Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PHYS 216 > Particle Motion And Wave Propragation > Flashcards

Particle Motion And Wave Propragation Flashcards

1
Q

At the most basic levels of sonography what are the five steps ?

A
  1. Operator control
  2. Transducer activation (Sending)
  3. Sound interaction
  4. Transducer action (receiving)
  5. Image display
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the Piezoelectric effect?

A

When pressure waves are applied to certain crystals they produce electric pulses or a voltage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is reverse piezoelectric effect?

A

When electric pluses or voltages are applied to certain crystals they produce sound waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the term acoustic mean?

A

Refers to sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is propagation?

A

Refers to travel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is acoustic Propagation?

A

Refers to the effect tissues cause on sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does Bioeffects mean?

A

Refers to the effects of a ultrasound on tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is sound?

A

Sound is a propagation variation (a wave).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What can an sound waves carry?

A

Sound waves can carry energy not matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Does sound waves require a medium to travel?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are variables?

A

Qualities of waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What variables apply when sound travels through mediums?

A
  1. Pressure
  2. Density
    -Rarefaction-low density
    -compressions-high density
  3. Particle motion
  4. Temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is density?

A

The concentration of particles or mass per unit of volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is rarefactions

A

Regions of low density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are compressions?

A

Areas of high density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In terms of sound what role does temperature play?

A

Sound is an energy.
Energy creates heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are sound waves?

A

Sound is a mechanical wave and therefore, requires a medium to travel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the two types of sound waves?

A

Longitudinal and transverse waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are longitudinal waves?

A

Back and forth particle motions parallel to direction of wave travel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are transverse waves?

A

Perpendicular motion to wave travel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What types of mediums support longitudinal waves?

A

Solids, liquids and gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What mediums can support transverse waves?

A

Solids only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is mode conversion?

A

When one type of wave is converted into another form.
An example of this may occur at a tissue bone interface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

In terms of waves what is common to all waves? 6

A
  1. Frequency
  2. Period
  3. Wavelength
  4. Propagation speed
  5. Amplitude
  6. Intensity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is Frequency?
Simply a measurement of how often something happens. With sound we can say it is the number of complete variations goes through in one second
26
What is the unit of frequency?
Hertz (Hz)
27
What frequency does ultrasounds run on?
MHz (megahertz)
28
What is period (T)?
The time it takes for one cycle to occur
29
How is Period measured?
Period is measured in seconds, or in ultrasound in microseconds
30
What is wavelength?
The length of space one cycle takes up
31
What is the formula for frequency?
F=1/T and W=C/F
32
What does the Frequency formula tell us about the relationship?
If Frequency increases time and wavelength decrease. and vice versa
33
What is propagation speed (c)?
The speed with which the wave moves through a medium
34
How much is Propagation speed (c)?
1.54 mm/us or 1540 m/sec
35
What are variables we need to find wave strength?
Amplitude, intensity, and power
36
What is amplitude?
Maximum variation of an acoustics variation
37
What is intensity?
Power of wave divided by the area It is also equal to amplitude squared
38
What is power?
Total energy over the entire cross- sectional area
39
What is the formula for power/intensity?
I= P/A
40
In a sound beam where is the intensity the greatest?
Greatest and the centre and falls off near the periphery
41
What is Spatial intensities?
The greatest intensity found across the beam. This is called the spatial peak.
42
Where is the Spatial peak found? And what is it?
Near the centre of the beam, and is the place of the beam with the greatest intensity
43
What is spatial average? And where is it found?
Average intensity measured over the entire beam, it is usually found at edge of the transducer or the edge of the flashlight
44
How are SP(spatial peak) and SA(spatial average) related
They are related based on the uniformity ratio (BUR)
45
What is the Uniformity ratio (BUR)
BUR= SP/SA
46
What is Temporal Peak (TP)?
The greatest intensity found in the pulse
47
What is pulse average?
Average for all values found inside a pulse
48
Can TP and PA be used interchangeably?
Yes, they are almost identical and can be used interchangeably
49
How do we convert the SP to SA
Divide it by BUR
50
How do we convert SA to SP
X BUR
51
How do we convert TP to TA?
We X DF
52
How do we convert the TA to TP
We divide by DF
53
Considering SPTA what different modes of ultrasounds from lowest value to the highest are available
1. M mode 2. Real Time B mode 3. Doppler 4. Continuous wave (no dead time SPTP)
54
Ultrasound machines are calibrated to what speed?
1540 m/s
55
If Ultrasounds machines are calibrated to C, Does that velocities do the same?
No velocities actually differ in different tissues and as a result artifacts may occur
56
What is the actual velocities found in fat?
1460 m/s
57
What is the actual velocity found in bone?
4080 m/s
58
What is the distance equation?
D = C x T
59
In the distance equation what is D?
D is the distance to the reflector and back
60
What is C in the distance equation?
C is the average speed of sound in soft tissue
61
What is T in the distance formula?
T is the time for the round trip
62
How do we get the distance to the reflector?
We get the distance and then divide it by 2
63
What is the 1 CM rule?
In 13 microseconds the sound wave travels to and back from a object 1 cm away
64
What are two categorizes of waves and what type of wave is used in ultrasound?
Two types of waves are electromagnetic and mechanical. Ultrasound uses mechanical
65
Which combined intensity has the lowest value
SATA
66
What is the purpose of describing intensities in both space and time?
This terminology is needed to asses for bioeffects since we must consider the amount of sound transmitted into the patient along with the time of exposure
67
How does the intensity change when the area of the sound beam is reduced by half?
It is halved because intensity is indirectly proportional to the area

PHYS 216 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions