-
name 4 acoustic variables
- pressure
- density
- temperature
- particle motion
-
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what is propigation velocity in soft tissue
1540 m/s
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how many mu sec does it take sound to travel 1cm
6.5 mu sec
-
how long does it take to image to a depth of 1cm
- 6.5 mu sec x 2cm (travel time)=
- 13mu sec
-
what is density represented by?
p
-
what is density equasion
- density(p) = mass kgvolume m3
-
What are the 4 wave parameters
- frequency/period
- wavelenght
- propagation velocity
- amplitude
-
what is frequency/ period determined by and what are its units
wave source
cycles/second or HZ
-
what is wavelength determined by
wave source and medium
any form of distance mm
-
what is propagation velocity determined by and what are its units
medium
m/s
-
what is amplitued determined by and what is its units
- wave source but decreases with distance
- volts or Decibels dB
-
what is the equasion for wavelength
- wavelenght = propigation velocityfrequency
lamda= c/f
-
define amplitude
size, strength, or volume
-
what is amplitued equasion
-
what is range of infrasound
<20Hz
-
What is range of Ultrasound
>20 kHz
-
What is range of audible sound
20Hz-20kHz
-
What is formula for bulk modulus?
- change in pressure
- change in volume
volume
-
High bulk modulus material is
- incompressible
- inelastic
- stiff
-
low bulk modulus material is
- compressible
- elastic
- not stiff
-
what is equasion for prop v as related to Bulk modulus
- c=square root of B modp (density)
-
what is prop v in air
331
-
What is prop v in bone?
4080 m/s
-
what is prop v in soft tissue?
1540 m/s
-
what is prop v range for gases
ie... air, helium, hydrogen
331-1286 m/s
-
what is prop v range for liquids
ie... water, alcohol
1130-1530 m/s
-
what is prop v range for solids
ie... lead, steel , diamonds
1322- 12,000 m/s
-
higher bulk modulus does what to prop v
increase
-
lower bulk modulus does what to prop v
decreases
-
power is directly proportional to
voltage2 or Amplitude2
-
What does the transmit power button control?
changes the signals amplitude
-
what are alternitive names for transmit power?
- acoustic power
- output power
- transmit gain
- power gain
- output intensity
- acoustic output
-
intensity is directly proportional to what?
power
-
what is intensity equasion?
- Intensity= power watts
- Beam area m2
-
what is the power equasion for dB
- Pf is power final
- pi is power initial
-
what is the amplitude equasion for dB
- af is amplitude final
- ai is amplitude initial
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