Ptha 1431 Test 3

Front 1

Define Electromagnetic Radiation

Back 1

-electric and magnetic fields which are oriented perpendicular to each other.
-it takes the form of self-propagating waves moving in a vacuum or matter.

Front 2

Describe UV in PT

Back 2

-use of ultraviolet light (electromagnetic energy) for treatment
-EME (abbr. for electromagnetic energy)
-was used in PT; out, coming back
-Light source, not heat

Front 3

What are 3 types of UV bands?

Back 3

-UVA
-UVB
-UVC

Front 4

What is UVA?

Back 4

-long wave
-penetrates deepest
-safest and produces less erythema
-use with psoralen to increase intensity, but not to the point of UVB

Front 5

What is UVB?

Back 5

-middle wave
-Most erythema (redness)

Front 6

What is UVC?

Back 6

-short wave
-ionizing (can deform cells)
-germicidal
-don't use on body (too strong)

Front 7

Effects of UV Radiation

Back 7

-erythema production
-tanning
-epidermal hyperplasia (thickening on skin)
-Vit D. synthèses
-Bactericidal effects

Front 8

Indications for UV Use:

Back 8

-skin disorders
-psoriasis
-vitiligo
-eczema
-acne
-wound healing
**don't use now, earlier PT's got cancer

Front 9

Clinical considerations with UV:

Back 9

-UVA with psoralen is used to treat skin disorders
-Aka...PUVA...psoralen before UVA
-UVB is used, but NOT with psoralen (cream)

Front 10

Contraindications for UV

Back 10

***too much exposure can suppress immune system
-irradiation of eyes
-skin cancer
-most systemic disorders (SLE,TB, Renal and Hepatic pathology, Diabetes M)
-Fever

Front 11

Precautions for UV

Back 11

-photosensitizing medications/supplements (antibiotics)(e.g. St. John's Wort)
-photosensitivity (very pale skin)
-recent X-ray therapy
-If previous dose has not disappeared (skin is still pink or red)

Front 12

List 4 adverse effects of UV

Back 12

-burning
-premature aging of skin
-CA
-eye damage

Front 13

What is done in the 1st treatment of UV

Back 13

checking for sensitivity

Front 14

What is absorption of electromagnetic energy

Back 14

-the taking in and assimilation of the energy

-energy must be absorbed before any physiologic changes can take place

Front 15

What is the most common UV treatment modality?

Back 15

-UVNA with psoralen (aka PUVA)

Front 16

Is psoralen used with UVB?

Back 16

-no, the combination would be too strong and produce burns

Front 17

What is a strip test?

Back 17

used to determine minimal erythemal dose (MED)

strip with 4 holes put on patient's arm, arm under lamp

1st hole uncovered for 120 seconds, then 2nd hole for 60 seconds, then 3rd and 4th for 30 seconds each (total exposure will be 240, 120, 60 and 30 seconds)

patient observes for 24 hours to see which area turns pink or red within 8 hours but disappears within 24 hours--this will be the MED

Front 18

What is SED?
What is MED?

Back 18

***sub-erythemal dose
-minimal erythemal dose...the smallest dose producing erythema within 8 hours and disappearing within 24 hours.

Front 19

What is a 1st degree erythemal dose (E1)?

2nd degree (E2)?

3rd degree (E3)?

Back 19

-MED x 2 1/2

-MED x 5

-MED x 10

****not used in PT

Front 20

What is the procedure with UV?

Back 20

-usually begin at approximately 30 inches from
-Time: as low as 15 seconds: can increase to 15 minutes
-Must wear goggles

Front 21

Shapes of UV strips

Back 21

-rectangular: 10sec...60 sec
-oval: 10sec...50 sec
-triangle: 10sec...40 sec
-circle: 10sec...30 sec
-square: 10sec...20 sec
-diamond: 10sec...10 sec.
****have no clue what the seconds mean

Front 22

Define diathermy:

Back 22

-diathermy is the use of high frequency electromagnetic energy (EME) to produce heat and/or other physiological changes within tissues.

-if thermal, heat produced by vibration caused by resistance of EME entering tissue

Front 23

Thermal & non thermal effects can:

Back 23

-pulse to get non-thermal

-it depends on how frequent pulse is.

Front 24

2 types of medical diathermy

Back 24

-Microwave diathermy
-shortwave diathermy

Front 25

What is microwave diathermy?

Back 25

-2450 MHz
-continuous...thermal, deep
-pulsed...non-thermal
-penetrates up to 3 cm.
***no longer used

Front 26

What is shortwave diathermy (SWD)?

Back 26

-27.12 MHz
-continuous....thermal, deep
-pulsed....non-thermal
-penetrates ups to 5 cm.
***pulsed & non-thermal are not necessarily the same.

Front 27

SWD generates both an ____ & a ____ field

Back 27

-electrical & magnetic

Front 28

In SWD, ratio depends on ____ of _____

Back 28

characteristics of generator

Front 29

What does an inductive coil create?

Back 29

-creates stronger magnetic field than electrical field.

Front 30

What do capacitive plate applicators do?

Back 30

-creates stronger electrical field than magnetic field

Front 31

When EME passes through ___, it causes ____ of charged particles >>>increased ____ ____ energy

Back 31

-tissues
-oscillation
-internal kinetic

Front 32

Is SWD detected?

Back 32

-Initially, it may not be detected, but if current is adequately strong, and as absorption of energy increases, it causes an increase in temperature.
***increased friction (movement) causes heat

Front 33

How does thermal diathermy produce heat?

Back 33

heat is produced by vibration caused by resistance to EME energy entering tissue

Front 34

In what portion of the electromagnetic spectrum does diathermy operate?

Back 34

10 - 100 MHz (book says 1.8 - 30 MHz) - shortwave
300 MHz - 300 GHz - microwave

Front 35

What is continuous shortwave diathermy?

Back 35

-thermal
-deep
-produces heat in tissue
-penetrates up to 5cm (longer wavelength than microwave, penetrates deeper)

Front 36

What is pulsed shortwave diathermy (PSWD)?

Back 36

-non-thermal
-does not produce heat in tissue
-vibrates tissues and causes reactions at cellular level
-penetrates up to 5 cm (longer wavelength than microwave, penetrates deeper)

Front 37

What is continuous microwave diathermy?

Back 37

-thermal
-deep
-produces heat in tissue
penetrates up to 3 cm (shorter wavelength than shortwave, doesn't penetrate as deep)

Front 38

What is pulsed microwave diathermy?

Back 38

-non-thermal
-does not produce heat in tissue
-vibrates tissues and causes reactions at the cellular level
-penetrates up to 3cm (shorter wavelength than shortwave, doesn't penetrate as deep)

Front 39

Means of administering diathermy (equipment types)

Back 39

-capacitive plates
-inductive coil

Front 40

How does inductive coil work?

Back 40

patient is placed in the electromagnetic field

Front 41

Tissue with ___ ___ ___ have higher ___ and tend to ___ in temperature

Back 41

-high water content
-conductivity
-increase

(muscle)...bone/cartiledge wont heat up as much

Front 42

How does the inductive coil work?

Back 42

-AC flows through coil & produces magnetic field perpendicular to current
-coil housed in drum...current flows in coil...producing rotating magnetic field which causes friction/imitation in molecules

Front 43

Set up of capacitive field?

Back 43

-conducting (metal) electrodes encased in plastic housing
-placed close to body part (placed 1-3 inches from patient)( refer to mfr. guide)
-may use towel separating electrodes from pt, esp. with thermal, to absorb preservation
****KNOW*** PATIENT COMPLETES THE ELECTRICAL CIRCUIT. PT IS PART OF THE CIRCUIT, AS ENERGY PASSES FROM ELECTRODE TO ELECTRODE THRU PT.

Front 44

Another name for capacitive field is:

Back 44

-condenser field

Front 45

How do capacitive plates work?

Back 45

-high frequency alternating current flows from one plate to another through pt producing magnetic field perpendicular to it.
-current passes through tissue, causing oscillation of charged particles.
-current tends to concentrate in superficial tissues (doesn't penetrate through fat very well)
***MORE SUPERFICIAL HEATING

Front 46

Microwave diathermy (MWD)

Back 46

-***a form of deep heat
-***can use continuous or pulsed
-***does not penetrate as deeply as SWD
-magnetron oscillator produces high frequency alternating current in antenna, which then produces EME.
-antenna beams EME to patient.
-director (antenna + reflector) must be tuned.

Front 47

Effects of Thermal diathermy:

Back 47

-metabolism increased
-extensibility increased
-pain threshold increased
-vasodilation increased

Front 48

Effects of Non-thermal:

Back 48

-alters cell permeability
-stimulates production of ATP
-increases protein synthesis
-increases microvascular perfusion...capillary beds, increases O2, nutrients & phagocytes.
****Non-thermal works like LASER***

Front 49

Indications for thermal diathermy

Back 49

-muscular skeletal
-pain, sub-acute, chronic
-decreased circulation (esp. with M.S. conditions)
-joint/ST stiffness

Front 50

Indications for Pulsed Diathermy (non-thermal)

Back 50

-edema
-pain
-wounds (incisions, ulcers)
-nerve injury
-bone injury (like stress fracture)

Front 51

Contraindications for diathermy

Back 51

-metal...in the field (even if on table, jewelry)
-pacemaker, other metals, stimulators
-CA
-pregnancy (patient & therapist)
-eyes
-testes
-growing epiphyses (children who still have growing bones)
-obesity (can't conduction thru fat)
-deep organs
-electronic or magnetic equipment in the vicinity
-infectious disease as "treater"-leave area because of metal in wrist.

Front 52

Adverse effects of diathermy

Back 52

-controversy around possibility of EME causing CA or other medical problems
-PT/PTA treating with diathermy have some exposure
-new units do not leak like the older ones.
-some POSSIBLE connection between EME and fetal deformities.

Front 53

Treatment time for SWD and MWD

Back 53

-continuous is 20-30 min
-pulsed is 30-60 minutes.

Front 54

Which means of administering diathermy penetrates muscle best? Fat and bone?

Back 54

-Inductive coil penetrates muscle deepest
-capacitive plates penetrates fat. then muscle (and bone)

Front 55

What ultimately determines whether diathermy heats tissue?

Back 55

amount of energy absorbed by tissue

Front 56

Benefit of SWD for therapist

Back 56

requires little time for application and does not require clinician to be in direct contact with the patient throughout the treatment

Front 57

PSWD uses what type of applicators:

Back 57

-inductive coil applicators
-in drum form or capacitive plates

Front 58

Heating with an inductive coil diathermy applicator is known as;

Back 58

-heating by the magnetic field method

-because the electric current that generates the heat is induced in the tissues by a magnetic field.

Front 59

Amount of heat generated in SWD with inductive coils is influenced by:

Back 59

-strength of the magnetic field
-strength & density of induced electric eddy currents.

Front 60

strength of the magnetic field generated in SWD with inductive coils is determined by:

Back 60

-distance of tissue from applicator

(decreases in proportion to the square of the distance of the tissue from the applicator according to the inverse square law but does not vary with tissue type_

Front 61

What is sound?

Back 61

-propagation of vibratory motion; pressure changes in air or other medium.

Front 62

What is the range of human hearing?

Back 62

16 Hz-20,000 Hz

Front 63

What is the range of ultrasound

Back 63

>than 20,000 Hz.

Front 64

Who can hear ultrasound?

Back 64

bats, dolphins, dogs

Front 65

What is the range of infrasound?

Back 65

<16 Hz. Below what humans can hear.

Front 66

Who can hear infrasound?

Back 66

-elephants, giraffes, rhinos

Front 67

Ultrasound is ___ ___.

Back 67

-mechanical energy

Front 68

List 3 medical uses of ultrasound:

Back 68

1) radiography-imaging of internal structures
2) surgery-destruction of tissue
3) physical therapy-therapeutic US

Front 69

Describe how ultrasound is generated:

Back 69

-Electricity of 110 V (alternating current) (60 Hz) is transformed to a higher voltage.

-Higher voltage >higher frequency

Front 70

An ultrasound unit uses a ___ ___. It is within the sound head or transducer.

Back 70

Piezoelectric crystal

Front 71

Describe the crystal within the sound head.

Back 71

-It may be natural (quartz) or Synthetic (either Plumbum zirconium titanate (PZT) or Barium Titanate.

Front 72

Which type of synthetic crystal is most common in ultrasound?

Back 72

Plumbum zirconium titanate (PZT)

Front 73

Describe piezolectric properties

Back 73

-material which responds to an alternating current by expanding and contracting at the same frequency at which the current changes polarity

-when the crystal expands, it compresses the material in front of it, and when it contracts it rarefies the material in front of it

Front 74

What is conversion in Ultrasound?

Back 74

-is a form of energy transfer.

Front 75

What are the 2 types of conversion of energy with Ultrasound?

Back 75

-electrical energy converts to mechanical energy

-mechanical energy can be converted to heat (thermal) within the tissue. (vibration of molecules).

**remember: electrical to sound; sound to heat.

Front 76

____ and ____ of ultrasound waves affect the crystal and the tissue.

Back 76

-rarefaction
-compression

Front 77

What is rarefaction of molecules?

Back 77

-negative wave phase, crystal contracts and the molecules decompress

Front 78

What is compression of molecules?

Back 78

-positive wave phase, crystal expands and molecules compress. (condensation)

Front 79

What are the Ultrasound frequencies in PT?

Back 79

either 1Mhz or 3Mhz.

Front 80

Which frequency provides a deeper penetration? 1 MHz or 3 MHz?

Back 80

1 MHz. It penetrates up to 5 cm (2 inches). It is a more divergent beam

Front 81

What is the penetration depth for 3 MHZ?

Back 81

1-2 cm. (0.4-0.8 inches) It absorbs quicker so it does not penetrate as deep. It has a more collimated beam.

Front 82

What is the equivalent to 1 Hz?

Back 82

1 cps (cycle per second)

Front 83

What is the equivalent to 1 MHz?

Back 83

1,000,000 cps (cycles per second)

Front 84

What are the two types of wave form used in US?

Back 84

-continuous and pulsed

Front 85

What is the continuous wave form used in therapeutic ultrasound?

Back 85

-delivery throughout the Px. It is thermal.

continuous = heat.

Front 86

What is the pulsed wave form used in therapeutic massage?

Back 86

-deliver of US during portion of cycle. It is non-thermal. No time to build up heat.

pulse=could create heat, but not necessarily.

Front 87

Define Duty Cycle in Ultrasound

Back 87

-is part of the pulsed wave form however, it is
the proportion of total Rx. time that US is ON. Percentage or ratio.

-ex: DC = on 10 ms and off 30 ms.
10/ 10+30= 10/40=1/4=25%.
-ex: DC = on 20 ms and of 20 ms.
20/ 20+20= 20/40=1/2=50%

(DC= Total time on over total time on + off.)

Front 88

What is the importance of beam non-uniformity?

Back 88

peaks in the energy can cause stinging or burning

Front 89

What is Spatial Peak Intensity? (SPI)

Back 89

-greatest intensity anywhere within beam
(usually greatest in center, lowest at edges)

Front 90

What is Spatial Average Intensity? (SAI)

Back 90

-average intensity of US output; measured at short distance from transducer.

Front 91

What does BNR stand for?

Back 91

Beam Non-uniformity ratio

Front 92

What is BNR?

Back 92

the ration of SPI:SAI (Peak to average)

Front 93

What is ratio is considered acceptable BNR?

Back 93

6:1 (or lower)
-It is regulated by FDA. (BNR specks are in the machine manual or the machine itself)

Front 94

The ___ the ratio the more comfortable the US treatment is to the patient

Back 94

lower

Front 95

The higher the BNR ratio is:

Back 95

-the less uniform the beam is. the more uncomfortable the pt is. Higher beams can sting or burn pt.

Front 96

What is the ERA?

Back 96

-Effective Radiating Area.

-it is the area of transducer from which energy radiates.

Front 97

Which is smaller, the ERA or transducer?

Back 97

The ERA. Because the transducer also has an adhesive to keep the crystal in place.

Front 98

Where does the ultrasound transducer release the most energy?

Back 98

-greater amount of energy in center of beam.

Front 99

List 3 ways US beam is transmitted:

Back 99

1) absorption
2) reflection
3) refraction

Front 100

What happens with US absorption?

Back 100

-highest in tissue with high collagen content.
(bone, cartilage, tendon)-most affected.

-the energy continues along a straight line (equal to incidence) into the tissue

Front 101

What happens with US reflected?

Back 101

-beam is redirected away from the surface. (does not enter)

Front 102

What happens with US refracted?

Back 102

-beam changes direction of course (bent)

Front 103

What can cause US reflection?

Back 103

bad contact or bad medium

Front 104

What are the biophysical effects of thermal US?

Back 104

-Thermal..rapid vibration produces heat within tissue.
-It is a continuous wave.
-It is deep heat (1-5cm using 1MHz) or (1-2cm using 3MHz)

Front 105

What is the difference between continuous US vs. a hot pack?

Back 105

-continuous US can increase temp 4 degree C at a depth of 3cm.

-A HP can increase temp 0.8 degree C at depth of 3 cm.

-US up to 5X more effective

Front 106

What are the effects of non-thermal pulsed wave US?

Back 106

there is a small, brief heating effect

-depending on the duty cycle, this heat may or may not dissipate. (will dissipate at 20%, les so at 50%)

Front 107

List 3 effects of non-thermal pulsed wave US:

Back 107

1)acoustic streaming
2) cavitation
3) micro-streaming

these are thought to alter cell membrane permability

Front 108

What is acoustic streaming?

Back 108

-circular flow of cellular fluids induced by ultrasound.

-if put in water, makes waves

Front 109

What is cavitation?

Back 109

-formation and pulsation of gaseous bubbles. During compression, bubbles in the tissue are squashed. During rarefaction, they expand.

-if stable...good

if unstable...bubble explodes...not good

Front 110

What is micro-streaming?

Back 110

-micro-scale eddying occurring near small vibrating object.

-occurs around the gas bubbles set into oscillation by cavitation.

Front 111

What are the effects of thermal ultrasound?

Back 111

-increase metabolic rate
-increase circulation
-increase ST extensibility
-decreased pain
-increase in nerve conduction velocity changes
-decrease in muscle spasm
-mild warmth

Front 112

What are the effects of non-thermal (pulsed) US?

Back 112

-increased skin and cell membrane permeability
-increased macrophage response
-increased protein synthesis
-decrease inflammation
-increased intracellular calcium levels

Front 113

Indications for ultrasound:

Back 113

-soft tissue shortening (that has high collagen-use thermal)
-pain (thermal/subacute or pulsed/acute)
-dermal ulcers (pulsed)
-surgical skin incisions (pulsed)
-tendon & ligament injuries (thermal/subacute or pulsed/acute)
-fractures (special US unit with a lower intensity)
-calcium resorption (bone spurs, frozen shoulder. Not used as much)
-trigger points.

Front 114

Contraindications for US

Back 114

-malignant tumor (not the area)
-pregnancy (over lower back, distal extremities ok)
-over eyes or reproductive organs
-CNS tissue (SC, post laminectomy)
-plastic or cement in joint (metal ok),
-pacemaker
-thrombophlebitis
-complete relief of severe pain
-thermal on pts with impaired sensation

Front 115

Precautions for US

Back 115

-acute inflammation (pulsed ok)
-epiphyseal plates in growing persons
-fractures (low-dose intensity ok)
-over bony prominences
-over breast implants.

Front 116

What are treatment choices for US?

Back 116

-frequency...1 MHZ; 3 MHz
-duty cycle...continuous; pulsing (when in doubt go with 20%)

Front 117

What is the application for US?

Back 117

-requires couplant aka polysonic(gel or water)

-duration///area of 2X the size of the ERA 5-10 min (per cameron).

-cover 1 " sq every 1-2 minutes (Hayes)

Treat smaller areas with smaller head.

Front 118

You need to keep the transducer moving, but how do you decide how fast?

Back 118

if using unit with good BNR (2:1 to 5:1) you can move more slowly, like 1 cm/second

if using unit with poor BNR (6:1-9:1) you need to move it more quickly due to the higher peaks which may sting or burn; use 4 cm/second

Front 119

What is phonophoresis?

Back 119

application of US with topical drug mixed with medium

ex-hydrocortisone cream

Front 120

What are some theories of phonophoresis?

Back 120

-ultrasound pressure drives the drug through the skin

heating increases vasodilation and absorption

increased permeability of the stratum corneum through cavitation enhances absorption (this one is the most cred

Front 121

Why does 1 MHz penetrate deeper?

Back 121

longer wavelengths penetrate deeper

Front 122

What variables do you control in ultrasound?

Back 122

- duty cycle (continuous or pulsed)
- frequency (1 MHz or 3 MHz)
- intensity (0.1 - 3.0 W/cm sq)
- time (5-10 minute treatment)
- size of transducer head

Front 123

What are the intensity parameters for delivery of ultrasound?

Back 123

up to 3 W/cm sq

IN GENERAL:
- if using 1 MHz use about 1.0-1.5 W/cm sq
- if using 3 MHz use about 0.5-1.0 W/cm sq

of course, the above also depends upon patient comfort