion

What are the 5 steps for the production of laser?

1) Pumping of active medium

2) Population inversion

3) Spontaneous Emission

4) Stimulated Emission

5) Amplification

Which of the three properties of laser light is the same wavelength and all in phase?

Coherence

Which of the three properties of laser light is a single color?

Monochromatic

Which of the three properties of laser light is when photons move in parallel fashion and they don't diverge?

Collimation

What are the 4 types of lasing media?

1) Gas

2) Liquid

3) Solid

4) Semiconductor (diode)

What type of laser is two layers of material in a silicon matrix with a layer of lasing medium between, so the layer interference is reflective so the photons can bounce back and forth and gain energy?

Semiconductor (diode) laser

What 4 things affect depth and penetration of laser?

1) Wavelength

2) Melanin

3) Hemoglobin

4) Concentration

How does wavelength affect depth of penetration?

Longer wavelength = deeper penetration

(900-1000 nm wavelengths penetrate the deepest)

How does melanin concentration affect the depth of laser penetration?

Melanin absorbs laser so darker skin means less depth of penetration

How does hemoglobin concentration affect depth of penetration?

As [hemoglobin] increases = depth of penetration decreases

What is the difference between a superluminous diode or an LED and a laser diode?

Super luminous diodes and LEDs produce noncoherent light

Laser diodes produce coherent light

NOTE: they ALL produce monochromatic collimated light

When applying laser, it should be applied ______ degrees to the skin. It can be in contact with the skin or non-contact. It can also be applied like a _____ (cm by cm) or it can be _________ over the surface of the treatment area?

90 degrees

Grid

Scanning

Do the 4 laws of electromagnetic energy apply to laser?

YES

What are photochemimcal effects which is either photobiostimulation at lower doses of laser or photobioinhibition at higher doses of laser?

Photobiomodulation

What is a molecule that accept energy from photons of laser and are cytochrome enzymes in the mitochondria?

Chromophore

What are 4 cellular mechanisms affected by laser therapy?

1) Movement of Na, K, Ca across membranes

2) Increased RNA synthesis

3) ATP synthesis

4) Leukocyte activity

What effects of laser are cellular effects due to direct interaction of photons with cytochromes?

Primary effects

What effects of laser are cellular effects in the same cell including cell proliferation, protein synthesis, degranulation, GF secretion, ect?

Secondary effects

What effects of laser are indirect responses of distant cells to changes in other cells which have interacted directly with the photons, and these effects are the least predictable?

Tertiary effects

What are the 3 photobiomodulation effects of laser?

1) Pain management

2) Tendinopathy Management

3) Wound management

Which FDA class of lasers is exempt, invisible lasers such as printers and CD players?

Class 1

What FDA classification of lasers is safe for the eyes?

Class 1M

What FDA classification of lasers are visible lasers that are hazardous to the eyes?

Class II

What FDA classification of lasers are divided into a and b lasers with most therapeutic lasers being in the b category?

Class III (a & b)

What FDA classification of lasers is high powered hazardous lasers?

Class IV

What is the recommended safety protocol for laser therapy?

Therapist & patient both should wear protective glasses

How does multi-radiance laser change the dose?

By changing frequency of pulses

-- more pulses (high frequency) = more laser light and higher dose

-- fewer pulses (low frequency) means less laser light and lower dose

What is the cutt-off for changing form low frequency (low dose) to high frequency (high dose) with the Multi Radiance laser?

500 Hz

What is UV used to treat?

Superficial dermatoses (skin conditions)

What is the use of artificial UV light for therapeutic purposes?

phototherapy

What is the use of artificial UV light with a chemical photosensitizing agent for therapeutic purposes?

Photochemical effect

UV light is divided into what 3 regions?

UVA, UVB, & UVC

What requires the use of a natural photosensitizing agent, pso-ralen to enhance the patients erythemal response, which would be weak if exposed to UVA light alone?

PUVA

Which type of UVB is braodband UVB? Narrow Band UVB?

BUVB

NBUVB

Which UV light region is photogermicidal effects (kills bacteria and viruses)?

UVC

How deeply is UV light abosrbed by the skin?

the first 1-2 mm

What are the 4 physiological effects of UV light?

1) Alters cells biochemistry & metabolism

2) cause cell damage & death

3) Inflammatory reaction

4) Increased capillary permeability

How do you know how much UV dose to use?

Test the skin first with the minimal erythema dose (faint redness 24 hours after treatment)

or use Fitzpatrick's Skin Phototypes

What are 4 indications for UV?

1) Psoriasis

2) Atopic dermatitis

3) Vitiligo

4) Mycosis Fungoides

What photosensitizing drugs are used to treat psoriasis?

Psoralens

What mechanism of heat transfer is the direct application of heat or cold?

Conduction

What mechanism of heat transfer is moving air or water particles that swirl around the body part causing heating or cooling?

Convection

What mechanism of heat transfer is used in vapocoolant sprays and cools the skin as it leaves the skin?

Evaporation

What mechanism of heat transfer is the transfer of heat from a warmer surface to a cooler surface through air or a vacuum?

Radiation

What mechanism of heat transfer is the formation of another form of energy into heat?

Conversion

Hydrocollator packs or Paraffin baths are an example of what type of heat transfer?

Conduction

Ultrasound and diathermy are an example of what type of heat transfer?

Conversion