Ultrasound physics chap 3

7 parameters

1. amplitude

2. wavelength

3. frequency

4. power

5. intensity

6. speed

7. period

what is the source?

the ultrasound system and trasnducer

what are the two types of sources

1. sonographer- can adjust levels of parameter

2. ultrasound system- adjusts the quantity/ level of parameters

what is period

time it takes for one wave to complete a cycle

what is frequency?

# of waves that complete in 1 cycle

what are the 3 types of sound?

1. infrasound- below 20 Hz

2. audible- between 20Hz - 20,000Hz

3. ultrasound- above 20,000 Hz

what kind of relationship does period and frequency have?

inversely related and a reciprocal relationship

what does bigness parameters mean

describes size, magnitude, and strength of a wave

what are the three bigness parameters

1. amplitude

2. power

3. intensity

what is amplitude and what is it determined by?

bigness of a wave, determined by sound source

power and what is it determined by?

rate of energy transferred/ brightness and determined by sound source

what is intensity and determined by what?

concentration of energy in a sound beam, determined by sound source

what is the equation for intensity

intensity= power/area

all three parameters have what relationship?

directly related

What is the relationship between power and amplitude?

directly related

wavelength and what is it determined by?

distance or length of one complete cycle (mm) and its determined by both source and medium

what is the difference between period and wavelength?

period is time

wavelength is distance

What is the relationship between wavelength and frequency

inversely related

propagation speed and what is it determined by?

rate at which a sound wave travels through a medium (mm/us), determined by a medium

what is the typical value of propagation speed?

1.54mm/us

what are the two characteristics of a medium affect the speed of sound?

1. stiffness- ability of an object to resist compression

2. density- relative weight of a material

what is the rule of thumb? and What is the relationship between speed and density

inversely related