ultrasound & shockwave Flashcards
(83 cards)
1
Q
Ultrasound frequency Is higher than sound human can hear. T or F.
A
- True
2
Q
What is the ultrasound frequency?
A
- 20,000 cycles per second or hertz
3
Q
What is seen at the inner end of the transducer head?
A
- piezoelectric head
4
Q
AC stands for
A
Alternating current
5
Q
Ultrasound is produced through ____ through ______
A
- Reverse piezoelectric effect
- Through application of high frequency AC to a piezoelectric crystal
- Causes mechanical change to piezoelectric crystal
6
Q
Most commonly used piezoelectric material
A
- Plumbium zirconium titanate
7
Q
All types of piezoelectric material used
A
- Plumbium zirconium titanate
- Quartz
- Barium titanate
8
Q
When crystal expands
A
- It compresses material in front of it
9
Q
When crystal compresses
A
- It rarefies the material
10
Q
Alternating compression-rarefaction is
A
- Ultrasound wave
11
Q
Outside crystal is the
A
- Plate
12
Q
Fresnel zone is the
A
- Near field
13
Q
Describe the fresnel zone
A
- Absence of divergence
- Maxima and minima are close to each other
14
Q
Length of near field depends on
A
- Diameter of treatment head
- Frequency
15
Q
Fraunhofer zone is the
A
- Far field
16
Q
Describe the fraunhofer zone
A
- More divergent
- Nearly absent interference that gradually decreases with increasing distance to transducer
○ Decreased with increasing distance to transducer
○ Practical application: underwater technique
- Nearly absent interference that gradually decreases with increasing distance to transducer
17
Q
Body tissue should be in which field
A
- Between near and far field
- Has nicest sound wave
- Not too divergent or convergent
18
Q
Ultrasound is attenuated in the tissue by
A
- Absorption, reflection, refraction
19
Q
Attenuation
A
Decreasing US intensity as wave travels through tissue
20
Q
Attenuation is greatest with
A
- High collagen content
High US frequencies
21
Q
Critical angle of Ultrasound
A
- 15 degrees
22
Q
Ultrasound heats tissues with
A
- High collagen content
- High absorption coefficient
23
Q
What are tissues with high collagen content
A
- Tendons
- Ligaments
- Joint capsules
- Fascia
24
Q
Ultrasound is ideal for muscles. T or F.
A
- False
25
For thermal effects, US should be in what mode?
- Continuous
26
Thermal effects of US
- Increase metabolic rate
- Reduction of pain and spasm
- Inc nerve conduction velocity
- Inc in blood flow
- Inc tissue extensibility
27
Non thermal effects is given in what mode?
- Pulsed mode
28
Non-thermal effects
- Inc cell membrane permeability
- Inc intracellular calcium ions
- Promotes macrophage responsiveness
- Inc protein synthesis by fibroblasts
29
Acoustic streaming
- Steady circular flow of cellular fluids induced by US
- Reason for US being used in phonophoresis
○ US pushes meds into body
30
Cavitation
- Formation, pulsation and growth of gas-filled bubbles
- Responsible for cell permeability
- Macrophages and fibroblasts
31
Micromassage
- Microscopic movement or oscillation of body fluids and tissues
32
Indications for thermal
- Pain
- Before stretching shortened soft tissues
- When needs increase of blood flow
33
Indications for non thermal
- Accelerate tissue healing
○ Ulcers, surgical skin incisions, tendon injuries, bone fractures
- Phonophoresis/sonophoresis
○ Transdermal localized drug delivery
34
Mild thermal effects increase body temp by
- 1 degree
35
Mild thermal effects are for
- Subacute injury hematoma
36
Moderate thermal effects inc body temp by
2 deg
37
Moderate thermal effects are for
- Chronic inflammation
- Pain
- Trigger points
38
Vigorous thermal inc body temp by
- 4 degrees
39
Vigorous thermal is for
- stretching
40
Patient shouldn't feel anything during US. T or F.
- False, pt should feel warmth
41
Parameters of US
- Frequency
- Intensity
- Duty cycle
- Treatment duration
- Effective radiating area
42
Duty cycle for continuous is
- 100%
43
3 mhz is used for
- Superficial
44
Max temp achieved is higher in
- 3 mhz
| - Because nearer and more concentrated target area
45
High frequency usually partnered with
Low intensity
46
Higher temperatures in achieved in tissues with
- High collagen content
47
Depth of penetration for 3mhz
1 to 2 cm deep
48
Depth of penetration for 1 mhz
Up to 5 cm deep
49
In near field, energy distribution is uniform or not uniform?
- Not uniform
50
In far field, energy distribution is
- Uniform but more divergent
51
For non-thermal effects duty cycle usually starts at
- 20% for acute stage
52
If targeting thermal effects, pt should feel
- Warmth that is very mild
53
Usual intensity in clinics is
- 1.5 W/cm2
54
Beam non-uniformity ratio is
- Ratio of spatial peak intensity to spatial average intensity
55
Spatial average intensity is
- What you set on machine
56
If BNR is 6:1, and you set US to 1.5 w/cm2 what is the spatial peak intensity?
- 9 W/cm^2
57
When shortened soft tissues, what setting will you do
- 0.5-1.0 W/cm^2, 3mhz, 5-10 mins
| - 1.5-2.5 W/cm^2, 1 mhz, used for 5-10 mins
58
Stretching is recommended to be applied during heating and maintained for 5-10 mins after US. T or F.
True
59
For painful areas, setting is
- 0.5-3.0 w/cm^2, 1 or 3 mhz, for 3-10 mins
60
For wound healing, setting is
- 0.5-1.0 w/cm^2, 3mhz, 20% duty cycle for 3-10 mins
- Surrounding wound
- Can be underwater technique
61
For acute tendon and ligamental repair, setting is
- 0.5-1.0 w/cm^2, 3 mhz, pulsed mode
| - Accelerates tissue healing
62
For chronic tendon and ligamental repair, setting is
- High enough intensity to increase tissue temp in continuous mode
- To address tissue shortening
63
For bone fracture, setting is
- 0.15 w/cm^2, 1.5 mhz, pulse mode 20% duty cycle, 15-20 mins
64
For carpal tunnel syndrome, setting is
- 0.5-1.0 w/cm2, 1 mhz, pulsed 1:4 for 5-15 mins
65
For phonophoresis
0.5-1 w/cm2, 3mhz, 20% duty cycle for 5-10 mins
66
Duration is dependent on
- Effective radiating area
67
Usually 5-10 mins is for
- each treatment area that is 2x the ERA
68
If era is 10 cm2 and area of body is 20 cm2, time should be
5-10 mins
69
If era is 10mc2 and area of body part is 40 cm2, duration should be
- 10-20 mins
70
Duration is generally increased when
- Lower intensities or lower frequencies are used
- Areas larger than twice the era
- Heating effects are desired
71
If area of body is more than twice the era, intensity is higher. T or f.
- False
72
Methods of application
- Direct
- Glove or balloon technique
- Underwater
73
Glove technique used for
- Irregular surface areas
74
Rate of moving US head
- Between 2 and 8 cm/sec
75
Strokes overlapping half of era is not recommended. T or F.
- F
76
Properties of gel
- Non staining
- Not irritating to skin
- Ease of application
- Cost
77
Examples of gel
- Soni gel
- Degassed water
- Aquasonic gel and mineral oil
78
Can we apply HMP before US?
- Yes
79
What's the effect of applying HMP before US?
- Increase temp of skin while not affecting deeper tissue layers
80
Can we apply cryo before US?
- If US for thermal effects, no.
81
Contraindications (8)
- Tumor
- Pregnancy (not near abdomen)
- CNS tissue (4 inches away)
- Joint cement or plastic components of arthroplasty
- Pacemaker (cannot apply near chest, 6 inches away)
- Thrombophlebitis
- Over the eyes
- Reproductive organs
82
Precaution
- Acute inflammation (use pulse mode)
- Epiphyseal plates in children
- Fractures (use very low dose)
- Breast implants (can pop)
83
documentation
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- US duty cycle
○ Continuous or pulse mode
- Size of head
- Frequency
- Intensity
- Duration in mins
- Area of body
○ Laterality
○ Body part
- Patient position
○ If you stretched an area, etc.
- Method of application
- Goal or rationale
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